Fluid circuits for temperature control in a thermal therapy system

• US 20110230753A1
• Filed: 03/09/2011
• Published: 09/22/2011
• Est. Priority Date: 03/09/2010
• Status: Active Grant

• Current Assignee: Profound Medical Inc. (Profound Medical Corp.)
• Original Assignee: Profound Medical Inc. (Profound Medical Corp.)
• Inventors: Donaldson, Sean, Mahon, Cameron
• Granted Patent: US 9,566,455 B2
• Time in Patent Office: Days
• US Class Current: 600/411
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00092 using thermocouples
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61N 7/022 intracavitary

Abstract

A system and method for fluid control in a thermal therapy system is disclosed. A fluid circuit permits passage of a fluid through a fluid circuit, including into and out of a treatment zone so as to cool or heat or maintain a temperature in said treatment zone at or near a desired temperature. The temperature is sensed at a point in the circuit between a discharge of a fluid pump and the treatment zone. MRI based thermometry of tissue in the treatment zone is accomplished in some aspects. Furthermore, a desired temperature may be programmably set to a given value or within a band of values using a processor and a temperature controller. In some aspects, leakage of fluid from a patient or from the fluid control system is captured by a leak-proof member to protect imaging and treatment equipment from damage.

Claims

1. A fluid control system for use in a thermal therapy system, the fluid control system comprising:

a volume for filling with a fluid, said fluid adapted for flow through a fluid circuit portion of said apparatus;

a pressure source that drives said fluid through said fluid circuit;

an inlet portion of said fluid circuit that allows said fluid to pass into a portion of said thermal therapy system;

an outlet portion of said fluid circuit that allows said fluid to pass out of said portion of said thermal therapy system;

a temperature sensor disposed between said pressure source and said portion of the thermal therapy system, that senses a temperature of said fluid, or a temperature of a patient'"'"'s tissue proximal to a position of said temperature sensor, and provides a corresponding temperature sensor output signal indicative of said temperature;

a temperature controller that receives said temperature sensor output signal and that receives a reference signal indicative of a desired temperature setting, and that provides an output control signal; and

a thermal element that receives said output control signal and that acts to change the quantity of heat energy in the fluid so as to maintain the temperature of said fluid substantially at or near the desired temperature setting,

2. The fluid control system of claim 1, further comprising fluid couplings that couple a first portion of said system that lies within an imaging and treatment chamber from a second portion of said system that lies outside said imaging and treatment chamber.

3. The fluid control system of claim 1, further comprising a warning circuit that senses an unwanted condition of said system and delivers a warning signal corresponding to said condition.

4. The fluid control system of claim 3, said unwanted condition including a temperature that departs from said desired temperature setting.

5. The fluid control system of claim 3, said unwanted condition including a pressure in said fluid circuit that departs from a desired pressure setting.

6. The fluid control system of claim 3, said unwanted condition including a fluid leak.

7. The fluid control system of claim 1, further comprising a fluid catchment member that collects any leaked fluid to avoid undesired spilling of said leaked fluid.

8. The fluid control system of claim 7, said catchment member comprising a spill-proof disposable sheet.

9. The fluid control system of claim 7, said catchment member comprising a plastic pan that collects any said leaked fluid.

10. The fluid control system of claim 7, said catchment member comprising an absorptive material that absorbs and holds any said leaked fluid.

11. The fluid control system of claim 7, further comprising a drainage channel for draining leaked fluid from the catchment member.

12. The fluid control system of claim 1, further comprising a second temperature sensor that senses a temperature proximal to a second location of said second sensor and provides a second temperature sensor output signal to said temperature controller.

13. The fluid control system of claim 1, said heat element comprising an element that adds heat to said fluid so as to raise a temperature of said fluid.

14. The fluid control system of claim 1, said heat element comprising an element that removes heat from said fluid so as to lower a temperature of said fluid.

15. The fluid control system of claim 1, further comprising a gas removal member to de-gas said fluid within desired gas content limits.

16. The fluid control system of claim 1, said inlet portion providing a supply of said fluid to a location in said thermal treatment system proximal to an ultrasonic treatment applicator of the thermal therapy system to heat or cool a region of tissue of a patient undergoing thermal therapy, as needed, and said outlet portion taking a return of said fluid from said location in said thermal treatment system.

17. A method for controlling a fluid in a prostate thermal therapy system, comprising:

providing a fluid in a fluid circuit;

pumping said fluid, using a pump, through an inlet portion of the fluid circuit to a location in a thermal applicator proximal to which thermal therapy is to be carried out;

receiving a return of said fluid from said location into a return portion of said fluid circuit;

measuring a temperature of said fluid, at a location in said fluid circuit between said pump and said location where thermal therapy is to be carried out, and generating a temperature sensing signal corresponding to said temperature;

comparing said temperature sensing signal to a reference signal; and

controlling a heat element to add heat to said fluid if its temperature drops below a desired setting or to remove temperature from said fluid if its temperature rises above said desired setting.

19. The method of claim 18, further comprising collecting any fluid that may leak from said fluid circuit.

20. The method of claim 18, further comprising sensing an undesired condition within said fluid circuit.

21. The method of claim 18, said measuring step comprising measuring a temperature of said fluid at or near a discharge of said pump.

22. The method of claim 18, further comprising carrying out MRI-based thermometry scans of said location where the thermal therapy is to be carried out to determine a temperature of at least a portion of