Tracking an Implantable Device Powered by Ultrasound Waves

Claims

1. A method for detecting an implantable device powered by ultrasonic waves, comprising the steps of: (a) emitting an ultrasonic beam to focus sequentially on a plurality of focal points; (b) at each focal point of the set of focal points: (i) maintaining a focused ultrasound beam at a focal point for a time interval that allows the implantable device, when positioned at the focal point, to convert energy from the ultrasound waves of the ultrasound beam into electrical energy to enter an on state from an off state, (ii) receiving ultrasonic backscattered radiation corresponding to an ultrasonic beam focused at a focal point, and (iii) comparing the received ultrasound backscattered radiation with a predetermined pattern associated with the implantable device to be detected to generate a score indicating how likely the ultrasound backscattered radiation is to contain the predetermined pattern; and (c) determining the location of the implantable device from the plurality of focal points based on a plurality of estimates generated for each focal point in the plurality of corresponding focal points.

2. The method of claim 1, comprising the step of instructing the implantable device to enter an on state.

3. The method according to claim 1 or 2, further comprising the step of establishing an ultrasonic communication line with the implantable device using ultrasonic waves emitted by an interrogating device focused at a focal point corresponding to a specific location of the implantable device.

4. The method according to any one of paragraphs 1-3, wherein the plurality of focal points corresponds to the adjustable range of the ultrasonic beam.

5. The method according to any one of paragraphs 1-4, wherein the predetermined pattern comprises one or more rectangular waves.

6. The method according to any one of paragraphs 1-5, wherein the predetermined template uniquely identifies the implantable device.

7. The method according to any one of claims 1-6, wherein the predetermined template comprises information encoded by the implantable device into the ultrasonic backscattered radiation.

8. The method of claim 7, wherein the implantable device receives ultrasonic waves from the emitted ultrasonic beam and encodes information into ultrasonic backscattered radiation by modulating an electrical signal generated from the ultrasonic waves received in the implantable device.

9. The method according to any one of claims 1-8, wherein determining the location of the implantable device comprises the step of selecting a focal point from a subset of focal points in a plurality of focal points, wherein the score corresponding to each focal point in the subset of focal points is above a predetermined threshold value.

10. The method according to any one of claims 1-8, wherein determining the location of the implantable device comprises the step of selecting a focal point from a plurality of focal points as the most probable location of the implantable device based on a plurality of estimates.

11. The method according to claim 9 or 10, comprising confirming the location of the implantable device, comprising the steps of: emit an ultrasonic beam to focus on a selected focal point for a predetermined period of time; and analyze the ultrasound backscatter received while the ultrasound beam is focused on a selected focal point to confirm that the implantable device is located at the selected focal point.

12. The method of claim 11, comprising, in response to confirming that the implantable device is at the selected focal point, the step of maintaining the ultrasound beam at the selected focal point.

13. The method according to any one of paragraphs 1-12, wherein the method for detecting the implantable device is performed in the interrogating device.

14. The method of claim 13, wherein the interrogating device comprises a plurality of measuring transducers in an array of measuring transducers, and wherein emitting an ultrasonic beam to sequentially focus on a plurality of focal points comprises a step in which the plurality of measuring transducers are controlled to transmit ultrasonic waves in the ultrasonic beam to sequentially focus on a plurality of focal points.

15. The method according to claim 14, wherein the emission of the ultrasonic beam comprises a step in which the focused ultrasonic beam is sequentially directed to each focal point of a plurality of focal points in an adjustable angular range of the array of measuring transducers.

16. The method of claim 14, wherein emitting the ultrasonic beam comprises the step of mechanically moving the array of transducers to sequentially direct the focused ultrasonic beam to each focal point of the plurality of focal points.

17. The method according to any one of claims 14-16, wherein emitting the ultrasonic beam comprises the step of controlling when power is supplied to each transducer in the array of transducers to sequentially direct the focused ultrasonic beam to each focal point of the plurality of focal points.

18. The method according to any one of claims 1-17, wherein the implantable device comprises one or more capacitors for storing electrical energy converted from ultrasonic waves of the ultrasonic beam to enter an on state from an off state.

19. The method according to any one of claims 1 to 18, wherein the ultrasonic beam has a spot size of less than 10 mm.

20. A system for detecting an implantable device powered by ultrasonic waves, comprising: (a) a transducer array containing a plurality of transducers; and (b) a controller configured to: (i) control the array of transducers to emit an ultrasonic beam sequentially focused onto a plurality of focal points; (ii) at each focal point of the set of focal points: maintain a focused ultrasound beam at a focal point for a time interval that allows the implantable device, when positioned at the focal point, to convert energy from the ultrasound waves of the ultrasound beam into electrical energy and to enter an on state from an off state, receive ultrasonic backscattered radiation corresponding to the emitted ultrasonic beam, and compare the received ultrasound backscattered radiation with a predetermined pattern associated with the implantable device to be detected to generate an estimate indicating how likely the ultrasound backscattered radiation contains the predetermined pattern; and (iii) determine the location of the implantable device from the plurality of focal points based on the plurality of estimates generated for the plurality of corresponding focal points.