Abstract:
A treatment apparatus includes a heater, a structure supporting the heater against tissue, and a controller connected to the heater for maintaining a tissue temperature under the structure in a normothermic range of 36° C. to 38° C. The apparatus is useful for treating tissue, wounds, and the like.

Description:
CROSS-REFERENCES TO RELATED PATENT AND COPENDING APPLICATIONS 
     This application is a continuation of U.S. Pat. Application Ser. No. 09/609,346, filed Jul. 5, 2000 for TISSUE TREATMENT APPARATUS, which is a continuation of U.S. patent application Ser. No. 09/055,605, filed Apr. 6, 1998 for WOUND TREATMENT APPARATUS FOR NORMOTHERMIC TREATMENT OF WOUNDS, now U.S. Pat. No. 6,095,992. 
     This application contains material related to the following commonly assigned pending U.S. patent applications: 
     Ser. No. 07/900,656, filed Jun. 19, 1992, for “THERMAL BODY TREATMENT APPARATUS AND METHOD”; 
     Ser. No. 08/342,741, filed Nov. 21, 1994, for “WOUND TREATMENT DEVICE”; 
     Ser. No. 08/356,325, filed Feb. 21, 1995, for “WOUND COVERING”; 
     Ser. No. 08/785,794, filed Jan. 21, 1997, for “NORMOTHERMIC HEATER WOUND COVERING”; 
     Ser. No. 08/786,713, filed Jan. 21, 1997, for “NORMOTHERMIC TISSUE HEATING WOUND COVERING”; 
     Ser. No. 08/786,714, filed Jan. 21, 1997, for “NEAR HYPOTHERMIC HEATER WOUND COVERING”; and 
     Ser. No. 08/838,618, filed Apr. 11, 1997, for “FLEXIBLE NON-CONTACT WOUND TREATMENT DEVICE”; 
     Ser. No. 08/843,072 filed on Apr. 11, 1997 entitled “FLEXIBLE NON-CONTACT WOUND TREATMENT DEVICE WITH A SINGLE JOINT”; 
     Ser. No. 09/056,191, filed Apr. 16, 1998, for “WOUND TREATMENT APPARATUS WITH A HEATER, A HEAT CONDUCTIVE BANDAGE, AND A HEAT-SPREADING MEANS ACTING BETWEEN THE HEATER AND BANDAGE”; 
     Ser. No. 09/055,725, filed Apr. 6, 1998 for “WOUND TREATMENT APPARATUS WITH INFRARED ABSORPTIVE WOUND COVER”; 
     Ser. No. 09/056,063, filed Apr. 6, 1998 for “WOUND TREATMENT APPARATUS WITH IR-TRANSPARENT OR IR-TRANSMISSIVE WOUND COVER”; and 
     Ser. No. 09/055,597, filed Apr. 6, 1998 for “WOUND TREATMENT APPARATUS WITH A HEATER ADHESIVELY JOINED TO A BANDAGE”. 
    
    
     STATEMENT OF REGARDING FEDERALLY 
     SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wound treatment device with a bandage and heater that are essentially planar, yet flexible, and are connected or joined by an attachment device that promotes heat transfer from the heater through the bandage to a wound treatment area where the temperature of tissue is maintained by control of the heater&#39;s operation in a normothermic temperature range. 
     2. Description of the Related Art 
     Wounds, in general, are breaks in the integrity of the skin of a patient. A first type of wound may result from mechanical trauma that produces a cut, tear, or an abrasion. There are many instruments of causality for such wounds, including knives, glass, gravel, or a scalpel. A second type of wound may be caused by a combination of heat and pressure wherein the heat alone is insufficient to cause an outright burn. Such wounds include pressure sores, decubitus ulcers, or bed sores, and reflect an injury that is chronic in nature. A wound may also be vascular in origin. In this third type of wound, blood flow through a region may be altered sufficiently to cause secondary weakening of tissues which are eventually disrupted, thus forming a wound. In the case of arterial causes, the primary difficulty is getting oxygenated blood to the affected area. For venous causes, the primary difficulty is fluid congestion in the affected area which backs up, decreasing the flow of oxygenated blood. Because these wounds manifest underlying chronic disease processes, such as atherosclerotic vascular disease, congestive heart failure, and diabetes, these vascular injuries also are chronic in nature, forming wounds with ulcerated bases. 
     Heat therapy has been used to treat wounds since the days of Hippocrates, with varying results. Up to now, heat therapy for wounds has involved the application of heat under conditions that make the tissues of a wound hyperthermic. Hyperthermia impedes wound healing and may actually damage the wound tissues. 
     The “normal” range of temperature for the human body is 37° C.±1° C. (36° C.-38° C.). This is termed the “normothermic” range. Humans exhibit a thermoregulatory response to core temperature changes as little as ±0.1° C., wherein “core” as used herein refers to interior portions of the body. This extremely tight temperature control is necessary because virtually all cellular functions, chemical reactions and enzymatic reactions are optimum at normothermia. 
     Surface tissue varies in temperature according to where on the body it is located. The skin of the torso is usually hypothermic, while the skin of the legs is always hypothermic. The normal skin temperature of the distal leg is approximately 32° C., which is considered to be “moderately hypothermic”. The skin temperature of the distal leg of a patient with vascular insufficiency may be as low as 25° C., which is “severely hypothermic”. The hypothermic condition of wounds and ulcers inhibits healing. Severely hypothermic skin or wound tissue is in a state that may be termed “suspended animation”. In suspended animation, tissue is living, but cellular functions necessary for cell division and collagen deposition are slowed or even stopped. Further, the immune system is inhibited, allowing wounds to become heavily colonized with bacteria. The local application of heat to hypothermic skin will cause some degree of vasodilatation, resulting in an increase in local blood flow. Increased blood flow increases the subcutaneous oxygen tension (PsqO 2 ) which, in turn, increases both collagen deposition and immune function. 
     Many references report that the immune system is inhibited by hypothermia and activated by mild hyperthermia (fever). Persp Biol Med:439-474, Spring 1980, reports that local body temperature is a critical factor determining host susceptibility, the location of lesions and contracting infectious diseases. New Eng J Med 305:808-814, 1981, reports that animals exposed to cold environments are more susceptible to infectious diseases, whereas exposure to high ambient temperatures often produces a beneficial result. Wound Rep Reg 2:48-56, 1994 and Acta Anaesth Scand 38:201-205, 1994, report that infections caused by a standard inoculum of  e. coli  or  s. aureus  were significantly more severe in hypothermic guinea pigs than in normothermic control animals. New Eng J Med 334:1209-1215, 1996, reports that hypothermic colorectal surgical patients had three times more wound infections (19% vs. 6%) than those who were kept normothermic during surgery with a Bair Hugger® patient warming system described in commonly assigned U.S. Pat. Nos. 5,324,320, 5,300,102 and 5,350,417. Further, six weeks of warming therapy with the Bair Hugger® patient warming system has successfully healed chronic progressive ulcers which heretofore have been resistant to antibiotic therapies. 
     As stated hereinabove, enzymatic reactions are promoted by normothermia. Both platelet adhesion and the clotting cascade result from a series of enzymatic chemical reactions. Research efforts have been reported that show hypothermic patients bleeding more than normothermic patients. J Thorac Cardiovasc Surg 104:108-116, 1992, and Ann Surg 205:175-181, 1987, report that skin cooling produces a reversible platelet dysfunction and prolonged bleeding times. Lancet 347 (8997):289-292, 1995, reports that mildly hypothermic total hip arthroplasty patients lost an average of 500 ml more blood and had an 88% higher incidence of transfusion than patients who were kept normothermic with the aforementioned Bair Hugger® Patient Warming System. Anesthesiology 85: A66, 1996, reports that hypothermic liver transplant patients required twice as many units of blood (18.6 vs.9.8) and 57% more units of all blood products (46.2vs. 29.4) than patients who were kept normothermic with the Bair Hugger® Patient Warming System. 
     When used to treat wounds; heat has been applied at higher than normothermic temperatures, with the goal of making the wounds mildly hyperthermic. These higher temperatures have often resulted in increasing tissue damage, rather than promoting wound therapy and healing. 
     Currently available medical devices that apply heat to wounds include infrared lights, warm water pads, warm water bottles, whirlpools and Sitz baths. All types of lesions, such as surgical, chronic, traumatic, donor sites, infected wounds and bums, have been treated with these warming modalities. Particularly difficult has been the application of heat to open wounds such as ulcers. Treatment of a wound with infrared light requires that the wound be positioned under the light during therapy, necessitating patient immobility. Further, the infrared heat causes wounds to dry, thereby slowing the healing process. Warm water pads and bottles and electrical heating pads are cumbersome, reduce patient mobility, and are usually applied to the extremities and held in place with inconvenient wraps such as straps, hook-and-eye material or tabs. Whirlpools and Sitz baths reduce mobility and limit the duration of warming therapy due to skin maceration by the water. None of these modalities is capable of prolonged, uniform, normothermic heat treatment of a wound. 
     SUMMARY OF THE INVENTION 
     This invention is designed to elevate the temperature of hypothermic skin and subcutaneous tissue of a treatment area to a temperature which is close to normothermic. The invention, in operation, maintains the temperature of such tissue in a normothermic range of about 36° C. to 38° C. 
     Still another object is to provide a low profile, flexible wound treatment apparatus that includes a heater attached to a bandage and a controller connected to the heater for operating the heater so that the apparatus provides a normothermic therapy regime to a wound. 
     Other objects and advantages of the invention will become apparent upon reading the following description taken together with the accompanying drawings. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a first embodiment of the treatment apparatus being applied to a person&#39;s body. 
     FIG. 2 is an isometric view of the treatment apparatus applied to the person&#39;s body. 
     FIG. 3 is an exploded isometric view of the treatment apparatus; 
     FIG. 4 is a cross-sectional view of the treatment apparatus applied to the person&#39;s body; 
     FIG. 5 is an exploded cross-sectional illustration of an embodiment of the invention above a treatment area of the person&#39;s body; 
     FIG. 6 is a view taken along plane VI—VI of FIG. 5; 
     FIG. 7 is a view taken along plane VII—VII of FIG. 5; 
     FIG. 8 is a view taken along plane VIII—VIII of FIG. 5; 
     FIG. 9 is a view taken along plane IX—IX of FIG. 5; 
     FIG. 10 is a view taken along plane X—X of FIG. 5; 
     FIG. 11 is a view taken along plane XI—XI of FIG. 5; 
     FIG. 12 is a view taken along plane XII—XII of FIG. 5; 
     FIG. 13 is an exploded cross-sectional view of the first embodiment of the treatment apparatus after attaching an attachment device to the heater; 
     FIG. 14A is a planar illustration of an electrical resistance element embedded in a flexible layer for uniform heating; 
     FIG. 14B is a view taken along plane XIVB—XIVB of FIG. 14A; 
     FIG. 15A is a planar view of an electrical resistance element embedded in a flexible layer for heating a portion of a treatment area; 
     FIG. 15B is a view taken along plane XVB—XVB of FIG. 15A; 
     FIG. 16A is a planar view of an electrical resistance element embedded in a flexible layer for uniform heating of a central portion of a treatment area; 
     FIG. 16B is a view taken along plane XVIB—XVIB of FIG. 16A; 
     FIG. 17 is an exploded cross-sectional view of another embodiment of the invention shown above a treatment area; 
     FIG. 18 is a view taken along plane XVIII—XVIII of FIG. 17; 
     FIG. 19 is a view taken along plane XIX—XIX of FIG. 17; 
     FIG. 20 is a view taken along plane XX—XX of FIG. 17; 
     FIG. 21 is a view taken along plane XXI—XXI of FIG. 17; 
     FIG. 22 is a view taken along plane XXII—XXII of FIG. 17; 
     FIG. 23 is a view taken along plane XXIII—XXIII of FIG. 17; 
     FIG. 24 is a view taken along plane XXIV—XXIV of FIG. 17; 
     FIG. 25 is a view taken along plane XXV—XXV of FIG. 17; 
     FIG. 26 is a view taken along plane XXVI—XXVI of FIG. 17; 
     FIG. 27 is a view taken along plane XVII—XXVII of FIG. 17; 
     FIG. 28 is a view showing schematically the engagement of the intermittent adhesives shown in FIGS. 26 and 27; 
     FIG. 29 is an isometric illustration of a further embodiment of the treatment apparatus applied to a treatment area on the person&#39;s body; 
     FIG. 30 is an exploded cross-sectional illustration of the apparatus shown in FIG. 29 shown above the treatment area; 
     FIG. 31 is an exploded cross-sectional illustration of the FIG. 29 embodiment with an adhesive attachment device applied to the heater; 
     FIG. 32 is a block diagram that illustrates the present treatment apparatus for implementing normothermic heat therapy; 
     FIG. 33 is a graph showing tissue and heater temperatures over a plurality of duty cycles; 
     FIG. 34 is a temperature versus time graph showing tissue and heater temperature over a number of therapy cycles; 
     FIG. 35 is a graph showing temperature versus time similar to the graph shown in FIG. 38 except the temperature is set at an average instead of a set amount; 
     FIG. 36 is a graph of temperature versus time for a plurality of duty cycles wherein the temperature is sensed at the heater; 
     FIG. 37 is a graph of temperature versus time of a plurality of therapy cycles wherein the temperature is sensed at the heater; and 
     FIG. 38 is a graph of temperature versus time showing a plurality of therapy cycles wherein temperature is sensed at the heater. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIGS. 1-31, wherein like reference numerals designate like or similar parts throughout the several views there are shown various embodiments of a treatment apparatus in according to the invention. 
     As shown in FIGS. 1-6, one embodiment of the treatment apparatus  100  includes a thermally conductive bandage  102  which has first (lower) and second (upper) surfaces  104  and  106 , a heater  108  which has first (lower) and second (upper) surfaces  110  and  112  and an attachment device  114  for joining the heater  108  and the bandage  102  in such a manner as to transfer heat from the heater  108  to the bandage  102 . Preferably, the attachment device maintains surface-to-surface contact between the second surface  106  of the bandage  102  and the first surface  110  of the heater. In FIGS. 2 and 4, the treatment apparatus  100  is shown in place covering a tissue treatment area  116  that includes a wound on a person&#39;s body  118 , the wound being shown depressed. Immediately adjacent the wound is a periwound area  120  which is typically a peripheral band of tissue around the wound area with less trauma than the tissue of the wound area. As will be explained in more detail hereinafter, the treatment apparatus is capable of treating a treatment area of tissue such as the wound and/or the periwound area, as desired. 
     The second surface  106  of the bandage preferably comprises a sheet of smooth material. In a preferred embodiment, this surface may be provided by a polymeric film. A layer  122  of hydrogel, hydrocolloid, or hydrated alginate may be affixed to the polymeric film  106  by any suitable means, such as an adhesive, and may provide the first surface  104 . It is preferred that any of these combinations provide the bandage with high thermal conductivity and maintain a moist environment at the wound. In the layer  122 , a foam or gauze may be used in lieu of the compounds enumerated above. If the gauze or foam provides the first surface  104 , the gauze or foam will absorb moisture from the wound, providing the desired heat conductivity and moist environment. Alternatively, the bandage  102  may simply be a single layer or film of a heat-conductive polymer so as to optimize heat conductivity of the bandage. In any embodiment of the bandage, it is preferred that the bandage be planar, as shown in FIGS. 3 and 5, and be flexible to conform to the wound in the treatment area  116  as shown in FIG. 4, as well as the person&#39;s body, as shown in FIGS. 1 and 2. 
     In the embodiment  100  of the treatment apparatus, the heater  108  includes means for generating heat that may be electrically operated. For example, the means may take the form of an electrical resistance element  124  which is embedded in or laminated to a flexible planar member  126 , made from a material such as polyethylene, silicon, rubber or flexible cloth. In the preferred embodiment, the heater  108  is substantially planar, as shown in FIGS. 1,  3  and  5 , and yet flexible in order that it conform, with the bandage, to the wound in the treatment area  116 , as shown in FIG. 4, and to the person&#39;s body as shown in FIGS. 2 and 4. As will be explained in more detail hereinafter, the adhesive attachment device  114  joins the heater  108  to the bandage  102 , as shown in FIG. 4, so as to maximize heat transfer between the heater  108  and the bandage  102 . 
     As illustrated in FIGS. 1 and 4, the electrical resistance element  124  is connected to first and second electrical conductors  128  and  130 , which are connected to an electrical power source  132 , via a controller  134 . The purpose of the controller  134  is to control electrical power provided to the electrical resistance element.  124  to maintain a normothermic environment at the wound in the treatment area  116 . As shown in FIGS. 1 and 2, the electrical resistance element  124  may extend back and forth in the flexible layer  126  with a desired spacing to promote uniform heating of the bandage  102 . 
     As shown in FIG. 6, the first surface  104  of the bandage  102  is provided with an open pattern of adhesive  136  at or near its periphery. The adhesive pattern  136  may completely encompass the treatment area so as to trap the natural moisture of the body which, in turn, moistens the layer  122  of the bandage, or otherwise maintains a moist environment across the treatment area for therapy purposes. Accordingly, the pattern of adhesive  136  has inner and outer boundaries  138  and  140  wherein, in the preferred embodiment, the outer boundary  140  coincides with the outer perimeter of the bandage. It should be understood that the bandage  102 , the heater  108 , and the pattern of adhesive may take various shapes, such as the square, shown in the drawings, or a rectangle, circle or ellipse, or any other regular or irregular shape, depending upon various shapes of wound treatment areas. 
     The preferred adhesive attachment device  114  is a double-sided tape, as shown in FIG.  5 . It is preferred that the double-sided tape be a polymeric film with first and second surfaces with first and second layers of adhesive  142  and  144  thereon. The double-sided tape comes with first and second release liners  146  and  148  which are removed so that the adhesive layers  142  and  144  can be joined to the second surface  106  of the bandage  102  and to the first surface  110  of the heater  108 , respectively, as shown in FIGS. 1,  4  and  5 . In FIG. 1, the release liner  146  is partially removed from the adhesive layer  142  (see FIG. 5) in preparation for attaching the heater  108  to the second surface  106  of the bandage  102 . The double-sided tape  114  is very flexible and conducts heat between the heater  108  and the bandage  102 . It is preferred that the planar dimensions of the double-sided tape  114  be the same as the planar dimension of the heater  108  so as to transfer heat from the entire first surface  110  of the heater  108  to the bandage  102 . It should be noted that, because of the polymeric film  106  forming the second surface of the bandage  102 , transfer of heat by conduction to the bandage  102  is promoted. 
     When heat therapy is interrupted or terminated, it may be desirable to detach the heater  108  from the bandage  102 . In this regard, the heater  108  is preferably detachably joined to the bandage  102 . Detachment in the embodiment just described will necessitate pulling the heater  108  away from the bandage  102 , thereby subjecting each adhesive layer therebelow to a pull force. In order for the bandage  102  to remain in place while the heater  108  is being removed, the pull strength of the attachment device  114  must be less than the pull strength of the pattern adhesive  136 . Various means for achieving this objective with double-sided tape are shown in FIGS. 7-12. FIGS. 7 and 8 show the adhesive layers  142  and  144  completely covering the surfaces of the polymeric film. One of these surfaces will be required to have less pull strength than the pull strength of the pattern of adhesive  136 . In a preferred embodiment, the adhesive layer  142  has less pull strength than each of the pattern of adhesive  136  and the adhesive layer  144 , allowing the heater  108  to be removed from the bandage  102  without leaving any adhesive on the bandage. This may be accomplished by employing an adhesive layer  142  which is less tacky than each of the pattern of adhesive  136  and the adhesive layer  144 . Less tack can be achieved by doping the same adhesive with a solvent or inert filler, such as talcum or chalk, or employing another adhesive with a tack known to be less than the tack of the adhesives  136  and  144 . If it is desired to leave the adhesive on the bandage  102 , then the roles of the tack would be switched between the adhesive layers  142  and  144 . 
     Lower pull strength of the adhesive between the heater  108  and the bandage  102 , as compared to the pull strength of the adhesive attaching the bandage  102  to a person&#39;s body, can be provided by intermittent adhesive patterns such as the circular regions  142   i  shown in FIG.  9 . In contrast, as shown in FIG. 10, the adhesive layer  144  would be an entire plane so that when the heater is pulled, the double-sided tape leaves with the heater  108  rather than being retained on the bandage  102 . As shown in FIG. 9, the adhesive regions  142   i  may be numerous circular dots of adhesive which are sized and spaced from one another in a matrix to provide a pull strength of the adhesive attachment device that is less than the pull strength of the pattern of adhesive  136  and less than continuous adhesive layer  144 . With this arrangement, the same adhesive may be used for the adhesive layers  142  and  144  of the double-sided tape and the pattern of adhesive  136  on the bandage. Again, the layers  142  and  144  of the double-sided tape  114  may be switched if it is desired to leave the double-sided tape on the bandage  102  when the heater  108  is pulled therefrom. Another intermittent adhesive pattern is shown at  142   s  in FIG. 11, wherein diagonal spaced-apart strips of adhesive material are provided across the polymeric film. Here again, the sizing of the strips and their spacing from one another are arranged so that the pull strength of the adhesive attachment device is less than the pull strength of each of the body adhesive layer  136  and the full plane adhesive layer  144  in FIG.  12 . It should be understood that the intermittent adhesive structure may take various patterns in order to achieve the desired reduction in pull strength. The spacing between the intermittent layers should be made as small as possible so as to promote conductive heat transfer between the heater  108  and the bandage  102 . 
     In FIG. 13 the adhesive layer  142  of the double-sided tape has been applied to the first surface  110  of the heater  108  and the release liner  146  has been partially removed from the first adhesive layer  142 , similar to the showing in FIG.  1 . The heater  108  may be supplied with the double-sided tape in place, as shown in FIG. 13, or may be supplied separately as described and shown in FIG.  5 . 
     Manifestly, an attachment device should permit the heater and bandage to be joined in such a way as to maximize heat transfer therebetween while permitting the heater to be detached from the bandage without detaching the bandage from the skin. While various adhesive configurations are shown for this purpose, it is contemplated that other attachment mechanisms could be used. 
     FIGS. 14-16 illustrate various embodiments of electrical resistance heaters  108 . In the heater  108   a  shown in FIG. 14A, and electrical resistance element  124   a  winds back and forth within the flexible planar member  126 , similar to what is shown in FIG.  1 . The spacing between the windings of the electrical resistance element  124   a  may be sized so as to ensure substantially uniform heating. FIG. 14B shows the electrical resistance element embedded or laminated in the flexible planar member  126 . In FIG. 15A, the electrical resistance element  124   b  takes a path along a peripheral zone of the flexible planar member  126 , so that the periphery of the heater  108   b  is uniformly heated to a temperature greater than a central portion of the heater. Again, these electrical resistance elements  124   b  are shown embedded or laminated in the flexible planar member  126  in FIG.  15 B. In FIG. 16A, the electrical resistance element  124   c  takes a spiral path out and back within a central region of the heater  108   c  so as to uniformly heat the central region of the heater to a higher temperature than regions outbound therefrom. The heater  108   a  is adapted for applying heat to both the wound and periwound area  116  and  120  in FIG. 4, the heater  108   b  is adapted for applying heat principally to the periwound area  120 , and the heater  108   c  is adapted for applying heat principally to the wound  116 . 
     Another embodiment  200  of the treatment apparatus is illustrated in FIG. 17, wherein an adhesive layer  202  is on the second surface  106  of the bandage  102  and/or an adhesive layer  204  is on the first surface  110  of the heater  108 . Various embodiments of these attachment devices are illustrated in FIGS. 18-28. The first embodiment of the attachment device is shown in FIGS. 18 and 19, wherein the heater  108  is provided with the adhesive layer  204  and the bandage  102  is not provided with any adhesive layer. In FIGS. 20 and 21, the situation is reversed wherein the bandage  102  is provided with the adhesive layer  202  and the heater  108  does not have an adhesive layer. FIGS. 22 and 23 illustrate a still further embodiment wherein the bandage  102  is provided with the adhesive layer  202  and the heater  108  is provided with the adhesive layer  204 . The adhesive layers  202  and  204  in FIGS. 22 and 23 may be made from an adhesive which will bond only when these two adhesive layers are placed in contact with one another. Otherwise, the adhesive layer  204  will not bond to the polymeric surface surrounding the adhesive layer  202 , or any other surface including a person&#39;s skin. This scheme antage from the standpoint that adhesive layers  202  and  204  on the bandage  102  and the heater  108 , respectively, will not attach to anything until they are brought into contact between the heater  108  and the bandage  102 . This promotes manufacturability, logistics and operation of the invention. A suitable adhesive for this purpose is 3M Acrylic Adhesive A40 (of the kind used in 3M Repositionable tape, product number 665). It is desirable that the pull strength of the adhesive attachment devices shown in FIGS. 18-23 be lower than the pull strength of the body adhesive  136  shown in FIG.  6 . This can be accomplished by making the tack of the adhesive attachment device less than the tack of the pattern of adhesive  136 . 
     Attachment devices employing intermittent adhesive patterns are shown in FIGS. 24-28. The embodiment in FIGS. 24 and 25 shows the heater  108  provided with circular spaced-apart adhesive regions  204   c , while the bandage  102  is not provided with any adhesive. In the embodiment shown in FIGS. 26 and 27, each of the bandage  102  and the heater  108  is provided with diagonal spaced-apart adhesive strips  202   d  and  204   d , respectively. When these adhesive strips are brought into contact with one another, as shown in FIG. 28, they criss-cross one another to provide the desired bonding between the heater  108  and the bandage  102 . 
     The adhesive areas of the intermittent adhesive patterns shown in FIGS. 24-28 are sized and spaced from one another so that the pull strength of each attachment device is less than the pull strength of the pattern of adhesive  136  shown in FIG. 6, as discussed hereinabove. Again, the size of the intermittent adhesive patterns and the spacing therebetween should be tailored to maximize thermal conductivity between the heater  108  and the bandage  102  and yet ensure that the pull strength between the heater and the bandage is less than the pull strength between the bandage and the person&#39;s body. 
     Another embodiment  300  of the treatment apparatus is illustrated in FIGS. 29-31. In this embodiment, a heater  302  employs heated water as the means for generating heat to be provided to the bandage  102  and then to a treatment area covered by the bandage. The heater  302  may comprise a pouch  304  which has water channels extending back and forth in series from an inlet end  308  to an outlet end  310 . The pouch  304  may be made by thermo-setting the periphery as well as channel lines of a pair of polymeric films  312  and  314  as shown in FIG.  30 . The bottom film  314  may be stiffer than the top film  312 . Heated water is supplied by inlet and outlet water lines  316  and  318  which are connected to a water heater  320  via a pump  322 . A controller  324  is provided for controlling the temperature of the water in the water heater  320  and the amount of water pumped by the pump  322 . The heated water is preferably maintained at such a temperature and flow rate that the tissue in the treatment area  116  is maintained at a normothermic temperature. The bandage  102  may comprise any of the aforementioned embodiments. Further, the attachment device for attaching the heater  302  to the bandage  102  may comprise any of the aforementioned adhesive attachment devices. or any equivalent devices or arrangements that connect the heater and bandage for maximum thermal conductivity, yet allow detachment of the heater from the bandage without detaching the bandage from a patient&#39;s skin. The preferred attachment device is the double-sided tape  114  shown in FIG. 30, which has been described in detail hereinabove. Another suitable attachment device is shown in FIG. 31 wherein the water heater  302  is provided with an adhesive layer  326  and a release liner  328 . The release liner  328  is simply pulled from the adhesive layer  326  and the adhesive layer  326  is employed for attaching the water heater  302  to the polymeric surface  106  of the bandage  102 . 
     FIG. 32 is a block diagram of a treatment apparatus  900  for providing normothermic heat therapy to a treatment area on a limb or body portion of a patient. The treatment apparatus  900  includes a heater  902  disposed on a bandage  904  over a treatment area (not shown) on a limb or body portion  906  of a person or patient. The heater  902  is disposed on the bandage  904  over the treatment area for conduction of heat from the heater  902 , through bandage  906 , to the treatment area. The heater  902  makes contact with the bandage  904  and may be attached to it by any of the numerous attachment schemes discussed previously, or any equivalents thereto. A power supply  908  provides electrical power to the heater  902  by way of a controller  910 . The controller  910  may comprise, for example, a processor  912 . Preferably the processor  912  includes manual entry logic  914 , normothermia logic  916 , and timing logic  918 . Manual entry logic  914  may be conventional logic of the kind used, for example, to set various timing functions in a wrist watch. For the purposes of the controller  910 , the manual entry logic  914  receives, from conventional manually-operated devices, such as buttons, a user input for setting a temperature of the heater  902  (SET TEMP), a user input for setting a number of cycles (SET CYCLE), and a user input for setting cycle duration (SET DURATION). These inputs are only examples. Other inputs may set therapy cycle duration, number of duty cycles per therapy cycle, average heater temperature per duty cycle, average heater temperature per therapy cycle, and peak and minimum temperatures for a therapy cycle. The timing logic  918  is conventional, providing timing functions for implementing cycle times and durations. The normothermia logic  916  controls connection of the power supply  908  to the heater  902  in a manner that implements normothermic treatment of tissue by heating the tissue in and near a treatment area to a temperature in a normothermic range. In order to control the course of such treatment, the normothermia logic  916  receives signals from sensors  920 ,  922  and  924  that indicate, respectively, an ambient temperature, the heater temperature, and the tissue temperature at or near the treatment area. The heater  902  is powered by a heater on/off signal that comprises a voltage obtained from the power supply  908 . 
     The controller  910  may comprise a programmable, general purpose processor, a programmable special purpose processor, a specially-designed electronic circuit, or an application specific integrated circuit (ASIC), or any equivalent. Preferably, the controller  910  is a multi-state machine that may transition between specified states of operation automatically, in response to manual inputs, or programmed functions, or both. Assuming that at least some of the fimctions of the controller  910  are implemented in the controller by programming, the normothermnia logic  916  may include a control program embodied in a programmable memory, a programmable logic circuit, or both. Further the manual entry logic  914  permits a user to enter or change parameter values and provides user control of functions and operations. The controller  910 , and power supply  908  may be integrated mechanically into a single unit that may include the heater  902 , or provided in a separate package that is electrically connected to the heater  902 . The power supply  908  may comprise a battery, battery pack, an AC/DC converter, or any other equivalent device that may be switched on and off to the heater  902 . 
     The controller  910  controls the temperature and one or more heat cycles of the heater  902  so as to maintain normothermic or near-normothermic tissue temperature at a treatment area on a person&#39;s body. By sensing the temperature of tissue at the treatment area with the sensor  924 , the temperature of the heater  902  may be controlled to accomplish this purpose. Alternatively, normothermic or near-normothermic temperature of tissue at the treatment area may be maintained in response to the temperature of the heater itself  902 , which is sensed by the sensor  922 . If the sensor  922  at the heater  902  is used instead of the sensor  924 , A, compensation may be made for any heat loss in the thermal path from the heater  902 , through the bandage  904 , to the treatment area. Preferably, the heater  902 , the bandage  904 , and the interface between them are designed to minimize heat loss. If heat loss is small, any differential between heat measured by the sensor  922  and heat measured by the sensor  924  may be small enough to merit elimination of one of the sensors. In any event, either, or both, of the sensors  922  and.  924  may be deployed to measure the temperature of the heater  902  and the tissue at the treatment area. 
     Preferably, the controller  910  operates the heater  902  in such a manner as to maintain a limited heat range, centered on the normothermic level of temperature, at a treatment area. Preferably, this range is from about 36° C. to about 38° C., although it may be somewhat greater or smaller. To accomplish this purpose, the controller  910  may turn the heater  902  on and off over one or more duty cycles of the heater  902  and one or more therapy cycles. In this regard, a therapy cycle is a plurality of duty cycles followed by a period of time during which the heater  902  is off. A plurality of therapy cycles may constitute a therapeutic sequence that may last for one day or longer. After a number of therapy cycles in a therapeutic sequence, the heater  902  is turned off for a longer period of time and then may be turned on again for another plurality of therapy cycles. When the heater  902  is turned off at the end of a therapeutic sequence, the temperature of the treatment apparatus  900  and the temperature of the treatment area may approach the ambient temperature in the space where the patient is located. It is assumed that the ambient temperature is at or below normothermia. 
     By way of example, and without limiting the scope of treatment versatility, FIG. 33 is a graphic representation of a normothermic treatment regimen that may be implemented by the normothermia logic  916  and actually delivered by operation of the treatment apparatus  900 . In FIG. 33, a plurality of duty cycles  980  has been depicted as a curve  982  over a therapy cycle; tissue temperature response to the therapy cycle is represented by a curve  983 , the tissue temperature response being indicated by the temperature sensor  924  of FIG.  32 . Time (t) is represented along the abscissa and temperature (T) along the ordinate. A tissue temperature target value T tar , which is preferably normothermic, has been entered into the heater controller  910  and the heater  902  is started at t 0 . The tissue temperature is initially at T a  and the heater  902  is initially at ambient temperature T amb . By turning on the heater at to, the first of the plurality of duty cycles for the heater begins in order to provide heat with which to raise the tissue temperature to T tar . The heater controller  910  raises the operating temperature of the heater  902  to T h  based on the value, either programmed or input, for T tar ; the heater controller causes the heater  902  to operate according to a duty cycle to provide T tar  to at least a portion of the selected treatment area. The tissue target temperature T tar  value is reached at t l , at which time the heater is turned off. Alternatively, although not shown, upon reaching T tar , the controller  910  could have changed T h  to a lower value and kept the heater active in order to maintain the tissue temperature at T tar . 
     By way of another example, and not limiting in scope of treatment versatility, a plurality of therapy cycles  984  actually delivered by operation of the treatment apparatus  900  are depicted in FIG. 34, wherein individual duty cycles within each therapy cycle have been averaged out for purposes of clarification and for purposes herein are treated as the heater being “on”. A first therapy cycle begins at to as depicted by the heater  902  turning “on”, as shown by a heater temperature curve  986 . A tissue temperature target value T tar  has been entered into the heater controller  910 ; the tissue temperature response is shown in a curve  988 . The tissue start temperature is T a  and the starting heater temperature is at about ambient, T amb . The heater remains “on” until the tissue temperature has reached T tar  as monitored directly by the sensor  924  in FIG. 32, or as predicted by an appropriate heating paradigm employing the sensor  922 . As shown, T tar  is reached at t l  at which time the heater is turned “off”. As in the previous example, an alternative is that the heater controller  910  selects an alternate heating output, chosen to maintain the tissue temperature at about T tar . As depicted in FIG. 34, however, the tissue temperature is allowed to drift downwardly with the heater “off” until the tissue temperature reaches a temperature T min  that is either programmed or pre-selected as a value in the controller  910  or the program control  912 . Upon reaching T min , the heater  902  is turned “on” again, as shown at t 2 , so as to provide heat to the selected treatment area so as to raise the tissue temperature to T tar . This first therapy cycle ends at t 2  when a second therapy cycle begins by turning “on” the heater again. As in the first therapy cycle, this second therapy cycle provides heat to the tissue to reach the tissue target temperature, T tar . Alternatively this second therapy cycle may have a different T tar , or optionally may have a different cycle length calling for the controller  910  to change the heater output. The present invention anticipates the use of any number of therapy cycles having any length or duration per cycle and different set temperatures, and a plurality of therapy cycles contributing to a therapeutic sequence. 
     For the above examples, T tar  may be programmed in the controller  910  or directly selected by an operator employing the manual entry logic  914 . For the present invention, this tissue target temperature is in a range preferably of about 360° C. to 38° C. Another aspect of therapy control according to the present invention is the averaging tissue target temperatures of duty cycles, therapy cycles and a therapeutic sequence, as depicted in FIG.  35 . 
     In FIG. 35, a therapy cycle  990  starts at t 0  and ends at t 0 . The tissue target temperature average T avg    992  for this therapy cycle may be selected or programmed. The tissue temperature change, as depicted by a temperature curve  994 , begins at a temperature T a , rises as it is heated by the heater to a peak temperature T b  during the “on” phase of the heater  902 , as depicted by a heater temperature curve, and then drifts downwardly to a minimum temperature T c  over an additional period of time such that the total period of time is equivalent to the period t 0  to t l . T avg    992  represents the average of the temperatures between T c  and T b , wherein each of the temperature T a  and T c , are within the normothermic range of 360° C. to 38° C. 
     An alternative approach, also depicted in FIG. 35, anticipates the programming of a number of therapy cycles as elements of a therapeutic sequence, in this example there being two therapy cycles  990  and  996  of varying times and tissue target temperatures. The present invention provides for the inputting of an average tissue target temperature T avg    998  between minimum and peak temperatures T a  and T c  for a therapeutic sequence extending from t 0  to t t . A tissue temperature response curve has not been shown for this example. 
     By way of example, and not limiting in scope of treatment versatility, FIG. 36 is a graphic representation of a therapy cycle  1000  represented by a plurality of duty cycles  1002 . At t 0 , the heater is at ambient temperature T amb  and the first of the duty cycles  1002  begins at t 0  when the heater  902  reaches T min . Upon reaching T peak  by t l , the heater power is turned off and the heater cools to T min . The first duty cycle is completed at t 3  when the heater is turned back on to begin the next duty cycle. This first duty cycle and subsequent duty cycles maintain an average heater temperature T set  as sensed by the temperature sensor  922  in FIG.  32 . The duty cycle can also be governed by the total duration t l , to t 3  and the ratio of heat on duration t l , to t 3  over total duration t l , to t 3 . A therapy cycle for this example is the time duration from t 0  to t t  during which time the heater temperature has been allowed to fall to T amb , where at t t  the heating regimen begins again starting the next therapy cycle. As shown in FIG. 39, a peak temperature, T peak  and a minimum temperature T min  may be parameters inputted into the program. An average temperature T set  may then be selected to operate between T min  and T peak  within a normothermic range of 36° C. to 38° C. 
     By way of another example, and not limiting in scope of treatment versatility, a plurality of therapy cycles  1004 ,  1005  and  1006  are depicted in FIG. 37, wherein individual duty cycles within each therapy cycle have been averaged out for purposes of clarification and for purposes herein are treated as the heater being “on”. A first therapy cycle begins at to as depicted by the heater turning “on”, i.e., a series of duty cycles is begun, and the heater heats to T set    1007 . This “on” segment goes until ti at which time the heater is turned “off” and allowed to cool to T amb . This first therapy cycle  1004  ends at t 2  when the second therapy cycle  1005  begins by turning “on” the heater  902  again. As in the first therapy cycle, this second therapy cycle heats to T set    1009  and has a duration from t 2  to t 3 . The third therapy cycle  1006  begins at t 3  turning “on” the heater  902 . For purposes of example to depict anticipated versatility of the present invention, this third therapy cycle is given a different T set    1008 . The heater  902  is turned “off” at t 4 . This entire period of multiple therapy cycles may also be part of a therapeutic sequence as that period of time from t 0  to t t  encompassing three therapy cycles. The present invention anticipates the use of any number of therapy cycles having any length or duration per cycle and different set temperatures, whether the temperatures be a set level or averaged. 
     Another aspect of heat therapy control is the averaging of a number of therapy cycles in a therapeutic sequence, as depicted in FIG.  38 . In FIG. 38 a therapy cycle  1010  starts at t 0  and ends at t l . The overall average heater temperature T avg  for this therapy cycle may be selected or programmed. The heater  902 , beginning at an ambient temperature T amb , heats to an appropriate temperature for the “on” phase and then is “off” for an additional appropriate time such that the total period of time is equivalent to the period t 0  to t l , and the average temperature for this period is equivalent to T avg    1012 . 
     An alternative approach, also depicted in FIG. 38, anticipates the selection or programming of a number of therapy cycles as elements of a therapeutic sequence, in this example there being three therapy cycles  1012 ,  1014  and  1016  of varying time and heater temperatures. The present invention versatility provides for the inputting of an average temperature T avg    1018  for the therapeutic sequence. The therapeutic sequence begins at time t 0  and ends at time t t . The heater temperatures and durations of the therapy cycles within the therapeutic sequence are averaged by the controller  910  over the entire period of time from t 0  to t t  so as to achieve the therapeutic average temperature T avg    1018 . Each of these average temperatures is preferably at a level to maintain an average tissue temperature of between 36° C. to 38° C. for implementing normothermic heat treatment during a series of duty cycles followed by a heater off period at the end of each therapy cycle. It should be understood, however, that the invention can be employed to maintain tissue temperature at any desired set temperature level or temperature average. 
     Clearly, other embodiments and modifications of this invention will occur readily to those of ordinary skill in the art in view of these teachings. Therefore, this invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings.