WO2002102223A2

WO2002102223A2 - Motility analysis within a gastrointestinal tract

Info

Publication number: WO2002102223A2
Application number: PCT/IL2002/000386
Authority: WO
Inventors: Arkady Glukhovsky; Gavriel Meron; Ofra Zinati
Original assignee: Given Imaging Ltd.
Priority date: 2001-06-20
Filing date: 2002-05-19
Publication date: 2002-12-27
Also published as: WO2002102223A3; IL159451A0; US7200253B2; US20050281446A1; US20030077223A1; AU2002304266A1; US6944316B2

Abstract

A system and method for measuring and analyzing motility within a body lumen such as the gastrointestinal (GI) tract, where an in vivo imaging device such as a capsule captures images and transmits the images to a processor, which calculates the motility of the device based on comparison of the images. Preferably, the processor compares the intensity of pairs of images or of elements of pairs of images, generates a variance for the compared images, and calculates the motility of the imaging device from the variances. The motility data may be presented to a user in various manners; for example, a plot of motility over time may be generated, or indications of low motility may be presented to the user of the system.

Description

MOTILITY ANALYSIS WITHIN A GASTROINTESTINAL TRACT

FIELD OF THE INVENTION

The present invention relates to a method and system for analysis of motility within a

body lumen, such as within the gastrointestinal (GI) tract.

BACKGROUND OF THE INVENTION Normal peristalsis within a GI tract is responsible for transporting swallowed food and

aiding in digestion and eventual evacuation. Peristalsis results in pressure waves moving along

the GI tract, in turn resulting in the motility of a bolus within the GI tract. Thus, changes in

motility along the GI tract may indicate normal conditions such as food passing from one

section of the GI tract to another (such as passage from the stomach to the small intestine or passage from the small intestine to the large intestine). Certain pathological conditions can alter

the normal motility within the GI tract. Low motility may be caused by an obstruction or

blockage or by other pathological conditions. It is often difficult to detect areas of low or

abnormal motility within the GI tract, since these areas may be in difficult to reach locations. It

is difficult to "see" inside the tract, especially in sections that are hard to reach via conventional methods, such as the small intestines. Motility is the result of complex neuro-physiological

processes. Motility disorders may be caused by nervous disorders, and may not necessarily be

visible as, for example, physiological changes in the intestinal tissue.

Various in vivo measurement systems for examining a body lumen are known in the art. A commonly known and used type of system is an endoscope. Endoscopes are devices which include a tube (either rigid or flexible) and an optical system, and which are introduced into the

body to view the interior. The range of endoscopes - the portion of the GI tract, which endoscopes are capable of viewing - is limited. Endoscopes are usually not helpful in providing

information on GI tract motility. Probes, such as pressure probes, may be used to measure

peristaltic pressure waves. Other systems that may be used for obtaining information on GI tract

motility include dissolvable vehicles containing non dissolving markers that are visible by X-

ray. The vehicle is ingested and the progression of the markers, which are released in the GI

tract once the vehicle is dissolved, can be followed by X-ray. This method, however, can not be

used for continuous monitoring and also exposes the patient to hazardous X-rays.

A non hazardous system and method for monitoring andor analyzing movement along

the entire GI tract is needed, inter alia, for facilitating the understanding of GI tract motility and

for expanding diagnostic (and perhaps therapeutic) possibilities in the GI tract.

SUMMARY OF THE INVENTION

An exemplary embodiment of the system and method of the present invention measures

and analyzes motility within a body lumen such as the GI tract. In another embodiment of the

invention a method is provided for diagnosis of in vivo conditions in the GI tract of a patient.

In one embodiment an in vivo imaging device such as an ingestible imaging capsule captures

images and transmits the images to a processor, which calculates the motility of the device

based on comparison of the images. In one embodiment the processor compares the intensity of

pairs of images or of elements of pairs of images, generates an average difference for the

compared images, and calculates the motility of the imaging device from the average differences. In other embodiments indicators, such as radio frequency (RF) signals, strain gauges, velocity meters or accelerometers may be used to calculate the motility of a device. In

another embodiment a geometrical location or in vivo position of the device may be determined

for later calculation of the motility. The motility data may be presented to a user in various manners; for example, a plot of motility over time may be generated, or indications of low or

abnormal motility may be presented to the user of the system.

According to an embodiment of the invention motility analysis data is examined for at least one parameter, the parameter is compared to a reference and at least one condition in the

GI tract is deduced from the comparison.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully from the following

detailed description taken in conjunction with the drawings in which:

Fig. 1 is a schematic illustration of an in vivo imager system, according to one

embodiment of the present invention;

Figs. 2 A and 2B show a simplified series of images, which may be captured by the vivo imager system of Fig. 1;

Fig. 3 depicts a motility chart produced by the system of Fig. 1, according to one

embodiment of the present invention;

Fig. 4 is a flow chart showing the steps for determining the motility of a device

recording images from a body lumen accordmg to an exemplary embodiment of the present

invention; and

Figs. 5A and 5B are histograms used to calculate motility according to an embodiment

of the present invention. DETAILED DESCRIPTION OF THE INVENTION 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 apparent to 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.

The present invention relates to a method and system for analyzing motility within a GI tract and for displaying motility to a user such as a health professional, who may use such data

to, for example, diagnose pathologies. In an exemplary embodiment of the present invention,

the motility of a capsule or other vehicle, which is propelled through the GI tract by the natural

action of the GI tract is measured, giving an indication of the motility in the GI tract, in different

portions of the GI tract. In one embodiment, the motility of the vehicle is calculated via an analysis of sequential images captured by the vehicle; the greater the difference between

sequential images, the greater the motility.

Reference is made to Fig. 1, which shows a schematic diagram of an in vivo imaging

system according to one embodiment of the present invention. In an exemplary embodiment,

the system comprises a capsule 40 having an imager 46, for capturing images, an illumination source 42, for illuminating the body lumen, and a transmitter 41, for transmitting image and

possibly other information to a receiving device. An optical system (not shown), including, for

example, lenses or mirrors, may aid in focusing reflected light onto the imager 46. The capsule

40 is swallowed by a patient and preferably traverses the patient's GI tract. In alternate embodiments the capsule 40 may have different configurations and include other sets of components. Preferably, while the capsule 40 traverses a patient's GI tract, the capsule 40 transmits

image and possibly other data to components located outside the patient's body, which receive

and process the data. Preferably, located outside the patient's body in one or more locations, are

an image receiver 12, preferably including an antenna or antenna array, an image receiver storage unit 16, a data processor 14, a data processor storage unit 19, and an image monitor 18,

for displaying, inter alia, the images recorded by the capsule 40 and motility information. In

one embodiment, the image receiver 12 and image receiver storage unit 16 are small and

portable, and are worn on the patient's body during recording of the images. Optionally, data

processor 14, data processor storage unit 19 and monitor 18 may be part of a personal computer or workstation, which includes standard components such as processor 14, a memory, a disk

drive, and input-output devices, although alternate configurations are possible.

Data processor 14 may include any standard data processor, such as a microprocessor,

multiprocessor, accelerator board, or any other serial or parallel high performance data processor. Image monitor 18 may be a computer screen or a conventional video display, but

may, in addition, be a printer or any other device capable of providing an indication of image and/or position data.

Preferably, the imager 46 is a suitable CMOS camera, such as a "camera on a chip" type CMOS imager specified by Given Imaging Ltd. of Israel and designed by Photobit Corporation

of California, USA. In alternate embodiments, the imager 46 may be, for example, a CCD. The

illumination source 42 may be, for example, a light emitting diode.

hi operation, imager 46 captures images and sends data representing the images to

transmitter 41, which transmits images to image receiver 12 using, for example, electromagnetic radio waves. Image receiver 12 transfers the image data to image receiver storage unit 16. After a certain period of time of data collection, the image data stored in storage unit 16 is sent

to data processor 14 or data processor storage unit 19. For example, the image receiver storage unit 16 may be taken off the patient's body and connected to the personal computer or

workstation which includes the data processor 14 and data processor storage unit 19 via a

standard data link, e.g., a serial or parallel interface of known construction. The image data is

then transferred from the image receiver storage unit 16 to the data processor storage unit 19.

Data processor 14 analyzes the data and provides the analyzed data to the image monitor 18, where a health professional views, for example, the image data and motility information.

The image data collected and stored may be stored indefinitely, transferred to other

locations, or manipulated or analyzed. A health professional may use the images to diagnose

pathological conditions of the GI tract, and, in addition, the system may provide information

about the location of these pathologies. While, using a system where the data processor storage

unit 19 first collects data and then transfers data to the data processor 14, the image data is not viewed in real time, other configurations allow for real time viewing. In such systems, image

motility may be calculated and displayed in real time.

The image monitor 18 presents the image data, preferably in the form of still and moving pictures, and in addition may present other information. In an exemplary embodiment, such additional information may include, but is not limited to, absolute time elapsed for the

current image being shown and the relative or absolute motility of the capsule 40, over the

course of the capsule's travel through the GI tract, and/or at the time corresponding to the

current image being displayed. Absolute time elapsed for the current image being shown may

be, for example, the amount of time that elapsed between the moment the capsule 40 was first activated and the image receiver 12 started receiving transmissions from the capsule 40, and the

moment that the current image being displayed was captured. Various methods may be used to display the motility of the capsule 40; such methods are discussed below. In an exemplary

embodiment, the various categories of information are displayed in windows. Multiple monitors may be used to display image and other data. Preferably, the image data recorded and transmitted by the capsule 40 is digital color

image data, although in alternate embodiments other image formats may be used. In an

exemplary embodiment, each frame of image data includes 256 rows of 256 pixels each, each

pixel including data for color and brightness, according to known methods. For example, in

each pixel, color may be represented 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 the overall pixel is recorded by a one byte {i.e., 0-255) brightness value.

Preferably, images are stored sequentially in data processor storage unit 19. The stored data is

comprised of one or more pixel properties, including color and brightness.

While, preferably, information gathering, storage and processing is performed by certain units, the system and method of the present invention may be practiced with alternate

configurations. For example, components providing for motility analysis may be located inside

a capsule or, alternately, on a portable device worn on the patient. Furthermore, the components gathering image information need not be contained in a capsule, but may be contained in any

other vehicle suitable for traversing a lumen in a human body, such as an endoscope, stent,

catheter, needle, etc.

The in vivo imager system may collect a large volume of data, as the capsule 40 may

take several hours to traverse the GI tract, and may record images at a rate of, for example, two

images every second, resulting in the recordation of tens of thousands of images. The series of

still images collected may later be presented as still images or as a moving image of the traverse of the GI tract. The image recordation rate (or frame capture rate) may be varied; for example,

the image recordation rate may be varied based on capsule motility. While in the GI tract, the capsule 40 undergoes intermittent motion with long residence time at some positions. These

periods of long residence may be normal or can be due to pathologies, such as blockages, within the digestive tract. The system and method of the present invention aids health professionals in monitoring the capsule motion and in diagnosing and locating, for example, areas of blockage.

In addition, changes in motility may be indicative of a normal condition such as the passage of

the capsule 40 from one section of the GI tract to another, and thus the system and method of

the present invention may use motility data to determine the position of the capsule 40 or other

diagnostic device.

hi an exemplary embodiment, each image Pi in the data stream of images is compared to

its predecessor image P,^ (or to other previous image P_1-n) to determine the motility of the

capsule 40 during the time between the capture of the two images. Various methods of deteπnining motility based on image comparison may be used. In an exemplary embodiment,

the system and method analyze image similarity to obtain a measure of motility. It can be

assumed that the more similar two compared images are, the slower the movement of the capsule 40 between the times the two images are captured. In an extreme situation — if the two

compared images are identical - it can be assumed the capsule 40 has not moved between the

times the two images were captured. If two compared images differ greatly, it is an indication

that the capsule 40 was moving quickly between the times of capture of the images. This

concept is illustrated further in Figs. 2 A and 2B.

Figs. 2A and 2B show a simplified series of images, which may be captured by the vivo

imager system of Fig. 1. Referring to Figs. 2A and 2B, a comparison of images provides

information about the speed of the capsule 40. In Fig. 2A, several consecutive images are

shown in which a specific point X is located in approximately the same location within each of

the images, i Fig. 2B, the same point X is located in varying positions within the images, taken over the same period of time. It can be inferred that the images shown in Fig. 2A were taken by an imager whose position did not change by much between the times each image was

taken, and thus which had relatively low motility. It can be inferred that the images shown in Fig. 2B were taken by an imager which is moving more rapidly. Preferably, data processor storage unit 19 stores a series of images recorded by a capsule

40. The images may be combined consecutively to form a moving image of the images the

capsule 40 recorded as it moved through a patient's GI tract. This moving image may be

displayed in a window on monitor 18. The moving image may be frozen to view one frame,

speeded up, or reversed; sections may be skipped; or any other method for viewing an image

may be applied to the moving image. While the following discussion relates to the case where

data from a capsule 40 is stored for later use, the system and method of the present invention

may be used with systems allowing for real time viewing of image data.

In an exemplary embodiment, to determine the motility of the capsule 40 at various

points during its journey through the GI tract, data processor 14 first receives image data from

data processor storage unit 19. Data processor 14 then compares each image Pj in the data

stream to its predecessor image PM (or Pj._n) to determine the motility of the capsule 40 during the time between the capture of the two images.

The comparison of images may be made on a pixel-by pixel basis or, alternatively, on a

pixel cluster basis, hi alternate embodiments, images may be compared without division into

sections such as pixels or clusters. In an exemplary embodiment, the 256x256 pixel grid of

each image is divided into a 32x32 grid of pixel clusters, to form 1,032 clusters. In alternate

embodiments, other methods of dividing an image may be used. Based on the comparison of

the two images, data processor 14 calculates the relative motility for the capsule 40 that

captured the images for the time period between the capture of the two images. In an exemplary

embodiment, the resulting motility value at a certain point is a relative number on a certain scale, which indicates the motility of the capsule 40 relative to other points in the capsule's traverse of the GI tract. In alternate embodiments, absolute motility may be calculated.

The motility calculation is repeated for all or a set of images in the series of images, and

a series of motility values is generated. The resulting motility values may be presented to the user in various manners. Preferably, the monitor 18 includes a window displaying an image

frame or a moving image, a window showing the absolute time elapsed in the image series for

the frame being displayed (or the current point in the moving image), and a window including a

chart of the relative motility of the capsule 40 plotted against time. An indication may be

provided on the display on monitor 18 connecting certain motility values, or regions having low

motility or certain motility patterns, to images or sections of the moving image. The user may

be able to indicate certain motility values or a portion of the motility chart or plot by, for

example, clicking with a mouse, and have displayed the corresponding still or moving image.

Additional windows may display other data. For example, the position of the capsule 40

as it traverses the GI tract may be graphed as a two-dimensional rendering of the

three-dimensional path; such data may be combined with or linked to image or motility data.

Areas of low motility, or areas of altered or abnormal patterns of motility, may be indicated on such a capsule path representation by using, for example, color changes or labels.

In one embodiment, a spectral analysis of the motility data may be performed, and the

spectral analysis may be presented to the user or may be used for diagnostic or other purposes.

In a normal human GI tract, peristaltic waves are typically generated with some repetition. A

spectral analysis, according to known methods, of the peristaltic waves of different time periods or sections of the series of motility data, may be performed and, for example, presented to the

user. Such a spectral analysis may present, for example, the frequency of repetition of peristaltic

waves at different times or positions in a vehicle's travel through the GI tract. In alternate

embodiments, other visual indications of motility may be provided.

According to one embodiment of the invention, motility data can be examined for at

least one parameter or measurement that may be presented as, for example, a specific pattern or

representation of a pattern in a spectral analysis of the motility data or a specific repetition or representation of a repetition of peristaltic waves. The parameter, possibly represented by a pattern or specific patterns, can be compared to a reference, such as a parameter value in a

normal or healthy individual or a specific pattern typical of a pathological condition in the GI

tract. The comparison results can indicate, for example, a prevailing condition (or conditions)

in the GI tract, thereby providing a diagnostic tool for identifying conditions in the GI tract. For

5 example, a spectral analysis may be performed on the motility of an in-vivo device. The

spectral analysis may be represented, for example, as a graph of movement waves over time;

other ways of representing a spectral analysis may be used. A pattern matching module (for

example, processor 14 operating according to software) may seek to match the recorded spectral

analysis to spectral analyses corresponding to various conditions, and a match or near match

l o may be reported to a user.

Fig. 3 depicts a motility chart produced, for example, by the system of Fig. 1, according

to one embodiment of the present invention. The plot or chart 100 includes a time axis 102, a relative motility axis 104, and a motility plot or graphing 106. Preferably, if the health

professional indicates a certain point along the motility chart, using, for example, a pointing

15 device such as a mouse, the corresponding image appears in the image window. While, in an exemplary embodiment, the relative motility is expressed in arbitrary units (for example, 0 to

10, adjusted logarithmically), other methods of expressing motility may be used, and absolute

motility may also be expressed.

The chart 100 may include indications of low motility 108, which may be, for example,

0 marks or colored or shaded regions indicating areas where motility is low enough to warrant

investigation by a health professional. The data processor 14 may filter for certain patterns of motility, where such patterns may commonly indicate either normal conditions, such as passage between areas of the GI tract, or pathological conditions. Such conditions may be labeled on the motility chart. In response to such indications of low motility, the health professional may click or otherwise indicate the area on the motility chart in question, and view images (still or

moving) of the corresponding area in the GI tract.

Any number of methods may be used to analyze the image data to form motility data.

For example, motility analysis may be based on a calculation of the difference in a given

5 property between corresponding pixels of two, not necessarily consecutive, frames; a calculation

of the cross-correlation function between two, not necessarily consecutive, frames; a calculation

of the changes of local statistical distributions in two, not necessarily consecutive, frames; or a

calculation of the changes between corresponding local statistical distributions in two, not

necessarily consecutive, frames. Local statistical distributions may include, but are not limited

l o to, the mean, the variance, or the standard deviation of pixel clusters.

In an exemplary embodiment, each image in a pair of images being compared is divided

into a number of sections. Each section in the first image is compared to the corresponding

section in the second image. The variance of the difference of the brightness for the two

sections, normalized by the number of sections, is calculated. The variance is used to ascertain

15 the relative motility of the vehicle capturing images, which in an exemplary embodiment is

capsule 40.

Reference is now made to Fig. 4, a flow chart showing the steps for determining the

motility of a device recording images from a body lumen according to an exemplary

embodiment of the present invention.

20 In step 200, image data is recorded by the capsule 40 and transmitted to the data

processor storage unit 19. In step 202, data processor 14 receives from data processor storage

unit 19 images Pj and P,_+x, where x is usually, but not necessarily, 1. If the stream of images is

too lengthy or rapid, a decimation may be performed and non-adjacent images may be

compared, e.g., image P, and P_1+x, where x>l. In step 204, data processor 14 may divide each of the two images into pixel clusters,

sections or cells, hi an exemplary embodiment, each image Pi is divided into 1024 clusters

A,(m,n), where Km<32 and Kn<32.

In step 206, data processor 14 calculates the average intensity i_Aι(m,_n) of each cluster

A^m_^n) of each of image P, and P_ι+ . Preferably, the intensity value for a cluster is the average

of the brightness values for the pixels in the cluster. A matrix of the intensities of the clusters

may be formed for each image. Alternate methods of calculating intensity may be used; for

example, color data may be used to compare images.

In step 208, data processor 14 determines the absolute value D^mm) of the difference of

the average intensities I of A,(m,n) and A_ι+X(m,n) of corresponding clusters A(m,n) in the frames

P, and P,_+x. D,(m,n) is defined as:

A matrix of the absolute values of differences is formed, one value being generated for each

cluster compared.

In step 210, data processor 14 determines the average difference {Dijf) between the two

images, h an exemplary embodiment, the average difference is calculated by first subtracting

from each absolute value in the matrix created in step 208 the average value of all the

differences in the matrix, summing the resulting values, taking the square root of the resulting

sum, and dividing by the number of the differences in the matrix (in an exemplary embodiment 1024). This may be expressed by the formula:

Diff = ∑£>,(w,«)/1024 m=l,32,H=l,32

where Dijf corresponds to the average of the values in the difference matrix. In an exemplary embodiment, the resulting average difference is a value from 0 to U,

where U is an arbitrary upper limit which depends upon the input parameters. A low average

difference indicates that the measured value (in an exemplary embodiment, brightness) varies

little between the compared frames, and a high value of the average difference indicates that the

measured value varies a large amount. A low difference is an indication of low motility, as, if

the capsule 40 is not moving quickly, the images in the two compared frames will not vary by a

large amount.

In step 212, if more frames exist in the image stream, data processor 14 returns to step 202. If no more frames exist, data processor 14 proceeds to step 214. At this point, the

difference data exists as a series of difference values, one for each frame pair analyzed,

preferably X-l variances, where X is the number of frames analyzed.

In step 214, data processor 14 may normalize or decimate the resulting difference data to an arbitrary scale. This normalized data represents the relative motility of the capsule 40. In an

exemplary embodiment, each difference datum, represented as a value from 0-U, is normalized

to a number between 0 and 10; other ranges may be used. The normalization process may be

linear or may be non-linear - for example, a logarithmic function may be used. In alternate

embodiments, other normalization or decimation functions may be used; for example, the difference data may be translated to a set of integers. During normalization, various functions,

such as logarithmic functions, may be applied to the data.

In step 216, data processor 14 provides an indication of motility for the capsule 40. In an exemplary embodiment, data processor 14 creates a plot or graph of relative motility over time for display on the monitor 18 using the normalized values created in step 214. Data processor 14 may augment the graph with indications of low motility or indications of certain conditions. For example, sections of the graph where motility falls below a certain threshold

may be marked in a certain color or pattern, or may be otherwise labeled.

In alternate embodiments, other methods of analyzing the image data to form motility

data may be used. For example, for each frame pair, data processor 14 may organize the

difference values Dj(k,l) into a chart, for example, a histogram, as shown in Figs. 5 A and B.

Figs. 5 A and B depict histograms used to calculate motility according to an embodiment of the

present invention. Referring to Figs. 5A and B, the absolute value Dj(m,n) of the difference is

plotted on the x-axis of the histograms and the number of corresponding pairs of cells, Ai(m,n) and Ai_+X(m,n), which have a difference of magnitude D;(k,l), is plotted on the y-axis. The

histogram of in Fig. 5 A represents a histogram of cells in relatively similar frames, while the

histogram of Fig. 5B shows a histogram of cells in significantly different frames. It should be

readily apparent that if two images are similar, the histogram of the differences in the cells of

these images are concentrated at low values of Di(m,n). It should also be readily apparent that the center of mass CM_a (the average difference between the two images) of the histogram

shown in Fig. 5 A has a smaller value of D than the center of mass CM of the histogram shown

in Fig. 5B, and corresponds to a slower moving capsule 40. To calculate the difference between

the two frames, processor 14 determines the centers of mass CM of the histograms corresponding to the two frames, and creates a difference value based on the location of the CM.

In another embodiment image analysis may be used to determine the location of the

capsule 40 in vivo (for example by identifying image parameters that are typical to a specific

region in the GI tract) and the position information together with known factors; either the time that has elapsed during the translocation of the capsule 40 or the velocity of the capsule 40 along its path, can be used to calculate the motility. Similarly, the location of the capsule may be

determined by other known methods and the location information can be used to calculate motility. In alternate embodiments, methods of measuring motility may be used which are not

based on image analysis. For example, the capsule 40 may include an accelerometer, which

determines the instantaneous acceleration of capsule 40 as it moves through the GI tract. An

integrator may convert the acceleration data to velocity data, and this velocity data may be used

by the data processor to determine motility. Alternately, a pressure sensor or shear gauge

attached to the capsule 40 may detect peristaltic induced pressure or movement exerted by the

walls of the small intestine. The relationship between pressure and velocity may be determined

empirically, and then utilized to determine the velocity or relative velocity of the capsule 40. A

sensor in the capsule 40 may detect movement relative to an artificially induced magnetic field,

which is generated in the area of the patient's GI tract. The magnetic field induces a current in a

coil in the sensor, whose magnitude is a function of the velocity of the coil through the field.

Data on the induced current is converted to motility information. Further, external sensors may

also be used, such as a Doppler ultrasound unit, which continuously tracks the capsule 40.

Additionally, the receiver 12, which, according to one embodiment is adapted to receive RF

signals from the transmitter 41, may be used to monitor the intensity of the transmitted signal,

whereas signals of unchanging intensities indicate that the transmitter 41 (and hence the capsule

40) is unmoving and signals of different intensities indicate that the transmitter 41 is moving.

One or more of the above methods, or other methods, may be combined to provide a

determination of capsule motility.

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 hereinabove. Rather the scope of the

invention is defined by the claims that follow:

Claims

1. A method for measuring and analyzing motility within a body lumen, the method

comprising the steps of:

accepting images acquired by a vehicle disposed within said body lumen; and

calculating a motility of the vehicle within said body lumen based on comparison of said

accepted images.

2. The method as in claim 1 , wherein said vehicle is a capsule.

3. The method as in claim 1 , wherein said motility is relative motility.

4. The method as in claim 1 , wherein said motility is absolute motility.

5. The method as in claim 1 , wherein said comparison is a comparison of image intensity.

6. The method as in claim 1 , further comprising the steps of:

comparing two images;

generating a variance for the two images; and

repeating the comparing and variance generating steps for a plurality of image pairs to

generate a series of variance values.

7. The method as in claim 1, wherein the step of comparing the images includes, for a pair of images to be compared, at least the steps of: dividing each image into sections; comparing corresponding sections of the images to produce a matrix of difference

values; and

calculating a variance between the two images, the variance based on a function of the

matrix.

8. The method as in claim 1 wherem said vehicle transmits image data from a

gastrointestinal tract.

9. The method as in claim 1, comprising displaying an indication of motility.

10. The method as in claim 1, comprising creating a plot which displays motility as a

function of time.

11. The method as in claim 10, comprising: allowing a user to indicate a point on the plot; and

displaying to the user a set of images corresponding to said point on the plot.

12. The method as in claim 1, comprising the step of providing a visual indication of which of the images correspond to a motility which is below a threshold.

13. A system for measuring and analyzing motility within a body lumen, the system

comprising: an image storage memory accepting images acquired by a vehicle disposed within said

body lumen; and an image processor calculating a motility of the vehicle within said body lumen based on

comparison of properties of said accepted images.

14. The system as in claim 13, wherein said vehicle is a swallowable vehicle.

15. The system as in claim 13 , wherem said vehicle is a capsule.

16. The system as in claim 13, wherein said motility is relative motility.

17. The system as in claim 13, wherein said motility is absolute motility.

18. The system as in claim 13, wherein said comparison is a comparison of image intensity.

19. The system as in claim 13, comprising a processor performing the steps of:

comparing two images; generating a variance for the two images; and

generate a series of variance values.

20. The system as in claim 13, wherein said vehicle includes a fransmitter.

21. The system as in claim 13 , comprising a display on which a plot of motility as a function of time is displayed.

22. The system as in claim 21, comprising: an input device accepting an indication from a user of a point on the plot, wherein in

response to said indication a set of images corresponding to said point on the plot is displayed

on said display.

23. A system for measuring and analyzing motility within a body lumen, the system

comprising:

an image storage means for accepting images acquired by an image capture means

disposed within said body lumen; and

an image processor means for calculating a motility of the image capture means within

said body lumen based on comparison of properties of said accepted images.

24. The system as in claim 23, wherein said image capture means is disposed within a

swallowable vehicle.

25. The system as in claim 23, wherein said image capture means is disposed within a

capsule.

26. The system as in claim 23, wherein said motility is relative motility.

27. The system as in claim 23, wherein said motility is absolute motility.

28. The system as in claim 23, wherein said comparison is a comparison of image intensity.

29. The system as in claim 23, comprising a processing means for:

comparing two images; generating a variance for the two images; and

repeating, for a plurality of image pairs, comparing and generating a variance, to

generate a series of variance values.

30. The system as in claim 23, wherein said image capture means includes a transmitting

means.

31. The system as in claim 23, comprising a display means on which a plot of motility as a

function of time is displayed.

32. The system as in claim 31, comprising:

an input means accepting an indication from a user of a point on the plot; wherein in

on said display means.

33. A method for measuring and analyzing motility within a body lumen, the method

comprising:

accepting images acquired by a vehicle disposed within said body lumen;

comparing two images;

generating a variance for the two images;

generate a series of variance values; and

calculating a motility of said vehicle within said body lumen based on said series of

variance values.

34. A method for measuring and analyzing motility within a body lumen, the method comprising:

accepting images acquired by a capsule disposed within said body lumen;

comparing pairs of said images;

calculating a motility of said capsule within said body lumen based on said comparisons;

and

creating a plot which displays motility as a function of time.

35. A method for measuring and analyzing motility within a body lumen, the method

comprising: accepting images acquired by a vehicle disposed within said body lumen;

comparing two images;

generating a variance for the two images;

generate a series of variance values;

calculating a motility of said vehicle within said body lumen; and

providing an indication of motility.

36. A method for measuring and analyzing motility within a body lumen, the method

comprising: accepting images acquired by a capsule disposed within said body lumen; comparing a set of images;

generating a variance for the set of images; repeating the comparing and variance generating steps to generate a series of variance

values; calculating a motility of said capsule within said body lumen; and

providing an indication of motility of the capsule.

37. A method for measuring and analyzing motility within a body lumen, the method

comprising:

accepting images acquired by a capsule disposed within said body lumen; and

calculating a motility of the capsule within said body lumen based on comparison of

said accepted images.

38. A method for determining at least one condition in a GI tract comprising the steps of:

calculating a motility of a device within the GI tract;

creating a spectral analysis of said motility;

examining the spectral analysis for at least one parameter;

comparing said parameter to a reference; and

determining a condition, if any, in the GI tract based on the comparison.

39. The metliod according to claim 38 further comprising creating a plot, which displays

motility as a function of time.

40. The method according to claim 38 comprising accepting images acquired by

the device.

41. The method according to claim 38 wherein calculating the motility includes

at least comparing images accepted from the device.

42. The method according to claim 38 wherein calculating the motility includes

at least monitoring the intensity of RF signals transmitted from a capsule

disposed within said GI tract.

43. The method according to claim 38, wherein said device is a capsule.

44. A system for determining at least one condition in a GI tract, the system

comprising:

a receiver capable of receiving signals from a device within the GI tract; and

a controller capable of:

calculating a motility of the device;

creating a spectral analysis of said motility;

examining the spectral analysis for at least one parameter;

comparing said parameter to a reference; and determining a condition, if any, in the GI tract, based on the comparison.

45. The system according to claim 44 wherein the controller is capable of

creating a plot which displays motility as a function of time.

46. The system according to claim 44 wherein calculating the motility includes at

least comparing images accepted from the device.

47. The system according to claim 44, wherein said device is a capsule.