Telemetric sensing using micromachined ultrasonic transducer

• US 8,767,514 B2
• Filed: 12/02/2008
• Issued: 07/01/2014
• Est. Priority Date: 12/03/2007
• Status: Active Grant

• Current Assignee: Kolo Medical, Ltd.
• Original Assignee: Kolo Technologies, Inc.
• Inventors: Huang, Yongli
• Primary Examiner(s): Lobo, Ian J
• Application Number:
  US12/326,769
• Publication Number:
  US 20090141592A1
• Time in Patent Office: 2,037 Days
• Field of Search: 367/181, 600/459
• US Class Current: 367/181
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/4472 Wireless probes
• CPC Class Codes: A61B 8/56 Details of data transmission or power supply
• CPC Class Codes: A61B 8/565 involving data transmission via a network
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: G01S 15/00 Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
• CPC Class Codes: H04R 23/00 Transducers other than those covered by groups H04R9/00 - H04R21/00 diaphragms for transducers of the distributed-mode type H04R7/045

Abstract

Implementations of a cMUT have a telemetric antenna operative to telemetrically transmit an output signal generated by the cMUT in reception mode (RX). The cMUT generates the output signal by converting a received energy applied on the cMUT. The received energy may be an acoustic wave or a low-frequency pressure signal. The acoustic wave may be generated by a separate acoustic energy source. The cMUT may form a modulated signal using a carrier signal modulated with the output signal, and telemetrically transmit the modulated signal carrying the output signal to increase efficiency. The antenna may also receive an input signal from outside to telemetrically power on the cMUT.

Claims

1. A capacitive micromachined transducer (cMUT) system comprising:

a cMUT operative in a reception mode (RX) to convert an external energy applied on the cMUT to an output signal;

an AC signal source on a first side of the cMUT for generating a carrier signal that passes across an electrode gap of the cMUT to a second side of the cMUT, so that a carrier frequency of the carrier signal is modulated with the output signal, that is output by the cMUT, to become a modulated signal carrying the output signal; and

an antenna on the second side of the cMUT to wirelessly transmit the modulated signal carrying the output signal.

2. The cMUT system of claim 1, wherein the external energy comprises an ultrasonic acoustic wave.

3. The cMUT system of claim 1, wherein the external energy comprises a pressure having a frequency substantially lower than an ultrasound frequency range.

4. The cMUT system of claim 3, wherein the frequency of the pressure is in a range of 0 Hz≦

frequency≦

20 kHz.

5. The cMUT system of claim 3, wherein the output signal modulates the carrier signal having the carrier frequency higher than the frequency of the pressure to create a modulated signal.

6. The cMUT system of claim 1, wherein the antenna comprises an inductive member.

7. The cMUT system of claim 6, wherein the inductive member is connected to the cMUT and has an inductance tuned for an impedance of the cMUT.

8. The cMUT system of claim 6, wherein the inductive member and the cMUT form a resonator having a resonant frequency at or around the carrier frequency.

9. The cMUT system of claim 1, the cMUT comprises a cMUT array having a plurality of cMUT elements.

10. The cMUT system of claim 9, wherein the plurality of cMUT elements each have an antenna comprising a respective inductive member.

11. The cMUT system of claim 1, the system further comprising a telemetric circuit including a switch circuit operative to power on the telemetric circuit when triggered by a telemetric signal received by the antenna from outside.

12. The cMUT system of claim 1, wherein the external energy comprises an acoustic wave generated by a separate source.

13. The cMUT system of claim 1, the system being adapted for placement inside a human body for sensing.

14. The cMUT system of claim 1, the system being operative in a transmission mode (TX) to convert an input signal to an actuation energy applied on a medium.

15. The cMUT system of claim 1, wherein the antenna is a first antenna, the cMUT system further comprising:

a second antenna operative to receive the output signal wirelessly transmitted by the first antenna.

16. A capacitive micromachined transducer (cMUT) system comprising:

a cMUT operative in at least a reception mode (RX) to convert a received energy applied on the cMUT to an output signal, the cMUT having a first electrode and a second electrode separated from each other by an electrode gap so that a capacitance exists between the first electrode and the second electrode, and a spring member supporting the second electrode for enabling the first electrode and the second electrode to move toward or away from each other;

an AC signal source for generating a carrier signal on a first side of the cMUT so that the carrier signal passes across the electrode gap to a second side of the cMUT, wherein the cMUT is configured to modulate a carrier frequency of the carrier signal with the output signal to generate a modulated signal that includes the output signal; and

an antenna on the second side of the cMUT to telemetrically transmit the modulated signal and/or to telemetrically receive an input signal.

17. The cMUT system of claim 16, wherein the cMUT is operative in the reception mode (RX) only, and the input signal is operative to telemetrically power on the cMUT.

18. A method for operating a capacitive micromachined transducer (cMUT) system, the method comprising:

providing a cMUT operative in at least a reception mode (RX) to convert a received energy applied on the cMUT to an output signal;

generating a carrier signal from a AC signal source on a first side of the cMUT, the carrier signal passing across an electrode gap of the cMUT to a second side of the cMUT, wherein a carrier frequency of the carrier signal is modulated, by the cMUT, with the output signal to produce a modulated signal having a modulated frequency; and

transmitting the modulated signal carrying the output signal via an antenna on the second side of the cMUT.

19. The method as recited in claim 18, further comprising receiving, by a second antenna, the modulated signal transmitted by the first antenna.