System And Method For Correlating Proton Resonance Frequency Thermometry With Tissue Temperatures

Patent metadata

Field	Value
Publication number	US-2025099179-A1
Application number	US-202418972796-A
Country	US
Kind code	A1
Filing date	Dec 6, 2024
Priority date	Jun 12, 2020
Publication date	Mar 27, 2025
Grant date	—

Abstract

Devices and systems used to ablate tissue of a tumor using laser energy are disclosed. The devices and systems include a laser probe and a magnetic resonance (MR) safe temperature probe. The MR safe temperature probe includes an optical sensor. A bone anchor fixture separates the laser probe and the MR safe temperature probe to prevent interference in the MR safe temperature probe data. Proton Resonance Frequency (PRF) thermometry is used to model a temperature of a pixel of an MR image located adjacent the optical sensor. The modeled pixel temperature and the measured temperature are compared and monitored. Exceeding a threshold difference value causes an intervening action to occur.

First claim

What is claimed is:

1 . A system comprising:
a magnetic resonance (MR) safe temperature probe comprising a temperature sensor; a bone anchor fixture configured to maintain a target distance between the MR safe temperature probe and a laser diffusion fiber (LDF); a processor to: receive measured temperature data from the MR safe temperature probe; correlate a pixel in a magnetic resonance image with a location of the temperature sensor; compare a calculated temperature of the pixel from a temperature model with the measured temperature data from the MR safe temperature probe; and determine when a difference between the calculated temperature and the measured temperature data exceeds a threshold.

2 . The system of claim 1 , wherein the temperature sensor comprises a gallium arsenide crystal.

3 . The system of claim 1 , wherein the target distance is between 5 millimeters and 10 millimeters.

4 . The system of claim 1 , wherein the target distance is 8 millimeters.

5 . The system of claim 1 , wherein the bone anchor fixture comprises:
a bone anchor body comprising a first lumen through which the LDF is to be inserted; and an adapter coupled to the bone anchor body and extending to a side of the bone anchor, the adapter comprising a second lumen that is the target distance away from the first lumen, wherein the MR safe temperature probe is to be inserted through the second lumen.

6 . The system of claim 1 , wherein the bone anchor fixture comprises:
a bone anchor body with a single lumen; and a guide member disposed within the bone anchor body, wherein the guide member separates the LDF and the MR safe temperature probe within the single lumen by the target distance.

7 . The system of claim 1 , wherein when the threshold is exceeded, the processor causes an intervening action to occur;
wherein to cause the intervening action comprises at least one of generating an alert, transmitting a control signal to a laser ablation system, and updating the temperature model.

8 . The system of claim 1 , wherein the processor is further configured to record a time stamp associated with the calculated temperature data and the measured temperature data and compare the calculated temperature data and the measured temperature data of the pixel across time.

9 . A non-transitory computer-readable medium including instructions that when executed by one or more processors of a temperature control system cause the temperature control system to:
receive measured temperature data from a magnetic resonance (MR) safe temperature probe comprising a temperature sensor; correlate a pixel in a magnetic resonance image with a location of the temperature sensor; compare a calculated temperature of the pixel from a temperature model with the measured temperature data from the MR safe temperature probe; and determine when a difference between the calculated temperature and the measured temperature data exceeds a threshold, wherein when the threshold is exceeded, cause an intervening action to occur.

10 . The non-transitory computer-readable medium of claim 9 , wherein the intervening action comprises generating an alert on a computer interface.

11 . The non-transitory computer-readable medium of claim 9 , wherein the instructions are further to cause the temperature control system to:
track a second calculated temperature with a second pixel, wherein the second pixel is at a location removed from the MR safe temperature probe; compare the second calculated temperature of the second pixel from the temperature model with the measured temperature data from the MR safe temperature probe; and determine when a temperature delta between the calculated temperature and the measured temperature data exceeds a second threshold, wherein when the second threshold is exceeded, cause the intervening action to occur.

12 . The non-transitory computer-readable medium of claim 9 , wherein the intervening action is chosen based on an amount of excess of the calculated temperature over the threshold,
wherein for a greater excess the intervening action comprises transmitting a control signal to a laser ablation system to cause the laser ablation system to stop emitting a laser output, and wherein for a smaller excess the intervening action comprises updating the temperature model based on the measured temperature.

13 . The non-transitory computer-readable medium of claim 9 wherein the instructions are further to cause the temperature control system to:
record a time stamp associated with the calculated temperature and the measured temperature data; and
compare the calculated temperature and the measured temperature data of the pixel across time.

14 . A method for temperature control for tumor ablation, the method comprising:
receiving measured temperature data from a magnetic resonance (MR) safe temperature sensor; correlating a pixel in a magnetic resonance image with a location of the temperature sensor; comparing a calculated temperature of the pixel from a temperature model with the measured temperature data from the MR safe temperature sensor; and determining when a difference between the calculated temperature and the measured temperature data exceeds a threshold.

15 . The method of claim 14 , wherein the temperature sensor comprises a fluoroptic sensor whose fluorescence changes in response to temperature.

16 . The method of claim 14 , further comprising positioning the temperature sensor and a laser diffusion fiber (LDF) a target distance apart using a bone anchor fixture.

17 . The method of claim 16 , wherein the target distance is between 5 millimeters and 10 millimeters.

18 . The method of claim 16 , wherein the target distance is 8 millimeters.

19 . The method of claim 14 , wherein when the threshold is exceeded, cause an intervening action to occur;
wherein to cause the intervening action comprises at least one of generating an alert, transmitting a control signal to a laser ablation system, and updating the temperature model.

Assignees

• Medtronic Navigation Inc

Inventors

• Capote Marco
• Esparza-Coss Emilio
• Vincelette Rebecca
• Lemley Katherine
• Baxter Eric
• Santana Shawn

Classifications

• A61B5/015 Primary

  By temperature mapping of body part · CPC title

• A61B5/0036

  including treatment, e.g., using an implantable medical device, ablating, ventilating · CPC title

• A61B2017/00911

  for fields applied by a magnetic resonance imaging system · CPC title

• A61B5/055

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title

• A61B2018/00803

  with temperature prediction · CPC title