Method and system for controlling heat delivery to a target

• US 6,671,535 B1
• Filed: 12/20/2002
• Issued: 12/30/2003
• Est. Priority Date: 11/09/1999
• Status: Active Grant

• Current Assignee: Visualase, Inc. (Medtronic Plc)
• Original Assignee: BioTex Incorporated
• Inventors: Gowda, Ashok, McNichols, Roger J.
• Primary Examiner(s): Vo, Hieu T.
• Application Number:
  US10/324,973
• Time in Patent Office: 375 Days
• Field of Search: 607/96, 607/100, 607/102, 600/407, 600/410, 600/411, 600/412, 600/437, 600/438, 600/442, 600/549
• US Class Current: 600/407
• CPC Class Codes: A61B 18/08 by means of electrically-heated probes
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 18/20 using laser
• CPC Class Codes: A61B 2017/0007 Pyrometers
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2018/00636 Sensing and controlling the application of energy
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00714 Temperature
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/015 By temperature mapping of body part
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation
• CPC Class Codes: A61N 1/403 for thermotherapy, e.g. hyperthermia
• CPC Class Codes: A61N 5/04 Radiators for near-field treatment
• CPC Class Codes: A61N 5/0601 Apparatus for use inside the body
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

A method and system for using real time closed loop feedback to control the delivery of heat energy is disclosed herein. An energy delivery system may be used to deliver heat energy to a target to effect a change in the target. For example, medical professionals use laser energy to irreversibly damage cells found in cancerous tumors without damaging the surrounding healthy cells. The energy delivery system includes a temperature detection system, a data processor, and a heat generating device. The temperature detection system obtains temperature data from a target and transmits the data to the data processor. The data processor may process the temperature data to provide real time feedback control to the heat generating system, as well as display the data as one or more images on a graphical user interface. The heat generating system receives control commands from the data processor and modulates its heat output accordingly.

Claims

1. A system comprising:

a data processing module having a plurality of input output nodes; and

a memory having a plurality of input output nodes coupled to the plurality of input output nodes of the data processing module, wherein the memory stores operational instructions that cause the processing module to;

receive input data from a detection device that interrogates a tissue portion with radiation as part of acquiring the input data, wherein the input data corresponds to a tissue portion and includes temperature sensitive information;

determining at the data processor a property of the tissue portion based on temperature sensitive information, wherein operation of a heat generating device is to be based on the first characteristic; and

displaying the first property to the operator of the heat generating device, wherein the value of the first property effects the operators control of the heat generating device.

2. A system comprising:

a data processing module having a plurality of input output nodes; and

a memory having a plurality of input output nodes coupled to the plurality of input output nodes of the data processing module, wherein the memory stores operational instructions that cause the processing module to;

receive input data from a magnetic resonance device which interrogates a portion of an animal body with radiation as part of acquiring the input data, wherein the input data corresponds to a portion of the animal body and includes temperature sensitive information;

further receive additional input data wherein additional input data is from a user, and wherein the additional input data contains information corresponding to a desired heating result;

determine a first characteristic for a heat generating device based on the temperature sensitive information, wherein operation of the heat generating device is to be based on the first characteristic; and

provide control data to the heat generating device, wherein the control data is based on the first characteristic.

3. The system of claim 2, wherein the magnetic resonance device is equipped to acquire proton resonance frequency sensitive images.

4. The system of claim 3, wherein the laser based device delivers laser energy to a target using a fiberoptic applicator.

5. The system of claim 2, wherein the input data represents one or more data sets acquired using a proton resonance frequency sensitive method.

6. The system of claim 2, wherein the step of receiving input data includes receiving the input data at a network interface.

7. The system of claim 2, wherein the additional input data which is further received includes one or more of:

a user selected point, line, area, volume, plane, locus, perimeter, temperature, damage, and intensity.

8. The system of claim of claim 2, wherein the additional input data is specified relative to a magnetic resonance based image of a portion of an animal body representing one or more of:

a physical structure, a temperature distribution, a tissue damage distribution, a contrast-enhanced image, and a processed contrast-enhanced image.

9. The system of claim 2, wherein the information corresponding to a desired heating result includes specification of one or more limit temperatures.

10. The system of claim 2, wherein the information corresponding to a desired heating result includes specification of one or more points to be damaged.

11. The system of claim 2, wherein the information corresponding to a desired heating result includes specification of one or more points to be spared from damaged.

12. The system of claim 2, wherein the step of determining includes determining the control data using a first characteristic and a rule set.

13. The system of claim 2, wherein the beat generating device is a laser based device.

14. The system of claim 2, wherein the step of providing includes providing command data to the heat generating device.

15. The system of claim 2, wherein the step of determining includes determining the first characteristic based upon the temperature sensitive information of a first portion of the input data, wherein the first portion of the input data corresponds to a first region of the animal body.

16. The system of claim 15, wherein the step of determining includes determining a tissue damage of the first region of the animal body.

17. A method comprising the steps of:

receiving input data at a data processor, wherein the input data is from a detection device that interrogates a tissue portion with radiation as part of acquiring the input data, wherein the input data corresponds to a tissue portion and includes temperature sensitive information;

determining at the data processor a first property of the tissue portion based on temperature sensitive information, wherein operation a heat generating device is to be based on the first property; and

displaying the first property to the operator of the heat generating device wherein the value of the first property effects the operator'"'"'s control of the beat generating device.

18. The method of claim 17, wherein the step of receiving input data includes the detection device being a magnetic resonance device.

19. The method of claim 18, where in the magnetic resonance device is an imaging system equipped to generate proton resonance frequency sensitive images.

20. The method of claim 17, wherein the operation of the beat generation device results in heating of the tissue portion.

21. The method of claim 17, wherein the first property is tissue temperature.

22. The method of claim 21, wherein the temperatures are used in an Arrhenius rate equation to estimate the amount of tissue that is irreversibly damaged.

23. A method comprising the steps of:

receiving input data at a data processor, wherein the input data is from a magnetic resonance device which interrogates a portion of an animal body with radiation as part of acquiring the input data, wherein the input data corresponds to a portion of the animal body and includes temperature sensitive information;

further receiving additional input data at a data processor, wherein the additional input data is from a user, and wherein the additional input data contains information corresponding to a desired heating result;

determining at the data processor a first characteristic for a heat generating device based on the temperature sensitive information and the desired heating result, wherein operation of the heat generating device is to be based on the first characteristic; and

providing control data to the heat generating device, wherein the control data is based on the first characteristic.

24. The method of claim 23, wherein the magnetic resonance device is equipped to acquire proton resonance frequency sensitive images.

25. The method of claim 24, wherein the input data represents one or more data sets acquired using a proton resonance frequency sensitive method.

26. The method of claim 25, wherein the data sets correspond to one or more magnetic resonance images.

27. The method of claim 25, wherein the data sets correspond to complex frequency domain data.

28. The method of claim 25, wherein the temperature sensitive information includes the complex phase of the data contained in the data sets.

29. The method of claim 23, wherein the magnetic resonance device is equipped to acquire T1-weighted images.

30. The method of claim 29, wherein the input data represents one or more data sets acquired using a T1-weighted imaging method.

31. The method of claim 30, wherein the data sets correspond to one or more magnetic resonance images.

32. The method of claim 30, wherein the data sets correspond to complex frequency domain data.

33. The method of claim 30, wherein the temperature sensitive information includes the magnitude of the data contained in the data sets.

34. The method of claim 23, wherein the step of receiving input data includes receiving the input data at a network interface.

35. The method of claim 34, wherein the network interface transmits and/or receives data using a Transmission Control Protocol/Internet Protocol (TCP/IP) protocol.

36. The method of claim 35, wherein network interface transmits and/or receives data using a Server Message Block (SMB) protocol.

37. The method of claim 35, wherein network interface transmits and/or receives data using a File Transfer Protocol (FTP) protocol.

38. The method of claim 37, wherein data processor periodically queries magnetic resonance device for the presence of new input data.

39. The method of claim 38, wherein the step of periodically querying magnetic resonance device consists of periodically requesting the status of a file or file resident on storage connected to or in memory of magnetic resonance device.

40. The method of claim 35, wherein network interface transmits and/or receives data using a Network File Sharing (NFS) protocol.

41. The method of claim 40, wherein input data is periodically transferred to data processor by magnetic resonance device.

42. The method of claim 35, wherein network interface transmits and/or receives data using one or more of

an Apple Filing Protocol File System (AFPFS) protocol and

an Apple Talk protocol.

43. The method of claim 23, wherein the additional input data which is further received includes one or more of a user selected point, line, area, volume, plane, locus, perimeter, temperature, damage, and intensity.

44. The method of claim 43, wherein the additional input data is specified relative to a magnetic resonance based image of a portion of an animal body representing one or more of:

a physical structure a temperature distribution, a tissue damage distribution, a contrast-enhanced image, and a processed contrast-enhanced image.

45. The method of claim 44, wherein the magnetic resonance based image is constructed from mathematical operations performed on one or a series of such images.

46. The method of claim 45, wherein the one or a series of such images were acquired prior to initiation of heating.

47. The method of claim 45, wherein the one or a series of such images are acquired after administration of a magnetic resonance contrast agent.

48. The method of claim 23, wherein the information corresponding to a desired heating result includes specification of one or more limit temperatures.

49. The method of claim 23, wherein the information corresponding to a desired heating result includes specification of one or more points, areas, loci, and/or perimeters to be damaged.

50. The method of claim 23, wherein the information corresponding to a desired heating result includes specification of one or more points to be spared from damage.

51. The method of claim 23, wherein the information corresponding to a desired heating result includes specification of one or more areas to be spared from damage.

52. The method of claim 23, wherein the information corresponding to a desired heating result includes specification of one or more loci to be spared from damage.

53. The method of claim 23, wherein the information corresponding to a desired heating result includes specification of one or more perimeters to be spared from damage.

54. The method of claim 23, wherein the step of determining includes determining the control data using a first characteristic and a rule set.

55. The method of claim 54, wherein the rule set consists of one or more temperature limits associated with one or a plurality of locations.

56. The method of claim 55, wherein the first characteristic of the heat generating device is to have its output intensity reduced.

57. The method of claim 23, wherein the step of determining includes determining the control data based on the first characteristic and on subsequent user input, wherein subsequent user input is based on the first characteristic.

58. The method of claim 23, wherein the heat generating device is a laser based device.

59. The method of claim 58, wherein the laser based device delivers laser energy to a target using a fiberoptic applicator.

60. The method of claim 59, wherein the fiberoptic applicator includes diffusing tip.

61. The method of claim 58, wherein the laser based device is a diode laser.

62. The method of claim 61, wherein the diode laser device operates at one or a plurality of wavelengths at or around 980 nm.

63. The method of claim 61, wherein the diode laser device operates at one or a plurality of wavelengths at or around 940 nm.

64. The method of claim 61, wherein the diode laser device operates at one or a plurality of wavelengths at or around 810 nm.

65. The method of claim 23, wherein the step of providing includes providing command data to the heat generating device.

66. The method of claim 65, wherein the command dam is communicated to the heat generating device using one or more of:

a point-to-point interfere, an IEEE-488 interface, an RS-232 interface, a parallel interface, a serial interface, and digital I/O interface.

67. The method of claim 65, wherein the command data consists of a pulse-width-modulation signal which controls the output intensity of the heat generating source.

68. The method of claim 23, wherein the step of determining includes determining the first characteristic based upon the temperature sensitive information of a first portion of the input data, wherein the first portion of the input data corresponds to a first region of the animal body.

69. The method of claim 68, wherein the step of determining includes determining a tissue damage of the first region of the animal body.

70. The method of claim 69, wherein determining the tissue damage includes evaluating a mathematical function that is dependent upon the temperature sensitive information for a specific location with respect to time to determine a damage indicator.

71. The method of claim 70, wherein the mathematical function is based on an Arrhenius rate process.

72. The method of claim 71, wherein the mathematical function comprises $\int$

Ae-EaRT

(t)



t,

where A is the frequency factor constant for a tissue, Ea is the activation energy constant for the tissue, R is the universal gas constant, t is time, and T(t) is the time-dependent temperature of the tissue.

73. The method of claim 72, wherein the mathematical function is evaluated numerically.

74. The method of claim 73, wherein interpolation is used to increase the number of points T(t) at which the friction is evaluated.

75. The method of claim 23, wherein the input data consists of one or more data sets acquired using magnetic resonance imaging.

76. The method of claim 75, wherein the data sets represent images along one or more planes through the animal body.

77. The method of claim 75, wherein at least two of the planes are orthogonal.

78. The method of claim 76, wherein at least two of the planes are parallel.

79. The method of claim 75, wherein at least two of the planes are oblique.

80. The method of claim 75, wherein the data sets are used to construct a three-dimensional rendering of portions of the animal body.

81. The method of claim 75, wherein the data sets are used to construct a three-dimensional rendering of damage to tissues in portions of the animal body.

82. The method of claim 75, wherein the data sets are used to construct a three-dimensional rendering of temperature distributions in tissues in portions of the animal body.