U.S. patent application number 10/493751 was filed with the patent office on 2006-07-13 for device, system and method for selective activation of in vivo sensors.
Invention is credited to Tal Davidson, Mordechai Frisch, Arkady Glukhovsky, Gavriel Meron.
Application Number | 20060155174 10/493751 |
Document ID | / |
Family ID | 32595215 |
Filed Date | 2006-07-13 |
United States Patent
Application |
20060155174 |
Kind Code |
A1 |
Glukhovsky; Arkady ; et
al. |
July 13, 2006 |
Device, system and method for selective activation of in vivo
sensors
Abstract
A device, system and method for selectively activating or
altering the operational mode of an autonomous in vivo device in
response to in vivo conditions. The system includes an in vivo
sensing device with a condition tester, and a controller. The in
vivo sensing device may be in communication with an external
receiver.
Inventors: |
Glukhovsky; Arkady; (Santa
Clarita, CA) ; Frisch; Mordechai; (Moreshet, IL)
; Davidson; Tal; (Yoqneam, IL) ; Meron;
Gavriel; (Petach Tikva, IL) |
Correspondence
Address: |
PEARL COHEN ZEDEK, LLP
1500 BROADWAY 12TH FLOOR
NEW YORK
NY
10036
US
|
Family ID: |
32595215 |
Appl. No.: |
10/493751 |
Filed: |
December 16, 2003 |
PCT Filed: |
December 16, 2003 |
PCT NO: |
PCT/IL03/01080 |
371 Date: |
April 27, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60433586 |
Dec 16, 2002 |
|
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|
Current U.S.
Class: |
600/301 ;
600/300 |
Current CPC
Class: |
A61B 1/041 20130101;
A61B 5/14539 20130101; A61B 1/00016 20130101; A61B 1/00055
20130101; A61B 2560/0209 20130101; A61B 5/073 20130101; A61B 1/04
20130101; A61B 1/00036 20130101 |
Class at
Publication: |
600/301 ;
600/300 |
International
Class: |
A61B 5/00 20060101
A61B005/00 |
Claims
1. A system for in vivo sensing, said system comprising: an in vivo
sensing device, said device comprising a condition tester; and a
controller to control an operational mode of said in vivo sensing
device; wherein said condition tester is operatively linked with
said controller.
2. The system according to claim 1 comprising an image sensor.
3. The system according to claim 2 wherein the image sensor is
selected from a group consisting of: CCD and CMOS.
4. The system according to claim 2 wherein the image sensor
comprises one subgroup of pixels said one subgroup being sensitive
to a first range of colors, and another subgroup of pixels, said
other subgroup of pixels being sensitive to a second range of
colors.
5. The system according to claim 4 comprising a spectral
analyzer.
6. The system according to claim 1 wherein the condition tester is
selected from a group consisting of: a pH tester, a blood detector,
a thermometer, a pressure sensor, a biosensor, a spectral analytic
image sensor, an image sensor, and a counter.
7. The system according to claim 1 wherein the condition tester is
to test in vivo conditions.
8. The system according to claim 1 wherein the controller is
incorporated in the in vivo sensing device.
9. The system according to claim 1 wherein the controller is an
external controller.
10. The system according to claim 1 wherein the controller
comprises a counter.
11. The system according to claim 1 wherein the controller is
selected from a group consisting of: mechanical switch, software,
and circuitry.
12. The system according to claim 1 wherein the controller is a
circuit, said circuit comprising an amplifier and a comparator.
13. The system according to claim 12 wherein the condition tester
is a thermistor.
14. The system according to claim 1 comprising an in vivo
transmitter.
15. The system according to claim 1 comprising an in vivo
illumination source.
16. The system according to claim 1 comprising a photodiode.
17. The system according to claim 1 wherein the in vivo sensing
device is an autonomous device.
18. The system according to claim 1 wherein the in vivo sensing
device is a capsule.
19. The system according to claim 1 wherein the in vivo sensing
device comprises an ASIC wherein said ASIC is operatively connected
to a component of the in vivo sensing device.
20. The system according to claim 19 wherein the component is
selected from the group consisting of: an in vivo transmitter, an
in vivo illumination source, an in vivo power source, a controller,
an in vivo image sensor, a condition tester, an in vivo receiver,
and an ASIC wherein said ASIC is operatively connected to the in
vivo receiver.
21. The system according to claim 19 wherein the controller is an
integral part of the ASIC.
22. The system according to claim 1 comprising an in vivo
receiver.
23. The system according to claim 1 comprising an external
receiver.
24. The system according to claim 1 wherein said external receiver
includes a processing unit and a storage unit.
25. The system according to claim 1 comprising a monitor and a data
processor.
26. The system according to claim 25 wherein said data processor
comprises a storage unit and a processor.
27. The system according to claim 1 wherein the condition tester
includes a color-changing material.
28. The system according to claim 27 wherein the color-changing
material is selected from a group including: temperature sensitive
material, pH sensitive material, and a blood sensitive
material.
29. The system according to claim 1 wherein the condition tester
includes a layer of pH sensitive and/or time sensitive dissolvable
material.
30. The system according to claim 1 wherein the in vivo sensing
device comprises a compartment coated with a pH sensitive and/or
time sensitive dissolvable material.
31. The system according to claim 1 wherein the in vivo sensing
device comprises a sampling inlet coated with a pH sensitive and/or
time sensitive dissolvable material.
32. The system according to claim 1 wherein the in vivo sensing
device comprises a switch coated with a pH sensitive and/or time
sensitive dissolvable material.
33. A method for controlling an in vivo imaging device said method
comprising: sensing a condition in vivo; and triggering an event in
said in vivo imaging device based on said sensing.
34. The method according to claim 33 wherein sensing a condition in
vivo is selected from a group consisting of: time sensing, pH
sensing, temperature sensing, pressure sensing, blood sensing, and
biosensing.
35. The method according to claim 33 wherein the triggering is by a
controller.
36. The method according to claim 33 wherein the triggering is by
an external receiver.
37. The method according to claim 33 wherein the event comprises a
change in an operational mode of the in vivo imaging device.
38. The method according to claim 37 wherein the change in
operational mode is selected from a group consisting of: activating
a sensor, deactivating a sensor, altering data capture rate;
altering signal format and frequency range of transmission;
altering processing of sensory data; altering frame capture rate of
an in vivo image sensor, altering illumination intensity, altering
image plane of an in vivo image sensor, activating in vivo sample
collection, releasing a drug, altering power consumption mode, and
altering floatation mode.
39. The method according to claim 33 comprising delaying triggering
of an event.
40. The method according to claim 33 comprising ingesting a volume
of cold or hot water.
41. The method according to claim 33 wherein the triggering is by a
pH sensitive and/or time sensitive dissolvable material.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the field of in vivo
devices. More specifically, the present invention relates to a
device, system and method for selectively activating or altering
the operational mode of an in vivo device, for example, in response
to in vivo conditions.
BACKGROUND OF THE INVENTION
[0002] Certain in vivo devices may be introduced into a body in a
location remote to the area where their sensing, diagnosing or
other functions may be performed. For example, an in vivo device
for imaging areas of the small intestine may be introduced into a
body through the mouth and pass through the stomach and other parts
of the gastrointestinal (GI) tract by way of peristalsis until
reaching the small intestine. Similarly, an in vivo device may be
introduced into a body wherein the location of an area of interest
or of a suspected pathology may be unknown or uncertain, thereby
necessitating that an in vivo device pass from its point of
introduction and locate the area of pathology where its sensing
functions or other functions may be required for diagnosing
pathologies or performing other functions.
[0003] In vivo devices such as sensors are generally configured to
capture sensory data on a fixed schedule that may be set or
programmed into the in vivo sensor before it may be introduced into
a body. For example, an in vivo image sensor may be configured to
capture images at fixed intervals beginning with the time that it
is introduced into the body. Typically, an in vivo sensor may be
activated by a doctor or medical practitioner who assists in
introducing such sensor into the body. Other in vivo sensors may be
activated before ingestion, for example, automatically upon their
removal from their original packaging. As a result, an in vivo
sensor introduced to a location in the body that may be remote from
an area of interest or suspected pathology in a body, may perform
its sensing functions or other functions in locations other than
the area of interests for example where no pathology or suspected
pathology exists. The performance of such superfluous sensing may
inefficiently utilize the power supply, data collection, data
transfer (bandwidth), data storage capacity and/or other of the
sometimes limited resource of the in vivo sensor. Redundant data
may be required to be reviewed by the physician, increasing the
overall review time.
[0004] The capturing of data by an in vivo sensor based on a fixed
schedule may result on the one hand, in superfluous data being
collected in areas that may be of little diagnostic or other
interest, and, on the other hand, in insufficient sensory data
being captured of in vivo areas that may be of particular
diagnostic or other interest. For example, an in vivo image
capturing system may be programmed to capture in vivo images at a
rate of, for example, two frames per second. While such frame
capture rate may be for example sufficient to generally capture
adequate images of most of the small bowel, such frame capture rate
may be too slow to achieve the level of imaging detail that may be
required for areas such as the esophagus or other areas.
[0005] There is therefore a need for a system and method for
allowing an efficient and effective operation of an in vivo
device.
SUMMARY OF THE INVENTION
[0006] There is thus provided according to one embodiment of the
invention, a system for in vivo sensing including for example an in
vivo sensing device with a condition tester, and a controller. The
condition sensor may for example be operatively linked with the
controller so as to control for example an operational mode of the
in vivo sensing device.
[0007] It is also provided according to an embodiment of the
invention, a method for controlling, for example an in vivo imaging
device by, for example, sensing a condition in vivo and triggering
an event in the in vivo imaging device based on the sensing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention will be understood and appreciated
more fully from the following detailed description taken in
conjunction with the appended drawings in which:
[0009] FIG. 1A is a schematic illustration of an in vivo device
that may be used in accordance with an embodiment of the present
invention;
[0010] FIG. 1B is a schematic illustration of a receiver in
accordance with an embodiment of the present invention;
[0011] FIG. 1C is a schematic illustration of a data processor in
accordance with an embodiment of the present invention;
[0012] FIG. 2 is a schematic illustration of an in vivo device with
a condition sensitive, color-changing material in accordance with
an embodiment of the present invention;
[0013] FIG. 3 is a schematic illustration of a device with two
image sensors in accordance with an embodiment of the present
invention;
[0014] FIG. 4 is a schematic illustration of a condition tester in
the form of a coating in accordance with an embodiment of the
present invention;
[0015] FIGS. 5A and 5B are schematic illustrations of a floatable
device according to an embodiment of the invention;
[0016] FIG. 6 sets forth a flow chart of the operation of a
controller in accordance with an embodiment of the present
invention;
[0017] FIG. 7 sets forth a flow chart of the operation of a device
in accordance with an embodiment of the present invention;
[0018] FIG. 8 sets forth a schematic diagram of a temperature
triggered circuit in accordance with an embodiment of the current
invention;
[0019] FIG. 9 is a chart depicting a change in mode based on a pH
trigger in accordance with an embodiment of the current invention;
and
[0020] FIG. 10 is a chart depicting a change in mode initiated by a
pH trigger and combined with a timed delay in accordance with an
embodiment of the current invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In the following description, various aspects of the present
invention will be described. For purposes of explanation, specific
configurations and details are set forth in order to provide a
thorough understanding of the present invention. However, it will
also be appreciated by one skilled in the art that the present
invention may be practiced without the specific details presented
herein. Furthermore, well-known features may be omitted or
simplified in order not to obscure the present invention.
[0022] According to some embodiments of the invention, a system,
method and device are provided for triggering an event such as, for
example, activating or altering the operational mode of an in vivo
device and/or a receiving (and/or processing, and/or reviewing)
unit, typically located outside a patient's body, in response to in
vivo conditions as may be detected by an in vivo condition tester.
Such activating, deactivating or altering operational modes may
include for example, activating or deactivating one or more
components of the in vivo device and/or the receiving unit,
increasing or decreasing the power consumption, increasing or
decreasing the level of illumination, increasing or decreasing the
rate of sensing, such as, for example, increasing the data capture
rate from, for example, 2 images per second to for example, 14
images per second, or altering the sensing parameters such as, for
example, in the case of an in vivo image sensor, increasing or
decreasing the illumination intensity of the light sources or
altering the image plane of the image sensor. Other operational
modes may be changed and other data capture rates may be used. In
certain embodiments, more than one in vivo sensor may be included
in a single device. A change in the operational mode of the device
may in such embodiments include activating or deactivating one or
both of such sensors or alternating the activation of such more
than one sensor. For example, an in vivo image sensor may include
two image sensors. A change in operational mode may in such example
mean activating or deactivating one or both of such image sensors,
or alternating the activation of such image sensors. In other
embodiments, one in vivo device may activate or deactivate one or
more components in second in vivo device. Communication between two
or more in vivo devices may be for example through one or more
external receivers or may be through for example direct
communication between one or more in vivo devices.
[0023] In certain embodiments changes in the operational mode may
for example include changes in the methods or procedures of
processing sensory data obtained, and optionally transmitted, from
the in vivo device. For example, sensory data such as images or
ultrasound readings from endo-luminal areas that have villi may
return distorted images as a result of the irregular surfaces of
the villi. In certain cases, such distortions may be corrected
through changes in the methods of processing of the sensory data by
the data processor. For example, specific image processing
algorithms may be activated. According to one embodiment methods of
processing sensory data may be executed, for example, in an
external receiving unit. In another embodiment the change may be in
the mode of the data presentation (reviewing mode), e.g.
presentation of the images in double image vs. single image
mode.
[0024] The invention according to certain embodiments, comprises an
in vivo device such as, for example, an in vivo image capture
system, an in vivo condition tester such as, for example, any of an
in vivo pH tester, blood detector, thermometer, pressure tester,
spectral analytic image sensor, biosensor for biosensing,
accelerometer, or motion detector, and a controller for linking the
condition tester with the in vivo device and for signaling the
change to be made in the operational mode of the in vivo device.
Other condition testers may also be used as well as a combination
of two or more condition sensor may be used. In one exemplary
embodiment a biosensor may be used to sense, for example, colon
specific flora in a colon. In another exemplary embodiment a
pressure tester may be used to sense, for example, a change in
pressure, such as a change in pressure pattern. For example, a drop
in pressure may be sensed by a pressure tester, for example, when
the device moves from the small intestine to the cecum (at the
beginning of the colon). Various signals emitted by the condition
tester such as mechanical, electrical, electromagnetic, chemical,
or optical signals may also be used.
[0025] Embodiments of the present invention may be used with in
vivo devices and recording/receiving and display systems such as
various embodiments described in U.S. Pat. No. 5,604,531, assigned
to the common assignee of the present application and incorporated
herein by reference, and/or Publication Number WO 01/65995, also
assigned to the common assignee of the present application and
incorporated herein by reference. Other in vivo systems, having
other configurations, may be used.
[0026] Embodiments of the device may be typically autonomous and
typically self-contained. For example, the device may be a capsule
or other units where all the components are substantially contained
within a container or shell, and where the device does not require
any wires or cables to, for example, receive power or transmit
information. The device may communicate with an external receiving
and display system to provide display of data, control, or other
functions. For example, power may be provided by an internal
battery or a wireless receiving system. Other embodiments may have
other configurations and capabilities. For example, components may
be distributed over multiple sites or units. Control information
may be received from an external source.
[0027] An in vivo imaging system for example, that may be included
in an ingestible device such as a capsule may capture and transmit
images of the GI tract while the capsule may pass through the GI
lumen. In addition to the imaging system, a device such as a
capsule may include, for example, an optical system for imaging an
area of interest onto the imaging system and a transmitter for
transmitting the image output of the image sensor. A capsule may
pass through the digestive tract and operate as an autonomous video
endoscope. It may image difficult to reach areas of the GI tract,
such as the small intestine. Other devices may be included, and
devices including sensors other than image sensors may be used.
Configurations other than capsules may also be used.
[0028] Reference is made to FIG. 1A, a schematic illustration of an
in vivo device in the form of for example, a swallowable capsule
that may be used in accordance with an embodiment of the present
invention. Device 40 may comprise an image sensor 46, an in vivo
optical system 41 for focusing light reflected back from in vivo
areas (not shown) onto image sensor 46, an illumination source 42,
such as one or more light emitting diodes (LEDs) or other suitable
sources, a dome 44 that may be useful, inter alia, for protecting
the optical system from body fluids, a circuit or controller 48 for
controlling the operational mode, such as for example settings of
the device 40, a condition tester 49 such as for example, a pH
tester or thermometer, an in vivo memory unit 39, an in vivo power
source 45 such as a set of batteries, an in vivo receiver 43 for
collecting signals transmitted to device 40, and an in vivo
transmitter 47 for transmitting signals and/or image data to a
receiver. One or more of in vivo image sensor 46, in vivo
illumination source 42, controller 48, in vivo memory unit 39, in
vivo transmitter 47, in vivo receiver 43 and condition tester 49
may in certain embodiments of the present invention be operatively
connected, for example to/or through PCB 38, or included or
embedded within an application specific integrated circuit (ASIC)
50. In other embodiments, image sensor 46, controller 48 and
condition tester 49 may be operatively linked to each other without
an ASIC 50 or PCB 38 or other connecting means. A wired or wireless
connection, such as for example a microwave connection or other
suitable connections may be used between elements in the capsule.
Such an ASIC 50 may provide control for the capsule. Alternatively,
another component such as transmitter 47 may provide such
control.
[0029] In certain embodiments, image sensor 46 may be a CCD or a
CMOS image sensor that may have arrays of various typically color
pixels. Other suitable image sensors or no image sensors may be
used. In one embodiment of the invention, image sensor 46 may also
function as a condition tester. For example, an image sensor may be
used to detect for example, blood vessel structures typically found
in colon, or villi structures typically found in small intestine.
Detection of such structures, detection of lack of such structures,
or detection of other structures or colors such as for example
color specific to content in the intestine may be used to trigger
an event in the in vivo device. Other suitable structures or colors
detected may be used as a trigger. Detection, according to an
embodiment of the invention, could be aided by appropriate image
processing algorithms and/or suitable software.
[0030] In other configurations of device 40, components such as
capsule receiver 43, power source 45, in vivo memory unit 39 or
other units may be omitted.
[0031] Typically, device 40 is swallowed by a patient and traverses
a patient's GI tract. Other suitable body lumens or cavities may be
imaged or examined.
[0032] Reference is now made to FIG. 1B, a schematic illustration
of an external receiver 12 in accordance with an embodiment of the
present invention. External receiver 12 may typically be located
outside the patient's body and may receive and/or record and/or
process the data transmitted from device 40. External receiver 12
may typically include a receiver antenna (or antenna array) 15, for
receiving image and other data from device 40 and stored in for
example storage unit 16. Typically, external receiver 12 may be
portable, and may be worn on the patient's body during recording of
the images.
[0033] External receiver 12 may also be equipped with processing
unit 11, such as for example signal processing unit and/or control
software or for example a control mechanism or circuit emulating
such functionality that may control for example, evaluate and
respond to signals transmitted by device 40. External receiver 12
may also include a transmitter and receiver transmitter 17 that may
enable external receiver 12 to transmit signals such as control
signals to device 40. External receiver 12 may also include a user
interface (not shown) that may inter alia provide indications to a
user or patient as to changes made in the operational mode of a
device. For example, passage of a capsule through the stomach may
be identified by changes detected in pH levels that may for example
trigger a change in the operational mode of a sensor such as an
image sensor. A patient may be signaled via a user interface that
such mode change is being made and prompted to take certain actions
such as for example, changing positions (such as for example,
changing from a sitting position to a reclining position),
ingesting a laxative, or certain liquids, etc.
[0034] Reference is now made to FIG. 1C, a schematic illustration
of a data processor in accordance with an embodiment of the present
invention. Preferably, data processor 14, data processor storage
unit 19 and monitor 18 are part of a personal computer or
workstation that may include standard components such as a
processor 13, a memory (such as storage unit 19, or other memory),
a disk drive, and input-output devices. Alternate configurations
are possible. In alternate embodiments, the data reception and
storage components may be of another configuration. Further, image
and other data may be received in other manners, by other sets of
components. Typically, in operation, image data is transferred from
external receiver 12 to data processor 14, which, in conjunction
with processor 13, storage 19, and software, stores, possibly
processes, and displays the image data on monitor 18. Other systems
and methods of storing and/or displaying collected image data may
be used. In other embodiments, processing of data can be performed
by components within the external receiver 12.
[0035] Typically, device 40 may capture an image and transmit the
image by using, for example, radio frequencies, to receiver
antenna(s) 15. In alternate embodiments external receiver 12 is an
integral part of data processor 14. Typically, the image data
recorded and transmitted is digital color image data, although in
alternate embodiments other suitable image formats (e.g., black and
white image data, infrared image data, etc.) may be used. In one
embodiment, each frame of image data may include 256 rows of 256
pixels each, each pixel including data for color and brightness,
according to known methods. For example, color may be represented
in each pixel by a mosaic of four sub-pixels, each sub-pixel
corresponding to primaries such as red, green, or blue (where one
primary is represented twice). The brightness of each sub-pixel may
be recorded by, for example, a one byte (i.e., 0-255) brightness
value. Other data suitable formats may be used. In one embodiment,
image sensor 46 may capture or transmitter 47 may transmit image or
other data in a diluted mode, capturing or transmitting for
example, 16 rows of 16 pixels each.
[0036] In an embodiment, in vivo transmitter 47 may include at
least a modulator (not shown) for modulating the image signal from
the image sensor 46, a radio frequency (RF) amplifier (not shown),
and an impedance matcher (not shown). The modulator may convert the
input image signal that may have for example, a cutoff frequency
f.sub.c of less than 5 MHz to an RF signal having a carrier
frequency f.sub.r, that may typically be in the range of 1 GHz. The
carrier frequency may be in other bands, e.g. a 400 MHz band. The
modulated RF signal may typically have an appropriate bandwidth of
f.sub.t. The impedance matcher may match the impedance of the
circuit to that of the antenna. Other suitable transmitters or
arrangements of transmitter components may be used, utilizing
different signal formats and frequency ranges. In one embodiment of
device 40, transmission may occur at a frequency for example of 434
MHz, using for example Phase Shift Keying (PSK) or MSK (Minimal
Shift Keying). In alternate embodiments, other suitable
transmission frequencies and methods, such as for example AM or FM
may be used.
[0037] External receiver 12 may detect a signal having the carrier
frequency f.sub.r and the bandwidth f.sub.c such as described
hereinabove. External receiver 12 may be similar to those found in
televisions or it may be one similar to those described on pages
244-245 of the book "Biomedical Telemetry" by R. Stewart McKay and
published by John Wiley and Sons, 1970. The receiver may be digital
or analog. In alternate embodiments, other receivers, responding to
other types of signals, may be used.
[0038] In certain embodiments, condition tester 49 may be an in
vivo pH tester, as is well known in the art, for example a pH
tester using the technology used in known pH measuring capsules.
Such pH tester may utilize as electrodes an external ring electrode
made of antimony and the zinc-silver chloride electrode of the
battery that powers the tester. A saline solution such as for
example, a 0.9% physiologic saline solution may be introduced into
the electrode chamber immediately prior to the testing. The
potential difference that develops between the two electrodes and
that depends on the pH may be applied to a transistor as a
frequency-determining measuring voltage.
[0039] Other pH testers, such as ion selective field effect
transistors (ISFET), may also be used as condition tester 49 to
evaluate pH in areas adjacent to the location of the device 40.
ISFET sensor chips that may be used for in vivo pH detection are
known in the art as may be described, for example, in Wang, L.,
Integrated Micro-Instrumentation for Dynamic Monitoring of the
Gastro-Intestinal Tract, as presented at the IEEE Instrumentation
and Measurement Technology Conference, May 2002, retrieved on Oct.
15, 2002 from the Internet: <URL:
http://www.see.ac.uk/naa.publications.html>. Other suitable pH
testers may also be used. An ISFET sensor serving as condition
tester 49 may be operatively connected to ASIC 50 or otherwise may
be connected directly to image sensor 46. In a typical embodiment,
an ISFET sensor serving as condition tester 49 may be situated
adjacent to the outer wall of the device 40 so as to maximize the
exposure of such condition tester 49 to the in vivo conditions
outside of such wall of device 40.
[0040] In some embodiments, controller 48 may be substituted or
complimented by an external controller located out of the body. For
example the external controller may be an integral part of
processor 11. In such embodiments, triggering may be external
triggering. Condition tester 49 may transmit a signal to in vivo
transmitter 47 that transmits such signals to receiver antenna(s)
15. External receiver 12 may process such signals and transmit back
triggering signal such as instructions by way of receiver
transmitter 17 to in vivo receiver 43. In vivo receiver 43 may then
direct a change in the mode of operation of device 40. In some
embodiments, external receiver 12 may be capable of overriding or
initiating a change in the mode of operation of device 40 in
response to a signal that is input to receiver by medical
personnel.
[0041] A condition tester such as for example, a pressure sensor
may use a strain gauge as a condition detector, such as for
example, a thin foil, typically a semiconductor or a piezoelectric
material. Such strain gauge may accept power through a wire and
provide a variable strain signal on such wire.
[0042] In other embodiments, condition tester 49 may take the form
of a condition sensitive, color-changing material. Reference is now
made to FIG. 2, which is a schematic illustration of an in vivo
sensor with a condition sensitive, color-changing material 202 in
accordance with an embodiment of the present invention. Material
202 may be temperature sensitive. "Temperature-sensitive" in the
context of the present invention may be defined as reactive to a
change in temperature. This temperature change may include a range
of temperatures or a change from a reference temperature to another
temperature. In other embodiments, material 202 may be
pressure-sensitive, pH sensitive or sensitive to the presence of
certain substances such as for example, blood, with color-changing
characteristics varying with changes in such conditions. Thus,
different properties within the environment of the body lumen can
be measured in a manner similar to the one described for
temperature hereinbelow. For example, a pH condition tester may use
litmus paper as a color-changing material 202, and a blood detector
may use a polyelectrolyte as a color-changing material 202, as
known in the art.
[0043] In an embodiment, the temperature-sensitive, color-changing
material 202 may be a Thermotropic Liquid Crystal (TLC) paint or
coating, such as are offered by Hallcrest, Inc. of Glenview, Ill.
The TLCs, that may, for example, be cholesteric (including
sterol-derived chemicals) or chiral nematic (including non-sterol
based chemicals) liquid crystals, or a combination of the two,
provide color changes in response to temperature changes. These
color changes may be reversible or hysteretic. In certain
embodiments that include materials 202 that may be capable of
reversible color changes, controller 48 may be programmed to
reverse or further alter the operational mode changes in image
sensor 46 in the event that a condition tester ceases to detect the
changed color of material 202.
[0044] The TLC can be used in several forms according to several
embodiments, including but not limited to paints, microencapsulated
coatings and slurries, TLC coated polyester sheets, and unsealed
films.
[0045] As shown in FIG. 2, temperature-sensitive color-changing
material 202 may be placed on the inside of capsule 200, with
color-changing portions facing inwards. By placing material 202 on
the inside of the capsule, potential problems associated with the
biocompatibility and the resilience of material 202 in light of
bodily fluids and pH changes may be avoided. However, it should be
apparent that color-changing material may also be placed on the
outside of capsule 200 where it may be in contact with bodily
fluids. Such contact between material 202 and bodily fluids may
facilitate testing of such bodily fluids for reactions with
material 202. In certain embodiments, it may be necessary to
achieve contact between bodily fluids and material 202. The
attachment or placement of material 202 can be accomplished in
several ways. For example, material 202 may be in the form of
paint, and may be painted onto the capsule. In another embodiment,
material 202 may be attached onto the capsule with adhesive. In a
further embodiment, material 202 may be sprayed onto the dome 44 as
a coating. In yet a further embodiment, material 202 may be
enclosed in a semi-permeable membrane in contact with bodily
fluids.
[0046] In the course of the function of capsule 200, light from a
light source 204 may be directed towards material 202. Light source
204 may include one or several components, preferably light
emitting diodes (LEDs) that may be placed in various locations
within capsule 200. Light source 204 may also be used as or
provided by illumination source 42 shown in FIG. 1, to illuminate
the environment being imaged (outside of the capsule), or a
separate illumination source 204 may be included for that
purpose.
[0047] Changes in in vivo conditions, such as, for example, changes
in temperature, pH, pressure, the presence of blood and the like
(depending on the nature of material 202), may in certain
embodiments cause various materials that can be used as
color-changing material 202, to change color. Image sensor 46
detects the appearance of the new color when light from light
source 204 is reflected back from material 202 onto image sensor
46. Referring to FIG. 2, such detection of changes in color may in
certain embodiments be performed by a subgroup of pixels 206
included in the pixel array of image sensor 46. In one embodiment
of the invention, pixel array of image sensor may have one subgroup
of pixels that are sensitive to a first range of wavelengths e.g.,
colors and another subgroup of pixels sensitive to second range of
wavelengths, e.g., colors. In some embodiments such one subgroup of
pixels, or specific pixels may be positioned on the pixel array of
image sensor 46 to be exposed to light reflected back from material
202 considering the angle of incidence 208 and angle or return 208'
of the light directed onto and reflected back from material 202.
Similarly, in certain embodiments, such subgroup of pixels 206 may
be sensitive to a specified range of colors that appear on material
202 once the designated in vivo environmental condition may be
detected. In an alternative embodiment special photodiode(s) may be
used in addition to or in place of a subgroup of pixels 206 to
detect color changes.
[0048] When a designated change in color of material 202 is
detected by a subgroup of pixels 206, a signal may be sent to
controller 48 by such a subgroup of pixels 206 or by another
component operatively connected to a subgroup of pixels 206. In
certain embodiments, a subgroup of pixels 206 may be replaced or
supplemented by a spectral analyzer that is capable of detecting
color changes in material 202. Other color-sensitive detectors may
also be used. Such detection or processing may also be aided or
performed by a processor or circuitry located in ASIC 50, external
receiver 12 or data processor 14.
[0049] In certain embodiments, a range of color sensitive pixels,
some of which may be sensitive to the various colors that can
appear on material 202 may be situated on pixel array 210 of image
sensor 46. Signals produced by each of such specific pixels 206 may
vary depending on the color appearing on material 202. Controller
48 may detect and differentiate between such various signals, for
example by utilizing appropriate image processing algorithms, and
issue instructions to a sensor in response to each thereof.
According to one embodiment a change of color may be detected in
the in vivo environment that is being imaged. For example, a spot
of bleeding may appear in a certain image. The change of color,
that may indicate, for example, pathology in the GI tract, may be
recognized by known methods. For example, controller 48 or data
processor 14 may generate a probability indication of presence of
colorimetric abnormalities on comparison of color content of the
images and at least one reference value, for example, as described
in PCT publication WO 02/073507, published on 19 Sep., 2002, that
is assigned to the common assignee of the present invention.
According to some embodiments, once a color change may be detected
the controller 48 or data processor 14 may initiate a change in the
mode of operation of device 40, of the external receiver 12, of
both or of any other component or combination of components of the
system. In other embodiments, a photodiode maybe used to detect
changes in material 202. Such photodiode may in certain embodiments
be connected to an amplifier that may be further connected to a
comparator. A mode change may thereby be triggered by analog rather
than digital electronics.
[0050] In one embodiment of the invention, one or more photodiodes
may be used to detect light, such as for example, visible light, IR
light, or other ranges of light illuminated for example externally
through the skin toward an in vivo area of interest. A photodiode
or other light detecting unit, for example incorporated in an in
vivo device may sense illumination when approaching for example
toward such area of interest. Such detection may trigger a change
in operational mode. Other suitable signals besides light may be
used to penetrate the skin or other tissue and other suitable
detection units may be used to pick up penetrated signal in vivo.
For example, an acoustic signal may be used.
[0051] In an embodiment, capsule 200 may operate in a low power
consumption mode until a color change in material 202 may be
detected. For example, until such color change may be detected,
light sources 204 may be set to illuminate once every second,
thereby consuming less power than used by the overall capsule 200
during full operation that might in certain embodiments illuminate
several times a second or more. In response to a signal that may be
detected from specific pixels 206, controller 48 (or another
component located in capsule 200, external receiver 12 or data
processor 14) may alter the mode of operation of capsule 200 or of
any other component of the system. For example, in certain
embodiments, any or both of light source 204 and image sensor 46
may be directed to increase the rate of capture of images in order
to more fully image the endo-luminal vicinity wherein a specific
condition may have been detected. Controller 48 may direct other
activations or alterations in the mode or operation of capsule 200.
In other embodiments, the response of controller 48 to signals from
specific pixels 206, may be, for example, any of turning on the
image sensor 46 that may theretofore have been inactive, changing
mode of image sensor or transmitter, collecting samples of in vivo
liquids or other materials, releasing encapsulated drugs that were
held in capsule 200 or performing other functions.
[0052] In some embodiments, the pixels receiving the color
indication may be, for example, the regular pixels of image sensor
46. Post processing circuitry or software located in capsule 200,
external receiver 12 or data processor 14 may analyze the signals
from the set of pixels (set being understood to include one unit)
and make a mode change determination therefrom.
[0053] Other embodiments besides calorimetric changes may include,
for example, temperature measurement using devices such as
thermistors (located in a capsule for example as a discrete
component or as part of ASIC) or using pH electrodes, and other
embodiments.
[0054] Reference is now made to FIG. 3 that is a schematic
illustration of a capsule 300 with two image sensors in accordance
with an embodiment of the present invention. Capsule 300 has one
image sensor 302 at one end of capsule 300 and a second image
sensor 304 at another end of capsule 300. In an embodiment of the
present invention, condition tester such as a color-changing
material 202 such as those described in FIG. 2 may be installed
proximate to image sensor 302, and such image sensor 302 may in
such embodiment have specific pixels 206 similar to those described
above for detecting color changes in material 202. When a change in
color of material 202 is detected by image sensor 302, a signal of
such change is sent to controller 48 of capsule 300. Controller 48
may in such embodiment alter the operational mode, such as for
example by activating a component, for example the image sensor 304
of capsule 300. For example, the operational mode of both or either
of image sensors 302 and 304 may be changed. Such a mode change
may, for example, increase the number of images to be captured of
such area or alter the orientation of images captured or
differential activation of either one or both image sensors may be
affected in response to a signal, or other mode changes discussed
herein.
[0055] In certain embodiments, controller 48 may be configured to
delay issuing operational mode change orders to until more than one
signal from condition detector 49 may have been received. In an
embodiment of the present invention, controller 48 may be
configured with a delay mechanism in the form of for example a
counter 51 that causes controller 48 to delay activating or
altering the operational mode of image sensor 304 until several
signals from condition tester 202 may have been received, or until
signals signifying that a certain condition exists may be received
over the course of a certain period of time. Such activation may,
for example, reduce the chance that a false reading or fleeting
condition activates image sensor 304, or may provide "debouncing"
in case conditions may change in a variable manner between one
relatively steady state and another. For example, in one
embodiment, capsule 300 may operate in a first mode (e.g., low
power consumption, or at a first frame capture rate) in the mouth
and esophagus, where the pH is generally approximately 7-8. When
capsule 300 reaches the stomach, where the pH is typically about 2,
a pH detector on or within capsule 300 may detect a change in pH,
and the operational mode may change, for example to a different
power consumption, or a different frame capture rate. Later, when
capsule 300 reaches the small intestine, capsule 300 may detect a
change in pH to, for example 7-8, and the operational mode may
change again. A change in pH may cause alteration in the
operational mode only if received for, for example, one minute
(other suitable time periods may be used). Other methods of
debouncing or guarding against fleeting conditions may be used.
[0056] Controller 48 may in certain embodiments be a software
controller embedded into ASIC 50. In other embodiments, controller
48 may be a simple switch or circuit connected to for example a
condition tester such as a thermistor 800. The controller may
include, for example, an amplifier 802 and a comparator 804,
comparing the measured signal to some pre-defined threshold 806, as
are depicted forth, for example, in FIG. 8. Such switch or circuit
may in certain embodiments power on or trigger the activation of
ASIC 50 when the proper condition may be detected. In other
embodiments, such switch or circuit may signal ASIC 50 to, for
example, begin operation or change the mode of operation of the
sensor.
[0057] In a further embodiment, the switch from one condition and
then back to another may be the trigger for a mode change. For
example, in case a high pH is detected for a period, then a low pH,
then again a high pH, the mode change may occur only on the third
condition change. Other suitable signals or series of signals may
be used to trigger other suitable functionalities. Further,
altering the mode based on detection of a condition change may be
combined with, for example, a delay. For example, capsule 300 may
wait, for example, one hour after detecting a condition change to
effect a mode change. FIG. 4 is a schematic illustration of a
condition tester in the form of a coating in accordance with an
embodiment of the present invention. In such embodiment, a portion
of capsule 400 may be coated with one or more layers of a
dissolvable material 402. Each layer of dissolvable material 402
may be comprised of varying substances that dissolve at varying
rates or when exposed to specific materials or environments. For
example, a first, outer layer 404 of dissolvable material may be pH
sensitive and dissolve when exposed to the acidic environment of
the stomach, and may expose certain components such as for example
switches 412, sensors 408 or drug compartment 410 with an opening,
while capsule 400 may be in a specified site such as for example,
the stomach. A second inner layer 406 may for example, dissolve in
the more basic environment of the small intestine and may activate
other sensors or release other encapsulated drugs. Other materials
that may be sensitive to elapsed time and dissolve in accordance
with a specific period of time after introduction to the GI tract
may also be possible as a means of delaying activation of certain
functions of capsule 400. An example of dissolvable materials that
may be used as such coatings include starches, such as gelatinous
materials, waxes, biodegradable plastics, and other known
biodegradable materials. Other suitable dissolvable materials with
other characteristics may also be used.
[0058] Dissolvable material 402 may cover any or all of a sensor
408, such as for example, a pH sensor, a switch 412, such as for
example a switch that turns on an image sensor, an encapsulated
drug compartment 410 that releases its contents or a sampling inlet
414 that lets surrounding fluids enter a compartment where such
fluids may be sampled, captured or evaluated by a sensor. When
dissolvable material 402 dissolves, sensor 408 may be exposed,
switch 412 may be activated, sampling inlet 414 may be opened or an
encapsulated drug compartment 410 may release its contents into the
surrounding area. In other embodiments, the dissolving of
dissolvable material 402 may facilitate contact between electrical
leads that had theretofore been separated, such contact may signal
a change in operational mode. According to another embodiment a
magnet may be held in the vicinity of the capsule 400 such that it
affects the ON/OFF status of the capsule. In some embodiments the
magnet may be embedded in a dissolvable coating, such as
dissolvable material 402, such that while the coating is intact,
the capsule is OFF. When the coating dissolves, for example, in
response to environmental pH, the magnet may be freed and may
become dissociated from the capsule allowing the capsule to be ON.
In other embodiments other suitable environmental triggers may
cause the dissolving of coatings.
[0059] Another embodiment is schematically illustrated in FIGS. 5A
and 5B. In this embodiment an imaging capsule 500 may be a
floatable capsule, for example, a capsule having a specific gravity
of less than 1. A floatable capsule is described, for example, in
Publication Number WO 02/095351, published on Nov. 28, 2002
assigned to the common assignee of the present inventions and is
hereby incorporated in its entirety by reference. Such a capsule
may be advantageous for passage through portions of a voluminous
cavity, such as the stomach and/or large intestine. In other
portions of voluminous cavities (e.g., the descending portion of
the large intestine) a floatable capsule may be delayed rather than
advanced. Thus, a floatable capsule may benefit from having the
option of loosing its floatation characteristics at a given point
during its passage through the GI tract, for example, while in the
large intestine.
[0060] According to one embodiment, a capsule may have a fluid
chamber such as for example a floatation compartment 502 that may
be filled with a fluid, a gas, or other suitable material that is
lighter than the endo-luminal fluid, for example, air. In certain
embodiments, floatation compartment may be as small as 5% of the
volume of capsule 500. Other suitable volumes may be used. The
floatation compartment 502 may have a valve 504 keeping the
compartment 502 closed and the capsule 500 floating. Upon
triggering, valve 504 may be opened (see FIG. 5B). Floatation
compartment 502 may then be filled with endo-luminal liquid,
raising the specific gravity of capsule 500 and rendering capsule
500 non-floating. As such the floatation mode of a capsule may be
altered.
[0061] A number of mechanisms for opening valve 504 may be
implemented, such as, electronic, mechanical or chemically based
mechanisms. For example instant heating (requiring only a small
amount of battery energy) may be applied, melting material of valve
504. The signal for effecting the change may be as described
above.
[0062] FIG. 6 sets forth a flow chart of the operation of a
controller 48 in accordance with an embodiment of the present
invention. Such controller may in an embodiment be a software
controller in the form of logic programmed into, for example ASIC
50, controller 48, external receiver 12 or other suitable
components. Such software controller may have a flag to indicate
the operational mode to which a sensor is set. Settings of such
flag may be 0 or 1 for on or off, or other suitable settings to
indicate other settings to which a sensor may then be operating.
Software controller may also include a counter that may in certain
embodiments count signals received from condition tester 49
indicating the detection of the conditions to be tested by
condition tester 49. Software controller may also be operatively
linked to an operation activator of an in vivo component such as
image sensor 46 that controls the operation of such sensor. For
example, operation activator may be an internal clock that controls
the timing of the image capture rate of image sensor 46 or the
operation of light source 204.
[0063] In its initial state 602, the flag of software controller
may be set to 0, the counter may be set to 0 and the activator may
be set to 0. In such settings, image sensor 46 may not be capturing
images or may be in some other reduced mode of operation. In step
604, condition tester 49 may detect a changed condition in the in
vivo area surrounding capsule 40 and may signal software controller
48 as to such changed condition. Such signal increments counter to
1 Step 604 may be repeated by condition tester 49 at periodic
intervals that match the sampling rate of condition tester 49. Each
signal delivered by condition tester 49 that indicates the changed
condition may increment the counter by 1 (605). Once the counter
reaches a designated threshold in step 606, the flag switches to 1
in step 608. Such switch by the flag to 1 switches the sensor
activator to 1 as in Step 610. The activator may then change the
mode of operation of image sensor 46. Such change may for example
be an increase in the frame capture rate of image sensor 46 or any
other suitable change in the operational mode of the sensor.
[0064] In certain embodiments, the counter may be decremented each
time condition tester 49 sends a signal to controller 48 that
indicates the absence of an elevated condition, thereby possibly
indicating that conditions may have returned to pre-defined normal
levels. Once the counter may have been decremented below a
pre-defined threshold level, the flag may revert to 0 and may reset
the activator to its initial setting so that such sensor may resume
the operational mode that was in effect prior to the change
described above, or some other suitable operational mode.
[0065] In other embodiments, condition tester 49 may be, for
example, a clock such as for example an internal clock embedded
into ASIC 50 or otherwise operatively connected to image sensor 46.
In such case, controller 48 may be a component such as for example
a switch operatively attached to such embedded clock that may turn
on once a designated period has elapsed. Such elapsed period may be
the estimated time that it takes capsule 300 to pass through the
stomach and into the small intestine where the desired image
capturing may take place. Other periods may also be designated
depending on where in the GI tract the desired image capturing may
be designated to begin.
[0066] In yet further embodiments, an ingestible capsule may be
meant for imaging or otherwise sensing distal portions of the GI
tract, such as the large intestine. A method for economically using
an imaging (or other sensing) capsule is provided according to an
embodiment of the invention. FIG. 7 illustrates a method for
imaging or otherwise sensing distal parts of the GI tract according
to an embodiment of the invention. An inactive device such as for
example a capsule (e.g., does not sample or transmit images or
other data) is swallowed (710) by a patient. According to one
embodiment the capsule may comprise temperature sensing
capabilities. Any in vivo temperature sensing mechanism, such as
those known in the art, may be used. After a capsule is swallowed a
patient may be made to ingest a volume of cold or hot water (720)
at regular intervals. According to one embodiment the patient may
ingest cold or hot water over a period of a few hours (e.g., 3-5
hours), for example, a period in which the capsule has most
probably left the stomach. According to another embodiment the
patient may be made to ingest a volume of cold or hot water until
alerted that the capsule has left the stomach (further detailed
below). While the capsule may be in the stomach an ingested volume
of cold or hot water may cause a change of temperature in the
stomach environment. Once in the small intestine, the effect of a
cold or hot drink may no longer be felt. According to one
embodiment a capsule may be programmed to sense a periodical change
in temperature (700), for example to sense a temperature above or
below a certain threshold, at predetermined intervals. While a
temperature change may be sensed at predetermined intervals, the
capsule may be kept inactive (701). If a temperature change is not
sensed at one predetermined time, the capsule may be triggered (for
example, as detailed above) to activate the image sensor or other
components (702). Thus, the capsule may begin collecting data only
after leaving the stomach for example, such that it is closer to
the large intestine thereby saving energy and allowing effective
and complete action of the capsule in the large intestine.
[0067] According to some embodiments activating the capsule may
cause a signal to be transmitted (703) to an external receiving
unit so as to activate an alert 730 (e.g., a beep or a flashing
light), that may alert a patient to start or stop an action for
example to stop drinking the cold or hot drink (740). Also, the
patient may then be prepared for the expected imaging or otherwise
sensing of the large intestine, for example, the patient may thus
be warned to begin taking a laxative.
[0068] Reference is made to FIG. 9 that is a chart depicting a
change in mode based on a pH trigger in accordance with an
embodiment of the current invention. As depicted in FIG. 9, a
device may be in a first operational mode from, for example
beginning with the time it is turned on and while it is for
example, in the stomach wherein pH is low. As the device may leave
the stomach, pH may rise. Such rise may set off the pH trigger that
may change the operational mode of the device. Other suitable
triggers may be used as well. Such change may, for example, be a
component such as for example a switch of the device imaging with
two image sensors 302 and 304 (as are depicted, for example, in
FIG. 3) to imaging with only a first image sensor 302. In such an
embodiment effective viewing of the upper regions of the GI tract
may be enabled, by using two image sensors whereas, a power saving
mode may then be switched to in the small intestine where one image
sensor may be enough to provide effective viewing.
[0069] Reference is made to FIG. 10 that is a chart depicting a
change in mode initiated by a pH trigger and combined with a timed
delay in accordance with an embodiment of the current invention. As
depicted in FIG. 10, a device may be in a first mode of operation
immediately when it is introduced into a body. The mode of
operation may change, such as for example, going to off or some
other inactive state, until a trigger occurs such as for example a
change in pH. Other suitable triggers may be used as well. The
trigger may initiate, for example, a time delay during which the
mode of operation may remain initially unchanged, but during which
the device counts down until the delay ends, whereupon the mode
change may be implemented. A trigger combined with a time delay may
be useful for example where the large intestine may be the area to
be imaged. In such an embodiment, the trigger may be the pH change
that occurs when the device leaves the stomach. The time delay may
be the approximate time required for the device to traverse the
small intestine (e.g., 3-6 hours). Once the device nears the large
intestine it may change modes of operation to image the desired
area. In this way, the device may preserve its power supply until
many hours after it is introduced into a body and until it reaches
the targeted imaging area. Other suitable combinations of time
delays and triggers are possible.
[0070] It will be appreciated by persons skilled in the art that
the present invention is not limited by what has been particularly
shown and described herein above. Rather the scope of the invention
is defined by the claims.
* * * * *
References