Smart capsule with GI-tract-location-specific payload release

1. A remotely activatable capsule, comprising:

a housing configured to be swallowed by a subject, the hosing comprising a main body and a detachable cap positioned at one end of the main body;

an electrical energy reservoir having a first terminal and a second terminal disposed in the housing;

a remotely activatable switch disposed in the housing and configured to be remotely activated, the remotely activatable switch is a magnetic switch having a first terminal and a second terminal, the first terminal of the magnetic switch coupled to the first terminal of the electrical energy reservoir, the magnetic switch configured to be i) open in a non-activation mode thereby providing an open circuit between the first and second terminals of the magnetic switch, and ii) closed in an activation mode when a magnetic field is applied thereby providing a closed circuit between the first and second terminals of the magnetic switch, wherein the magnetic field can be provided by an implanted magnet or by an externally worn magnet;

a drug compartment containing a drug, the drug compartment disposed in the housing and electrically coupled to the remotely activatable switch and to the electrical energy reservoir and configured to release the drug when the remotely activatable switch is activated, the drug compartment comprising a release mechanism electrically coupled to the second terminal of the magnetic switch and to the second terminal of the electrical energy reservoir and mechanically coupled to the detachable cap, the release mechanism configured to i) sealably maintain the detachable cap against the main body of the housing in the non-activation mode, and ii) allow the cap to be detached from the main body in the activation mode, the release mechanism comprising:

a first biasing member coupled to the detachable cap and held in a biased position in the non-activation mode;

a heating wire coupled to the second terminal of the magnetic switch and to the second terminal of the electrical energy reservoir; and

a fuse member disposed between the heating wire and the first biasing member and configured to burn in the activation mode and thereby cause the first biasing member to move from the biased position to an unbiased position.

2. The remotely activatable capsule of claim 1 , the release mechanism further comprising a space filled with a fluid under pressure, wherein in the activation mode, the fluid pressure causes the detachable cap to become detached, and wherein the biasing force exerted by the first biasing member is greater than the force acting on the detachable cap by the fluid pressure.

3. The remotely activatable capsule of claim 2 , wherein the fluid is air.

4. The remotely activatable capsule of claim 2 , wherein the fluid is gasified saline.

5. The remotely activatable capsule of claim 1 , the release mechanism further comprising a second biasing member coupled to the detachable cap and to the main body and bias to detach the detachable cap, wherein the biasing force of the first biasing member is greater than then biasing member of the second biasing member.

6. The remotely activatable capsule of claim 1 , the electrical energy reservoir is a capacitor.

7. The remotely activatable capsule of claim 1 , the housing includes two terminals coupled to the capacitor for charging the capacitor.

8. The remotely activatable capsule of claim 1 , the electrical energy reservoir is a battery.

9. The remotely activatable capsule of claim 1 , the housing is made from a polymer-based material.