The present invention relates to data gathering and sensing techniques,
and more particularly, but not exclusively, relates to techniques for gathering
data from one or more pest control devices.
The removal of pests from areas occupied by humans, livestock, and
crops has long been a challenge. Pests of frequent concern include various types
of insects and rodents. Subterranean termites are a particularly troublesome type
of pest with the potential to cause severe damage to wooden structures. Various
schemes have been proposed to eliminate termites and certain other harmful pests
of both the insect and noninsect variety. In one approach, pest control relies on
the blanket application of chemical pesticides in the area to be protected. However,
as a result of environmental regulations, this approach is becoming less desirable.
Recently, advances have been made to provide for the targeted delivery
of pesticide chemicals. U.S. Patent Number 5,815,090 to Su is one example. Another
example directed to termite control is the SENTRICON™ system of Dow AgroSciences
that has a business address of 9330 Zionsville Road, Indianapolis, Indiana. In this
system, a number of units each having a termite edible material are placed in the
ground about a dwelling to be protected. The units are inspected routinely by a
pest control service for the presence of termites, and inspection data is recorded
with reference to a unique barcode label associated with each unit. If termites
are found in a given unit, a bait is installed that contains a slow-acting pesticide
intended to be carried back to the termite nest to eradicate the colony.
A device for sensing termites and other living organisms is disclosed
in US-A-6 100 805.
However, techniques for more reliably sensing the activity of termites
and other pests is desired. Alternatively or additionally, the ability to gather
more comprehensive data relating to pest behavior is sought. Thus, there is a continuing
demand for further advancement in the area of pest control and related sensing technologies.
SUMMARY OF THE INVENTION
One embodiment of the present invention includes a unique sensing
technique applicable to the control of pests according to claims 1 and 22. In another
embodiment, a unique technique to gather data concerning pest activity is provided.
A further embodiment includes a unique pest control device to detect and exterminate
one or more selected species of pest. As used herein, a "pest control device" refers
broadly to any device that is used to sense, detect, monitor, bait, feed, poison,
or exterminate one or more species of pest.
Another embodiment of the present invention includes a unique pest
control system. This system includes a number of pest control devices and an apparatus
to gather data from the pest control devices. In one embodiment, the apparatus communicates
with the pest control devices using wireless techniques and can also be arranged
to locate the devices. The pest control devices can be of different types, at least
some of which are configured to provide information relating to different levels
of pest activity in addition to an indication of whether pests are present or not.
Still another embodiment of the present invention includes a pest
control device with a circuit including one or more sensing elements operable to
be consumed or displaced by one or more pests. This circuit monitors an electrical
and/or magnetic property of the one or more sensing elements that is indicative
of different nonzero levels of pest consumption or displacement.
In yet another embodiment of the present invention, a pest control
device includes a circuit with an element operably changed by a degree of consumption
or displacement that is comprised of an electrically conductive, nonmetallic material.
Additionally or alternatively, this element can be composed of a material having
a volume resistivity of at least 0.001 ohm-cm.
In still another embodiment, a sensor includes one or more portions
operable to be separated or removed from each other and a circuit operable to monitor
a property corresponding to electrical capacitance that changes with removal or
separation of the one or more portions from the sensor. This separation or removal
can occur due to consumption or displacement by pests; wear, erosion, or abrasion
by mechanical means, and/or a chemical reaction. Accordingly, the sensor can be
used to monitor various pest activities, mechanical operations, and chemical alterations
to name only a few.
In an alternative embodiment of the present invention, a pest control
device includes a unique monitoring bait that is at least partially comprised of
a magnetic material. In a further alternative, a pest control device includes one
or more environmental sensors to gather data about one or more corresponding environmental
Other embodiments, forms, aspects, features, and objects of the present
invention shall become apparent from the drawings and description contained herein.
BRIEF DESCRIPTION OF THE DRAWINGS
DESCRIPTION OF THE PREFERRED EMBODIMENTS
- Fig. 1 is a diagrammatic view of a first type of pest control system according
to the present invention that includes several of a first type of pest control device.
- Fig. 2 is a view of selected elements of the system of Fig. 1 in operation.
- Fig. 3 is an exploded, partial sectional view of a pest monitoring assembly
of the first type of pest control device.
- Fig. 4 is an exploded, partial sectional view of the pest monitoring assembly
of Fig. 3 along a view plane perpendicular to the view plane of Fig. 3.
- Fig. 5 is a partial, top view of a portion of a communication circuit subassembly
of the pest monitoring assembly shown in Figs. 3 and 4.
- Fig. 6 is an exploded assembly view of the first type of pest control device
with the pest monitoring assembly of Fig. 3.
- Fig. 7 is an exploded assembly view of the first type of pest control device
with a pesticide delivery assembly in place of the pest monitoring assembly of Fig.
- Fig. 8 is a schematic view of selected circuitry of the system of Fig. 1.
- Fig. 9 is a schematic view of circuitry for the pest monitoring assembly of
- Fig. 10 is a flowchart of one example of a process of the present invention
that may be performed with the system of Fig. 1.
- Fig. 11 is a diagrammatic view of a second type of pest control system according
to the present invention that includes a second type of pest control device.
- Fig. 12 is an exploded, partial assembly view of the second type of pest control
- Fig. 13 is an end view of an assembled sensor of the second type of pest control
- Fig. 14 is a diagrammatic view of a third type of pest control system according
to the present invention that includes a third type of pest control device.
- Fig. 15 is a partial cutaway view of a sensor for the third type of pest control
- Fig. 16 is a sectional view of the sensor for the third type of pest control
device taken along the section line 16-16 shown in Fig. 15.
- Fig. 17 is a diagrammatic view of a fourth type of pest control system according
to the present invention that includes a fourth type of pest control device.
- Fig. 18 is a partial cutaway view of a sensor for the fourth type of pest control
- Fig. 19 is a sectional view of the sensor for the fourth type of pest control
device taken along the section line 19-19 shown in Fig. 18.
- Fig. 20 is a diagrammatic view of a fifth type of pest control system according
to the present invention that includes pest control devices of the second, third,
and fourth types, and further includes a fifth type of pest control device.
- Fig. 21 is a diagrammatic view of a sixth type of pest control system according
to the present invention that includes a sixth type of pest control device.
- Fig. 22 is a diagrammatic view of a seventh type of pest control system according
to the present invention that includes a seventh type of pest control device.
- Fig. 23 is a flowchart of one example of a procedure of the present invention
that may be performed with one or more of the first, second, third, fourth, fifth,
sixth, or seventh systems.
For the purpose of promoting an understanding of the principles of
the invention, reference will now be made to the embodiments illustrated in the
drawings and specific language will be used to describe the same. It will nevertheless
be understood that no limitation of the scope of the invention is thereby intended.
Any alterations and further modifications in the described embodiments, and any
further applications of the principles of the invention as described herein are
contemplated as would normally occur to one skilled in the art to which the invention
Fig. 1 illustrates pest control system 20 of one embodiment of the
present invention. System 20 is arranged to protect building 22 from damage due
to pests, such as subterranean termites. System 20 includes a number of pest control
devices 110 positioned about building 22. In Fig. 1, only a few of devices 110 are
specifically designated by reference numerals to preserve clarity. System 20 also
includes interrogator 30 to gather information about devices 110. Data gathered
from devices 110 with interrogator 30 is collected in Data Collection Unit (DCU)
40 through communication interface 41.
Referring additionally to Fig. 2, certain aspects of the operation
of system 20 are illustrated. In Fig. 2, a pest control service provider P is shown
operating interrogator 30 to interrogate pest control devices 110 located at least
partially below ground G using a wireless communication technique. In this example,
interrogator 30 is shown in a hand-held form convenient for sweeping over ground
G to establish wireless communication with installed devices 110. Additional aspects
of system 20 and its operation are described in connection with Figs. 8-10, but
first further details concerning a representative pest control device 110 are described
with reference to Figs. 3-7.
Figs. 3-7 illustrates various features of pest control device 110.
To initially detect pests, pest control device 110 is internally configured with
pest monitoring assembly 112. Referring more specifically to Figs. 3 and 4, pest
monitoring assembly 112 is illustrated along centerline assembly axis A. Axis A
coincides with the view planes of both Figs. 3 and 4; where the view plane of Fig.
4 is perpendicular to the view plane of Fig. 3.
Pest monitoring assembly 112 includes sensor subassembly 114 below
communication circuit subassembly 116 along axis A. Sensor subassembly 114 includes
two (2) bait members 132 (see Figs. 3 and 6). Bait members 132 are each made from
a bait material for one or more selected species of pests. For example, bait members
132 can each be made of a material that is a favorite food of such pests. In one
example directed to subterranean termites, bait members 132 are each in the form
of a soft wood block without a pesticide component. In other examples for termites,
one or more of bait members 132 can include a pesticide, have a composition other
than wood, or a combination of these features. In still other examples where pest
control device 110 is directed to a type of pest other than termites, a correspondingly
different composition of each bait member 132 is typically used.
Sensor subassembly 114 also includes sensor 150. Sensor 150 is depicted
between bait members 132 in Figs. 3 and 6; where Fig. 6 is a more fully assembled
view of pest control device 110 than Fig. 3. Sensor 150 is generally elongated and
has end portion 152a opposite end portion 152b as shown in Figs. 4 and 6. A middle
portion of sensor 150 is represented by a pair of adjacent break lines separating
portions 152a and 152b in Fig. 4, and bait members 132 are not shown in Fig. 4 to
prevent obscuring the view of sensor 150.
Sensor 150 includes substrate 151. Substrate 151 carries conductor
153 that is arranged to provide sensing element 153a in the form of an electrically
conductive loop or pathway 154 shown in the broken view of Fig. 4. Along the middle
sensor portion represented by the break lines of Fig. 4, the four segments of pathway
154 continue along a generally straight, parallel route (not shown), and correspondingly
join the four pathway segments of end portion 152a ending at one of the break lines
with the four pathway segments of end portion 152b ending at another of the break
lines. Pathway 154 terminates with a pair of electrical contact pads 156 adjacent
substrate edge 155 of end portion 152a.
Substrate 151 and/or conductor 153 are/is comprised of one or more
materials susceptible to consumption or displacement by the pests being monitored
with pest monitoring assembly 112. These materials can be a food substance, a nonfood
substance, or a combination of both for the one or more pest species of interest.
Indeed, it has been found that materials composed of nonfood substances will be
readily displaced during the consumption of adjacent edible materials, such as bait
members 132. As substrate 151 or conductor 153 are consumed or displaced, pathway
154 is eventually altered. This alteration can be utilized to indicate the presence
of pests by monitoring one or more corresponding electrical properties of pathway
154 as will be more fully described hereinafter. Alternatively, substrate 151 and/or
conductor 153 can be oriented with respect to bait members 132 so that a certain
degree of consumption or displacement of bait members 132 exerts a mechanical force
sufficient to alter the electrical conductivity of pathway 154 in a detectable manner.
For this alternative, substrate 151 and/or conductor 153 need not be directly consumed
or displaced by the pest of interest.
Pest monitoring assembly 112 further includes circuit subassembly
116 coupled to sensor subassembly 114. Circuit subassembly 116 is arranged to detect
and communicate pest activity as indicated by a change in one or more electrical
properties of pathway 154 of sensor subassembly 114. Circuit subassembly 116 includes
circuit enclosure 118 for housing communication circuitry 160 and a pair of connection
members 140 for detachably coupling communication circuitry 160 to sensor 150 of
sensor subassembly 114. Various operational aspects of this arrangement are described
in connection with Figs. 8-10 hereinafter. Enclosure 118 includes cover piece 120,
o-ring 124, and base 130, that each have a generally circular outer perimeter about
axis A. Enclosure 118 is shown more fully assembled in Fig. 4 relative to Fig. 3.
Cover piece 120 defines cavity 122 bounded by inner lip 123. Base 130 defines channel
131 (shown in phantom) sized to receive o-ring 124 and also includes outer flange
133 configured to engage inner lip 123 when base 130 is assembled with cover piece
120 (see Fig. 4).
Communication circuitry 160 is positioned between cover piece 120
and base 130. Communication circuitry 160 includes coil antenna 162 and printed
wiring board 164 carrying circuit components 166. Referring also to Fig. 5, a top
view is shown of an assembly of base 130, connection members 140, and wireless communication
circuitry 160. In Fig. 5, axis A is perpendicular to the view plane and is represented
by like labeled cross-hairs. Base 130 includes posts 132 to engage mounting holes
through printed wiring board 164. Base 130 also includes mounts 134 to engage coil
antenna 162 and maintain it in fixed relation to base 130 and printed wiring board
164 when assembled together. Base 130 further includes four supports 136 each defining
opening 137 therethrough as best illustrated in Fig. 4. Base 130 is shaped with
a centrally located projection 138 between adjacent pairs of supports 136. Projection
138 defines recess 139 (shown in phantom in Fig. 3).
Referring generally to Figs. 3-5, connection members 140 each include
a pair of connection nubs 146. Each nub 146 has neck portion 147 and head portion
145 that extend from opposing end portions of the respective connection member 140.
For each connection member 140, projection 148 is positioned between the corresponding
pair of nubs 146. Projection 148 defines recess 149. Connection members 140 are
formed from an electrically conductive, elastomeric material. In one embodiment,
each connection member 140 is made from a carbon-containing silicone rubber, such
as compound 862 available from TECKNIT, having a business address of 129 Dermody
Street, Cranford, NJ 07016. Nonetheless, in other embodiments, a different composition
can be used.
To assemble each connection member 140 to base 130, the corresponding
pair of nubs 146 are inserted through a respective pair of openings 137 of supports
136, with projection 148 extending into recess 139. Head portion 145 of each of
nubs 146 is sized to be slightly larger than the respective opening 137 through
which it is to pass. As a result, during insertion, head portions 145 are elastically
deformed until fully passing through the respective opening 137. Once head portion
145 extends through opening 137, it returns to its original shape with neck 147
securely engaging the opening margin. By appropriate sizing and shaping of head
portion 145 and neck portion 147 of nubs 146, openings 137 can be sealed to resist
the passage of moisture and debris when base 130 and connection members 140 are
assembled together. As shown in Fig. 5, printed wiring board 164 contacts one nub
146 of each connection member 140 after assembly.
After connection members 140 are assembled with base 130, enclosure
118 is assembled by inserting base 130 into cavity 122 with o-ring 124 carried in
channel 131. During insertion, cover piece 120 and/or base 130 elastically deform
so that flange 133 extends into cavity 122 beyond inner lip 123, such that cover
piece 120 and base 130 engage each other with a "snap-fit" type of connection. The
angled profile of the outer surface of base 130 facilitates this form of assembly.
Once cover piece 120 and base 130 are connected in this manner, o-ring 124 provides
a resilient seal to resist the intrusion of moisture and debris into cavity 122.
The inner surface of cover piece 120 engaged by base 130 has a complimentary profile
that can also assist with sealing.
After communication circuit subassembly 116 is assembled, sensor 150
is assembled to subassembly 116 by asserting end portion 152a into recess 149 of
each connection member 140 carried by base 130. Connection members 140 are sized
to be slightly elastically deformed by the insertion of end portion 152a into recess
149, such that a biasing force is applied by connection members 140 to end portion
152a to securely hold sensor 150 in contact therewith. Once end portion 152a is
inserted into connection members 140, each pad 156 is electrically contacted by
a different one of connection members 140. In turn, each nub 146 that contacts printed
wiring board 164 electrically couples pathway 154 to printed wiring board 164.
Referring to Fig. 6, an exploded view of pest control device 110 and
pest monitoring assembly 112 is depicted. In Fig. 6, sensor subassembly 114 and
circuit subassembly 116 are shown assembled together and nested in carrying member
190 to maintain pest monitoring assembly 112 as a unit. Carrying member 190 is in
the form of a frame that includes base 192 attached to opposing side members 194.
Only one of side members 194 is fully visible in Fig. 6, with the other extending
from base 192 along the hidden side of pest monitoring assembly 112 in a like manner.
Side members 194 are joined together by bridge 196 opposite base 192. Bridge 196
is arranged to define a space 198 contoured to receive the assembled enclosure 118
of circuit subassembly 116.
Pest control device 110 includes housing 170 with removable cap 180
arranged for placement in the ground as shown, for example, in Fig. 2. Housing 170
defines chamber 172 intersecting opening 178. Pest monitoring assembly 112 and carrying
member 190 are sized for insertion into chamber 172 through opening 178. Housing
170 has end portion 171 a opposite end portion 171 b. End portion 171 b includes
tapered end 175 to assist with placement of pest control 110 in the ground as illustrated
in Fig. 2. End 175 terminates in an aperture (not shown). In communication with
chamber 172 are a number of slots 174 defined by housing 170. Slots 174 are particularly
well-suited for the ingress and egress of termites from chamber 172. Housing 170
has a number of protruding flanges a few of which are designated by reference numerals
176a, 176b, 176c, 176d, and 176e in Fig. 6 to assist with positioning of pest control
device 110 in the ground.
Once inside chamber 172, pest monitoring assembly 112 can be secured
in housing 170 with cap 180. Cap 180 includes downward prongs 184 arranged to engage
channels 179 of housing 170. After cap 180 is fully seated on housing 170, it can
be rotated to engage prongs 184 in a latching position that resists disassembly.
This latching mechanism can include a pawl and detent configuration. Slot 182 can
be used to engage cap 180 with a tool, such as a flat-bladed screwdriver, to assist
in rotating cap 180. It is preferred that carrying member 190, base 130, cover piece
120, housing 170, and cap 180 be made of a material resistant to deterioration by
expected environmental exposure and resistant to alteration by the pests likely
to be detected with pest control device 110. In one form, these components are made
from a polymeric resin like polypropylene or CYCOLAC AR polymeric plastic material
available from General Electric Plastics, having a business address of One Plastics
Avenue Pittsfield, MA 01201.
Typically, pest monitoring assembly 112 is placed in chamber 172 after
housing 170 is at least partially installed in the ground in the region to be monitored.
Assembly 112 is configured to detect and report pest activity as will be more fully
explained in connection with Figs. 8-10. In one mode of operation, pest control
device 110 is reconfigured to deliver a pesticide after pest activity is detected
with pest monitoring assembly 112. Fig. 7 is an exploded assembly view of one example
of such a reconfiguration. In Fig. 7, pest control device 110 utilizes pesticide
delivery assembly 119 as a substitute for pest monitoring assembly 112 after pest
activity has been detected. Substitution begins by rotating cap 180 in a direction
opposite that required to latch it, and removing cap 180 from housing 170. Typically,
the removal of cap 180 is performed with housing 170 remaining at least partially
installed in the ground. Pest monitoring assembly 112 is then extracted from housing
170 by pulling carrying member 190. It has been found that application of pest control
device 110 to pests such as termites can lead to the accumulation of a substantial
amount of dirt and debris in chamber 172 before pest monitoring assembly 112 is
removed. This accumulation can hamper the removal of pest monitoring assembly 112
from chamber 172. As a result, member 190 is preferably arranged to withstand at
least 40 pounds (lbs.) of pulling force, and more preferably at least 80 lbs. of
After pest monitoring assembly 112 is removed from chamber 172, pesticide
delivery assembly 119 is placed in chamber 172 of housing 170 through opening 178.
Pesticide delivery assembly 119 includes pesticide bait tube 1170 defining chamber
1172. Chamber 1172 contains pesticide bearing matrix member 1173. Tube 1170 has
a threaded end 1174 arranged for engagement by cap 1176, which has complimentary
inner threading (not shown). Cap 1176 defines aperture 1178. Circuit subassembly
116 is detached from sensor 150 before, during, or after removal of pest monitoring
assembly 112 from housing 170. Aperture 1178 is accordingly sized and shaped to
securely receive circuit subassembly 116 after disassembly from pest monitoring
assembly 112. After pesticide delivery assembly 119 is configured with circuit subassembly
116, it is placed in chamber 172, and cap 180 can re-engage housing 170 in the manner
Fig. 8 schematically depicts circuitry of interrogator 30 and pest
monitoring assembly 112 for a representative pest control device 110 of system 20
shown in Fig. 1. Monitoring circuitry 169 of Fig. 8 collectively represents communication
circuitry 160 connected to conductor 153 of sensor 150 by connection members 140.
In Fig. 8, pathway 154 of monitoring circuitry 169 is represented with a single-pole,
single-throw switch corresponding to the capability of sensor 150 to provide a closed
or open electrical pathway in accordance with pest activity. Further, communication
circuitry 160 includes sensor state detector 163 to provide a two-state status signal
when energized; where one state represents an open or high resistance pathway 154
and the other state represents an electrically closed or continuous pathway 154.
Communication circuit 160 also includes identification code 167 to generate a corresponding
identification signal for device 110. Identification code 167 may be in the form
of a predetermined multibit binary code or such other form as would occur to those
skilled in the art.
Communication circuitry 160 is configured as a passive RF transponder
that is energized by an external stimulation or excitation signal from interrogator
30 received via coil antenna 162. Likewise, detector 163 and code 167 of circuitry
160 are powered by this stimulation signal. In response to being energized by a
stimulation signal, communication circuitry 160 transmits information to interrogator
30 with coil antenna 162 in a modulated RF format. This wireless transmission corresponds
to the bait status determined with detector 163 and a unique device identifier provided
by identification code 167.
Referring additionally to Fig. 9, further details of communication
circuitry 160 and monitoring circuitry 169 are depicted. In Fig. 9, a broken line
box represents printed wiring board 164, circumscribing components 166 that it carries.
Circuit components 166 include capacitor C, integrated circuit IC, resistor R, and
PNP transistor Q1. In the depicted embodiment, integrated circuit IC is a passive,
Radio Frequency Identification Device (RFID) model no. MCRF202 provided by Microchip
Technologies, Inc of 2355 West Chandler Blvd., Chandler, AZ 85224-6199. Integrated
circuit IC includes code 167 and detector 163.
IC also includes two (2) antenna connections VA and VB,
that are connected to a parallel network of coil antenna 162 and capacitor C. Capacitor
C has a capacitance of about 390 picoFarads (pF), and coil antenna 162 has an inductance
of about 4.16 milliHenries (mH) for the depicted embodiment. IC is configured to
supply a regulated D.C. electric potential via contacts VCC and VSS,
with VCC being at a higher potential. This electric potential is derived
from the stimulus RF input received with coil antenna 162 via connections VA
and VB. The VCC connection of IC is electrically coupled to
the emitter of transistor Q1 and one of the electrical contact pads 156 of sensor
150. The base of transistor Q1 is electrically coupled to the other of electrical
contact pads 156. Resistor R is electrically connected between the VSS
connection of IC and the base of transistor Q1. The collector of transistor Q1 is
coupled to the SENSOR input of IC. When intact, the serially connected electrically
conductive pathway 154 and connection members 140 present a relatively low resistance
compared to the depicted value of 330 Kilo-ohms for resistor R. Accordingly, the
voltage presented at the base of transistor Q1 by the voltage divider formed by
R, connection members 140, and electrically conductive pathway 154 is not sufficient
to turn on transistor Q1-- instead shunting current through, R. As a result, the
input SENSOR to IC is maintained at a logic low level relative to VSS
via a pull-down resistor internal to IC (not shown). When the resistance of electrically
conductive path 154 increases to indicate an open circuit condition, the potential
difference between the emitter and base of transistor Q1 changes to turn-on transistor
Q1. In correspondence, the voltage potential provided to the SENSOR input of IC
is at a logic level high relative to VSS. The transistor Q1 and resistor
R circuit arrangement has the effect of reversing the logic level input to SENSOR
of IC compared to placing electrically conductive pathway 154 directly across VCC
and the SENSOR input.
In other embodiments, different arrangements of one or more components
may be utilized to collectively or separately provide communication circuitry 160.
In one alternative configuration, communication circuit 160 may transmit only a
bait status signal or an identification signal, but not both. In a further embodiment,
different variable information about device 110 may be transmitted with or without
bait status or device identification information. In another alternative, communication
circuit 160 may be selectively or permanently "active" in nature, having its own
internal power source. For such an alternative, power need not be derived from an
external stimulus signal. Indeed, device 110 could initiate communication instead.
In yet another alternative embodiment, device 110 may include both active and passive
Fig. 8 also illustrates communication circuitry 31 of interrogator
30. Interrogator 30 includes RF excitation circuit 32 to generate RF stimulation
signals and RF receiver (RXR) circuit 34 to receive an RF input. Circuits 32 and
34 are each operatively coupled to controller 36. While interrogator 30 is shown
with separate coils for circuits 32 and 34, the same coil may be used for both in
other embodiments. Controller 36 is operatively coupled to Input/Output (I/O) port
37 and memory 38 of interrogator 30. Interrogator 30 has its own power source (not
shown) to energize circuitry 31 that is typically in the form of an electrochemical
cell, or battery of such cells (not shown). Controller 36 may be comprised of one
or more components. In one example controller 36 is a programmable microprocessor-based
type that executes instructions loaded in memory 38. In other examples, controller
36 may be defined by analog computing circuits, hardwired state machine logic, or
other device types as an alternative or addition to programmable digital circuitry.
Memory 38 may include one or more solid-state semiconductor components of the volatile
or nonvolatile variety. Alternatively or additionally, memory 38 may include one
or more electromagnetic or optical storage devices such as a floppy or hard disk
drive or a CD-ROM. In one example, controller 36, I/O port 37, and memory 38 are
integrally provided on the same integrated circuit chip.
I/O port 37 is configured to send data from interrogator 30 to data
collection unit 40 as shown in Fig. 1. Referring back to Fig. 1, further aspects
of data collection unit 40 are described. Interface 41 of unit 40 is configured
for communicating with interrogator 30 via I/O port 37. Unit 40 also includes processor
42 and memory 44 to store and process information obtained from interrogator 30
about devices 110. Processor 42 and memory 44 may be variously configured in an
analogous manner to that described for controller 36 and memory 38, respectively.
Further, interface 41, processor 42, and memory 44 may be integrally provided on
the same integrated circuit chip.
Accordingly, for the depicted embodiment communication circuitry 160
transmits bait status and identifier information to interrogator 30 when interrogator
30 transmits a stimulation signal to device 110 within range. RF receiver circuit
34 of interrogator 30 receives the information from device 110 and provides appropriate
signal conditioning and formatting for manipulation and storage in memory 38 by
controller 36. Data received from device 110 may be transmitted to data collection
unit 40 by operatively coupling I/O port 37 to interface 41.
Unit 40 can be provided in the form of a laptop personal computer,
hand-held or palm type computer, or other dedicated or general purpose variety of
computing device that is adapted to interface with interrogator 30 and programmed
to receive and store data from interrogator 30. In another embodiment, unit 40 may
be remotely located relative to interrogator 30. For this embodiment, one or more
interrogators 30 communicate with unit 40 over an established communication medium
like the telephone system or a computer network like the internet. In yet another
embodiment, interrogator 30 is absent and unit 40 is configured to communicate directly
with communication circuitry 160. Interrogator 30 and/or unit 40 is arranged to
communicate with one or more pest control devices through a hardwired interface.
In still other embodiments, different interface and communication techniques may
be used with interrogator 30, data collection unit 40, and devices 110 as would
occur to those skilled in the art.
In a preferred embodiment directed to subterranean termites, substrate
151 is preferably formed from a nonfood material that is resistant to changes in
dimension when exposed to moisture levels expected in an in-ground environment.
It has been found that such a dimensionally stable substrate is less likely to cause
inadvertent alterations to the electrically conductive pathway 154. One preferred
example of a more dimensionally stable substrate 151 includes a paper coated with
a polymeric material, such as polyethylene. Nonetheless, in other embodiments, substrate
151 may be composed of other materials or compounds including those that may change
in dimension with exposure to moisture and that may alternatively or additionally
include one or more types of material favored as a food by targeted pests.
It has been found that in some applications, certain metal-based electrical
conductors, such as a silver-containing conductor, tend to readily ionize in aqueous
solutions common to the environment in which pest control devices are typically
used. This situation can lead to electrical shorting or bridging of the pest control
device conductive pathway by the resulting electrolytic solution, possibly resulting
in improper device performance. It has also been surprisingly discovered that a
carbon-based conductor has a substantially reduced likelihood of electrical shorting
or bridging. Accordingly, for such embodiments, pathway 154 is preferably formed
from a nonmetallic, carbon-containing ink compound. One source of such ink is the
Acheson Colloids Company with a business address of 600 Washington Ave.,' Port Huron,
Michigan. Carbon-containing conductive ink comprising conductor 153 can be deposited
on substrate 151 using a silk screening, pad printing, or ink jet dispensing technique;
or such other technique as would occur to those skilled in the art.
Compared to commonly selected metallic conductors, a carbon-based
conductor can have a higher electrical resistivity. Preferably, the volume resistivity
of the carbon-containing ink compound is greater than or equal to about 0.001 ohm-cm
(ohm-centimeter). In a more preferred embodiment, the volume resistivity of conductor
153 comprised of a carbon-containing material is greater than or equal to 0.1 ohm-cm.
In a still more preferred embodiment, the volume resistivity of conductor 153 comprised
of a carbon-containing material is greater than or equal to about 10 ohms-cm. In
yet other embodiments, conductor 153 can have a different composition or volume
resistivity as would occur to those skilled in the art.
In further embodiments, other electrically conductive elements and/or
compounds are contemplated for pest control device conductors that are not substantially
subject to ionization in aqueous solutions expected in pest control device environments.
In still further embodiments of the present invention, metal-based conductors are
utilized notwithstanding the risk of electrical bridging or shorting.
Referring generally to Figs. 1-9, certain operational aspects of system
20 are further described. Typically, interrogator 30 is arranged to cause excitation
circuit 32 to generate an RF signal suitable to energize circuitry 169 of device
110 when device 110 is within a predetermined distance range of interrogator 30.
In one embodiment, controller 36 is arranged to automatically prompt generation
of this stimulation signal on a periodic basis. In another embodiment, the stimulation
signal may be prompted by an operator through an operator control coupled to interrogator
30 (not shown). Such operator prompting may be either as an alternative to automatic
prompting or as an additional prompting mode. Interrogator 30 may include a visual
or audible indicator of a conventional type (not shown) to provide interrogation
status to the operator as needed.
Referring further to the flowchart of Fig.10, termite control process
220 of a further embodiment of the present invention is illustrated. In stage 222
of process 220, a number of pest control devices 110 are installed in a spaced apart
relationship relative to an area to be protected. By way of nonlimiting example,
Fig. 1 provides a diagram of one possible distribution of a number of devices 110
arranged about building 22 to be protected. One or more of these devices can be
at least partially placed below ground as illustrated in Fig. 2.
For process 220, devices 110 are initially each installed with a pest
monitoring assembly 112 each including a pair of bait members 132 of a monitoring
variety that are favored as a food by subterranean termites and do not include a
pesticide. It has been found that once a colony of termites establish a pathway
to a food source, they will tend to return to this food source. Consequently, devices
110 are initially placed in a monitoring configuration to establish such pathways
with any termites that might be in the vicinity of the area or structures desired
to be protected, such as building 22.
Once in place, a map of devices 110 is generated in stage 224. This
map includes indicia corresponding to the coded identifiers for installed devices
110. In one example, the identifiers are unique to each device 110. Pest monitoring
loop 230 of process 220 is next encountered with stage 226. In stage 226, installed
devices 110 are periodically located and data is loaded from each device 110 by
interrogation of the respective wireless communication circuit 160 with interrogator
30. This data corresponds to bait status and identification information. In this
manner, pest activity in a given device 110 may readily be detected without the
need to extract or open each device 110 for visual inspection: Further, such wireless
communication techniques permit the establishment and building of an electronic
database that may be downloaded into data collection device 40 for long term storage.
It should also be appreciated that over time, subterranean pest monitoring
devices 110 may become difficult to locate as they have a tendency to migrate, sometimes
being pushed further underground. Moreover, in-ground monitoring devices 110 may
become hidden by the growth of surrounding plants. In one embodiment, interrogator
30 and multiple devices 110 are arranged so that interrogator 30 only communicates
with the closest device 110. This technique may be implemented by appropriate selection
of the communication range between interrogator 30 and each of devices 110, and
the position of devices 110 relative to each other. Accordingly, interrogator 30
may be used to scan or sweep a path along the ground to consecutively communicate
with each individual device 110. For such embodiments, the wireless communication
subsystem 120 provided by interrogator 30 with each of devices 110 provides a procedure
and means to more reliably locate a given device 110 after installation as opposed
to more limited visual or metal detection approaches. Indeed, this localization
procedure may be utilized in conjunction with the unique identifier of each device
and/or the map generated in stage 224 to more rapidly service a site in stage 226.
In a further embodiment, the locating operation may be further enhanced by providing
an operator-controlled communication range adjustment feature for interrogator 30
(not shown) to assist in refining the location of a given device. Nonetheless, in
other embodiments, devices 110 may be checked by a wireless communication technique
that does not include the transmission of identification signals or a coordinating
map. Further, in alternative embodiments, localization of devices 110 with interrogator
30 may not be desired.
Process 220 next encounters conditional 228. Conditional 228 tests
whether any of the status signals, corresponding to a broken pathway 154, indicate
termite activity. If the test of conditional 228 is negative, then monitoring loop
230 returns to stage 226 to again monitor devices 110 with interrogator 30. Loop
230 may be repeated a number of times in this fashion. Typically, the rate of repetition
of loop 230 is on the order of a few days or weeks and may vary. If the test of
conditional 228 is affirmative, then process 220 continues with stage 240. In stage
240, the pest control' service provider places a pesticide laden bait in the vicinity
of the detected pests. In one example, pesticide placement includes the removal
of cap 180 by the service provider and extraction of pest activity monitoring assembly
130 from housing 170. Next, for this example, pest control device 110 is reconfigured,
exchanging pest monitoring assembly 112 with pesticide delivery assembly 119 as
previously described in connection with Fig. 7.
In other embodiments, the replacement device may include a different
configuration of communication circuit or lack a communication circuit entirely.
In one alternative, the pesticide is added to the existing pest sensing device by
replacing one or more of the bait members 132, and optionally, sensor 150. In still
another embodiment, pesticide bait or other material is added with or without the
removal of pest monitoring assembly 112. In yet a further embodiment, pesticide
is provided in a different device that is installed adjacent to the installed device
110 with pest activity. During the pesticide placement operation of stage 240, it
is desirable to return or maintain as many of the termites as possible in the vicinity
of the device 110 where the pest activity was detected so that the established pathway
to the nest may serve as a ready avenue to deliver the pesticide to the other colony
After stage 240, monitoring loop 250 is encountered with stage 242.
In stage 242, devices 110 continue to be periodically checked. In one embodiment,
the inspection of devices 110 corresponding to pesticide bait is performed visually
by the pest control service provider while the inspection of other devices 110 in
the monitoring mode ordinarily continues to be performed with interrogator 30. In
other embodiments, visual inspection may be supplemented or replaced by electronic
monitoring using the pest activity monitoring assembly 130 configured with poisoned
bait matrix, or a combination of approaches may be performed. In one alternative,
pathway 154 is altered to monitor pesticide baits such that it is typically not
broken to provide an open circuit reading until a more substantial amount of bait
consumption has taken place relative to the pathway configuration for the monitoring
mode. In still other alternatives, the pesticide bait may not ordinarily be inspected
- instead being left alone to reduce the risk of disturbing the termites as they
consume the pesticide.
After stage 242, conditional 244 is encountered that tests whether
process 220 should continue. If the test of conditional 244 is affirmative - that
is process 220 is to continue - then conditional 246 is encountered. In conditional
246, it is determined if more pesticide bait needs to be installed. More bait may
be needed to replenish consumed bait for devices where pest activity has already
been detected, or pesticide bait may need to be installed in correspondence with
newly discovered pest activity for devices 110 that remained in the monitoring mode.
If the conditional 246 test is affirmative, then loop 252 returns to stage 240 to
install additional pesticide bait. If no additional bait is needed as determined
via conditional 246, then loop 250 returns to repeat stage 242. Loops 250, 252 are
repeated in this manner unless the test for conditional 244 is negative. The repetition
rate of loops 250, 252 and correspondingly the interval between consecutive performances
of stage 242, is on the order of a few days or weeks and may vary. If the test of
conditional 244 is negative, then devices 110 are located and removed in stage 260
and process 220 terminates.
Data collected with interrogator 30 during performance of process
220 can be downloaded into unit 40 from time to time. However, in other embodiments,
unit 40 may be optional or absent. In still another alternate process, monitoring
for additional pest activity in stage 242 may not be desirable. Instead, the monitoring
units may be removed. In a further alternative, one or more devices 110 configured
for monitoring may be redistributed, increased in number, or decreased in number
as part of the performance of the process. In yet other embodiments, a data collection
unit is utilized to interface with one or more pest control devices in lieu of interrogator
30. Additionally or alternatively, interfacing with interrogator 30 and/or unit
40 may be through a hardwired communication connection.
Fig. 11 illustrates pest control system 300 of another embodiment
of the present invention where like reference numerals refer to like features previously
described. Pest control system 300 includes pest control device 310 and data collection
unit 390. Pest control device 310 includes circuitry 320 removably coupled to sensor
350 by connection members 140.
Referring additionally to the partial assembly view of Fig. 12, sensor
350 includes substrate 351 that carries electrically resistive network 353. Network
353 includes a number of sensing elements 353a in the form of electrically resistive
branches or pathways 354 spaced apart from one another along substrate 351. Resistive
pathways 354 are each schematically represented by a different resistor R1-R13 in
Fig. 11. Network 353 extends from contact pads 356 at edge 355 to substrate end
portion 357. When coupled together, network 353 and circuitry 320 comprise monitoring
With further reference to the end view of Fig. 13, a fully assembled
and implemented form of sensor 350 is shown. Sensor 350 is configured to be rolled,
folded, bent, or wrapped about assembly axis A1 as shown in Fig. 13 to provide a
number of adjacent layers 360, only a few of which are designated by reference numerals.
It should be understood that axis A1 in Fig. 13 is perpendicular to the Fig. 13
view plane and is correspondingly represented by like-labeled cross-hairs. Referring
back to Figs. 11 and 12, circuitry 320 is contained in circuit enclosure 318. Enclosure
318 can be configured in a manner like enclosure 118 of pest monitoring subassembly
114 for pest control device 110. Indeed, enclosure 318 is arranged to receive a
pair of connection members 140 to electrically couple pads 356 of sensor 350 to
circuitry 320 in the same manner that pads 156 of sensor 150 are coupled to circuitry
160. Circuitry 320 includes a reference resistor RR connected in series
with network 353 when circuitry 320 and sensor 350 are coupled together to form
monitoring circuit 369. A voltage reference VR is also coupled across
network 353 and reference resistor RR. The voltage across reference resistor
RR, designated Vi, is selectively digitized by Analog-to-Digital
(A/D) converter 324 using standard techniques. The digital output from A/D converter
324 is provided to processor 326. Processor 326 is operatively coupled to communication
Processor 326 can be comprised of one or more components. In one example,
processor 326 is a programmable digital microprocessor arrangement that executes
instructions stored in an associated memory (not shown). In other examples, processor
326 can be defined by analog computing circuits, hardwired state machine logic,
or other device types as an alternative or an addition to programmable digital circuitry.
Memory is also preferably included in communication circuitry 320 to store digitized
values determined with A/D converter 324 (not shown). This memory can be integral
to A/D converter 324 or processor 326, separate from either, or a combination of
Communication circuit 328 is of a wireless type, such as the active
and passive wireless communication circuit embodiments previously described in connection
with system 20. Communication circuit 328 is arranged to communicate with processor
326. Alternatively or additionally, communication circuit 328 can include one or
more input/output (I/O) ports for hardwired communication.
One or more of voltage reference VR, A/D converter 324,
processor 326 or communication circuit 328 can be combined in an integrated circuit
chip or unit. Further, circuitry 320, and correspondingly monitoring circuit 369,
can be of a passive type powered by an external source; active with its own power
source; or a combination of these.
Data collection unit 390 includes an active wireless transmitter /receiver
(TXR/RXR) 392 configured to communicate with communication circuit 328 of device
310, processor 394 coupled to TXR/RXR 392, interface 396, and memory 398. Processor
394 and memory 398 can be the same as processor 42 and memory 44 of data collection
unit 40, respectively, or be of a different arrangement as would occur to those
skilled in the art. Interface 396 provides for the option of a hardwired interface
to device 310 and/or other computing devices (not shown). Data collection unit 390
is configured to receive and process information from one or more pest control devices
as will be more fully described hereinafter.
Referring generally to Figs. 11-13, it should be understood that network
353 can be represented by an equivalent resistance RS; where RS
is a function of R1-R13 (RS = f(R1-R13)). When R1-R13 are known, RS
can be determined by applying standard electrical circuit analysis techniques for
series and parallel resistances. Furthermore, it should be understood that RR
and RS can be modeled as a voltage divider with respect to the reference
voltage VR such that the input voltage Vi to A/D converter
324 can be expressed by the following equation: Vi = VR* (RR/(RR
Substrate 351 and/or network 353 are provided from one or more materials
that are subject to consumption or displacement by one or more pests of interest.
As sensor 350 is consumed or displaced by such pests, resistive pathways 354 comprising
branches of network 353 are disrupted, becoming electrically open. As one or more
resistive pathways 354 become open, the value of RS changes. Accordingly,
with the proper selection of resistance values for resistive pathways 354 relative
to each other, RR, and VR; a number of different values of
RS can be provided in correspondence with the opening of different resistive
pathways 354 and/or different combinations of open pathways 354.
Unlike Fig. 12, Fig. 13 depicts sensor 350 after one or more pests
have begun consumption or displacement of substrate 351 and/or network 353. In Fig.
13, pest T is illustrated in connection with pest-created opening 370 that was caused
by pest consumption or displacement. The location of pest-created opening 370 relative
to network 353 corresponds to phantom overlay 380 shown in Fig. 12. Pest-created
opening 370 partially penetrates several layers 360 of sensor 350 from outer sensor
margin 372 towards the middle of sensor 350 in the vicinity of axis A1. The pest-created
opening 370 corresponds to separation or displacement of one or more portions of
sensor 350 relative to another portion that could result in opening one or more
of resistive pathways 354, depending on relative location. Such separation or displacement
can result from the removal of one or more pieces from sensor 350 due to pest activity.
Even if a piece of sensor 350 is not removed by pests, separation or displacement
of sensor 350 can still occur due to pest activity that separates or displaces a
first portion relative to a second portion in one sensor region, but leaves the
first and second portions connected together in another sensor region. For example,
in Fig. 13 sensor portion 374 is separated or displaced relative to sensor portion
376 by the formation of opening 370; however, sensor portions 374 and 376 remain
connected by sensor portion 378.
It should be further understood that by spatially arranging the resistive
pathways 354 in a predetermined manner, sensor 350 can be configured to generally
indicate a progressively greater degree of consumption and displacement as the value
of RS, and accordingly Vi, change. For instance, the arrangement
of substrate 351 shown in Fig. 13 can be used to place resistive pathways 354 closer
to substrate end portion 357 near the outer sensor margin 372, such as those resistive
pathways 354 corresponding to R8 and R9. Because these resistive pathways 354 are
closer to the outer margin 372, they are more likely to be encountered by pests
before other of the resistive pathways 354. In contrast, resistive pathways 354
nearer to the middle of the rolled substrate 351 (axis A1), such as those corresponding
to R1, R5 and R10, are most likely to be encountered last by the pests as they consume
and displace sensor 350. Thus, as RS changes with the progressive consumption
and displacement of pests from the outer sensor margin 372 towards the middle, the
corresponding input voltage Vi can be used to represent a number of different
nonzero degrees of consumption or displacement of sensor 350.
Processor 326 can be used to evaluate one or more values corresponding
to Vi digitized with A/D converter 324 to determine if a change in pest
consumption or displacement has occurred. This analysis could include various statistical
techniques to reduce the adverse impact of noise or other anomalies. Furthermore,
the analysis could be used to determine the rate of consumption or displacement
as well as any changes in that rate with respect to time. These results can be provided
by processor 326 via communication circuit 328 based on certain predefined triggering
thresholds, on a periodic basis, in response to an external query with data unit
390, or through a different arrangement as would occur to those skilled in the art.
It should be understood that like pest control devices 110 of system
20, several devices 310 can be used in a spaced apart relationship in a multiple
device pest control system. Devices 310 can be arranged for placement inground,
on-ground, or above-ground. Furthermore, devices 310 can be used with an interrogator
to assist in locating them as described in connection with system 20. Also, it should
be understood that a number of different resistive network arrangements could be
utilized at the same time in device 310 to facilitate the detection of differing
degrees of pest consumption or displacement. In another alternative embodiment,
a multilayer configuration is provided by stacking together a number of separate
layers and electrically interconnecting the layers as required to provide a desired
sensing network. In yet another alternative, sensor 350 is utilized in an unrolled,
single layer configuration rather than being arranged as shown in Fig.13. Still
other embodiments include a different resistive sensing network configurations as
would occur to those skilled in the art.
Referring to Figs. 14-16, a further pest control system embodiment
400 utilizing a resistive network to determine different degrees of pest activity
is illustrated; where like reference numerals refer to like features as previously
described. System 400 includes data collection unit 390 as described in connection
with system 300 and pest control device 410. Pest control device 410 includes circuitry
420 coupled to sensor 450. Circuitry 420 includes reference resistor RR,
voltage reference VR, A/D converter 324, and communication circuit 328
as previously described. Circuitry 420 also includes processor 426 that can be physically
the same arrangement as processor 326, but is configured to accommodate any processing
differences between sensors 350 and 450 as further explained hereinafter.
Sensor 450 includes substrate 451 with surface 451 a opposite surface
451 b. Substrate 451 defines a number of regularly spaced passages 456 from surface
451 a to surface 451 b. Resistive network 453 is comprised of a number of sensing
elements 453a in the form of electrically resistive members 455. Each resistive
member 455 extends through a different passage 456. Resistive members 455 are electrically
coupled in parallel to one another by electrically conductive layers 454a and 454b
that are in contact with substrate surfaces 451 a and 451 b, respectively. For this
configuration, substrate 451 is comprised of an electrically insulative material
relative to resistive members 455 and conductive layers 454a and 454b.
Collectively, circuitry 420 and network 453 comprise monitoring circuit
469. Referring specifically to Fig.14, the parallel resistive members 455 of network
453 are each schematically represented by one of resistors RP1, RP2, RP3, ... RPN-2,
RPN-1, and RPN; where "N" is the total number of resistive members 454. Accordingly,
the equivalent resistance RN of network 453 can be determined from the
parallel resistance law: RN= (1/RP1+1/RP2 ... +1/RPN) -1.
The equivalent resistance RN of network 453 forms a voltage divider with
reference resistor RR relative to reference voltage VR. The
voltage across reference resistor RR, Vi, is input to A/D
Substrate 451, layers 454a and 454b, and/or members 455 are provided
from a material that is consumed or displaced by pests of interest. Further, sensor
450 is arranged so that pest consumption or displacement results in opening the
electrical connections of the resistive members 455 to network 453 through separation
or displacement of one or more portions of sensor 450 relative to other portions
of sensor 450 as explained in connection with Fig 13. Fig. 16 depicts region 470
where material has been separated or displaced from sensor 450, resulting in open
electrical connections. In Fig. 16, the phantom outline 472 indicates the form factor
of sensor 450 prior to pest activity. As more resistive members 455 are electrically
opened, the equivalent resistance RN of network 453 increases, causing
a corresponding change in Vi that is monitored with circuitry 420 to
determine different relative levels of pest consumption or displacement activity.
In one embodiment, resistive members 455 each generally have the same
resistance, such that: RP1 = RP2 = ... = RPN within expected tolerances. In other
embodiments, the resistive members 455 can have substantially different resistances
relative to one another. Processor 426 is configured to analyze changes in consumption
and displacement as indicated by variation in Vi and transmit corresponding
data to data collection unit 390 as discussed in connection with system 300. Conductive
layers 454a and 454b can be coupled to circuitry 420 using an elastomeric connector
adapted to engage these surfaces or another arrangement as would occur to those
skilled in the art.
Besides resistance, other electrical characteristics of a sensing
element that change with pest consumption or displacement can be monitored to gather
pest activity data. Referring to Figs. 17-19, pest control system 500 of another
embodiment of the present invention is illustrated; where like reference numerals
refer to like features previously described. Pest control system 500 includes data
collection unit 390 and pest control device 510. Pest control device 510 is comprised
of circuitry 520 and sensor 550.
Referring specifically to Fig. 17, circuitry 520 includes voltage
reference VR, A/D converter 324, and communication circuit 328 as previously
described. Circuitry 520 also includes processor 526 coupled between A/D converter
324 and communication circuit 328. Processor 526 can be of the same physical type
as processor 326 of system 300, but is configured to accommodate aspects of system
500 that differ from system 300. For example, processor 526 is operably coupled
to a number of switches 530a, 530b, and 530c by signal control pathways 531 a, 531
b and 531 c, respectively. Processor 526 is arranged to selectively open and close
switches 530a-530c by sending corresponding signals along the respective pathways
531a-531c. Switches 530a-530c are each schematically illustrated as being of the
single-pole, single-throw operational configuration. Switches 530a-530c can be of
a semiconductor type, such as an Insulated Gate Field Effect Transistor (IGFET)
arrangement, an electromechanical variety, a combination of these, or such other
types as would occur to those skilled in the art.
Circuitry 520 also includes reference capacitor CR that
is coupled in parallel to switch 530c, and voltage amplifier (AMP.) 523. Voltage
amplifier 523 amptifies input voltage VQ and provides and amplified output
voltage Vi to A/D converter 324 to be selectively digitized.
In Fig. 17, sensor 550 includes sensing element 553a that is schematically
depicted in the form of a capacitor with electrode 554. Collectively, circuitry
520 and sensor 550 define monitoring circuit 569. Within monitoring circuit 569,
voltage reference VR, switches 530a-530c, reference capacitor CR,
and sensor 550 provide sensing network 553. In sensing network 553, voltage reference
VR forms a branch that is electrically coupled to ground and one terminal
of switch 530a. The other terminal of switch 530a is electrically coupled to electrode
554 and a terminal of switch 530b. The other terminal of switch 530b is coupled
to the input of voltage amplifier 523, to reference capacitor CR, and
to a terminal of switch 530c by a common electrical node. Switch 530c is coupled
in parallel to reference capacitor CR, both of which also have a terminal
that is grounded.
Referring also to Figs. 18-19, sensor 550 has end portion 555 opposite
end portion 557, and is comprised of multiple layers 560 including dielectric 551
and electrode 554. Dielectric 551 defines surface 551 a opposite surface 551b. Electrode
554 includes surface 554a in contact with surface 551a. As depicted, surfaces 551a
and 554a are generally coextensive.
Sensor 550 is depicted in Fig. 17 as a capacitor in an "open electrode"
configuration; where the electrical connection to ground is by way of dielectric
551, and possibly other substances such as an air gap between dielectric 551 and
the ground. In other words, sensor 550 does not include a predefined pathway to
ground-instead allowing for the possibility that the ground coupling will vary.
This dielectric coupling is symbolized by a dashed line representation 556 for sensor
550 in Fig. 17.
Dielectric 551 and/or electrode 554 is comprised of one or more materials
consumed or displaced by a pest of interest. As pests consume or displace these
materials, one portion of dielectric 551 and/or electrode 554 is removed or separated
relative to another. Fig. 19 illustrates region 570 that has been consumed or displaced
by pests. Region 570 corresponds to the phantom overlay 580 shown in Fig. 18. This
type of mechanical alteration of sensor 550 tends to change the ability of electrode
554 to hold charge Q and correspondingly changes capacitance CS of sensor
550. For example, as the area of electrode surface 554a decreases, the relative
charge-holding capacity or capacitance of electrode 554 decreases. In another example,
as the dielectric dimensions are altered or the dielectric composition changes,
capacitance typically varies. In a further example, a change in distance between
electrode 554 and the ground as caused by separation or displacement of one or more
portions of sensor 550 can impact the ability to hold charge.
Referring generally to Figs. 17-19, one mode of operating circuitry
520 is next described. For each measurement taken with this mode, a switching sequence
is executed by processor 526 as follows: (1) switch 530a is closed while holding
switch 530b open to place voltage reference VR across sensor 550, causing
a charge Q to build on electrode 554; (2) after this charging period, switch 530a
is opened; (3) switch 530b is then closed to transfer at least a portion of charge
Q to reference capacitor CR as switch 530c is held open; and (4) after
this transfer, switch 530b is reopened. The voltage VQ corresponding
to the charge TO transferred to reference capacitor CR is amplified with
amplifier 523 and presented as an input voltage Vi to A/D converter 324.
The digitized input to A/D converter 324 is provided to processor 526 and/or stored
in memory (not shown). After the voltage is measured, reference capacitor CR
can be reset by closing and opening switch 530c with processor 526. The sequence
is then complete. For a sensor capacitance CS that is much smaller than
the reference capacitance CR (CS<<CR), capacitance
CS can be modeled by the equation: CS = CR*(VQ/VR)
for this arrangement.
Processor 526 can be arranged to repeat this switching sequence from
time to time to monitor for changes in Q and correspondingly CS. This
data can be analyzed with processor 526 and reported through communication circuit
328 using the techniques described in connection with system 300. These repetitions
can be periodic or nonperiodic; by demand through another device such as communication
circuit 328; or through different means as would occur to those skilled in the art.
In an alternative embodiment, a burst mode of charge/capacitance monitoring
can be used. For the burst mode, processor 526 is configured to repeat the sequence
of: (1) closing switch 530a while switch 530b is held open to charge electrode 554
and isolate reference capacitor CR, (2) opening switch 530a, and then
(3) closing switch 530b to transfer charge to reference capacitor CR.
Switch 530c remains open throughout these repetitions for this mode. As a result,
reference capacitor CR is not reset as the repetitions are executed.
Once a desired number of the repetitions are completed (a "burst), A/D converter
324 digitizes input voltage Vi. By executing the repetitions rapidly
enough, the amount of charge Q transferred from electrode 554 to reference capacitor
CR increases. This increased charge transfer provides a relative increase
in gain. Accordingly, gain can be controlled by the number of repetitions executed
per burst. Also, reference capacitor CR operates as an integrator to
provide a degree of signal averaging.
In other alternative embodiments, network 560 can be operated to continuously
repeat the burst mode sequence with a resistor in place of switch 530c to facilitate
concurrent monitoring. For this arrangement the resistor used for switch 530c and
reference capacitor CR define a single pole, low pass filter. This continuous
mode has a "charge gain" (expressed in electric potential per unit capacitance)
determined as a function of the replacing resistor, the reference voltage VR,
and the frequency at which the repetitions are performed. In still other alternatives,
network 560 is modified to use an operational amplifier (opamp) integrator or unipolar
equivalent as described inCharge Transfer Sensing by Hal Phillip (dated 1997),
which is hereby incorporated by reference. In still other embodiments, a different
circuit arrangement to measure charge Q, voltage V0, CS, or
another value corresponding to CS can be used as would occur to those
skilled in the art.
Electrode 554 can be electrically connected to circuitry 520 with
an elastomeric connector or a different type of connector as would occur to those
skilled in the art. In an alternative embodiment, sensor 550 can be arranged to
include a defined pathway to ground rather than an open electrode configuration,
or a combination of both approaches. Still other embodiments include a stacked,
wrapped, folded, bent, or rolled arrangement of alternating electrode layers and
dielectric layers with one or more of the layers being of a material consumed or
displaced by pests of interest. Alternatively or additionally, a sensor can include
two or more separate electrodes or sensing capacitors arranged in a network in series,
in parallel, or a combination of these.
In other embodiments, electrode 554 of sensor 550 can be applied to
sense one or more properties besides pest consumption or displacement. In one example,
sensor 550 is arranged to detect wear, abrasion, or erosion. For this arrangement,
sensor 550 is formed from one or more materials disposed to wear away in response
to a particular mechanical activity that correspondingly changes the charge holding
capacity of electrode 554. For example, the area of surface 554a of electrode 554
could be reduced as one or more portions are removed due to this activity. Circuitry
520 can be used to monitor this change and report when it exceeds a threshold value
indicative of a need to replace or service a device being monitored with the sensor,
discontinue use of such device, or take another action as would occur to those skilled
in the art.
In another example, sensor 550 is formed from one or more materials
selected to separate or otherwise decrease charge holding capacity in response to
a change in an environmental condition to which the one or more materials are exposed,
a chemical reaction with the one or more materials, or through a different mechanism
as would occur to those skilled in the art. For these nonpest embodiments, operation
of processor 526 can correspondingly differ. Also, a hardwired connection, an indicator,
and/or other device may be utilized as an addition or alternative to communication
Referring to systems 300, 400, and 500 generally, one or more conductive
elements, resistive elements, or capacitive elements of sensors 350, 450, 550 can
be comprised of a carbon-containing ink as described in connection with pest control
device 110. Indeed, different resistance values for various sensing elements, such
as elements 353a and 453a, can be defined by using inks with different volume resistivities.
Alternatively or additionally, different resistance values can be defined by varying
dimensions of the material through which electricity is conducted and/or employing
different interconnected components for these elements. Furthermore, substrates
351, 451, and/or 551 can be formed from a paper coated with a polymeric compound,
such as polyethylene, to reduce dimensional changes due to moisture as described
in connection with pest control device 110.
Fig. 20 illustrates a fifth type of pest control system 620 that includes
pest control devices 310, 410, 510, and 610, where like reference numerals refer
to like features previously described. System 620 includes building 622 that houses
data collection unit 390. System 620 also includes a central data collection site
626 that is connected by communication pathway 624 to data collection unit 390.
Communication pathway 624 can be a hardwired connection through a computer network
such as the intemet, a dedicated telephone interconnection, a wireless link, a combination
of these, or such other variety as would occur to those skilled in the art.
For system 620, pest control devices 310 are depicted in-ground for
use as discussed in connection with system 20. Pest control devices 410 and 510
of system 620 are located within building 622, and are shown at or above ground
level. Pest control devices 310, 410, 510 are arranged to communicate with data
collection unit 390 through wireless means, hardwired means, through another device
like a hand-held interrogator 30, or a combination of these.
Pest control device 610 is comprised of circuitry 420 previously described
and sensor 650. Sensor 650 includes network 453 comprised of sensing elements 453a.
For sensor 650, network 453 is directly coupled to member 628 of building 622. Member
628 is comprised of one or more materials subject to destruction by one or species
of pests. For example, member 628 can be formed of wood when termites are the targeted
type of pest. As a result, pest activity relative to member 628 of building 622
is directly monitored with pest control device 610. Like pest control devices 310,
410, and 510, pest control device 610 communicates with data collection unit 390
through wireless means, hardwired means, through another device like a hand-held
interrogator 30, or a combination of these.
Central data collection site 626 can be connected to a number of data
collection units 390 arranged to monitor different buildings or areas each having
one or more of pest control devices 110, 310, 410, 510, and/or 610.
Fig. 21 illustrates pest control device system 720 of still another
embodiment of the present invention; where like reference numerals refer to like
features previously described. System 720 includes interrogator 730 and pest control
device 710. Pest control device 710 includes pest monitoring member 732 arranged
to be consumed and/or displaced by pests. In one example, member 732 is configured
as a bait that includes pest-edible material 734, such as wood in the case of termites,
and magnetic material 736 in the form of a coating on material 734. Magnetic material
736 may be a magnetic ink or paint applied to a wood core serving as material 734.
In other examples, material 734 may be formed from a substance other than a food
source that is typically removed or displaced by the targeted pests - such as a
closed cell foam in the case of subterranean termites. In yet other examples, material
734 may be comprised of food and non-food components.
Device 710 further includes wireless communication circuit 780 electrically
coupled to magnetic signature sensor 790. Sensor 790 comprises a series of magnetoresistors
794 fixed in a predetermined orientation relative to member 732 to detect a change
in resistance resulting from an alteration in the magnetic field produced by magnetic
material 736. Accordingly, material 736 and magnetoresistors 794 are alternatively
designated sensing elements 753a. Alterations in the monitored magnetic field can
occur, for instance, as member 732 is consumed, displaced, or otherwise removed
from member 732 by pests. Sensor 790 provides a means to characterize a magnetic
signature of member 732. In alternative embodiments, sensor 790 may be based on
a single magnetoresistor, or an alternative type of magnetic field sensing device
such as a Hall effect device or reluctance-based sensing unit.
The magnetic field information from sensor 790 may be transmitted
as variable data with communication circuit 780. Circuit 780 may further transmit
a unique device identifier and/or discrete bait status information as described
for communication circuit 160. Circuit 780, sensor 790, or both may be passive or
active in nature.
Interrogator 730 includes communication circuit 735 operable to perform
wireless communication with circuit 780 of device 710. In one embodiment, circuits
780 and 790 are of a passive type with circuit 780 being in the form of an RF tag
like circuitry 160. For this embodiment, communication circuit 735 is configured
comparable to circuits 32 and 34 of interrogator 30 to perform wireless communications
with device 710. In other embodiments, device 710 may be adapted to alternatively
or additionally include an active wireless communication circuit and/or hardwired
communication interface. For these alternatives, interrogator 730 is correspondingly
adapted, a data collection unit may be used in lieu of interrogator 730, or a combination
of both approaches may be utilized.
Interrogator 730 includes controller 731, I/O port 737, and memory
738 that are the same as controller 36, I/O port 37, and memory 38 of interrogator
30, except they are configured to receive, manipulate and store magnetic signature
information in addition or as an alternative to discrete bait status and identification
information. It should be appreciated that like the resistance characteristics of
devices 310, 410, and 610 or the capacitance characteristics of device 510; magnetic
signature information may be evaluated to characterize pest consumption behavior.
This behavior may be used to establish predictions concerning bait replenishment
needs and pest feeding patterns.
Fig. 22 depicts system 820 of still-another embodiment of the present
invention. System 820 includes pest control device 810 and data collector 830. Device
810 includes monitoring member 832 arranged to be consumed and/or displaced by the
pests of interest. Member 832 includes matrix 834 with a magnetic material 836 dispersed
throughout. Material 836 is schematically represented as a number of particles in
matrix 834. Matrix 834 may have a food composition, non-food composition, or a combination
Device 810 also includes communication circuit 880 and sensor circuit
890 electrically coupled thereto. Circuit 890 includes a series of magnetoresistors
894 fixed in relation to member 832 to detect change in a magnetic field produced
by material 836 as it is consumed, displaced, or otherwise removed from member 832.
Circuit 890 further includes a number of environmental (ENV.) sensors
894a, 894b, 894c configured to detect temperature, humidity, and barometric pressure,
respectively. Material 836 and sensor 894, 894a, 894b, and 894c are alternatively
designated sensing elements 853a. Sensors 894, 894a, 894b, 894c are coupled to substrate
838, and may provide a signal in either a digital or analog format compatible with
associated equipment. Correspondingly, circuit 890 is configured to condition and
format signals from sensors 894a, 894b, 894c. Also, circuit 890 conditions and formats
signals corresponding to the magnetic signature detected with magnetoresistors 894.
The sensed information-provided by circuit 890 is transmitted by communication circuit
880 to data collector 830. Communication circuit 880 may include discrete bait status
information, a device identifier, or both as described in connection with devices
110. Circuit 880 and circuit 890 may each be passive, active, or a combination of
both with data collector 830 being correspondingly adapted to communicate in accordance
with the selected approach.
For a passive embodiment of circuit 880 based on RF tag technology,
data collector 830 is configured the same as interrogator 30 with the exception
that its controller is arranged to manipulate and store the different forms of sensed
information provided by circuit 890. In another embodiment, data collector 830 may
be in the form of a standard active transmitter/receiver to communicate with an
active transmitter/receiver form of circuit 880. In still other embodiments, data
collector 830 and device 810 are coupled by a hardwired interface to facilitate
Referring generally to systems 300, 400, 500, 620, 720, and 820; in
other embodiments pest control devices 310, 410,510, 610,710, or 810 can include
one or more bait members 132 as described in connection with system 20. Furthermore,
any of pest control devices 310, 410, 510, 610, 710, and 810 can be configured for
in-ground placement, on-ground placement, or above-ground placement. According to
another embodiment, a pest control device is adapted to combine the sensing techniques
of two or more of pest control devices 310, 410, 510, 610, 710, or 810.
Alternatively or additionally, pest control devices 310, 410, 510,
610, 710, or 810 can be arranged to be completely or partially replaced by a pesticide
delivery device. This replacement can include removing a wireless communication
module circuit from a pest monitoring arrangement for incorporation into a pesticide
delivery arrangement as described in connection with system 20. In one arrangement,
any of pest control devices 310, 410, 510, 610, 710, or 810 can be configured to
simultaneously monitor pest activity and deliver pesticides. Alternatively or additionally,
these pest control devices are configured to deliver pesticide once a given degree
of pest consumption or displacement is detected. For this arrangement, delivery
can be triggered automatically by the respective processor in accordance with processor
evaluation of monitoring data and/or by an external command received via a communication
The flowchart of Fig. 23 depicts procedure 920 of yet another embodiment
of the present invention. In stage 922 of process 920, data is collected from one
or more devices 110, 310, 410, 510, 610, 710, and/or 810. In stage 924, gathered
data is analyzed relative to environmental conditions and/or location. Next, pest
behavior is predicted from this analysis in stage 926. In accordance with the predictions
of stage 926, action is taken in stage 928 that may include installation of one
or more additional devices.
Next, loop 930 is entered with stage 932. In stage 932, data collection
from devices continues and pest behavior predictions are refined in stage 934. Control
then flows to conditional 936 that tests whether to continue procedure 920. If procedure
920 is to continue, loop 930 returns to stage 932. If procedure 920 is to terminate
in accordance with the test of conditional 936, it then halts.
Examples of other actions that may be additionally or alternatively
performed in association with stage 928 include the application of pest behavior
patterns to better determine the direction pests may be spreading in a given region.
Accordingly, warnings based on this prediction may be provided. Also, advertising
and marketing of pest control systems can target sites that, based on procedure
920, are more likely to benefit. Further, this information may be evaluated to determine
if the demand for pest control servicing in accordance with one or more embodiments
of the present invention seasonally fluctuates. Allocation of pest control resources,
such as equipment or personnel, may be adjusted accordingly. Further, the placement
efficiency of pest control devices may be enhanced.
In other alternative embodiments, devices 110, 310, 410, 510, 610,
710, and 810, and corresponding interrogators, data collection units and data collectors
may be used in various other system combinations as would occur to one skilled in
the art. While Interrogator 30 is shown in a hand-held form, in other embodiments,
an interrogator can be in a different form, carried by a vehicle, or installed in
a generally permanent location. Indeed, a data collection unit can be utilized to
directly interrogate/receive information from a pest control device. Also, while
bait for devices 110, 310, 410, 510, 610, 710, and 810 may be provided in an edible
form suitable for termites, a bait variety selected to control a different type
of pest, insect or non-insect, may be selected and the device housing and other
characteristics adjusted to suit monitoring and extermination of the different type
of pest. Moreover, bait for devices 110, 310, 410, 510, 610, 710, and 810 may be
of a material selected to attract the targeted species of pest that is not substantially
consumed by the pest. In one alternative, one or more pest control devices include
non-food material that is displaced or altered by targeted pests. By way of nonlimiting
example, this type of material may be used to form a non-consumable sensing member
substrate with or without consumable bait members. In a further alternative, one
or more pest control devices according to the present invention lack a housing,
such as housing 170 (and correspondingly cap 180). Instead, for this embodiment
the housing contents may be placed directly in the ground, on a member of a building
to be monitored, or arranged in a different configuration as would occur to those
skilled in the art. Also, any of the pest control devices of the present invention
may be alternatively arranged so that bait consumption or displacement of a sensing
member causes movement of a conductor to close an electrical pathway instead of
causing an open circuit.
Pest control devices based on wireless communication techniques may
alternatively or additionally include hardwired communication connections to interrogators,
data collection units, data collectors, or such other devices as would occur to
those skilled in the art. Hardwired communication may be used as an alternative
to wireless communication for diagnostic purposes, when wireless communication is
hampered by local conditions, or when a hardwired connection is otherwise desired.
Moreover processes 220 and procedure 920 may be performed with various stages, operations,
and conditionals being resequenced, altered, rearranged, substituted, deleted, duplicated,
combined, or added to other processes as would occur to those skilled in the art
without departing from the spirit of the present invention.
Another embodiment of the present invention includes a sensor arranged
to be at least partially consumed or displaced by one or more pests and a circuit
responsive to consumption or displacement of the sensor to provide a first signal
representing a first nonzero degree of the consumption or displacement and a second
signal representing a second nonzero degree of the consumption or displacement.
In one form, this consumption or displacement of the sensor is detected by the circuit
in response to an electrical and/or magnetic characteristic that correspondingly
changes. In another form, consumption or displacement is detected by the circuit
with other than a pest sensing or monitoring member including a magnetic material
to provide a magnetic field that changes in response to removal of the magnetic
material from the member by the one or more pests. This form could be based on detection
of corresponding changes in an electrical characteristic of the sensor as it is
consumed or displaced.
In a further embodiment of the present invention, a pest control device
includes a circuit comprising a number of electrically coupled sensing elements
arranged to be consumed or displaced by one or more pests. The sensing elements
each correspond to a different one of a number of electrically resistive pathways.
The circuit is responsive to alteration of one or more of the sensing elements to
provide information representative of a degree of pest consumption or displacement.
In yet a further embodiment of the present invention, a sensing device
includes a member operable to be consumed or displaced by one or more pests in a
circuit including an electrode disposed relative to the member. Electrical capacitance
of the electrode is altered during consumption or displacement of the member and
the circuit is responsive to this alteration to provide an output representative
of a degree of pest consumption or displacement of the member.
Yet another embodiment includes: operating a pest control device including
a circuit with a sensor arranged to be at least partially consumed or displaced
by one or more pests; establishing a first nonzero degree of consumption or displacement
with the circuit in response to separation of a first portion of the sensor; and
determining a second nonzero degree of consumption or displacement with the circuit
in response to separation of a second portion of the sensor after separation of
the first portion.
A further embodiment of the present invention includes a pest control
device that has a pest-edible bait member with a magnetic material component. This
component provides a magnetic field. The field changes in response to consumption
of the pest-edible bait member. The device further includes a monitoring circuit
operable to generate a monitoring signal corresponding to the magnetic field as
In yet a further embodiment, a pest control device includes a pest
bait packaged with an environmental sensor and a circuit operable to communicate
information corresponding to an environmental characteristic detected with the sensor
and status of the bait.
A further embodiment includes a member operable to be consumed or
displaced by one or more pests and a circuit including an element carried with the
member. The circuit applies an electric potential to the element and the element
is operably changed by a degree of consumption or displacement of the member. The
element is comprised of an electrically conductive, nonmetallic material.
In another embodiment, a pest control device includes a member to
be consumed or displaced by one or more pests and a circuit including an element
carried with the member. The circuit defines an electrical pathway through the element
and the element is changed by a degree of consumption or displacement of the member.
The element is composed of a material having a volume resistivity of at least 0.001
A system of another embodiment includes a number of pest control devices.
These devices each include a circuit with at least one element comprised of a material
defining an electrical current carrying pathway through the respective element.
This material includes carbon.
Still another embodiment of the present invention includes: installing
a pest control device including a wireless communication circuit electrically connected
to a sensor; detecting the presence of one or more pests with the pest control device;
and reconfiguring the pest control device in response to this detection. This reconfiguration
includes introducing a pesticide bait member into the pest control device with the
wireless communication circuit and adjusting position of the wireless communication
In yet another embodiment, a pest control system includes a housing,
a monitoring bait member, a sensor, a wireless communication circuit, and a pesticide
bait member. The monitoring bait member, the sensor, and the wireless communication
can be arranged in a first assembly to be positioned in the housing to detect one
or more pests. Alternatively, the pesticide bait member and the wireless communication
circuit can be arranged in a second assembly different from the first assembly,
where the second assembly is positioned in the housing in place of the first assembly
after detection of pests with the first assembly.
In a further embodiment, a device includes a housing, an electrical
circuit associated with the housing, and a sensing member. The sensing member engages
the housing and includes an electrical conductor comprised of a carbon-containing
ink. A connection member can also be included to couple the sensing member to the
circuit. This connection member can be comprised of an electrically conductive elastomeric
material. Alternatively, the monitoring bait member and/or the pesticide bait member
may be part of the same assembly.
In another embodiment, a pest control device includes circuitry coupled
to one or more sensing elements with one or more elastomeric connection members.
The one or more elastomeric connection members can be comprised of a carbon-containing
synthetic compound, such as silicon rubber.