Method of determining the slow wave of a gastrointestinal tract

1 . A computerized method of determining the slow wave of a gastrointestinal tract comprising the steps of:

providing an ingestible capsule having a pressure sensor;

having a subject ingest said capsule;

recording measurements from said pressure sensor as said capsule passes through at least a portion of said gastrointestinal tract of said subject;

transmitting said measurements to a processor;

conditioning said measurements to provide pressure data as a function of a time interval;

interpolating missing pressure data in said time interval;

filtering said pressure data as a function of a desired bandpass;

differencing said pressure data;

windowing said pressure data;

applying a sample size and an overlap between samples to segment said pressure data;

applying a Fourier transform to said segmented pressure data to provide frequency pressure data;

selecting an FFT frequency bandpass;

computing power spectrum density of said transformed pressure data for said FFT bandpass;

plotting said transformed pressure data;

whereby a dominate pressure frequency correlating to a slow wave of at least a portion of said gastrointestinal tract is shown.

2 . The method set forth in claim 1 , wherein said step of transmitting said measurements to a processor comprises the steps of:

transmitting said measurements from said capsule to a receiver outside of said gastrointestinal tract of said subject; and

downloading said measurements from said receiver to said processor.

3 . The method set forth in claim 1 , wherein said step of conditioning said measurements to provide pressure data as a function of a time interval comprises the steps of:

screening said measurements to verify that they are valid;

converting said measurements to units of pressure;

compensating for temperature; and

applying a baseline compensation.

4 . The method set forth in claim 1 , wherein said missing pressure data is the result of an error in said pressure sensor measurement or a change in a sampling rate of said sensor.

5 . The method set forth in claim 1 , wherein said step of interpolating missing pressure data in said time interval comprises:

identifying a data gap;

fitting a curve to data on each side of said gap;

computing a value for said missing data as a function of said curve.

6 . The method set forth in claim 1 , wherein said step of interpolating missing pressure data in said time interval comprises:

identifying a data gap;

identifying a data value on one side of said gap; and

providing a value for said missing data based on said identified data value.

7 . The method set forth in claim 1 , wherein said step of filtering said pressure data as a function of a desired bandpass comprises the step of applying a Butterworth bandpass filter or applying a Butterworth lowpass filter.

8 . The method set forth in claim 1 , wherein said step of differencing said pressure data comprises the step of selecting each data value in a sequence and subtracting the next data value in said sequence from said selected data value.

9 . The method set forth in claim 1 , wherein said step of windowing said pressure data comprises the step of inputting parameters for said windowing.

10 . The method set forth in claim 1 , wherein said sample size is about twenty minutes.

11 . The method set forth in claim 1 , wherein said overlap is about eighteen minutes.

12 . The method set forth in claim 1 , wherein said FFT frequency bandpass is from about 4 CPM to about 15 CPM.

13 . The method set forth in claim 1 , wherein said step of computing power spectrum density comprises the steps of:

selecting a central frequency and determining an amplitude value for pressure data in said selected frequency;

squaring and taking the sum of said amplitudes and amplitude values for pressure data in a number N of neighboring frequencies; and

repeating the foregoing for each frequency in said FFT frequency bandpass.

14 . The method set forth in claim 13 , wherein said N is 6.

15 . The method set forth in claim 1 , wherein said plot is a graph.

16 . The method set forth in claim 15 , wherein said graph further comprises color representing said power spectrum density.

17 . The method set forth in claim 1 , and further comprising the step of identifying the location of said capsule as a function of said dominant pressure frequency.

18 . The method set forth in claim 17 , wherein said location is the small bowel of said gastrointestinal tract.

19 . The method set forth in claim 17 , wherein said location is the ileo-caecal junction of said gastrointestinal tract.

20 . The method set forth in claim 17 , wherein said step of identifying the location of said capsule is a function of pH measurements taken by said capsule.

21 . The method set forth in claim 20 , wherein said step of identifying the location of said capsule further comprises the steps of:

providing a pH sensor on said capsule;

recording measurements from said pH sensor as said capsule passes through said gastrointestinal tract of said subject;

transmitting said measurements to said processor; and

providing pH data as a function of said time interval.

22 . The method set forth in claim 21 , and further comprising the step of comparing said pH data to a pH reference.

23 . A computerized method of determining the slow wave of a gastrointestinal tract comprising the steps of:

providing an ingestible capsule having a pressure sensor;

having a subject ingest said capsule;

recording measurements from said pressure sensor as said capsule passes through at least a portion of said gastrointestinal tract of said subject;

transmitting said measurements to a processor;

conditioning said measurements to provide pressure data as a function of a time interval;

applying a sample size and an overlap between samples to segment said pressure data;

applying a Fourier transform to said segmented pressure data to provide frequency pressure data;

plotting said transformed pressure data;

whereby a dominate pressure frequency correlating to a slow wave of at least a portion of said gastrointestinal tract is shown.

24 . The method set forth in claim 23 , wherein said step of transmitting said measurements to a processor comprises the steps of:

transmitting said measurements from said capsule to a receiver outside of said gastrointestinal tract of said subject; and

downloading said measurements from said receiver to said processor.

25 . The method set forth in claim 23 , wherein said step of conditioning said measurements to provide pressure data as a function of a time interval comprises the steps of:

screening said measurements to verify that they are valid;

converting said measurements to units of pressure;

compensating for temperature; and

applying a baseline compensation.

26 . The method set forth in claim 23 , wherein said sample size is about twenty minutes.

27 . The method set forth in claim 23 , wherein said overlap is about eighteen minutes.

28 . The method set forth in claim 23 , wherein said plot is a graph.

29 . The method set forth in claim 23 , and further comprising the step of identifying the location of said capsule as a function of said dominant pressure frequency.

30 . The method set forth in claim 29 , wherein said location is the small bowel of said gastrointestinal tract.

31 . The method set forth in claim 29 , wherein said location is the ileo-caecal junction of said gastrointestinal tract.

32 . A computer-readable medium having computer-executable instructions for performing a method comprising:

receive pressure measurements recorded by a pressure sensor on an ingestible capsule ingested by a subject;

conditioning said measurements to provide pressure data as a function of a time interval;

applying a sample size and an overlap between samples to segment said pressure data;

applying a Fourier transform to said segmented pressure data to provide frequency pressure data;

plotting said transformed pressure data;

whereby a dominate pressure frequency correlating to a slow wave of at least a portion of said gastrointestinal tract is shown.

33 . The medium set forth in claim 32 , wherein said conditioning said measurements to provide pressure data as a function of a time interval comprises:

screening said measurements to verify that they are valid;

converting said measurements to units of pressure;

compensating for temperature; and

applying a baseline compensation.

34 . The medium set forth in claim 32 , wherein said sample size is about twenty minutes.

35 . The medium set forth in claim 32 , wherein said overlap is about eighteen minutes.

36 . The medium set forth in claim 32 , wherein said plot is a graphical representation of said transformed pressure data.

37 . The medium set forth in claim 32 , and further comprising identifying the location of said capsule as a function of said dominant pressure frequency.

38 . The medium set forth in claim 37 , wherein said location is the small bowel of said gastrointestinal tract.

39 . The medium set forth in claim 37 , wherein said location is the ileo-caecal junction of said gastrointestinal tract.

40 . A system for identifying the slow wave of a gastrointestinal tract comprising:

an ingestible capsule having a pressure sensor adapted to record pressure data as a function of time as said capsule passes through at least a portion of a subject's gastrointestinal tract;

a receiver adapted to received said data when transmitted from said capsule;

a processor adapted to communicate with said receiver;

a display in communication with said processor;

said processor programmed to

receive pressure measurements recorded by said pressure sensor,

condition said measurements to provide pressure data as a function of a time interval,

apply a sample size and an overlap between samples to segment said pressure data,

apply a Fourier transform to said segmented pressure data to provide frequency pressure data, and

plot said transformed pressure data on said display;

whereby a dominate pressure frequency correlating to a slow wave of at least a portion of said gastrointestinal tract is shown.

41 . The system set forth in claim 40 , wherein said conditioning said measurements to provide pressure data as a function of a time interval comprises:

screening said measurements to verify that they are valid;

converting said measurements to units of pressure;

compensating for temperature; and

applying a baseline compensation.

42 . The system set forth in claim 40 , wherein said sample size is about twenty minutes.

43 . The system set forth in claim 40 , wherein said overlap is about eighteen minutes.

44 . The system set forth in claim 40 , wherein said plot is a graphical representation of said transformed pressure data.