Real time ultrasound thermal dose monitoring system for tumor ablation therapy

• US 10,238,369 B2
• Filed: 06/10/2014
• Issued: 03/26/2019
• Est. Priority Date: 06/10/2014
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Guo, Xiaoyu, Boctor, Emad M., Jiang, Dengrong
• Primary Examiner(s): Remaly, Mark
• Application Number:
  US14/301,037
• Publication Number:
  US 20150351724A1
• Time in Patent Office: 1,750 Days
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/263 the conversion of laser energy into mechanical shockwaves taking place in a liquid
• CPC Class Codes: A61B 2505/05 Surgical care
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 8/0841 for locating instruments
• CPC Class Codes: A61B 8/085 for locating body or organic structures, e.g. tumours, calculi, blood vessels, nodules
• CPC Class Codes: A61B 8/5223 for extracting a diagnostic or physiological parameter from medical diagnostic data for algorithms to analyse biomedical images G06T7/0012
• CPC Class Codes: A61N 2007/0004 Applications of ultrasound therapy
• CPC Class Codes: A61N 2007/0052 using the same transducer for therapy and imaging
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092
• CPC Class Codes: A61N 7/022 intracavitary
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

An interventional system with real-time ablation thermal dose monitoring includes an interventional tool, an ultrasound transmitter at least one of attached to or integral with the interventional tool, an ultrasound receiver configured to receive ultrasound signals from the ultrasound transmitter after at least one of transmission through or reflection from a region of tissue while under an ablation procedure and to provide detection signals, and a signal processing system configured to communicate with the ultrasound receiver to receive the detection signals and to calculate, based on the detections signals, a thermal dose delivered to the region of tissue in real time during the ablation procedure.

Claims

1. An interventional system with real-time ablation thermal dose monitoring, comprising:

an ultrasound transmitter configured to be arranged proximate a region of tissue while undergoing an ablation procedure;

an ultrasound receiver configured to be arranged proximate the region of tissue such that the region of tissue is between the ultrasound transmitter and the ultrasound receiver,

the ultrasound receiver being further configured to receive ultrasound signals from the ultrasound transmitter after transmission through the region of tissue and to provide detection signals; and

a signal processing system configured to communicate with the ultrasound transmitter to obtain information concerning ultrasound pulse transmission times,

the signal processing system configured to communicate with the ultrasound receiver to receive the detection signals and to calculate, based on the detection signals, a thermal dose delivered to the region of tissue in real time during the ablation procedure,

wherein the ultrasound receiver provides information concerning reference detection times of pulses with known transmission times and provides corresponding detection times of detection signals from a thermal ablation zone of a tissue, and

wherein the signal processing system is configured to calculate the thermal dose based on time of flight information using the reference detection times and based on time of flight information using the corresponding detection times of the detection signals from the thermal ablation zone.

2. The interventional system according to claim 1, further comprising:

an ultrasound probe,

wherein the ultrasound receiver is incorporated into the ultrasound probe so as to be acoustically coupled to an exterior surface of a body undergoing the ablation procedure.

3. The interventional system according to claim 2, wherein the ultrasound receiver comprises at least one of a linear or phased imaging array.

4. The interventional system according to claim 1, further comprising:

an interventional tool,

wherein one of the ultrasound receiver and the ultrasound transmitter is at least one of attached to or integral with the interventional tool.

5. The interventional system according to claim 4, wherein the ultrasound receiver comprises at least one of a linear or phased imaging array.

6. The interventional system according to claim 4, wherein the ultrasound transmitter and the ultrasound receiver comprise common transducer elements for transmission and reception.

7. The interventional system according to claim 4, wherein the interventional tool is an interventional tool adapted to be used in conjunction with an ablation tool.

8. The interventional system according to claim 4, wherein the interventional tool is an interventional ablation tool.

9. The interventional system according to claim 8, wherein the interventional ablation tool and the ultrasound transmitter share at least some common components to provide dual effects of ultrasound transmission and ablation.

10. The interventional system according to claim 8, wherein the interventional ablation tool is at least one of:

a radio frequency,

laser,

high-intensity focused ultrasound, or

thermal ablation tool.

11. The interventional system according to claim 2, wherein the signal processing system is configured to calculate the thermal dose delivered to the region of tissue in real time based on time of flight measurements of ultrasound signals from the ultrasound transmitter that pass through regions undergoing ablation as well as regions immediately surrounding the regions undergoing ablation.

12. The interventional system according to claim 1, wherein the signal processing system is configure to retrieve reference data corresponding to the region of tissue prior to the thermal dose and to calculate the thermal dose delivered to the region of tissue in real time based on a comparison of the reference data to detection signals.

13. The interventional system according to claim 12, wherein the reference data is intra-operatively acquired reference data.

14. The interventional system according to claim 12, wherein the reference data is at least one of based on a model or based on pre-operative data.

15. The interventional system according to claim 1, wherein the signal processing system is configured to calculate the thermal dose delivered to the region of tissue in real time based on a dispersion of the ultrasound signals from the ultrasound transmitter after transmission through the region of tissue.

16. The interventional system according to claim 8, wherein the interventional ablation tool is high-intensity focused ultrasound (HIFU) ablation tool that is further configured to provide acoustic pulses for imaging by an acoustic radiation force (ARF) effect, and wherein the signal processing system is configured to calculate the thermal dose delivered to the region of tissue in real time based on the ARF effect.

17. The interventional system according to claim 16, wherein the signal processing system is further configured to calculate the thermal dose delivered to the region of tissue in real time based on shear waves produced by the ARF effect.

18. The interventional system according to claim 8, wherein the ultrasound transmitter is a photoacoustic ultrasound transmitter comprising a femtosecond-pulsed laser.

19. The interventional system according to claim 18, wherein the ultrasound transmitter further comprises a photoabsorptive component arranged in an optical path of light from the femtosecond-pulsed laser.

20. The interventional system according to claim 8, wherein the ultrasound transmitter is a photoacoustic ultrasound transmitter comprising a modulated pulsed laser that provides an encoded photoacoustic signal.

21. The interventional system according to claim 8, wherein the ultrasound transmitter is a photoacoustic ultrasound transmitter comprising a continuous wave laser.

22. An ultrasound transmitter of an interventional tool, the ultrasound transmitter, comprising:

a liquid cell for securing to the interventional tool;

an optical fiber having a transmitting end coupled to the liquid cell such that the transmitting end is fixed within an interior space defined by the liquid cell, the interior space containing a fluid; and

a laser optically coupled to the optical fiber, the optical fiber being configured to propagate a laser beam generated by the laser to the transmitting end of the optical fiber,

wherein the fluid is selected to absorb the laser beam generated by the laser at the transmitting end of the optical fiber and wherein the liquid cell comprises an expandable portion that is free to expand and transmit acoustic energy generated by the fluid due to thermal expansion and phase change of the fluid when contained within the liquid cell and while the fluid is being exposed to energy from the laser beam to induce a Giant Photo-Acoustic Effect of the fluid and generate the acoustic energy.

23. The ultrasound transmitter according to claim 22, wherein the expandable portion is a rubber film substantially of a semispherical shape.

24. An interventional system with real-time ablation thermal dose monitoring, comprising:

an interventional tool including an ultrasound transmitter configured to be arranged proximate a region of tissue while undergoing an ablation procedure, wherein the ultrasound transmitter comprises;

a liquid cell including a fluid containing a suspension of carbon particles; and

an optical fiber having a transmitting end coupled to the liquid cell such that the transmitting end is fixed within an interior space defined by the liquid cell, wherein the optical fiber is configured to be optically coupled to a laser, the optical fiber being configured to propagate a laser beam generated by the laser to the transmitting end of the optical fiber,

wherein the fluid is selected to absorb the laser beam generated by the laser at the transmitting end of the optical fiber and wherein the liquid cell comprises an expandable portion that is free to expand and transmit acoustic energy generated by the fluid due to thermal expansion and phase change of the fluid when contained within the liquid cell and while the fluid is being exposed to energy from the laser beam to induce a Giant Photo-Acoustic Effect of the fluid and generate the acoustic energy;

an ultrasound receiver configured to be arranged proximate the region of tissue such that the region of tissue is between the ultrasound transmitter and the ultrasound receiver, the ultrasound receiver being further configured to receive ultrasound signals from the ultrasound transmitter after transmission through the region of tissue; and

a signal processing system configured to communicate with the ultrasound transmitter to obtain information concerning ultrasound pulse transmission times, and the signal processing system configured to communicate with the ultrasound receiver to receive the detection signals and to calculate, based on the detection signals, a thermal dose delivered to the region of tissue in real time during the ablation procedure,

wherein the ultrasound receiver provides information concerning reference detection times of pulses with known transmission times and provides corresponding detection times of detection signals from a thermal ablation zone of a tissue, and

wherein the signal processing system is configured to calculate the thermal dose based on time of flight information using the reference detection times and based on time of flight information using the corresponding detection times of the detection signals from the thermal ablation zone.