Spectroscopic method and system for assessing tissue temperature

• US 8,376,955 B2
• Filed: 09/29/2009
• Issued: 02/19/2013
• Est. Priority Date: 09/29/2009
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Baker, Clark R. Jr.
• Primary Examiner(s): DOUGHERTY, SEAN PATRICK
• Application Number:
  US12/569,721
• Publication Number:
  US 20110077547A1
• Time in Patent Office: 1,239 Days
• Field of Search: 600/310, 600/340, 600/549
• US Class Current: 600/549
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2017/00057 Light
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20

Abstract

According to various embodiments, a medical system and method for determining tissue temperature may include a spectroscopic sensor. The spectroscopic sensors may be configured to provide information about changes in water absorption profiles at one or more absorption peaks. Such sensors may be incorporated into ablation systems for tissue ablation. Temperature information may be used to determine the scope, volume, and/or depth of the ablation.

Claims

1. A monitor, comprising:

a sensor interface;

a display; and

data processing circuitry configured to;

cause operation of a spectrophotometric sensor via the sensor interface, wherein the sensor comprises at least one emitter configured to emit light into a tissue of a patient and at least one detector configured to detect the light;

receive spectrophotometric data associated with a mean photon penetration depth in the tissue from the at least one detector via the sensor interface;

determine one or more temperatures of the tissue associated with the mean photon penetration depth from the spectrophotometric data; and

cause the display to display an indication related to the one or more tissue temperatures.

2. The monitor of claim 1, wherein determining the one or more tissue temperatures comprises determining a change in a magnitude of a water absorption peak.

3. The monitor of claim 2, wherein determining the one or more tissue temperatures comprises correlating the change in the magnitude of the water absorption peak to a tissue temperature associated with the change in the magnitude of the water absorption peak.

4. The monitor of claim 1, wherein the data processing circuitry is configured to activate an energy source configured to direct ablating energy into the patient'"'"'s tissue.

5. The monitor of claim 4, wherein the data processing circuitry comprises instructions for determining whether the tissue temperature is associated with heat from the ablating energy.

6. The monitor of claim 4, wherein the tissue temperature associated with heat from the ablating energy is greater than about 43°

C.

7. The monitor of claim 1, wherein the determining the one or more tissue temperatures comprises determining a temperature gradient in the tissue from a plurality of mean photon penetration depths.

8. The monitor of claim 2, wherein determining the one or more tissue temperatures comprises determining a change in a shape of the water absorption peak.

9. The monitor of claim 1, wherein causing operation of a spectrophotometric sensor via the sensor interface comprises driving the emitter to emit light in a range from about 945 nm to about 1035 nm.

10. The monitor of claim 1, comprising receiving information related to a tissue ablation;

and

assessing the tissue ablation based on the tissue temperature.

11. The monitor of claim 10, wherein assessing the tissue ablation comprises determining a viability of the tissue.

12. The monitor of claim 10, wherein assessing the tissue ablation comprises determining a volume of ablated tissue.

13. The monitor of claim 5, wherein determining whether the tissue temperature is associated with heat from the ablating energy comprises comparing the tissue temperature to a baseline temperature.

14. The monitor of claim 13, wherein the baseline temperature comprises a local or systemic temperature of the patient.

15. The monitor of claim 13, wherein the baseline temperature comprises a temperature calculated based at least in part upon spectrophotometric data generated before ablating energy is directed into the patient'"'"'s tissue.

16. The monitor of claim 1, wherein determining the one or more temperatures comprises using an estimation of lean water concentration in the tissue.