AUTONOMOUS INTRACORPOREAL CAPSULE WITH FREQUENCY CONVERSION ENERGY HARVESTING

• US 20150094786A1
• Filed: 09/29/2014
• Published: 04/02/2015
• Est. Priority Date: 10/01/2013
• Status: Active Grant

• Current Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Original Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Inventors: Deterre, Martin, Lefeuvre, Elie
• Granted Patent: US 9,511,237 B2
• Time in Patent Office: Days
• US Class Current: 607/61
• CPC Class Codes: A61N 1/362 Heart stimulators heart defibrillators A61N1/39
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: A61N 1/3785 generated by biological activity or substance, e.g. body movement
• CPC Class Codes: A61N 1/3975 Power supply A61N1/378 takes precedence
• CPC Class Codes: H02N 1/08 with conductive charge carrier, i.e. capacitor machines
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01
• CPC Class Codes: H10N 30/88 Mounts; Supports; Enclosures; Casings

Abstract

The energy harvester module of the capsule comprises: a primary oscillating structure subjected to an external low-frequency stress; a secondary oscillating structure comprising an elastic element and able to vibrate in high-frequency resonance; and an electrostatic structure with a first electrode coupled to the primary structure and a second electrode coupled to the secondary structure. The electrodes exert a mutual attraction between them driving the secondary structure away from its stable equilibrium position with tensioning of the elastic element, up to a limit beyond which the secondary structure is released by relaxation effect to vibrate at a resonance frequency. A transducer coupled to the secondary structure converts these high frequency vibration movements into electrical energy.

Claims

1. An autonomous intracorporeal capsule, comprising:

a body containing therein electronic circuits and an energy harvester module for supplying power to the electronic circuitry;

the energy harvester module comprising a transducer adapted to convert an external physical stress applied to the body of the capsule into electrical energy, wherein the external physical stress results from pressure variations in the environment surrounding the capsule and/or from movements of a wall to which the capsule is anchored;

wherein the energy harvester module further comprises;

a primary oscillating structure being adapted to be moved alternately in one direction and in the other at a first frequency;

a secondary oscillating structure comprising a secondary deformable elastic element and adapted to vibrate at a resonant frequency greater than the first frequency; and

an electrostatic structure comprising a first capacitor electrode coupled to the primary oscillating structure or to the body of the capsule, and a second capacitor electrode coupled to the secondary oscillating structure;

wherein the first and the second electrode are configured to interact so that, under the effect of a movement of the primary oscillating structure into an action area, the first and second electrode operate together under the effect of an electrostatic attraction force interaction thereby moving the secondary oscillating structure away from its stable equilibrium position causing tensioning of the secondary deformable elastic element;

the secondary oscillating structure being thus driven to a limit at which a tension force exerted by the elastic deformable element caused by the tensioning exceeds the electrostatic attraction force of the electrodes, such that the secondary oscillating structure is released by relaxation effect to vibrate at the resonant frequency; and

wherein the transducer is coupled to the secondary oscillating structure, to convert vibration movements thereof at the resonant frequency into electrical energy.

2. The capsule of claim 1, wherein the primary oscillating structure is subjected to the external physical stress.

3. The capsule of claim 2, wherein the secondary oscillating structure is not subjected to the external physical stress.

4. The capsule of claim 1, wherein the first frequency is the frequency of the external stress to which the first oscillating structure is subjected.

5. The capsule of claim 1, wherein the resonant frequency is a natural resonance eigenfrequency.

6. The capsule of claim 1, wherein the electrostatic structure comprises a pair of conversion electrodes forming a capacitor, one of these conversion electrodes being cyclically driven by the secondary oscillating structure, and the electrostatic structure operating by cyclic modification of surfaces vis-à

-vis and/or of the dielectric interval of conversion electrodes with correlative variation in the capacity of the capacitor.

7. The capsule of claim 6, wherein said conversion electrodes include said first and second electrodes of the electrostatic structure.

8. The capsule of claim 1, wherein the transducer is of the piezoelectric type comprising a deformable piezoelectric element configured to be cyclically stressed by the secondary oscillating structure.

9. The capsule of claim 1, wherein the transducer is of the electromagnetic type comprising a mobile magnetic element or a mobile coil configured to be cyclically driven by the secondary oscillating structure.

10. The capsule of claim 1, wherein the primary oscillating structure comprises an inertial mass coupled to the body of the capsule by an elastic suspension adapted to be stressed under the effect of the movements of the capsule in the surrounding medium.

11. The capsule of claim 1, wherein the primary oscillating structure is coupled to a deformable surface out of the body of the capsule and adapted to be stressed under the effect of pressure changes in the medium surrounding the capsule.

12. The capsule of claim 1, wherein the primary oscillating structure and the secondary oscillating structure are coupled to each other by the electrostatic structure.

13. The capsule of claim 12, wherein the secondary oscillating structure is coupled to the body of the capsule by the secondary deformable elastic element.

14. The capsule of claim 13, wherein the first electrode of the electrostatic structure is connected to the primary oscillating structure and the second electrode of the electrostatic structure is connected to the secondary oscillating structure.

15. The capsule of claim 1, wherein the primary oscillating structure and the secondary oscillating structure are coupled together by the secondary deformable elastic element.

16. The capsule of claim 15, wherein the first electrode of the electrostatic structure is connected to the body of the capsule, and the second electrode of the electrostatic structure is connected to the secondary oscillating structure.

17. The capsule of claim 1, wherein the first and second electrodes of the electrostatic structure are formed as respective fingers of one or more nested combs and one or more counter-combs.

18. The capsule of claim 17, wherein the fingers of at least one of the first and second electrodes of the electrostatic structure are elastically deformable fingers, forming together said deformable elastic element of the secondary oscillating structure.

19. The capsule of claim 18, wherein the distal ends of elastically deformable fingers of at least one of the first and second electrodes of the electrostatic structure are joined together by a rigid coupling.

20. The capsule of claim 1, wherein the pressure variations in the environment surrounding the capsule and/or from movements of a wall to which the capsule is anchored cause the primary structure to return to the action area, and wherein the first and the second electrode are configured to repeatedly interact when the primary structure returns to the action area so that the first and second electrode operate repeatedly together under the effect of the electrostatic attraction force interaction thereby moving the secondary oscillating structure away from its stable equilibrium position and causing subsequent release and resonant vibration of the second oscillating structure.

21. An energy harvester module, comprising:

a primary oscillating structure subjected to an external physical stress, the primary oscillating structure being adapted to be moved alternately in one direction and in the other;

a secondary oscillating structure not subjected to the external physical stress, the secondary oscillating structure comprising a secondary deformable elastic element and adapted to vibrate at a resonant frequency; and

an electrostatic structure comprising a first capacitor electrode coupled to the primary oscillating structure and a second capacitor electrode coupled to the secondary oscillating structure;

wherein the first and the second electrode are configured to interact so that, under the effect of the external physical stress applied to the primary oscillating structure, the first and second electrode operate together under the effect of an electrostatic attraction force interaction thereby moving the secondary oscillating structure away from its stable equilibrium position causing tensioning of the secondary deformable elastic element;

the secondary oscillating structure being thus driven to a limit at which a tension force exerted by the elastic deformable element caused by the tensioning exceeds the electrostatic attraction force of the electrodes, such that the secondary oscillating structure is released by relaxation effect to vibrate at the resonant frequency; and

wherein the transducer is coupled to the secondary oscillating structure, to convert vibration movements thereof at the resonant frequency into electrical energy.

22. The energy harvester module of claim 21, wherein the electrostatic structure comprises a pair of conversion electrodes forming a capacitor, one of these conversion electrodes being cyclically driven by the secondary oscillating structure, and the electrostatic structure operating by cyclic modification of surfaces vis-à

-vis and/or of the dielectric interval of conversion electrodes with correlative variation in the capacity of the capacitor.

23. The energy harvester module of claim 21, wherein the primary oscillating structure and the secondary oscillating structure are coupled to each other by the electrostatic structure.

24. The energy harvester module of claim 21, wherein the primary oscillating structure and the secondary oscillating structure are coupled together by the secondary deformable elastic element.

25. The energy harvester module of claim 21, wherein the first and second electrodes of the electrostatic structure are formed as respective fingers of one or more nested combs and one or more counter-combs.

26. A method for harvesting energy in an implantable device, comprising:

receiving an external force that causes a first oscillating structure to move in the direction of a second oscillating structure;

engaging the second oscillating structure with the first oscillating structure via the movement of the first oscillating structure towards the second oscillating structure;

pulling the second oscillating structure away from an equilibrium position to create tension in a deformable elastic element coupled to the second oscillating structure;

releasing the second oscillating structure from the first oscillating structure when the tension in the deformable elastic element exceeds a tension limit;

harvesting energy from the oscillations of the second oscillating structure when it is released from the first oscillating structure and vibrates at a resonant frequency.

27. The method of claim 26, further comprising:

receiving a second external force that causes the first oscillating structure to repeat movement in the direction of the second oscillating structure;

re-engaging the second oscillating structure with the first oscillating structure via the repeat movement of the first oscillating structure towards the second oscillating structure; and

causing repetition of the steps;

pulling the second oscillating structure away from an equilibrium position to create tension in a deformable elastic element coupled to the second oscillating structure;

releasing the second oscillating structure from the first oscillating structure when the tension in the deformable elastic element exceeds a tension limit;

harvesting energy from the oscillations of the second oscillating structure when it is released from the first oscillating structure and vibrates at a resonant frequency.