Ingestible device with relatively large payload volume
Ingestible devices with a relatively large payload volume or sample volume, as well as related components, systems and methods, are disclosed.
1. An ingestible device, comprising:
a housing comprising first and second components; and
a mechanism in an interior of the housing,
wherein:
the first component defines an anode;
the second component defines a cathode;
the ingestible device is configured so that, during use of the device, a portion of the anode electrolytically erodes to provide an opening in the housing;
the mechanism is configured to apply a mechanical force to a substance to propel the substance out of the housing via the opening;
the mechanism comprises at least one spring configured to provide the mechanical force;
the at least one spring comprises first, second and third springs;
the second spring is nested between the first and third springs;
a winding of the second spring runs in a direction opposite to a direction of a winding of the first spring; and
a winding of the third spring runs in the same direction as the winding of the first spring.
2. The ingestible device of claim 1 , wherein the ingestible device has a total volume and a second volume selected from the group consisting of a payload volume and a sample volume, and a ratio of second volume to the total volume is at least 0.1.
3. The ingestible device of claim 2 , wherein the ratio of the second volume to the total volume is at least 0.2.
4. The ingestible device of claim 2 , wherein the second volume of the ingestible device is at most 400 μL.
5. The ingestible device of claim 4 , wherein the second volume of the ingestible device is at least five μL.
6. The ingestible device of claim 5 , wherein the total volume of the ingestible device is at most 1,100 μL.
7. The ingestible device of claim 6 , wherein the ingestible device is at least two millimeters long and at most 20 millimeters long.
8. The ingestible device of claim 7 , wherein the first component comprises an exposed conductive surface, and an area of the exposed conductive surface is at most 0.1 mm 2 .
9. The ingestible device of claim 8 , wherein a thickness of a conductive material at the exposed conductive surface is at least 0.1 mm and at most 0.25 mm.
10. The ingestible device of claim 9 , further comprising an enteric coating.
11. The ingestible device of claim 10 , wherein the anode and the cathode are not at opposite ends of the ingestible device.
12. The ingestible device claim 2 , wherein the total volume of the ingestible device is at most 1,100 μL.
13. The ingestible device of claim 1 , wherein the ingestible device is at most 20 millimeters long.
14. The ingestible device of claim 13 , wherein the device is at least two millimeters long.
15. The ingestible device of claim 1 , wherein the first component comprises an exposed conductive surface.
16. The ingestible device of claim 15 , wherein an area of the exposed conductive surface is at most 0.1 mm 2 .
17. The ingestible device of claim 15 , wherein a thickness of a conductive material at the exposed conductive surface is at most 0.25 mm.
18. The ingestible device of claim 17 , wherein the thickness of the conductive material at the exposed conductive surface is at least 0.1 mm.
19. The ingestible device of claim 15 , further comprising an insulating coating on the first component in an area adjacent the exposed conductive surface.
20. The ingestible device of claim 1 , further comprising an enteric coating.
21. The ingestible device of claim 1 , wherein the anode and the cathode are not at opposite ends of the ingestible device.
22. The ingestible device of claim 1 , wherein the at least one spring comprises at least one member selected from the group consisting of a coil spring, a spiral spring and a torsion spring.
23. The ingestible device of claim 1 , further comprising a plunger between the at least one spring and the substance so that the plunger transfers the mechanical force from the at least one spring to the substance.