Recherche Images Maps Play YouTube Actualités Gmail Drive Plus »
Connexion
Les utilisateurs de lecteurs d'écran peuvent cliquer sur ce lien pour activer le mode d'accessibilité. Celui-ci propose les mêmes fonctionnalités principales, mais il est optimisé pour votre lecteur d'écran.

Brevets

  1. Recherche avancée dans les brevets
Numéro de publicationUS20050240250 A1
Type de publicationDemande
Numéro de demandeUS 11/159,656
Date de publication27 oct. 2005
Date de dépôt23 juin 2005
Date de priorité23 janv. 1998
Autre référence de publicationUS6558412, US7063718, US20010016764, US20030078641, US20030144714
Numéro de publication11159656, 159656, US 2005/0240250 A1, US 2005/240250 A1, US 20050240250 A1, US 20050240250A1, US 2005240250 A1, US 2005240250A1, US-A1-20050240250, US-A1-2005240250, US2005/0240250A1, US2005/240250A1, US20050240250 A1, US20050240250A1, US2005240250 A1, US2005240250A1
InventeursJohn Dobak
Cessionnaire d'origineDobak John D Iii
Exporter la citationBiBTeX, EndNote, RefMan
Liens externes: USPTO, Cession USPTO, Espacenet
Selective organ hypothermia method and apparatus
US 20050240250 A1
Résumé
A method and apparatus for performing hypothermia of a selected organ without significant effect on surrounding organs or other tissues. A flexible catheter is inserted through the vascular system of a patient to place the distal tip of the catheter in an artery feeding the selected organ. A compressed refrigerant is pumped through the catheter to an expansion element near the distal tip of the catheter, where the refrigerant vaporizes and expands to cool a flexible heat transfer element in the distal tip of the catheter. The heat transfer element cools the blood flowing through the artery, to cool the selected organ, distal to the tip of the catheter.
Images(4)
Previous page
Next page
Revendications(4)
1. A method for treating anoxic damage caused by a disruption of blood supply, comprising the acts of:
inducing hypothermia in the patient,
wherein hypothermia is induced by circulating a heat exchange fluid through a catheter positioned in the patient's central venous system.
2. The method according to claim 1, wherein a shape of the catheter transforms from an original shape to a shape having an enhanced heat transfer surface area upon circulation of the heat exchange fluid therethrough.
3. A method for treating anoxic damage caused by a disruption of blood supply to the brain, comprising the acts of:
inducing hypothermia in the patient,
wherein hypothermia is induced by circulating a heat exchange fluid through a catheter positioned in the patient's central venous system.
4. The method according to claim 3, wherein a shape of the catheter transforms from an original shape to a shape having an enhanced heat transfer surface area upon circulation of the heat exchange fluid therethrough.
Description
    CROSS REFERENCE TO RELATED APPLICATIONS
  • [0001]
    This application is a continuation application of co-pending U.S. application Ser. No. 10/324,476, filed Dec. 20, 2002, titled “Selective Organ Hypothermia Method And Apparatus,” which is a continuation application of U.S. application Ser. No. 09/834,054, filed Apr. 12, 2001, titled “Selective Organ Hypothermia Method and Apparatus,” now U.S. Pat. No. 6,558,412, which is a continuation of U.S. application Ser. No. 09/650,940, filed Aug. 30, 2000, titled “Selective Organ Hypothermia Method and Apparatus”, now U.S. Pat. No. 6,482,226, which is a continuation of U.S. application Ser. No. 09/306,866, filed May 7, 1999, titled “Selective Organ Hypothermia Method and Apparatus”, now U.S. Pat. No. 6,235,048, which is a divisional application of U.S. application Ser. No. 09/012,287, filed Jan. 23, 1998, titled “Selective Organ Hypothermia Method and Apparatus”, now U.S. Pat. No. 6,051,019.
  • STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
  • [0002]
    Not Applicable
  • BACKGROUND OF THE INVENTION
  • [0003]
    1. Field of the Invention
  • [0004]
    The current invention relates to selective cooling, or hypothermia, of an organ, such as the brain, by cooling the blood flowing into the organ. This cooling can protect the tissue from injury caused by anoxia or trauma.
  • [0005]
    2. Background Information
  • [0006]
    Organs of the human body, such as the brain, kidney, and heart, are maintained at a constant temperature of approximately 37° C. Cooling of organs below 35° C. is known to provide cellular protection from anoxic damage caused by a disruption of blood supply, or by trauma. Cooling can also reduce swelling associated with these injuries.
  • [0007]
    Hypothermia is currently utilized in medicine and is sometimes performed to protect the brain from injury. Cooling of the brain is generally accomplished through whole body cooling to create a condition of total body hypothermia in the range of 20° to 30° C. This cooling is accomplished by immersing the patient in ice, by using cooling blankets, or by cooling the blood flowing externally through a cardiopulmonary bypass machine. U.S. Pat. No. 3,425,419 to Dato and U.S. Pat. No. 5,486,208 to Ginsburg disclose catheters for cooling the blood to create total body hypothermia However, they rely on circulating a cold fluid to produce cooling. This is unsuitable for selective organ hypothermia, because cooling of the entire catheter by the cold fluid on its way to the organ would ultimately result in non-selective, or total body, cooling.
  • [0008]
    Total body hypothermia to provide organ protection has a number of drawbacks. First, it creates cardiovascular problems, such as cardiac arrhythmias, reduced cardiac output, and increased systemic vascular resistance. These side effects can result in organ damage. These side effects are believed to be caused reflexively in response to the reduction in core body temperature. Second, total body hypothermia is difficult to administer. Immersing a patient in ice water clearly has its associated problems. Placement on cardiopulmonary bypass requires surgical intervention and specialists to operate the machine, and it is associated with a number of complications including bleeding and volume overload. Third, the time required to reduce the body temperature and the organ temperature is prolonged. Minimizing the time between injury and the onset of cooling has been shown to produce better clinical outcomes.
  • [0009]
    Some physicians have immersed the patient's head in ice to provide brain cooling. There are also cooling helmets, or head gear, to perform the same. This approach suffers from the problems of slow cool down and poor temperature control due to the temperature gradient that must be established externally to internally. It has also been shown that complications associated with total body cooling, such as arrhythmia and decreased cardiac output, can also be caused by cooling of the face and head only.
  • [0010]
    Selective organ hypothermia has been studied by Schwartz, et. al. Utilizing baboons, blood was circulated and cooled externally from the body via the femoral artery and returned to the body through the carotid artery. This study showed that the brain could be selectively cooled to temperatures of 20° C. without reducing the temperature of the entire body. Subsequently, cardiovascular complications associated total body hypothermia did not occur. However, external circulation of the blood for cooling is not a practical approach for the treatment of humans. The risks of infection, bleeding, and fluid imbalance are great. Also, at least two arterial vessels must be punctured and cannulated. Further, percutaneous cannulation of the carotid artery is very difficult and potentially fatal, due to the associated arterial wall trauma. Also, this method could not be used to cool organs such as the kidneys, where the renal arteries cannot be directly cannulated percutaneously.
  • [0011]
    Selective organ hypothermia has also been attempted by perfusing the organ with a cold solution, such as saline or perflourocarbons. This is commonly done to protect the heart during heart surgery and is referred to as cardioplegia. This procedure has a number of drawbacks, including limited time of administration due to excessive volume accumulation, cost and inconvenience of maintaining the perfusate, and lack of effectiveness due to temperature dilution from the blood. Temperature dilution by the blood is a particular problem in high blood flow organs such as the brain. For cardioplegia, the blood flow to the heart is minimized, and therefore this effect is minimized.
  • [0012]
    Intravascular, selective organ hypothermia, created by cooling the blood flowing into the organ, is the ideal method. First, because only the target organ is cooled, complications associated with total body hypothermia are avoided. Second, because the blood is cooled intravascularly, or in situ, problems associated with external circulation of blood are eliminated. Third, only a single puncture and arterial vessel cannulation is required, and it can be performed at an easily accessible artery such as the femoral, subclavian, or brachial. Fourth, cold perfusate solutions are not required, thus eliminating problems with excessive fluid accumulation. This also eliminates the time, cost, and handling issues associated with providing and maintaining cold perfusate solution. Fifth, rapid cooling can be achieved. Sixth, precise temperature control is possible.
  • [0013]
    Previous inventors have disclosed the circulation of a cold fluid to produce total body hypothermia, by placing a probe into a major vessel of the body. This approach is entirely unfeasible when considering selective organ hypothermia, as will be demonstrated below.
  • [0014]
    The important factor related to catheter development for selective organ hypothermia is the small size of the typical feeding artery, and the need to prevent a significant reduction in blood flow when the catheter is placed in the artery. A significant reduction in blood flow would result in ischemic organ damage. While the diameter of the major vessels of the body, such as the vena cava and aorta, are as large as 15 to 20 mm., the diameter of the feeding artery of an organ is typically only 4.0 to 8.0 mm. Thus, a catheter residing in one of these arteries cannot be much larger than 2.0 to 3.0 mm. in outside diameter. It is not practical to construct a selective organ hypothermia catheter of this small size using the circulation of cold water or other fluid. Using the brain as an example, this point will be illustrated.
  • [0015]
    The brain typically has a blood flow rate of approximately 500 to 750 cc/min. Two carotid arteries feed this blood supply to the brain. The internal carotid is a small diameter artery that branches off of the common carotid near the angle of the jaw. To cool the brain, it is important to place some of the cooling portion of the catheter into the internal carotid artery, so as to minimize cooling of the face via the external carotid, since face cooling can result in complications, as discussed above. It would be desirable to cool the blood in this artery down to 32° C., to achieve the desired cooling of the brain. To cool the blood in this artery by a 5 C° drop, from 37° C. down to 32° C., requires between 100 and 150 watts of refrigeration power.
  • [0016]
    In order to reach the internal carotid artery from a femoral insertion point, an overall catheter length of approximately 100 cm. would be required. To avoid undue blockage of the blood flow, the outside diameter of the catheter can not exceed approximately 2 mm. Assuming a coaxial construction, this limitation in diameter would dictate an internal supply tube of about 0.70 mm. diameter, with return flow being between the internal tube and the external tube.
  • [0017]
    A catheter based on the circulation of water or saline operates on the principle of transferring heat from the blood to raise the temperature of the water. Rather than absorbing heat by boiling at a constant temperature like a freon, water must warm up to absorb heat and produce cooling. Water flowing at the rate of 5.0 grams/sec, at an initial temperature of 0° C. and warming up to 5° C., can absorb 100 watts of heat. Thus, the outer surface of the heat transfer element could only be maintained at 5° C., instead of 0° C. This will require the heat transfer element to have a surface area of approximately 1225 mm2. If a catheter of approximately 2.0 mm. diameter is assumed, the length of the heat transfer element would have to be approximately 20 cm.
  • [0018]
    In actuality, because of the overall length of the catheter, the water would undoubtedly warm up before it reached the heat transfer element, and provision of 0° C. water at the heat transfer element would be impossible. Circulating a cold liquid would cause cooling along the catheter body and could result in non-specific or total body hypothermia. Furthermore, to achieve this heat transfer rate, 5 grams/sec of water flow are required. To circulate water through a 100 cm. long, 0.70 mm. diameter supply tube at this rate produces a pressure drop of more than 3000 psi. This pressure exceeds the safety levels of many flexible medical grade plastic catheters. Further, it is doubtful whether a water pump that can generate these pressures and flow rates can be placed in an operating room.
  • BRIEF SUMMARY OF THE INVENTION
  • [0019]
    The selective organ cooling achieved by the present invention is accomplished by placing a cooling catheter into the feeding artery of the organ. The cooling catheter is based on the vaporization and expansion of a compressed and condensed refrigerant, such as freon. In the catheter, a shaft or body section would carry the liquid refrigerant to a distal heat transfer element where vaporization, expansion, and cooling would occur. Cooling of the catheter tip to temperatures above minus 2° C. results in cooling of the blood flowing into the organ located distally of the catheter tip, and subsequent cooling of the target organ. For example, the catheter could be placed into the internal carotid artery, to cool the brain. The size and location of this artery places significant demands on the size and flexibility of the catheter. Specifically, the outside diameter of the catheter must be minimized, so that the catheter can fit into the artery without compromising blood flow. An appropriate catheter for this application would have a flexible body of 70 to 100 cm. in length and 2.0 to 3.0 mm. in outside diameter.
  • [0020]
    It is important for the catheter to be flexible in order to successfully navigate the arterial path, and this is especially true of the distal end of the catheter. So, the distal end of the catheter must have a flexible heat transfer element, which is composed of a material which conducts heat better than the remainder of the catheter. The catheter body material could be nylon or PBAX, and the heat transfer element could be made from nitinol, which would have approximately 70 to 100 times the thermal conductivity of the catheter body material, and which is also superelastic. Nitinol could also be treated to undergo a transition to another shape, such as a coil, once it is placed in the proper artery. Certain tip shapes could improve heat transfer as well as allow the long tip to reside in arteries of shorter length.
  • [0021]
    The heat transfer element would require sufficient surface area to absorb 100 to 150 watts of heat. This could be accomplished with a 2 mm. diameter heat transfer tube, 15 to 18 cm. in length, with a surface temperature of 0° C. Fins can be added to increase the surface area, or to maintain the desired surface area while shortening the length.
  • [0022]
    The cooling would be provided by the vaporization and expansion of a liquid refrigerant, such as a freon, across an expansion element, such as a capillary tube. For example, freon R12 boiling at 1 atmosphere and a flow rate of between 0.11 and 0.18 liter/sec could provide between approximately 100 and 150 watts of refrigeration power. Utilizing a liquid refrigerant allows the cooling to be focused at the heat transfer element, thereby eliminating cooling along the catheter body. Utilizing boiling heat transfer to the expanded fluid also lowers the fluid flow rate requirement to remove the necessary amount of heat from the blood. This is important because the required small diameter of the catheter would have higher pressure drops at higher flow rates.
  • [0023]
    The catheter would be built in a coaxial construction with a 0.70 mm. inner supply tube diameter and a 2.0 mm. outer return tube diameter. This limits the pressure drops of the freon along the catheter length, as well as minimizing the catheter size to facilitate carotid placement. The inner tube would carry the liquid freon to the tubular heat transfer element at the distal end of the catheter body. If a heat transfer element surface temperature of 0° C. is maintained, just above the freezing point of blood, then 940 mm2 of surface area in contact with the blood are required to lower the temperature of the blood by the specified 5 C° drop. This translates to a 2.0 mm. diameter heat transfer tube by 15 cm. in length. To generate 0° C. on the nitinol surface, the freon must boil at a temperature of minus 28° C. It is important to have boiling heat transfer, which has a higher heat transfer coefficient, to maintain the surface temperature at 0° C. There are several freons that can be controlled to boil at minus 28° C., such as a 50/50 mixture of pentafluoroethane and 1,1,1 trifluoroethane or a 50/50 mixture of difluoromethane and pentafluoroethane. The 50/50 mixture of pentafluoroethane and 1,1,1 trifluoroethane would require a flow rate of approximately 7.0 liters/min or 0.52 gram/sec to absorb 100 watts of heat. At this flow rate, the pressure drop along the inner tube is less than 7 psi in 100 cm. of length, and the pressure drop along the outer tube is less than 21 psi in 100 cm. of length.
  • [0024]
    The inner supply tube of the catheter would be connected to a condenser, fed by the high pressure side of a compressor, and the outer return tube of the catheter would be connected to the low pressure side of the compressor.
  • [0025]
    The novel features of this invention, as well as the invention itself, will be best understood from the attached drawings, taken along with the following description, in which similar reference characters refer to similar parts, and in which:
  • BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
  • [0026]
    FIG. 1 is a schematic, partially in section, showing a first embodiment of the flexible catheter according to the present invention;
  • [0027]
    FIG. 2 is a perspective view of a second embodiment of the distal tip of the catheter of the present invention, after transformation;
  • [0028]
    FIG. 3 is a section view of a third embodiment of the distal tip of the catheter of the present invention, after expansion of the heat transfer element;
  • [0029]
    FIG. 4 is a partial section view of a fourth embodiment of the distal tip of the catheter of the present invention, after transformation;
  • [0030]
    FIG. 5 is an elevation view of a fifth embodiment of the distal tip of the catheter of the present invention, before transformation;
  • [0031]
    FIG. 6 is an elevation view of the embodiment shown in FIG. 5, after transformation to a double helix;
  • [0032]
    FIG. 7 is an elevation view of the embodiment shown in FIG. 5, after transformation to a looped coil;
  • [0033]
    FIG. 8 is an elevation view of a sixth embodiment of the distal tip of the catheter of the present invention, showing longitudinal fins on the heat transfer element;
  • [0034]
    FIG. 9 is an end view of the embodiment shown in FIG. 8;
  • [0035]
    FIG. 10 is an elevation view of a seventh embodiment of the distal tip of the catheter of the present invention, showing annular fins on the heat transfer element; and
  • [0036]
    FIG. 11 is an end view of the embodiment shown in FIG. 10.
  • DETAILED DESCRIPTION OF THE INVENTION
  • [0037]
    As shown in FIG. 1, the apparatus of the present invention includes a flexible catheter assembly 10, fed by a refrigeration compressor unit 12, which can include a condenser. The compressor unit 12 has an outlet 14 and an inlet 16. The catheter assembly 10 has an outer flexible catheter body 18, which can be made of braided PBAX or other suitable catheter material. The catheter body 18 must be flexible, to enable passage through the vascular system of the patient to the feeding artery of the selected organ. The inner lumen 19 of the catheter body 18 serves as the return flow path for the expanded refrigerant. The catheter assembly 10 also has an inner flexible refrigerant supply conduit 20, which can be made of nylon, polyimide, nitinol, or other suitable catheter material. The length and diameter of the catheter body 18 and refrigerant supply conduit 20 are designed for the size and location of the artery in which the apparatus will be used. For use in the internal carotid artery to achieve hypothermia of the brain, the catheter body 18 and refrigerant supply conduit 20 will have a length of approximately 70 to 100 centimeters. The catheter body 18 for this application will have an outside diameter of approximately 2.5 millimeters and an inside diameter of approximately 2.0 millimeters, and the refrigerant supply conduit will have an outside diameter of approximately 1.0 millimeter and an inside diameter of approximately 0.75 millimeter. A supply conduit 20 of this diameter will have a refrigerant pressure drop of only approximately 0.042 atmospheres per 100 centimeters. The return flow path through a catheter body 18 of this diameter will have a refrigerant pressure drop of only approximately 0.064 atmospheres per 100 centimeters.
  • [0038]
    The compressor outlet 14 is attached in fluid flow communication, by known means, to a proximal end of the refrigerant supply conduit 20 disposed coaxially within said catheter body 18. The distal end of the refrigerant supply conduit 20 is attached to an expansion element, which in this embodiment is a capillary tube 22 having a lenght of approximately 15 to 25 centimeters. The capillary tube 22 can be made of polyimide or nitinol, or other suitable material, and it can be a separate element attached to the supply conduit 20, or it can be an integral portion of the supply conduit 20. For the internal carotid artery application, the capillary tube 22 will have an outside diameter of approximately 0.6 millimeter and an inside diameter of approximately 0.25 millimeter. The expansion element, such as the capillary tube 22, has an outlet within a chamber of a flexible heat transfer element such as the hollow flexible tube 24. The tube 24 shown in this embodiment is flexible but essentially straight in its unflexed state. The heat transfer element must be flexible, to enable passage through the vascular system of the patient to the feeding artery of the selected organ. For the internal carotid application the flexible tube 24 will have a length of approximately 15 centimeters, an outside diameter of approximately 1.9 millimeters and an inside diameter of approximately 1.5 millimeters. The heat transfer element also includes a plug 26 in the distal end of the flexible tube 24. The plug 26 can be epoxy potting material, plastic, or a metal such as stainless steel or gold. A tapered transition of epoxy potting material can be provided between the catheter body 18 and the flexible tube 24.
  • [0039]
    A refrigerant, such as freon, is compressed, condensed, and pumped through the refrigerant supply conduit 20 to the expansion element, or capillary tube, 22. The refrigerant vaporizes and expands into the interior chamber of the heat transfer element, such as the flexible tube 24, thereby cooling the heat transfer element 24. Blood in the feeding artery flows around the heat transfer element 24, thereby being cooled. The blood then continues to flow distally into the selected organ, thereby cooling the organ.
  • [0040]
    A second embodiment of the heat transfer element is shown in FIG. 2. This embodiment can be constructed of a tubular material such as nitinol, which has a temperature dependent shape memory. The heat transfer element 28 can be originally shaped like the flexible tube 24 shown in FIG. 1, at room temperature, but trained to take on the coiled tubular shape shown in FIG. 2 at a lower temperature. This allows easier insertion of the catheter assembly 10 through the vascular system of the patient, with the essentially straight but flexible tubular shape, similar to the flexible tube 24. Then, when the heat transfer element is at the desired location in the feeding artery, such as the internal carotid artery, refrigerant flow is commenced. As the expanding refrigerant, such as a 50/50 mixture of pentafluoroethane and 1,1,1 trifluoroethane or a 50/50 mixture of difluoromethane and pentafluoroethane, cools the heat transfer element down, the heat transfer element takes on the shape of the heat transfer coil 28 shown in FIG. 2. This enhances the heat transfer capacity, while limiting the length of the heat transfer element.
  • [0041]
    A third embodiment of the expansion element and the heat transfer element is shown in FIG. 3. This embodiment of the expansion element is an orifice 30, shown at the distal end of the refrigerant supply conduit 20. The outlet of the orifice 30 discharges into an expansion chamber 32. In this embodiment, the heat transfer element is a plurality of hollow tubes 34 leading from the expansion chamber 32 to the refrigerant return lumen 19 of the catheter body 18. This embodiment of the heat transfer element 34 can be constructed of a tubular material such as nitinol, which has a temperature dependent shape memory, or some other tubular material having a permanent bias toward a curved shape. The heat transfer element tubes 34 can be essentially straight, originally, at room temperature, but trained to take on the outwardly flexed “basket” shape shown in FIG. 3 at a lower temperature. This allows easier insertion of the catheter assembly 10 through the vascular system of the patient, with the essentially straight but flexible tubes. Then, when the heat transfer element 34 is at the desired location in the feeding artery, such as the internal carotid artery, refrigerant flow is commenced. As the expanding refrigerant cools the heat transfer element 34 down, the heat transfer element takes on the basket shape shown in FIG. 3. This enhances the heat transfer capacity, while limiting the length of the heat transfer element.
  • [0042]
    A fourth embodiment of the heat transfer element is shown in FIG. 4. This embodiment can be constructed of a material such as nitinol. The heat transfer element 36 can be originally shaped as a long loop extending from the distal end of the catheter body 18, at room temperature, but trained to take on the coiled tubular shape shown in FIG. 4 at a lower temperature, with the heat transfer element 36 coiled around the capillary tube 22. This allows easier insertion of the catheter assembly 10 through the vascular system of the patient, with the essentially straight but flexible tubular loop shape. Then, when the heat transfer element 36 is at the desired location in the feeding artery, such as the internal carotid artery, refrigerant flow is commenced. As the expanding refrigerant cools the heat transfer element down, the heat transfer element takes on the shape of the coil 36 shown in FIG. 4. This enhances the heat transfer capacity, while limiting the length of the heat transfer element 36. FIG. 4 further illustrates that a thermocouple 38 can be incorporated into the catheter body 18 for temperature sensing purposes.
  • [0043]
    Yet a fifth embodiment of the heat transfer element is shown in FIGS. 5, 6, and 7. In this embodiment, an expansion element, such as a capillary tube or orifice, is incorporated within the distal end of the catheter body 18. This embodiment of the heat transfer element can be constructed of a material such as nitinol. The heat transfer element is originally shaped as a long loop 40 extending from the distal end of the catheter body 18, at room temperature. The long loop 40 has two sides 42, 44, which are substantially straight but flexible at room temperature. The sides 42, 44 of the long loop 40 can be trained to take on the double helical shape shown in FIG. 6 at a lower temperature, with the two sides 42, 44 of the heat transfer element 40 coiled around each other. Alternatively, the sides 42, 44 of the long loop 40 can be trained to take on the looped coil shape shown in FIG. 7 at a lower temperature, with each of the two sides 42, 44 of the heat transfer element 40 coiled independently. Either of these shapes allows easy insertion of the catheter assembly 10 through the vascular system of the patient, with the essentially straight but flexible tubular loop shape. Then, when the heat transfer element 40 is at the desired location in the feeding artery, such as the internal carotid artery, refrigerant flow is commenced. As the expanding refrigerant cools the heat transfer element down, the heat transfer element 40 takes on the double helical shape shown in FIG. 6 or the looped coil shape shown in FIG. 7. Both of these configurations enhance the heat transfer capacity, while limiting the length of the heat transfer element 40.
  • [0044]
    As shown in FIGS. 8 through 11, the heat transfer element 24 can have external fins 46, 48 attached thereto, such as by welding or brazing, to promote heat transfer. Use of such fins allows the use of a shorter heat transfer element without reducing the heat transfer surface area, or increases the heat transfer surface area for a given length. In FIGS. 8 and 9, a plurality of longitudinal fins 46 are attached to the heat transfer element 24. The heat transfer element 24 in such an embodiment can have a diameter of approximately 1.0 millimeter, while each of the fins 46 can have a width of approximately 0.5 millimeter and a thickness of approximately 0.12 millimeter. This will give the heat transfer element an overall diameter of approximately 2.0 millimeters, still allowing the catheter to be inserted into the internal carotid artery.
  • [0045]
    In FIGS. 10 and 11, a plurality of annular fins 48 are attached to the heat transfer element 24. The heat transfer element 24 in such an embodiment can have a diameter of approximately 1.0 millimeter, while each of the fins 48 can have a width of approximately 0.5 millimeter and a thickness of approximately 0.12 millimeter. This will give the heat transfer element an overall diameter of approximately 2.0 millimeters, still allowing the catheter to be inserted into the internal carotid artery.
  • [0046]
    While the particular invention as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages hereinbefore stated, it is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims.
Citations de brevets
Brevet cité Date de dépôt Date de publication Déposant Titre
US2308484 *16 janv. 193919 janv. 1943Davol Rubber CoCatheter
US2374609 *5 sept. 194224 avr. 1945 Heating apparatus
US2672032 *19 oct. 195116 mars 1954Edward Towse Robert AlbertCarcass freezing device
US3125096 *7 juil. 196117 mars 1964 Compressor
US3298371 *11 févr. 196517 janv. 1967Arnold S J LeeFreezing probe for the treatment of tissue, especially in neurosurgery
US3425419 *2 juil. 19654 févr. 1969Angelo Actis DatoMethod of lowering and raising the temperature of the human body
US3504674 *22 déc. 19667 avr. 1970Emil S SwensonMethod and apparatus for performing hypothermia
US3865116 *9 avr. 197311 févr. 1975Brooks Harold WMethod of controlling tissue hypothermia
US3888259 *21 août 197310 juin 1975Miley Robert CHypothermia system
US4153048 *14 sept. 19778 mai 1979Cleveland Clinic FoundationThermodilution catheter and method
US4190033 *21 juil. 197826 févr. 1980Foti Thomas MClosed flow caloric test method
US4275734 *12 août 197730 juin 1981Valleylab, Inc.Cryosurgical apparatus and method
US4318722 *9 avr. 19809 mars 1982Gerald AltmanInfrared radiation cooler for producing physiologic conditions such as a comfort or hypothermia
US4323071 *19 mai 19806 avr. 1982Advanced Catheter Systems, Inc.Vascular guiding catheter assembly and vascular dilating catheter assembly and a combination thereof and methods of making the same
US4427009 *30 juin 198124 janv. 1984Minnesota Mining And Manufacturing CompanyIntegrated cardioplegia delivery system
US4445500 *30 sept. 19821 mai 1984Thomas Jefferson UniversityStroke treatment utilizing extravascular circulation of oxygenated synthetic nutrients to treat tissue hypoxic and ischemic disorders
US4497890 *8 avr. 19835 févr. 1985Motorola, Inc.Process for improving adhesion of resist to gold
US4502286 *4 août 19835 mars 1985Hitachi, Ltd.Constant pressure type boiling cooling system
US4569355 *28 mai 198211 févr. 1986Hemodynamics Technology, Inc.Method and apparatus for monitoring and diagnosing peripheral blood flow
US4581017 *7 mars 19838 avr. 1986Harvinder SahotaCatheter systems
US4646735 *4 oct. 19853 mars 1987Seney John SPain-alleviating tissue treatment assembly
US4655746 *2 déc. 19857 avr. 1987Target TherapeuticsCatheter device
US4672962 *7 oct. 198516 juin 1987Cordis CorporationPlaque softening method
US4745922 *11 juil. 198624 mai 1988Taylor Kenneth GCervical heat transfer and immobilization device
US4748979 *13 avr. 19877 juin 1988Cordis CorporationPlaque resolving device
US4750493 *28 févr. 198614 juin 1988Brader Eric WMethod of preventing brain damage during cardiac arrest, CPR or severe shock
US4820349 *21 août 198711 avr. 1989C. R. Bard, Inc.Dilatation catheter with collapsible outer diameter
US4894164 *27 oct. 198716 janv. 1990Fresenius AgApparatus for treating blood in an extracorporeal circuit
US4904237 *16 mai 198827 févr. 1990Janese Woodrow WApparatus for the exchange of cerebrospinal fluid and a method of treating brain and spinal cord injuries
US4920963 *4 avr. 19881 mai 1990Brader Eric WApparatus for preventing brain damage during cardiac arrest, CPR or severe shock
US5000734 *26 janv. 198919 mars 1991Georges BoussignacProbe intended to be introduced within a living body
US5002531 *6 juin 198726 mars 1991Tassilo BonzelDilation catheter with an inflatable balloon
US5014695 *25 oct. 198914 mai 1991Benak Arnold MKidney cooling jacket
US5018521 *8 nov. 198828 mai 1991Campbell William PMethod of and apparatus for increased transfer of heat into or out of the body
US5019075 *31 juil. 199028 mai 1991The Beth Israel HospitalMethod and apparatus for angioplasty
US5024668 *20 janv. 198718 juin 1991Rocky Mountain Research, Inc.Retrograde perfusion system, components and method
US5078713 *30 nov. 19897 janv. 1992Spembly Medical LimitedCryosurgical probe
US5089260 *11 mai 199018 févr. 1992Emory UniversityMethod of treating ischemic tissue
US5092841 *17 mai 19903 mars 1992Wayne State UniversityMethod for treating an arterial wall injured during angioplasty
US5106360 *11 févr. 199121 avr. 1992Olympus Optical Co., Ltd.Thermotherapeutic apparatus
US5108390 *14 nov. 198828 avr. 1992Frigitronics, Inc.Flexible cryoprobe
US5110721 *10 févr. 19895 mai 1992The Research Foundation Of State University Of New YorkMethod for hypothermic organ protection during organ retrieval
US5112438 *29 nov. 199012 mai 1992Hughes Aircraft CompanyPhotolithographic method for making helices for traveling wave tubes and other cylindrical objects
US5117822 *5 avr. 19912 juin 1992Laghi Aldo ASilicone heart spoon
US5180364 *3 juil. 199119 janv. 1993Robert GinsburgValved self-perfusing catheter guide
US5190539 *10 juil. 19902 mars 1993Texas A & M University SystemMicro-heat-pipe catheter
US5191883 *22 mai 19909 mars 1993Prutech Research And Development Partnership IiDevice for heating tissue in a patient's body
US5196024 *3 juil. 199023 mars 1993Cedars-Sinai Medical CenterBalloon catheter with cutting edge
US5211631 *24 juil. 199118 mai 1993Sheaff Charles MPatient warming apparatus
US5281213 *16 avr. 199225 janv. 1994Implemed, Inc.Catheter for ice mapping and ablation
US5281215 *15 juin 199225 janv. 1994Implemed, Inc.Cryogenic catheter
US5306261 *22 janv. 199326 avr. 1994Misonix, Inc.Catheter with collapsible wire guide
US5310440 *2 avr. 199210 mai 1994International Business Machines CorporationConvection transfer system
US5322515 *15 mars 199321 juin 1994Abbott LaboratoriesLuer adapter assembly for emergency syringe
US5322518 *24 avr. 199221 juin 1994B. Braun Melsungen AgValve device for a catheter
US5383854 *19 août 199224 janv. 1995University Of Pittsburgh Of The Commonwealth System Of Higher EducationPortable and modular cardiopulmonary bypass apparatus and associated aortic balloon catheter and associated method
US5383918 *31 août 199224 janv. 1995Panetta; Thomas F.Hypothermia reducing body exclosure
US5395314 *1 juin 19937 mars 1995Life Resuscitation Technologies, Inc.Brain resuscitation and organ preservation device and method for performing the same
US5395331 *23 févr. 19937 mars 1995Minnesota Mining And Manufacturing CompanyRetrograde coronary sinus catheter having a ribbed balloon
US5403281 *25 sept. 19924 avr. 1995Minnesota Mining And Manufacturing CompanyInline heat exchanger and cardioplegia system
US5417686 *21 déc. 199223 mai 1995The Texas A&M University SystemTemperature control mechanisms for a micro heat pipe catheter
US5423745 *6 juil. 199413 juin 1995Research Medical, Inc.Irregular surface balloon catheters for body passageways and methods of use
US5423807 *24 janv. 199413 juin 1995Implemed, Inc.Cryogenic mapping and ablation catheter
US5486204 *20 sept. 199423 janv. 1996University Of Texas Health Science Center HoustonMethod of treating a non-penetrating head wound with hypothermia
US5486208 *18 oct. 199423 janv. 1996Ginsburg; RobertMethod and apparatus for controlling a patient's body temperature by in situ blood temperature modification
US5496271 *16 juin 19935 mars 1996American Medical Systems, Inc.Combined hyperthermia and dilation catheter
US5591162 *21 mars 19947 janv. 1997The Texas A&M University SystemTreatment method using a micro heat pipe catheter
US5620480 *20 sept. 199415 avr. 1997Urologix, Inc.Method for treating benign prostatic hyperplasia with thermal therapy
US5622182 *27 juin 199422 avr. 1997Jaffe; Richard A.System for measuring core body temperature in vivo
US5624392 *8 août 199429 avr. 1997Saab; Mark A.Heat transfer catheters and methods of making and using same
US5630837 *31 mars 199520 mai 1997Boston Scientific CorporationAcoustic ablation
US5709654 *7 juin 199520 janv. 1998Life Resuscitation Technologies, Inc.Apparatus for cooling living tissue
US5713941 *27 avr. 19933 févr. 1998Cancer Research InstituteApparatus for inducing whole body hyperthermia and method for treatment utilizing said whole body hyperthermia inducing apparatus
US5716386 *8 févr. 199610 févr. 1998The Ohio State UniversityNon-invasive aortic impingement and core and cerebral temperature manipulation
US5733318 *2 août 199631 mars 1998Augustine Medical, Inc.Convertible thermal blanket
US5735809 *5 déc. 19967 avr. 1998Matria Healthcare, Inc.Fiber assembly for in vivo plasma separation
US5861021 *20 déc. 199619 janv. 1999Urologix IncMicrowave thermal therapy of cardiac tissue
US5868735 *6 mars 19979 févr. 1999Scimed Life Systems, Inc.Cryoplasty device and method
US5871526 *13 oct. 199316 févr. 1999Gibbs; RosellePortable temperature control system
US5873835 *13 sept. 199523 févr. 1999Scimed Life Systems, Inc.Intravascular pressure and flow sensor
US5879316 *10 avr. 19979 mars 1999University Of Pittsburgh Of The Commonwealth System Of Higher EducationPortable and modular cardiopulmonary bypass apparatus and associated aortic balloon catheter and associated method
US5879329 *22 janv. 19979 mars 1999Radiant Medical, Inc.Infusion systems and methods for introducing fluids into the body within a desired temperature range
US5899898 *27 févr. 19974 mai 1999Cryocath Technologies Inc.Cryosurgical linear ablation
US5899899 *11 juil. 19974 mai 1999Cryocath Technologies Inc.Cryosurgical linear ablation structure
US5902268 *26 mai 199511 mai 1999Saab; Mark A.Heat transfer catheter apparatus and method of making and using same
US5906588 *11 août 199725 mai 1999Cardeon CorporationPortable and modular cardiopulmonary bypass apparatus and associated aortic balloon and associated method
US5906594 *8 janv. 199725 mai 1999Symbiosis CorporationEndoscopic infusion needle having dual distal stops
US5906636 *19 sept. 199725 mai 1999Texas Heart InstituteHeat treatment of inflamed tissue
US5910783 *2 juin 19978 juin 1999Intel CorporationPseudo barrel shifting for entropy encoding
US6019783 *2 mars 19991 févr. 2000Alsius CorporationCooling system for therapeutic catheter
US6022336 *6 mars 19978 févr. 2000Percusurge, Inc.Catheter system for emboli containment
US6024740 *8 juil. 199715 févr. 2000The Regents Of The University Of CaliforniaCircumferential ablation device assembly
US6033383 *19 déc. 19967 mars 2000Ginsburg; RobertTemperature regulating catheter and methods
US6042559 *24 févr. 199828 mars 2000Innercool Therapies, Inc.Insulated catheter for selective organ perfusion
US6051019 *23 janv. 199818 avr. 2000Del Mar Medical Technologies, Inc.Selective organ hypothermia method and apparatus
US6235048 *7 mai 199922 mai 2001Innercool Therapies, Inc.Selective organ hypothermia method and apparatus
US6354099 *11 avr. 200012 mars 2002Augustine Medical, Inc.Cooling devices with high-efficiency cooling features
US20020029073 *26 janv. 20017 mars 2002Schwartz Arthur E.Intravascular systems for corporeal cooling
US20020045852 *7 déc. 200118 avr. 2002Saab Mark A.Method for changing the temperature of a selected body region
Référencé par
Brevet citant Date de dépôt Date de publication Déposant Titre
US852961224 juin 200910 sept. 2013Mayo Foundation For Medical Education And ResearchGastroduodenal balloon tubes and methods for use in localized hypothermia
US919251018 août 201124 nov. 2015Mayo Foundation For Medical Education And ResearchLocalized hypothermia to treat weight disorders
US971762621 août 20131 août 2017Mayo Foundation For Medical Education And ResearchGastroduodenal balloon tubes and methods for use in localized hypothermia
US20100030190 *24 juin 20094 févr. 2010Singh Vijay PGastroduodenal balloon tubes and methods for use in localized hypothermia
Classifications
Classification aux États-Unis607/105, 607/113
Classification internationaleA61B17/00, A61F7/12, A61B18/02, A61F7/00
Classification coopérativeA61F2007/126, A61F2007/0056, A61F7/12
Classification européenneA61B18/02
Événements juridiques
DateCodeÉvénementDescription
31 août 2007ASAssignment
Owner name: INNERCOOL THERAPIES, INC., A DELAWARE CORPORATION,
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INNERCOOL THERAPIES, INC., A CALIFORNIA CORPORATION;REEL/FRAME:019781/0492
Effective date: 20060308
16 nov. 2007ASAssignment
Owner name: LIFE SCIENCES CAPITAL, LLC, NEW YORK
Free format text: SECURITY AGREEMENT;ASSIGNOR:INNERCOOL THERAPIES, INC.;REEL/FRAME:020125/0289
Effective date: 20071112
15 juil. 2008ASAssignment
Owner name: INNERCOOL THERAPIES, INC., CALIFORNIA
Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:LIFE SCIENCES CAPITAL, LLC;REEL/FRAME:021230/0753
Effective date: 20080701
5 nov. 2008ASAssignment
Owner name: MARVIN, ROBERT, MINNESOTA
Free format text: SECURITY AGREEMENT;ASSIGNOR:INNERCOOL THERAPIES, INC.;REEL/FRAME:021794/0394
Effective date: 20081105
9 mars 2009ASAssignment
Owner name: MARSHALL, ROBERT, TEXAS
Free format text: SECURITY AGREEMENT;ASSIGNOR:INNERCOOL THERAPIES, INC.;REEL/FRAME:022380/0013
Effective date: 20090227
13 oct. 2014ASAssignment
Owner name: PHILIPS ELECTRONICS NORTH AMERICA CORPORATION, MAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INNERCOOL THERAPIES, INC.;REEL/FRAME:033975/0849
Effective date: 20090722