Ingestible pressure sensing capsule
An improved capsule ( 15 ) for sensing a contractual force within a mammalian tract, comprising a shell ( 16 ), a flexible sleeve ( 17 ) affixed to the shell and defining a chamber ( 19 ) between the shell and the sleeve, and a pressure sensor ( 18 ) operatively arranged to sense pressure within the chamber, whereby a contraction force on the outside of the sleeve produces a corresponding pressure change within the chamber. The chamber may contain a fluid ( 22 ) and the fluid may be mineral oil.
1 . A capsule for sensing a contractual force within a mammalian tract, comprising:
a shell;
a flexible sleeve affixed to said shell and defining a chamber between said shell and said sleeve; and
a pressure sensor operatively arranged to sense pressure within said chamber;
whereby a contraction force on the outside of said sleeve produces a corresponding pressure change within said chamber.
2 . The capsule set forth in claim 1 , wherein said shell is rigid and said sleeve is more elastic than said shell.
3 . The capsule set forth in claim 1 , wherein said chamber contains a fluid.
4 . The capsule set forth in claim 3 , wherein said fluid is mineral oil.
5 . The capsule set forth in claim 3 , wherein said chamber is filled with said fluid to a base pressure and said sensor senses an increase in pressure in said chamber above said base pressure.
6 . The capsule set forth in claim 1 , wherein said chamber contains a gas.
7 . The capsule set forth in claim 6 , wherein said gas is inert.
8 . The capsule set forth in claim 3 , wherein said shell has an interior surface and an exterior surface, and said sensor is supported by said interior surface of said shell.
9 . The capsule set forth in claim 1 , wherein said shell comprises a fluid port communicating with said chamber.
10 . The capsule set forth in claim 9 , wherein said sensor, said chamber and said port are operatively arranged such that said sensor senses an increase in pressure in said port.
11 . The capsule set forth in claim 10 , wherein said sensor is a piezoelectric bridge or an oscillator coil and diaphragm.
12 . The capsule set forth in claim 1 , and further comprising:
a second sleeve affixed to said shell and defining a second chamber between said shell and said second sleeve; and
a second pressure sensor operatively arranged to sense pressure within said second chamber;
whereby a contraction force on the outside of said second sleeve produces a corresponding pressure change within said second chamber.
13 . The capsule set forth in claim 1 , and further comprising a plurality of ribs extending from said shell and supporting said sleeve.
14 . The capsule set forth in claim 13 , wherein said ribs are configured to form a plurality of sub-chambers, whereby a force on said sleeve produces a corresponding pressure in a sub-chamber that is channeled by said ribs towards said sensor.
15 . The capsule set forth in claim 13 , wherein said sleeve is stretched over said ribs.
16 . The capsule set forth in claim 1 , wherein said sleeve has an open end and a closed end and said open end is attached to said shell with adhesive.