OPTICAL CONTACT SENSING IN MEDICAL PROBES

• US 20110313280A1
• Filed: 06/16/2010
• Published: 12/22/2011
• Est. Priority Date: 06/16/2010
• Status: Abandoned Application

• Current Assignee: Biosense Webster Israel Ltd. (Johnson & Johnson)
• Original Assignee: Biosense Webster Israel Ltd. (Johnson & Johnson)
• Inventors: Govari, Assaf, Altmann, Andres Claudio, Ephrath, Yaron
• Application Number:
  US12/816,492
• Publication Number:
  US 20110313280A1
• Time in Patent Office: Days
• US Class Current: 600/424
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure

Abstract

A method for contact sensing includes transmitting optical radiation from an optical emitter coupled to a distal tip of medical probe that is positioned within a body cavity. A signal, which is indicative of a reflection of the optical radiation from tissue in the body cavity, is received from an optical detector coupled to the distal tip. A quality of contact between the distal tip and the tissue is assessed responsively to the signal.

Claims

1. A method for contact sensing, comprising:

transmitting optical radiation from an optical emitter coupled to a distal tip of medical probe that is positioned within a body cavity;

receiving from an optical detector coupled to the distal tip a signal, which is indicative of a reflection of the optical radiation from tissue in the body cavity; and

assessing a quality of contact between the distal tip and the tissue responsively to the signal.

2. The method according to claim 1, wherein assessing the quality of contact comprises estimating a distance between the distal tip and the tissue based on the received signal.

3. The method according to claim 1, wherein assessing the quality of contact comprises detecting a physical contact between the distal tip and the tissue based on the received signal.

4. The method according to claim 3, wherein detecting the physical contact comprises detecting that the received signal is at a maximal level.

5. The method according to claim 1, wherein transmitting the optical radiation comprises flashing the optical radiation on and off, so as to calibrate a zero level of the received signal.

6. The method according to claim 1, wherein transmitting the optical radiation comprises transmitting a first optical radiation from the optical emitter at a first wavelength, and comprising transmitting a second optical radiation from another optical emitter at a second wavelength that is different from the first wavelength, wherein receiving the signal comprises receiving first and second signals corresponding to respective reflections of the first and second optical radiations, and wherein assessing the quality of contact comprises distinguishing between the reflection from the tissue and the reflection from blood within the cavity by processing the first and second signals.

7. The method according to claim 1, and comprising calibrating a contact sensor coupled to the distal tip using the assessed quality of contact.

8. The method according to claim 1, wherein transmitting the optical radiation comprises transmitting the radiation from multiple optical emitters, wherein receiving the signal comprises receiving multiple signals indicative of the reflection from multiple optical detectors, and wherein assessing the quality of contact comprises determining the quality of contact based on the multiple signals.

9. The method according to claim 8, wherein transmitting the radiation comprises activating at least two of the optical emitters using a single input line.

10. The method according to claim 8, wherein receiving the multiple signals comprises receiving the signals from at least two of the optical emitters over a single output line.

11. Apparatus for contact sensing, comprising:

a medical probe for insertion into a body cavity, the probe having a distal tip comprising;

an optical emitter, which is configured to transmit optical radiation; and

an optical detector, which is configured to sense a reflection of the optical radiation from tissue in the body cavity and to produce a signal indicative of the sensed reflection; and

a processor, which is configured to receive the signal from the optical detector and to assess a quality of contact between the distal tip and the tissue responsively to the signal.

12. The apparatus according to claim 11, wherein the processor is configured to assess the quality of contact by estimating a distance between the distal tip and the tissue based on the received signal.

13. The apparatus according to claim 11, wherein the processor is configured to assess the quality of contact by detecting a physical contact between the distal tip and the tissue based on the received signal.

14. The apparatus according to claim 13, wherein the processor is configured to detect the physical contact by detecting that the received signal is at a maximal level.

15. The apparatus according to claim 11, wherein the optical emitter is configured to flash the optical radiation on and off, and wherein the processor is configured to calibrate a zero level of the signal received in response to the flashed radiation.

16. The apparatus according to claim 11, and comprising an additional optical emitter, wherein the optical emitter is configured to transmit a first optical radiation at a first wavelength, wherein the another optical emitter is configured to transmit a second optical radiation at a second wavelength that is different from the first wavelength, and wherein the processor is configured to receive first and second signals corresponding to respective reflections of the first and second optical radiations, and distinguish between the reflection from the tissue and the reflection from blood within the cavity by processing the first and second signals.

17. The apparatus according to claim 11, and comprising a contact sensor coupled to the distal tip, wherein the processor is configured to calibrate the contact sensor using the assessed quality of contact.

18. The apparatus according to claim 11, and comprising multiple optical emitters that are configured to transmit the optical radiation, and multiple optical detectors that are configured to sense the reflection, wherein the processor is configured to receive respective multiple signals indicative of the reflection from the multiple optical detectors, and to assess the quality of contact based on the multiple signals.

19. The apparatus according to claim 18, and comprising multiplexing circuitry, which is configured to activate at least two of the optical emitters using a single input line.

20. The apparatus according to claim 18, and comprising multiplexing circuitry, which is configured to multiplex the signals from at least two of the optical emitters over a single output line.

21. A computer software product, operated in conjunction with a medical probe having a distal tip for insertion into a body cavity, the distal tip comprising an optical emitter that transmits optical radiation and an optical detector that senses a reflection of the optical radiation from tissue in the body cavity and produces a signal indicative of the sensed reflection, the product comprising a non-transitory computer-readable medium, in which program instructions are stored, which instructions, when read by a computer, cause the computer to receive the signal from the optical detector and to assess a quality of contact between the distal tip and the tissue responsively to the signal.