Abstract:
A thermal monitoring sheet measures surface temperature distributions of large areas, even over large, contoured surfaces. The sheet incorporates conduits that terminate or intersect at temperature measurement locations with a fixed relative arrangement to form a two-dimensional grid for sensing temperature distributions.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of provisional application Ser. No. 61/056,937 filed May 29, 2008 entitled THERMAL MONITORING SHEET and which provisional application is incorporated herein in its entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     This invention was made with government support under Contract No. NIH 1R43-AR051278-01 awarded by the National Institute of Health. The government has certain rights in the invention. 
    
    
     BACKGROUND 
     For therapeutic use of heat in cancer therapy, it is critically important to monitor and control tissue temperature within a narrow window (˜40-45° C.) to ensure adequate therapy without complications. Hyperthermia clinics including, but not limited to, University of California San Francisco (UCSF) operate equipment such as, but not limited to, a Sonotherm 1000 (Labthermics Technologies, Champaign Ill.) 16 transducer 4×4 planar array 3.4 MHz ultrasound heating device and a Microtherm 1000 (Labthermics Technologies, Champaign Ill.) 16 antenna 4×4 planar array 915 MHz microwave heating device for applications such as, but not limited to, treating superficial tissue regions up to 15×15 cm square and as much as 4 cm deep (ultrasound) or 1.5 cm deep (microwave) below the skin. 
     Recently a 32 channel 915 MHz Conformal Microwave Array hyperthermia system has been approved for use in the patient clinic at University of California San Francisco and use on the first 14 patients demonstrated the ability to deliver highly adjustable heating patterns to much larger surface areas than ever before, even when the disease is spread across contoured portions of the anatomy such as the human torso. 
     The common problem in administering treatments with multi-element array-heating devices is gaining sufficient feedback about the tissue temperature under each independently powered heat source. The planar array microwave applicator comes with a small number of fiber-optic sensors, often less than the number of power sources, which are placed at a small number of points under the multi-element array applicator to sample the tissue temperature distribution. This small sampling of temperature is inadequate for real-time feedback control of multiple power amplifiers. For a better assessment of temperature distribution under such heating arrays, sensors may be pulled manually within special thermal mapping catheters lying on the tissue surface and temperatures recorded at 5-10 mm spaced positions across the surface. This thermal mapping procedure significantly increases the number of surface temperature measurements by providing one or more linear profiles of surface temperature under the heating array, but is tedious and time consuming to generate, and does not provide a true two dimensional characterization of surface temperature distribution. 
     SUMMARY 
     The needs for the invention set forth above as well as further and other needs and advantages of the present invention are achieved by the embodiments of the invention described herein below. 
     Various embodiments of this invention relate generally to measurement of two-dimensional temperature distributions. Numerous applications exist in, but are not limited to, laboratory, industrial, and clinical environments that can benefit from improved accuracy and simplicity of monitoring complete surface temperature distributions with a single convenient device. One medical application, but not limited to, is the monitoring and control of hyperthermia therapy for superficial tissue disease such as chest wall recurrence of breast cancer or plaque psoriasis. This type of therapy is conducted via heat treatment from multi-element array microwave or ultrasound hyperthermia applicators that spread heat as uniformly as possible over a contoured surface of the human body. 
     The limitations of past temperature monitoring approaches are overcome with a pre-configured thermal monitoring sheet (TMS) with appropriately spaced array of non-perturbing optical waveguide sensors that speed up and simplify critically important thermal monitoring procedures and allow continuous thermal feedback for possible use in automatic control that may be associated with such procedures including, but not limited to, control of power to multiple element heat applicators. 
     The thermal monitoring sheet should facilitate clinical temperature monitoring of large contoured surfaces. Fast and accurate characterization of temperature distributions coupled with automated feedback power control should provide significantly improved heating patterns from existing clinical hyperthermia applicators as well as encourage the design of new superficial hyperthermia applicators with increasing levels of adjustability to fit the complex curvature of the human torso. 
     Monitoring of the unknown skin surface temperature at an interface with a plastic membrane-encased waterbolus at another temperature is difficult. Existing techniques for monitoring surface temperature include single-sensor or multiple-sensor plastic-encased thermocouples, high resistance lead thermistors, and fiber-optic sensors. A plastic coating is required to make the sensors reusable (durable and cleanable), but serves as an insulating layer that impacts the temperature measurement result. Thermal mapping techniques have been used to increase the number of measured points by pulling individual sensors through catheters on the skin surface. Addition of a plastic catheter with larger diameter than the sensor in order to facilitate mapping adds uncertainty and time delay to the readings however, due to air around the sensor and asymetric contact of the smaller sensor to the inside wall of the round catheter. Thus the typically used round sensor cross-section and multiple layers of plastic and air insulation increase the uncertainty of skin surface measurements, particularly at the interface between two dissimilar materials (i.e. PVC encased waterbolus and tissue). With a present embodiment, a planar sheet of predetermined construction, employing regularly spaced arrays of stationary fiber-optic temperature sensors incorporating a series of removable connectors to access electronics and display components offers significantly improved measurement of the interface temperature. 
     Another embodiment includes a thermal monitoring device having a first plurality of conduits for conveying electromagnetic radiation in a first predetermined direction, a second plurality of conduits for conveying electromagnetic radiation in a second predetermined direction, the second plurality of conduits intersecting the first plurality of conduits at a plurality of intersecting positions; a plurality of temperature sensing components, with a separate temperature sensing component located at each of the intersecting positions; a flexible component maintaining the first and the second plurality of conduits in a fixed relative arrangement with respect to each other; each of the first plurality of conduits having a portion that terminates in a first connector; and each of the second plurality of conduits having a portion that terminates in a second connector; wherein electromagnetic radiation can be input through the first connector via the first plurality of conduits to each the temperature sensing component, each temperature sensing component providing an output through the second connector indicative of temperature substantially at the temperature sensing component. 
     Potential applications of the invention, but not limited thereto include, for example: 
     surface-temperature monitoring of skin or sub-surface tissue disease, with or without concurrent microwave or ultrasound heat treatment; 
     temperature measurement component of automatic feedback control circuit used to regulate power of multiple element heat applicators; 
     recording 2D temperature distributions of large flat or contoured surfaces, which may be either open to air or buried inside layered media; 
     industrial process monitoring which, might include surface temperature monitoring of large flat or contoured metal, plastic or other constituent surfaces as in monitoring temperature of machinery parts to ensure they do not get too hot during a machining process, 
     monitoring surface temperature distribution of the sidewall of a large mixing vessel for instance to monitor progress or completion of an exothermic reaction while mixing multiple component chemicals; 
     monitoring temperature distribution of an interface between two dissimilar materials or between layers of similar materials (solid or liquid) during heating or cooling to monitor temperature uniformity or for control feedback to obtain a desired non-uniform temperature, 
     although clinical hyperthermia monitoring applications have been highlighted here, this surface-monitoring device may be useful for numerous general laboratory applications in addition to clinical thermometry. For a better understanding of the present invention, together with other and further needs thereof, reference is made to the accompanying drawings and detailed description and its scope will be pointed out in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1A  is a schematic block diagram illustration featuring top view of a dielectric sheet TMS with an imbedded fiber-optic sensor array and low-profile multi-element connectors; 
         FIG. 1B  is a schematic block diagram illustration featuring side view of a dielectric sheet TMS shown in  FIG. 1A ; 
         FIG. 2A  is a schematic block diagram illustration with top view of a ribbon-format optical cable and low-profile multi-channel connector for use with the TMS incorporating an imbedded fiber-optic sensor array; 
         FIG. 2B  is a schematic block diagram illustration with side view of a ribbon-format optical cable and low-profile multi-channel connector shown in  FIG. 2A ; 
         FIG. 3A  is a schematic block diagram illustration featuring top view of another embodiment of a dielectric sheet TMS with an integrated optical waveguide sensor array and low-profile multi-element connectors; 
         FIG. 3B  is a schematic block diagram illustration featuring a side view of the dielectric sheet TMS as shown in  FIG. 3A ; 
         FIG. 3C  is a schematic block diagram illustration featuring another side view of a dielectric sheet TMS as shown in  FIG. 3A ; 
         FIG. 4A  is a schematic block diagram illustration with top view of another embodiment ribbon-format optical cable for use with the TMS incorporating an integrated optical waveguide sensor array; 
         FIG. 4B  is a schematic block diagram illustration with side view of a ribbon-format optical cable as shown in  FIG. 4A ; and 
         FIG. 5  is a schematic block system diagram for the TMS incorporating an integrated optical waveguide sensor array; 
     
    
    
     DETAILED DESCRIPTION 
     An embodiment of the thermal monitoring sheet (TMS) includes, but is not limited to, a number of temperature sensing elements (nodes) arranged to form a two dimensional array with fixed relative spacing between the points of measurement. The temperature sensing nodes may be accessed optically, especially in the case of optical temperature sensors including, but not limited to, fluorescence-decay temperature sensors. Cabling such as, but not limited to, fiber optic cable may be employed to interface between the TMS and readout electronics. 
     One embodiment is shown in  FIGS. 1A and 1B , for the case of, for example, but not limited to, a 32-element TMS sensor array  10 , as shown in  FIG. 1A , where temperature-sensing nodes  12  at the ends of conduits  14  such as, but not limited to, optical waveguides are arranged with a fixed relative spacing that is captured or formed, on or within a sheet material  16  exhibiting high thermal conductivity such as, but not limited to, Kapton material to form the thermal monitoring sheet. The other end of each of the conduits  14  is terminated in a connector  18 . For most applications, the sheet material  16  should have a high thermal conductivity and be flexible to conform to the surface being monitored. The connector  18  shown in  FIGS. 1A and 1B  could be a passive connector but could also contain devices for operating the temperature-sensing nodes  12 . 
     In applications where microwave, ultrasonic, or other radiation is to be passed through the TMS array, the physical parameters of the array should be selected to minimize any perturbations of the transmitted energy (especially perturbations leading to spatial non-uniformities in the radiation pattern). Many, but not all, embodiments for these applications would employ either fiber-optic or integrated-optical waveguide formats for the conduits  14 . Some techniques for implementing the embodiment shown in  FIGS. 1A and 1B  include, but are not limited to, the following: 
     Rectangular or other shape single sheet of dielectric (i.e. such as, but not limited to, Kapton, Polyimide, liquid crystal polymer (LCP), polyurethane, polyethylene, PVC, etc) with temperature sensors and conduits attached by, for example, but not limited to, gluing to one surface in a regularly spaced 2D array, with included optical connectors for interfacing with separate external cabling. 
     The TMS is made up of at least two layers of rectangular or other shape dielectric glued or otherwise held together as a sandwich with temperature sensors and conduits trapped in a regularly spaced 2D array between or within the layers, with included optical connectors for interfacing with separate external cabling. 
     Temperature sensors referenced above may be constructed from, but are not limited to, optical fiber coupled temperature sensitive material, high-resistance lead (e.g. carbon fiber) coupled thermistors, metal wire-coupled thermocouple junctions, or metal wire-coupled thermistors, or the like. 
     At least two layers of rectangular or other shape dielectric material can be identical to provide equal temperature sensitivity to surfaces in contact with the TMS array, or directional sensing of one surface relative to other surfaces may be provided using at least one layer with higher thermal resistance and at least one layer with lower thermal resistance on either side of the embedded temperature sensors. 
     A single layer sheet or double layer sandwich sensor array may be formed as the front skin-contacting surface of a closed flexible compartment containing temperature controlled liquid (e.g. water or oil) for coupling electromagnetic or ultrasonic energy into tissue. 
       FIGS. 2A and 2B  show a schematic embodiment of an embodiment of an interface cable  30  (shown in  FIG. 2A ) suitable for, but not limited to being used for, the TMS embodiment of  FIG. 1 . A ribbon cable  32  is made up of, but not limited to, conduits  34  such as, but not limited to, optical fibers that are individually terminated at connectors  36  on one end and terminated at a common connector  38 , shown in  FIGS. 2A and 2B , on the other end. 
     Another embodiment of a TMS ( 50 ) is shown schematically in  FIGS. 3A ,  3 B, and  3 C. As shown in  FIG. 3A , sheet  52  (also shown in  FIGS. 3B and 3C ) of material including, but not limited to, dielectric material with overlapping sets  54  and  56  of conduits such as, but not limited to, optical waveguides formed near, or at, a surface of the sheet using technologies such as, but not limited to, photo-masks, photoresist, ion-diffusion, laser etching, and photo-bleaching where one set of conduits  54  of the overlapping sets  54  and  56  of conduits is oriented generally in one direction and the other set of conduits  56  of the overlapping sets  54  and  56  of conduits are oriented generally in another direction yielding a relative orientation between the overlapping sets  54  and  56  of conduits including, but not limited to, an orthogonal relative orientation. A sensing temperature component  58  such as, but not limited to, a phosphor exhibiting temperature-dependent fluorescence decay, is located at each of the intersections of the overlapping sets  54  and  56  of conduits. Connectors  60  (shown in  FIGS. 3A and 3B ) and  62  (shown in  FIGS. 3A and 3C ) provide an interface to the overlapping sets  54  and  56 , respectively, of conduits. Either or both of the connectors  60  and  62  could be a passive connector but could also contain devices for operating the sensing temperature components  58  located at the intersections of overlapping sets  54  and  56 . Such devices include, but are not limited to, laser diodes, light emitting diodes (LED), optical detectors, infrared devices, and wireless devices. The connectors  60  and  62  could also be, but are not limited to being, detachable allowing for a disposable sheet  52  with reusable connectors  60  and  62 . 
     Examples of the TMS  50  include, but are not limited to, a single sheet of dielectric with surface waveguides, two sheets of dielectric with waveguides oriented parallel to each other in each sheet and the sheets rotated relative to each other and laser active ions diffused into the points of intersection between the two sandwiched sheets. 
     A method of use for the TMS  50  includes, but is not limited to, utilizing one conduit, for example, but not limited to, conduit  54   a  of the set of conduits  54  in a given period of time to activate only the temperature sensing components  58  located on the one conduit (for example, conduit  54   a ) substantially during that time period. The activation signal is received via the connector  60  and transmitted through the one conduit (for example, conduit  54   a ). In response to the activation, the activated temperature sensing components  58  output readout signals related to the temperatures being measured by the activated temperature sensing components  58 . The readout signals are conveyed substantially simultaneously by the set of conduits  56  to connector  62  for output from the TMS  50 . 
     Another period of time may involve a different one conduit, for example, but not limited to, conduit  54   b  of the set of conduits  54 . Only the temperature sensing components  58  located on the one conduit (for example, conduit  54   b ) are activated substantially during that time. The activation signal is received in the one conduit (for example, conduit  54   b ) via the connector  60 , for example. In response to the activation, the activated temperature sensing components  58  output readout signals related to the temperatures being measured by the activated temperature sensing components  58 . The readout signals are conveyed substantially simultaneously by the set of conduits  56  to connector  62  for output from the TMS  50 . This activation and readout procedure may be continued until all of the conduits of the set of conduits  54  have been used for activation, for example, one conduit at a time, so that, for example, all temperature-sensing components in the TMS  50  have been activated. The entire procedure may be repeated to provide on-going monitoring of temperature. 
     The embodiment and process described allows for a large number of temperature measurement points with minimal conduits. Present temperature measurement systems require one conduit for each measurement point. In contrast, the embodiments of this invention allow for the number of temperature measurement points to be substantially equal to the product of the number of conduits  54  and the number of conduits  56  of the overlapping sets  54  and  56  of conduits. For example, the total number of conduits, given the sum of the number of conduits in the sets of conduits  54  and conduits  56 , is substantially less than the number of temperature sensing components  58  (measurement points) that is given by the product of the number of conduits in the sets of conduits  54  and conduits  56 . This advantage greatly simplifies the sensor system design, and makes it possible to achieve a large number of temperature measurement points. 
       FIGS. 4A and 4B  show a schematic embodiment of an interface cable  70  suitable for, but not limited to being used for, the TMS embodiment of  FIG. 3A . As shown in  FIG. 4A , a ribbon cable  72  consists of conduits  74  such as, but not limited to, optical fibers that are individually terminated at connectors  76  on one end and terminated at a common connector  78  (shown in  FIGS. 4A and 4B ) on the other end. 
     A TMS system embodiment  90  is shown in  FIG. 5  utilizing a TMS  92  ( 50 ) and interface cables  94  ( 70 ) and  96  ( 70 ), as well as TMS electronics  98  and a display/control interface  100 . 
     One implementation of the TMS system embodiment  90  may be implemented with, but is not limited to, the TMS  50  in which the set of conduits  54  and  56 , comprise, but are not limited to, optical waveguides. The TMS electronics  98  may contain a source of electromagnetic radiation, for example, but not limited to, a laser-diode or LED for activating temperature sensing components  58 . The excitation (activation) light propagates in the interface cable  94 , comprising, for example, but not limited to, a fiber-optic cable assembly. The excitation light from the interface cable  94  enters the conduits  54  via the connector  60 , and subsequently propagates in the conduits  54  to the temperature sensing components  58 . The temperature sensing components  58  comprise, for example, but are not limited to, phosphors exhibiting temperature-dependent fluorescence decay. The set of conduits  56  comprise, for example, but are not limited to, optical waveguides delivering read-out light from the temperature sensing components  58  to the TMS electronics  98  via the connector  62 , and the interface cable  96 , comprising, for example, but not limited to, a fiber-optic cable assembly. In one mode of operation, for example, the TMS electronics  98  could provide light in only one conduit, for example, but not limited to, conduit  54   a , of the set of conduits  54  during one period of time to activate only the temperature sensing components  58  that are located on the one conduit (for example, conduit  54   a ) substantially during that time period. In response to the activation, the activated temperature sensing components  58  output readout signals related to the temperatures being measured by the activated temperature sensing components  58 . The readout signals are conveyed substantially simultaneously by the set of conduits  56  to connector  62 , subsequently enter the interface cable  96 , and propagate in the interface cable  96  to the TMS electronics  98  to provide a temperature readout on display control  100  based on the temperature at selected temperature sensing components  58 . The decay, for example, but not limited to, of the phosphor of temperature sensing component  58  provides information relating to the temperature at that site. 
     Another period of time may involve a different one conduit, for example, but not limited to, conduit  54   b  of the set of conduits  54 . Only the temperature sensing components  58  located on the one conduit (for example, conduit  54   b ) are activated substantially during that period of time. In response to the activation, the activated temperature sensing components  58  output readout signals related to the temperatures being measured by the activated temperature sensing components  58 . The readout signals are conveyed substantially simultaneously by the set of conduits  56  to connector  62 , subsequently enter the interface cable  96 , and propagate in the interface cable  96  to the TMS electronics  98 . This activation and readout procedure may be continued until all of the conduits of the set of conduits  54  have been used for activation, for example, one conduit of the set of conduits  54  at a time, so that, for example, all temperature-sensing components in the TMS  50  have been activated. The entire procedure may be repeated to provide on-going monitoring of temperature. 
     One use of the TMS may be in the form of a medical application, but is not limited thereto, monitoring temperatures at various locations on the skin surface of a patient undergoing hyperthermia treatment for large-area skin disease such as, but not limited to, chestwall recurrence of breast cancer. In this example, a two-dimensional array of microwave applicators provides heat to kill skin cancer cells over a wide area of the chest wall, usually in combination with radiation and/or chemotherapy. The TMS system embodiment of  FIG. 5  provides feedback of temperature data over the surface subjected to the microwave radiation so as to facilitate monitoring and control of thermal dosage. 
     It should be further realized that the thermal monitoring sheets described herein may be constructed, but are not limited to the concepts described below. For this purpose, standard commercial fiber-optic (single-point) temperature sensors conform to a two-dimensional array format. Plastic fiber used in the sensors is cut to form array segments of staggered length. A temperature-sensitive phosphor or the equivalent is then added at the sensing end of each segment, and the segments arranged so the sensing tips are located in a uniformly spaced 4×4 array with adjacent tips separated by 3.7 centimeters. The fiber array is embedded between two Kapton sheets to form a thermal monitoring sheet with a fixed-position array of temperature sensors. One embodiment of the array can be constructed using approximately 250 μm diameter fibers, although not limited thereto. 
     Each fiber of the thermal monitoring sheet may be individually terminated in an optical connector so that it could be accessed by commercial signal-conditioner readout electronics. A furcation tube, incorporating Kevlar (or similar material) reinforcement, protects the fiber extending from the connector over most of its length. The outer diameter of the furcation tubing may be 2 mm for a 250 μm fiber. This furcation tubing extends about 3 m, making the complete assembly about 3.4 meters in length. Near the thermal monitoring sheet, the furcation tubing is terminated with a section of transition tubing. The outer diameter of the transition tubing is 800 μm for 250 μm fibers, for example. The fiber extends past the end of the transition tubing so that a short length of exposed 250 μm fiber traverses the region of the sensing array. 
     The exposed sections of optical fiber protruding from the transition tubing are sandwiched between two layers of thin and flexible Kapton that are held together with adhesive. In one embodiment, the two layers of Kapton are identical to allow equal sensing of temperature on both sides of the sheet. In another embodiment, two different thickness layers are used to provide directional thermal sensitivity of the buried fiber optic sensor (one layer of Kapton, for example, is approximately 100 μm in thickness while the other is approximately 175 μm thick). The Kapton material is cut in a rectangular shape, for example, around the 4×4 sensor array sandwich. The Kapton sandwich captures approximately 5 cm of the transition tubing, adding strength to the probe/sheet junction. A 10 cm length of transition tubing is reinforced as it exits the sheet to further strengthen this stress point on the fibers. It should be realized that the dimensions are for example only and not to limit the present embodiments. 
     Each of the, for example, 16 sensors comprising the TMS array may be individually connected to conventional signal-conditioner readout electronics (not shown). Temperatures may be displayed in both graphical and digital format on a computer monitor. The sensor responses may be measured against a NIST traceable standard RTD after placing the thermal monitoring sheet into an oil bath held at a constant temperature of approximately 38° C. Sensor calibration information may be determined from this comparison to the temperature standard and stored in a calibration integrated circuit attached permanently to each individual sensor (in the connector housing). 
     Once calibrated, the arrays may be tested in experiments to assess their ability to record temperatures of a surface accurately without self-heating in high intensity microwave or ultrasound fields or perturbing ultrasound or microwave applicator power deposition patterns. In an initial prototype test, the thermal barrier properties were characterized for a 0.28 mm thick Kapton array with sixteen 250 μm diameter sensors (TMS-250) with the array placed between a large uniform temperature surface (well-circulated water bolus) and an air insulated thermal load. 
     Eight 0.64 mm OD Teflon encased multi-sensor thermocouples were placed above, and another eight thermocouples placed below the TMS-250 sheet in good thermal contact with the water bolus, Kapton sheet, and air bladder insulation layers to monitor interface temperatures. After circulating 23° C. water until steady state conditions were obtained, the tubing connections were switched to a preheated bath at time t=100 s and the water bolus increased rapidly towards 40.5° C. Sensors on opposing sides of the 0.28 mm Kapton sandwich registered different temperatures due to thermal resistance of the thin barrier. The temperature difference on either side of the TMS was, in this example test, about 2° C. initially reducing to just over 1° C. in steady state, as measured by the thinwall Teflon encased thermocouples. 
     Another test of the effect on microwave array heating patterns of a complete TMS array may be conducted, for example, using a 6-element sub-array of a large CMA applicator that has been used for treating large area chestwall disease. Insertion of the 0.28 mm thick thermal monitoring sheet with 250 μm fibers has essentially no effect on the radiated field from the microwave array other than to reduce the peak SAR at a depth of 5 mm in muscle by about 5%. Since a separate investigation demonstrated no absorption of microwave energy directly in the Kapton based sensor array, this minor reduction in transmitted power must have been due to slight changes in driving impedance and/or slight reflections at the additional dielectric interface (adding to reflections already occurring from the waterbolus PVC dielectric interface). That minor effect would easily be accommodated in clinical treatments by increasing the applied power, as necessary to achieve the desired skin surface temperature. 
     Additionally, the following observations and conclusions can be ascertained from the characterization of the TMS devices: 
     Thin (0.1-0.3 mm, typical) and flexible thermal monitoring sheet arrays can be constructed from readily available and easily manufactured dielectric sheets (e.g. Kapton) which support an array of 250-500 μm diameter (typical) plastic fibers; 
     0.1-0.3 mm Kapton TMS have no perceptible absorption or self-heating from 915 MHz microwave energy; 
     0.1-0.3 mm Kapton TMS with 250-500 μm fibers placed between microwave array applicator and tissue load produces no perceptible change in SAR pattern, and ≦5% reduction in peak SAR; 
     0.1-0.3 mm Kapton TMS has minimal absorption and perturbation of 3.4 MHz ultrasound energy, with self-heating of ≦1-2° C. across the array surface for typical applied power levels; 
     Kapton TMS fiber-optic arrays ≦0.3 mm thick offer a simple and accurate way to monitor surface temperature distributions, producing transient offsets &lt;0.5° C. even up to three times the typical clinical temperature gradient; and 
     TMS arrays should provide improved monitoring of temperature distributions in large surface areas due to fast simultaneous reading of multiple temperatures, consistent thermal resistance between sensors and surface to be measured, and fixed known location of all sensors in the array. 
     Although the invention has been described with respect to various embodiments, it should be realized this invention is also capable of a wide variety of further and other embodiments within the spirit and scope of the appended claims.