US20060030915A1 - Method and apparatus for reducing body temperature of a subject - Google Patents

Abstract

A cooling system includes a pressurized liquid refrigerant source having a liquid refrigerant and a cooling garment coupled to the liquid refrigerant source. The cooling garment defines chambers containing a heat transfer fluid. During operation, a user places the cooling garment in thermal communication with a body portion of a subject. As the cooling garment receives the liquid refrigerant from the pressurized source, the liquid refrigerant thermally contacts the heat transfer fluid and evaporates, thereby reducing the temperature of the heat transfer fluid. The heat transfer fluid, in turn, reduces the temperature of the body portion in thermal communication with the cooling garment. The heat transfer fluid acts to substantially evenly distribute cooling, as provided by the evaporation of the liquid refrigerant, to the body portion contacting the cooling garment to minimize localized “cold spots” within the chamber.

Description

RELATED APPLICATIONS
• This application is a continuation of U.S. Utility application Ser. No. 10/903,469 which claims benefit of U.S. Provisional Application Ser. No. 60/492,368 filed Aug. 4, 2003, the entire teachings of which are incorporated herein by reference.
BACKGROUND
• Those working in a hot environment are subject to discomfort, heat exhaustion or heat stroke. Discomfort due to heat greatly reduces worker productivity. Heat exhaustion precludes a continuation of work, and requires immediate medical attention. Heat stroke is often lethal. Workers that wear protective garments in a hot environment are particularly vulnerable to discomfort, heat exhaustion, and heat stroke.
• Soldiers are required to where a chemical protection suite if a threat of chemical or biological attack is present. In a hot environment, such as the desert during summer, wearing a chemical protection suit is very uncomfortable, and can quickly lead to heat exhaustion. Firefighters, wearing fire protection suits are also subject to discomfort and heat exhaustion. Many foundry and construction workers also are required to wear protective suites and work in hot environments.
• Induction of systemic hypothermia (e.g., a hypothermic state) in a patient may minimize ischemic injury when the patient suffers from a stroke, cardiac arrest, heart attack, trauma, surgery, or other injury or insult to the body resulting in ischemia. For example, in the case where the patient suffers a heart attack, the effectiveness of hypothermia is a function of the depth (e.g., within a temperature range between approximately 30° C. and 35° C. for example) and duration of the hypothermic state as applied to the heart. The effectiveness of the hypothermia is also a function of the amount of time that elapses between the original insult (e.g., heart attack) and achievement of protective levels of hypothermia. Also, for trauma and stroke patients, hypothermia aids in controlling swelling of the patient's brain. Furthermore, surgeons typically use hypothermia during brain and other invasive surgeries to protect the brain from surgical interruptions in blood flow.
• It has long been known that hypothermia (body temperature lower than normal) is neuroprotective. Hypothermia has a positive affect on all known mechanisms that lead to secondary brain injury. Hypothermia is routinely used during brain and other invasive surgeries to protect the brain from surgical interruptions in blood flow. Hypothermia has also been shown to be effective in controlling swelling of the brain in trauma and stroke patients.
• Systemic hypothermia has historically been applied, such as by immersion of the patient's body in a cool bath, where the depth and duration of hypothermia is limited by the patient's ability to tolerate the therapy. Currently, there are several conventional systemic hypothermia systems available. Such conventional systems include blankets or pads where cooled water is circulated through channels in the walls of the blanket or pad and the patient's body contacts the walls of the blanket.
• Attempts have been also made to induce hypothermia in a patient by local cooling the surface of the patient's head. For example, Huyghens et al. (Resuscitation 51 (2001) 275-281) demonstrated that it is feasible to remove a sufficient amount of heat through the scalp to induce hypothermia in an adult using a simple cooling cap.
• In another example, a conventional head-cooling device involves a head cap with a gel substance contained within the walls of the cap. Prior to use, for example, a user (e.g., medical technician) places the head-cooling device in a freezer to reduce the temperature of the gel within the cap. During operation, the user fits the reduced-temperature cap to the head of a patient. The gel within the walls of the cap absorbs heat from the head, thereby cooling the head of the patient.
• Other conventional devices induce systemic hypothermia in a patient by providing contact between a tissue region of interest and a cooling fluid. For example, one conventional device includes a flexible hood having multiple ribs or studs disposed on the inner surface of the hood. When a user places the hood on a head of a patient, the ribs or studs contact the head and maintain a fluid circulation space between the head and the hood and an edge, defined by the hood, contacts the patient's skin. A negative pressure source draws a cooling fluid through the flexible hood, under negative pressure, to cause the fluid to contact the scalp of the patient and draw heat away from (e.g., cool) the scalp.
• Furthermore, application of the negative pressure seals the edges of the hood against the skin of the patient (e.g., a region substantially free of hair).
• Additionally, intravascular catheter based systems directly cool the blood of the patient with an indwelling heat exchanger mounted on the end of a catheter that resides in the central venous system during use.
SUMMARY
• Conventional techniques for providing cooling a patient or providing systemic hypothermia to a patient suffer from a variety of deficiencies.
• As indicated above, systemic hypothermia reduces ischemic injury from stroke, cardiac arrest, heart attack, trauma, and surgery. However, there are several drawbacks to the approaches described above. For example, application of systemic hypothermia can take several hours to lower a patient's body to therapeutic temperatures. Such a time period delays achieving therapeutic temperatures within the patient and, therefore, allows the progression of irreversible injury to the brain or heart. In another drawback to known systemic hypothermia systems, systemic hypothermia cannot be initiated until after the patient has been admitted to the hospital.
• As indicated above, attempts have been made to induce systemic hypothermia by using head-cooling devices to cool the surface of the head, such as a head cap with a gel substance contained within the walls of the cap. For example, during operation, the user fits the reduced-temperature cap to the head of a patient. The gel within the walls of the cap absorbs heat from the head, thereby cooling the head of the patient. Reports from clinical trials using such devices indicate, however, that while these devices induce systemic hypothermia, such induction is performed at a relatively slow rate. A significant problem is that hair, especially dry hair, is a very effective insulator. There is significant variation from patient to patient in the thickness of hair on the head and its distribution on the head. A device that does not address the insulating effect of hair, and its variability among patients will be ineffective in rapidly inducing systemic hypothermia in a patient.
• A second significant deficiency with conventional head-cooling devices relates to the separation of the cooling medium (e.g., gel or circulating water) from the head by a material forming the device. Typically, head-cooling devices are made of plastic or woven material, both of which are highly insulative and greatly reduce the amount of heat that is transferred from the head into the cooling medium.
• Also as indicated above, conventional head-cooling devices include a flexible hood placed on the head of a patient. A cooling fluid is drawn through the flexible hood under negative pressure to contact the scalp of the patient and draw heat away from (e.g., cool) the patient's scalp. Because the flexible hood, however, relies on a negative pressure to draw the cooling fluid within a region between the scalp and the hood apparatus, a large number of regularly spaced ribs or studs are required to form fluid channels between the scalp and the apparatus. Furthermore, application of the negative pressure seals the edges of the hood against the skin of the tissue region. However, such sealing is ineffective when the edges are positioned over hair, such as hair protruding from a patient scalp. In the case where the edges contact the hair of a patient's scalp, the hair minimizes the seal between the hood and the patient, thereby allowing leakage of the cooling fluid from the hood apparatus.
• Additionally, the aforementioned intravascular catheter based systems provides relatively rapid cooling to a subject. However, use of such a device requires advanced imaging equipment to insert the catheter into the patient, and advanced surgical skill, precluding use in the emergent care setting.
• Furthermore, the aforementioned conventional cooling modalities to cool a subject working in a hot environment suffer from a variety of deficiencies.
• For example, the conventional head-cooling devices include a closed loop system comprising a console, which contains a pump, a reservoir of water, an electrical power source, a means of cooling the water, and a hood and umbilical having at least two fluid tubes. The use of the conventional head-cooling devices that rely on the closed loop circulation of water with a console to maintain worker comfort in a hot environment is not practical. Using a head cap with a gel substance contained within the walls of the cap to maintain worker comfort in a hot environment is also not practical. Conventional gel cap technology requires that the gel-filled head-cooling device be stored in a freezer until immediately prior to use. As such, this requirement also precludes use in most work places.
• By contrast, embodiments of the present invention significantly overcome such deficiencies and provide techniques for reducing temperature in a subject. A cooling system includes a pressurized liquid refrigerant source having a liquid refrigerant and a cooling garment coupled to the liquid refrigerant source. The cooling garment defines chambers containing a heat transfer fluid. During operation, a user places the cooling garment in thermal communication with a body portion of a subject. As the cooling garment receives the liquid refrigerant from the pressurized source, the liquid refrigerant thermally contacts the heat transfer fluid and evaporates, thereby reducing the temperature of the heat transfer fluid. The heat transfer fluid, in turn, reduces the temperature of the body portion in thermal communication with the cooling garment. The heat transfer fluid acts to substantially evenly distribute cooling, as provided by the evaporation of the liquid refrigerant, to the body portion contacting the cooling garment to minimize localized “cold spots” within the chamber. In one arrangement, the heat transfer fluid has a freezing point configured such that the surface of the cooling garment (e.g., the surface of a wall forming the chamber) in thermal communication with the body portion and in thermal communication with the heat transfer fluid maintains a temperature above approximately zero degrees centigrade (0° C.). In such an arrangement, with the surface of the cooling garment in contact with the body portion at a temperature above approximately 0° C., the heat transfer fluid provides heat transfer with the body portion (e.g., a maximal level of heat transfer) while minimizing injury, such as frostbite) to the body portion.
• Nowhere in the art is a method or apparatus for maintaining worker comfort in a hot environment described using a cooling cap, an umbilical having a single liquid conduit, and a cooling source connected to the cooling cap by the umbilical.
• Nowhere in the art is a method or apparatus for maintaining worker comfort in a hot environment described using a helmet with a liner, a removable umbilical having a single liquid conduit, and a cooling source that may be removably connected to the helmet by the umbilical; whereby the liner normally provides padding for comfort and fit, and in the instance where the worker becomes uncomfortable due to environmental heat, the helmet can be connected to the cooling source with the umbilical, where the liner then functions to cool the worker to obtain or maintain comfort.
• Nowhere in the art is a method or apparatus for maintaining worker comfort in a hot environment described using a cooling cap, an umbilical having a single liquid conduit, and a cooling source connected to the cooling cap by the umbilical; whereby the cooling source consists of a container of passively pressurized liquid, and an umbilical connection means.
• Nowhere in the art is a method or apparatus for maintaining worker comfort in a hot environment described using a cooling cap, an umbilical having a single liquid conduit, and a cooling source having passively pressurized cooling liquid connected to the cooling cap by the umbilical; whereby the cooling cap having a liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid.
• Nowhere in the art is a method or apparatus for maintaining worker comfort in a hot environment described using a cooling cap, an umbilical having a single liquid conduit, and a cooling source having a passively pressurized cooling liquid connected to the cooling cap by the umbilical; whereby cooling liquid enters the cooling cap under pressure and is evaporated into a gaseous state within the cooling cap, where evaporation of the liquid provides a cooling means, and where optionally the pressure of the resulting gas is regulated within the cooling cap to provide a means for expanding the walls of the cooling cap to provide a snug fit with the workers head.
• Nowhere in the art is a method or apparatus for maintaining worker comfort in a hot environment described using a cooling cap, an umbilical having a single liquid conduit, and alternately an umbilical having a liquid conduit and a gas conduit, and a cooling source connectable to the cooling cap by the umbilical; whereby the cooling source may consist of a container of liquid under pressure and a connection means for the single conduit umbilical, or may include a refrigeration unit with a connection means for the two conduit umbilical.
• Nowhere in the art is a method or apparatus for maintaining worker comfort in a hot environment described using a cooling cap, an umbilical having a single liquid conduit, and a cooling source including a passively pressurized cooling liquid connected to the cooling cap by the umbilical; whereby heat transfer between the workers head and the cooling cap is enhanced by means of a heat transfer gel or liquid in the space between the workers head and the cooling cap.
• Nowhere in the art is a method or apparatus for maintaining worker comfort in a hot environment described using a cooling cap, an umbilical having a single liquid conduit, a cooling source including a passively pressurized cooling liquid connected to the cooling cap by the umbilical, and heat transfer liquid or gel; whereby the liquid or gel having a suspension of metal power.
• Nowhere in the art is a method or apparatus for maintaining worker comfort in a hot environment described using a cooling cap, an umbilical having a single liquid conduit, a cooling source including a passively pressurized cooling liquid connected to the cooling cap by the umbilical, and heat transfer liquid or gel; whereby the liquid or gel including a topical anesthetic.
• Nowhere described in the art is a method and/or apparatus for inducing hypothermia to a therapeutic level in a patient using, a cooling cap, an umbilical having a single liquid conduit, a cooling source having a container of passively pressurized liquid and an umbilical connection means; whereby the cooling cap is connected to the cooling source by the umbilical.
• Nowhere in the art is an integrated apparatus for resuscitation described using a defibrillation means, a cooling cap, an umbilical having a single liquid conduit, a cooling source having a container of passively pressurized liquid and an umbilical connection means; whereby the cooling cap is connected to the cooling source by the umbilical. Nowhere in the art is a portable resuscitation apparatus described having a console that is small enough, and light enough to be hand carried to and alongside a patient having a defibrillator and a means for rapidly lowering patient body temperature to a temperature between 30 and 37 degrees centigrade; whereby the body temperature lowering means does not require electrical energy for operation.
• Therefore, embodiments of the invention to provide a method, and apparatus for preventing discomfort, heat exhaustion, or heat stroke in individuals working in a hot environment.
• In accordance with another embodiment of the invention is an apparatus for rapidly obtaining an optimal body temperature in a patient in the emergent care setting in which resuscitation is clinically indicated.
• In accordance with another embodiment of the invention is an apparatus for preventing discomfort, heat exhaustion, or heat stroke in an individual working in a hot environment whereby the apparatus does not interfere with the work of the individual in any significant manner.
• In accordance with another embodiment of the invention, is an apparatus that provides for rapid obtainment of an optimal body temperature in a patient undergoing resuscitation that does not interfere in any significant manner with resuscitation by widely accepted resuscitation practices.
• In accordance with another embodiment of the invention is an apparatus for preventing discomfort, heat exhaustion, or heat stroke in an individual working in a hot environment whereby the apparatus does not interfere with the work of the individual in any significant manner, having a cooling cap, an umbilical having a single liquid conduit, and a cooling source having a passively pressurized cooling liquid connected to the cooling cap by the umbilical.
• In accordance with another embodiment of the invention, is an apparatus that provides for rapid obtainment of an optimal body temperature in a patient undergoing resuscitation that does not interfere in any significant manner with resuscitation by widely accepted resuscitation practices, having a cooling cap, an umbilical having a single liquid conduit, and a cooling source having a passively pressurized cooling liquid connected to the cooling cap by the umbilical.
• In accordance with another embodiment of the invention is an apparatus for preventing discomfort, heat exhaustion, or heat stroke in an individual working in a hot environment where the apparatus does not interfere with the work of the individual in any significant manner, having a cooling cap, an umbilical having a single liquid conduit, and a cooling source connected to the cooling cap by the umbilical, whereby the cooling source consists of a disposable or reusable container of passively pressurized cooling liquid, and an umbilical connection means.
• In accordance with another embodiment of the invention, is an apparatus that provides for rapid obtainment of an optimal body temperature in a patient undergoing resuscitation that does not interfere in any significant manner with resuscitation by widely accepted resuscitation practices, having a cooling cap, an umbilical having a single liquid conduit, and a cooling source connected to the cooling cap by the umbilical, whereby the cooling source consists of a disposable, reusable, or refillable container of passively pressurized cooling liquid, and an umbilical connection means.
• In accordance with another embodiment of the invention is an apparatus for preventing discomfort, heat exhaustion, or heat stroke in an individual working in a hot environment whereby the apparatus does not interfere with the work of the individual in any significant manner, having a cooling cap, an umbilical having a single liquid conduit, and a cooling source having passively pressurized cooling liquid connected to the cooling cap by the umbilical, whereby the cooling cap has a cooling liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid, and a means for the individual to adjust the flow rate of the cooling liquid.
• In accordance with another embodiment of the invention, is an apparatus that provides for rapid obtainment of an optimal body temperature in a patient undergoing resuscitation that does not interfere in any significant manner with resuscitation by widely accepted resuscitation practices, having a cooling cap, an umbilical having a single liquid conduit, and a cooling source having passively pressurized cooling liquid connected to the cooling cap by the umbilical, whereby the cooling cap has a cooling liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid, and optionally a means for the caregiver to adjust the flow rate of the cooling liquid.
• In accordance with another embodiment of the invention is an apparatus for preventing discomfort, heat exhaustion, or heat stroke in an individual working in a hot environment whereby the apparatus does not interfere with the work of the individual in any significant manner, having a cooling cap, an umbilical having a single liquid conduit, and a cooling source having passively pressurized cooling liquid connected to the cooling cap by the umbilical, whereby heat transfer between the workers head and the cooling cap is enhanced by means of a heat transfer gel or liquid in the space between the workers head and the cooling cap.
• In accordance with another embodiment of the invention, is an apparatus that provides for rapid obtainment of an optimal body temperature in a patient undergoing resuscitation that does not interfere in any significant manner with resuscitation by widely accepted resuscitation practices, having a cooling cap, an umbilical having a single liquid conduit, and a cooling source having passively pressurized cooling liquid connected to the cooling cap by the umbilical, whereby heat transfer between the workers head and the cooling cap is enhanced by means of a heat transfer gel or liquid in the space between the workers head and the cooling cap.
• In accordance with another embodiment of the invention is an apparatus for preventing discomfort, heat exhaustion, or heat stroke in an individual working in a hot environment whereby the apparatus does not interfere with the work of the individual in any significant manner, having a cooling cap, an umbilical having a single liquid conduit, a cooling source having a passively pressurized cooling liquid connected to the cooling cap by the umbilical, and heat transfer liquid or gel; whereby the heat transfer liquid or gel includes a suspension of metal powder.
• In accordance with another embodiment of the invention, is an apparatus that provides for rapid obtainment of an optimal body temperature in a patient undergoing resuscitation that does not interfere in any significant manner with resuscitation by widely accepted resuscitation practices, having a cooling cap, an umbilical having a single liquid conduit, a cooling source having a passively pressurized cooling liquid connected to the cooling cap by the umbilical, and heat transfer liquid or gel; whereby the heat transfer liquid or gel having a suspension of metal power.
• In accordance with another embodiment of the invention is an apparatus for preventing discomfort, heat exhaustion, or heat stroke in an individual working in a hot environment whereby the apparatus does not interfere with the work of the individual in any significant manner, having a cooling cap, an umbilical having a single liquid conduit, a cooling source having a passively pressurized cooling liquid connected to the cooling cap by the umbilical, and heat transfer liquid or gel; whereby the heat transfer liquid or gel includes a topical anesthetic.
• In accordance with another embodiment of the invention, is an apparatus that provides for rapid obtainment of an optimal body temperature in a patient undergoing resuscitation that does not interfere in any significant manner with resuscitation by widely accepted resuscitation practices, having a cooling cap, an umbilical having a single liquid conduit, a cooling source having a passively pressurized cooling liquid connected to the cooling cap by the umbilical, and heat transfer liquid or gel; whereby the heat transfer liquid or gel includes a topical anesthetic.
• In accordance with another embodiment of the invention is an apparatus for preventing discomfort, heat exhaustion, or heat stroke in an individual working in a hot environment whereby the apparatus does not interfere with the work of the individual in any significant manner, having a cooling garment, an umbilical having a single liquid conduit, a cooling source connected to the cooling garment by the umbilical.
• In accordance with another embodiment of the invention, is an apparatus that provides for rapid obtainment of an optimal body temperature in a patient undergoing resuscitation that does not interfere in any significant manner with resuscitation by widely accepted resuscitation practices, having a cooling cap, one or more additional cooling garment(s), one or more umbilicals (e.g., connectors) having a single liquid conduit, a cooling source having a passively pressurized cooling liquid connected to the cooling cap and additional cooling garment(s) by the umbilical(s).
• In accordance with another embodiment of the invention, is an apparatus for rapidly obtaining an optimal body temperature in a patient in the emergency care setting that is small enough and light enough to be hand carried to a stricken patient, and to then be hand carried and operated in close proximity to the patient during patient transport and while the patient is in the care of the emergency department of a hospital having a cooling cap, an umbilical having a single liquid conduit, and a cooling source having a passively pressurized cooling liquid connected to the cooling cap by the umbilical, whereby the cooling cap has a cooling liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid, and optionally a means for the caregiver to adjust the flow rate of the liquid.
• In accordance with another embodiment of the invention, is an apparatus for rapidly obtaining an optimal body temperature in a patient in the emergency care setting that is small enough and light enough to be hand carried to a stricken patient, and to then be hand carried and operated in close proximity to the patient during patient transport and while the patient is in the care of the emergency department of a hospital having one or more cooling garment(s), an umbilical(s) having a single liquid conduit, and a cooling source having a passively pressurized cooling liquid connected to the cooling garment(s) by the umbilical(s), whereby the cooling garment(s) has a cooling liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cooling garment(s) containing convective heat transfer liquid and optionally a means for the caregiver to adjust the flow rate of the cooling liquid.
• In accordance with another embodiment of the invention is a small portable resuscitation apparatus having a defibrillation means, a cooling cap, an umbilical having a single liquid conduit, a cooling source having a container of passively pressurized liquid and an umbilical connection means; whereby the cooling cap is connected to the cooling source by the umbilical.
• In accordance with another embodiment of the invention is a small portable resuscitation apparatus having a defibrillation, device, a chest compression apparatus, an intravenous fluid infusion device, a cooling cap, an umbilical having a single liquid conduit, a cooling source having a container of passively pressurized liquid and an umbilical connection means; whereby the cooling cap is connected to the cooling source by the umbilical, and whereby the cooling cap has a liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid and optionally a means for the caregiver to adjust the flow rate of the cooling liquid.
• In accordance with another embodiment of the invention is a small portable resuscitation apparatus having a defibrillation means, one or more cooling garment(s), one or more umbilical(s) having a single liquid conduit, a cooling source having a container of passively pressurized liquid and an umbilical connection means; whereby the cooling garment(s) is connected to the cooling source by the umbilical(s), and whereby the cooling garment(s) has a liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cooling garment(s) containing convective heat transfer liquid and optionally a means for the caregiver to adjust the flow rate of the liquid.
• In accordance with another embodiment of the invention, is a combat helmet having a bullet resistant outer shell and a cooling inner liner, whereby the cooling inner liner has a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cooling liner containing convective heat transfer liquid.
• In accordance with another embodiment of the invention, is a construction helmet having a rigid and hard outer shell and a cooling inner liner, whereby the cooling inner liner has a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cooling liner containing convective heat transfer liquid.
• In accordance with another embodiment of the invention, an apparatus is provided that induces hypothermia in a patient's body such that the brain of the patient is cooled to a greater degree than the rest of the patient's body, whereby the apparatus has a cooling cap, an umbilical having a single liquid conduit, a cooling source having a container of passively pressurized liquid and an umbilical connection means; whereby the cooling cap is connected to the cooling source by the umbilical.
• In accordance with another embodiment of the invention, is an apparatus that effectively cools the head of a patient, thereby cooling the body of the patient, whereby the effectiveness the head cooling is not substantially affected by the thickness or distribution of the hair on the head, face, or neck of the patient, and whereby the apparatus includes a cooling cap, an umbilical having a single liquid conduit, a cooling source having a container of passively pressurized liquid, and an umbilical connection means, and heat transfer liquid or gel, whereby the cooling cap is connected to the cooling source by the umbilical, and the heat transfer liquid or gel diminishes the insulating effect of hair.
• In accordance with another embodiment of the invention is a cooling cap having an umbilical, or an umbilical connection means, at least one liquid evaporator, a cooling liquid flow control valve, a gas pressure regulation valve, and a space within the walls of the cooling cap containing thermal convection heat transfer fluid.
• In accordance with another embodiment of the invention, an apparatus for resuscitation is a crash cart having a means for lowering patient body temperature having a cooling cap, an umbilical having a single liquid conduit, a cooling source having a container of passively pressurized liquid, an umbilical connection means, and heat transfer liquid or gel, a means to store resuscitation medications, supplies and devices, and a means to transport the crash cart from a place of storage to a patient in need of resuscitation, whereby the cooling cap is connected to the cooling source by the umbilical, and the heat transfer liquid or gel diminishes the insulating effect of hair.
• In accordance with another embodiment of the invention, is an apparatus for rapidly obtaining and then maintaining an optimal body temperature in a patient in the emergency care setting that is small enough and light enough to be hand carried to a stricken patient, and to then be hand carried and operated in close proximity to the patient during patient transport and while the patient is in the care of the emergency department of a hospital having; a small portable console that includes a passively pressurized cooling liquid source, electronic controls, an electrically actuated cooling liquid flow control valve, an electrical battery, a means for the user to set a target patient body temperature, an umbilical connection means, and a patient temperature sensor connection means, a patient temperature sensor, a cooling cap having a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid, and an umbilical having a single liquid conduit, whereby the patient temperature sensor provides signals to the control circuit indicative of patient temperature and the control circuit adjusts the flow of cooling liquid to the cooling cap thereby providing thermostatic control of the temperature of the patient at the user set point.
• In accordance with another embodiment of the invention, is an apparatus for rapidly obtaining and then maintaining an optimal body temperature in a patient in the emergency care setting that is small enough and light enough to be hand carried to a stricken patient, and to then be hand carried and operated in close proximity to the patient during patient transport and while the patient is in the care of the emergency department of a hospital having; a small portable console that includes a passively pressurized cooling liquid source, electronic controls, an electrical battery, a means for the user to set a target patient body temperature, an umbilical connection means, and a patient temperature sensor connection means, a patient temperature sensor, a cooling cap having an electrically actuated cooling liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid, and an umbilical having a single liquid conduit and at least one electrical conduit that electrically connects the cooling liquid flow control valve to the console, whereby the patient temperature sensor provides signals to the control circuit indicative of patient temperature and the control circuit adjusts the flow of cooling liquid to the cooling cap thereby providing thermostatic control of the temperature of the patient at the user set point.
• In accordance with another embodiment of the invention, is a method of resuscitation including the steps of bringing to a stricken patient an apparatus that provides a means for lowering the patient's body temperature to a predetermined level, and then maintaining the patient's body temperature at the predetermined level for an extended period of time, where the apparatus includes a cooling cap that includes a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid, a small portable console that includes a passively pressurized cooling liquid source, electronic controls, an electrically actuated cooling liquid flow control valve, an electrical battery, a means for the user to set a target patient body temperature, an umbilical connection means, and a patient temperature sensor connection means, and a body temperature sensor, then initiating resuscitation, then placing the cooling cap on the head of the patient, then connecting the cooling cap to the small portable console with the umbilical, then activating the small portable console, whereby activating the small portable console initiates a cool down mode of operation whereby the cool down mode of operation includes a continuous flow of cooling liquid from the small portable console to the cooling cap, then placing the body temperature sensor on the patient's body and connecting the body temperature sensor to the small portable console either before activation of the system, or after activation of the system and before the patient's body temperature reaches the predetermined temperature, then when patient's body reaches the predetermined temperature, the small portable console enters a temperature maintenance mode of operation, whereby the temperature maintenance mode of operation includes an intermittent flow of cooling liquid from the small portable console to the cooling cap, whereby the intermittence of the flow of cooling liquid is adjusted by control algorithms within the control circuits of the small portable console according to signals received from the body temperature sensor in order to maintain the patient's body temperature at the predetermined level.
• In accordance with another embodiment of the invention, is a method of resuscitation including the steps of bringing to a stricken patient an apparatus that provides a means for lowering the patient's body temperature to a predetermined level, and then maintaining the patient's body temperature at the predetermined level for an extended period of time, the apparatus including a cooling cap that includes a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid, a small portable console that comprises a passively pressurized cooling liquid source, electronic controls, an electrically actuated cooling liquid flow control valve, an electrical battery, a means for the user to set a target patient body temperature, an umbilical connection means, and a patient temperature sensor connection means, and a body temperature sensor, then initiating resuscitation,10 then placing the cooling cap on the head of the patient, then connecting the cooling cap to the small portable console with the umbilical, then activating the small portable console, whereby activating the small portable console initiates a cool down mode of operation whereby the cool down mode of operation includes a continuous flow of cooling liquid from the small portable console to the cooling cap, then placing the body temperature sensor on the patient's body and connecting the body temperature sensor to the small portable console either before activation of the system, or after activation of the system and before the patient's body temperature reaches the predetermined temperature, then when patient's body reaches the predetermined temperature, the small portable console enters a temperature maintenance mode of operation, whereby the temperature maintenance mode of operation includes a continuous flow of cooling liquid from the small portable console to the cooling cap, whereby the flow rate of the cooling liquid is adjusted by control algorithms within the control circuits of the small portable console according to signals received from the body temperature sensor in order to maintain the patient's body temperature at the predetermined level.
• In accordance with another embodiment of the invention, is a method of resuscitation including the steps of bringing to a stricken patient an apparatus including a small battery operated console that provides a means for defibrillating the patient, and a means for rapidly lowering the body temperature of the patient where the apparatus includes a cooling cap connectable to the small portable battery operated console by an umbilical, then initiating resuscitation by defibrillating the patient with the defibrillation means provided by the small portable battery operated console, then placing the cooling cap on the head of the patient, then connecting the cooling cap to the small portable battery operated console, then activating the cooling means of the small portable battery operated console, then completing resuscitation of the patient.
• In accordance with another embodiment of the invention, is a method of resuscitation including the steps of bringing to a stricken patient an apparatus having a small battery operated console that provides a means for defibrillating the patient, and a means for lowering the body temperature of the patient to a predetermined level, and then maintaining the patient's body temperature at the predetermined level for an extended period of time, the apparatus having a cooling cap connectable to the small portable battery operated console by an umbilical, then initiating resuscitation by defibrillating the patient with the defibrillation means provided by the small portable battery operated console, then placing the cooling cap on the head of the patient, then connecting the cooling cap to the small portable battery operated console, then activating the cooling means of the small portable battery operated console, then completing resuscitation of the patient.
• In accordance with another embodiment of the invention, is a method of resuscitation including the steps of bringing to a stricken patient an apparatus having a small battery operated console that provides a means for defibrillating the patient, and a means for lowering the body temperature of the patient to a predetermined level by means of an internal store of passively pressurized cooling liquid, and then maintaining the patient's body temperature at the predetermined level for an extended period of time, the apparatus including a cooling cap connectable to the small portable battery operated console by an umbilical, then initiating resuscitation by defibrillating the patient with the defibrillation means provided by the small portable battery operated console, then placing the cooling cap on the head of the patient, then connecting the cooling cap to the small portable battery operated console, then activating the cooling means of the small portable battery operated console, then completing resuscitation of the patient, then deactivating the small portable battery operated console and then disconnecting the cooling cap from the small battery operated console, then connecting the cooling cap to a second console that is not battery operated, and then activating the second console thereby resuming cooling of the patient.
• In accordance with another embodiment of the invention, is a method for increasing the productivity of a worker by preventing discomfort due to heat, heat exhaustion, or heat stroke, including the steps of supplying the worker with a head-cooling system, then, instructing the worker to use the head-cooling system while working, and/or while the worker is on break, whereby the head-cooling system includes a head-cooling cap, or helmet equipped with a head-cooling liner, a source of passively pressurized cooling liquid, and a means to connect the head-cooling cap, or head-cooling helmet liner to the source of pressurized cooling liquid.
• In accordance with another embodiment of the invention is an apparatus for maintaining worker comfort in a hot environment including a cooling cap, an umbilical having a single liquid conduit, and a cooling source connected to the cooling cap by the umbilical; whereby liquid enters the cooling cap under pressure and is evaporated into a gaseous state within the cooling cap, where evaporation of the liquid provides a cooling means, and where the pressure of the resulting gas is regulated within the cooling cap to provide a means for expanding the walls of the cooling cap to provide a snug fit with the workers head.
• In accordance with another embodiment of the invention is an apparatus for maintaining worker comfort in a hot environment including a cooling cap, an umbilical having a single liquid conduit, and alternately an umbilical having a liquid conduit and a gas conduit, and a cooling source connected to the cooling cap by the umbilical; whereby the cooling source may consist of a container of liquid under pressure and a connection means for the single conduit umbilical, or may have a refrigeration unit with a connection means for the two conduit umbilical.
• In accordance with another embodiment of the invention is a liquid evaporator having metal foil walls, a liquid feed tube, and a manifold fitting.
• In accordance with another embodiment of the invention is a cooling cap including a means for delivering an anesthetic agent into the scalp by iontophoresis means, such as an anode, a cathode, and a power source coupled to the anode and the cathode.
• In accordance with another embodiment of the invention is a cooling cap including a cooling liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid.
• In accordance with another embodiment of the invention is a head-cooling system including a head-cooling cap, or helmet equipped with a head-cooling liner, a source of passively pressurized cooling liquid, and a means to connect the head-cooling cap, or head-cooling helmet liner to the source of passively pressurized cooling liquid, wherein the head-cooling means includes the evaporation of the pressurized cooling liquid within the walls of the head-cooling cap or the head-cooling helmet liner.
• In accordance with another embodiment of the invention is a cooling cap having a cooling liquid flow control valve, a gas pressure control valve, at least one liquid evaporator, and a space within the walls of the cap containing convective heat transfer liquid, whereby the cooling cap can be folded and stored indefinitely in a compact shape.
• In accordance with another embodiment of the invention is a cooling cap having a means for receiving pressurized cooling liquid, an outer wall having a gas permeable membrane, a space within the walls of the cap containing convective heat transfer liquid, and a cooling liquid distribution means within said space.
• In accordance with another embodiment of the invention is an apparatus for maintaining worker comfort in a hot environment including a helmet with a liner, a removable umbilical having a single liquid conduit, and a cooling source that may be removably connected to the helmet by the umbilical; whereby the liner normally provides padding for comfort and fit, and in the instance where the worker becomes uncomfortable due to environmental heat, the helmet can be connected to the cooling source with the umbilical, where the liner then functions to cool the worker to obtain or maintain comfort.
• In accordance with another embodiment of the invention is a console having a defibrillator means, and a passively pressurized cooling liquid container means.
• In accordance with another embodiment of the invention, is a kit including, a cooling cap, or a helmet, and directions for use, whereby the directions for use describe one or more of the methods for increasing worker productivity, or for resuscitation described in my patent above.
• Embodiments of the present invention provide an apparatus to improve worker productivity by preventing discomfort due to heat, heat exhaustion, or heat stroke. Embodiments of the invention provide an apparatus to increase the combat effectiveness of military forces operating in a hot battlefield environment. Embodiments of the invention provide an apparatus for inducing hypothermia in patients indicated for resuscitation rapidly. Embodiments of the invention provide an apparatus for initiating hypothermia therapy in a patient indicated for resuscitation prior to arrival at the hospital. Embodiments of the invention provide an apparatus for inducing hypothermia in a patient indicated for resuscitation where protective levels of hypothermia are rapidly and preferentially induced in the brain. Embodiments of the invention provide a practical means for removing excess body heat. Embodiments of the invention provide a compact and portable resuscitation apparatus that includes a defibrillation means and a hypothermia induction means.
• Embodiments of the invention provide an apparatus for rapidly inducing hypothermia in the pre-hospital setting, or upon arrival at the hospital, in a patient with cardiac arrest, acute myocardial infarction, brain trauma, embolic or hemorrhagic stroke, subarachnoid hemorrhage, or hemorrhagic shock. Embodiments of the invention provide a method of resuscitation for a patient stricken with cardiac arrest, acute myocardial infarction, brain trauma, embolic or hemorrhagic stroke, subarachnoid hemorrhage, or hemorrhagic shock. Embodiments of the invention provide a body cooling system that is compatible with emergency medical treatment practices. Embodiments of the invention provide a patient temperature control system including at least one body-cooling device that is capable of being operated by a small portable console that runs on a store of passively pressurized cooling liquid, that is also capable of being operated by a console that runs on electrical power from a wall outlet, whereby the body-cooling device may remain attached to the patient in an operational position while the body-cooling device is disconnected from one console and then connected to a second console. Other embodiments of the invention provide an integrated resuscitation apparatus, provide a method of improving worker productivity, and provide a method of increasing the combat effectiveness of military forces operating in a hot battlefield environment.
BRIEF DESCRIPTION OF THE DRAWINGS
• The foregoing and other objects, features and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
• FIG. 1 illustrates a cooling system showing a cooling source, a cooling cap, and an umbilical connecting the cooling source to the cooling garment.
• FIG. 2 depicts a resuscitation apparatus for cooling a patient having a portable console, a cooling cap, and a temperature sensor connected by umbilicals.
• FIG. 3 illustrates the resuscitation apparatus ofFIG. 2 having a second body-cooling garment.
• FIG. 4 illustrates the resuscitation apparatus ofFIG. 2 having a defibrillator device.
• FIG. 5 illustrates an arrangement of the cooling cap or cooling helmet liner ofFIG. 1.
• FIG. 6 depicts, in cross sectional view, an arrangement of the functional components and operation of the cooling cap ofFIG. 5.
• FIG. 7 depicts, in cross sectional view, an arrangement of the functional components and operation of the cooling cap ofFIG. 5.
• FIG. 8A illustrates a front view of the liquid evaporator assembly ofclaim6, according to one embodiment of the invention.
• FIG. 8B illustrates, in transverse cross sectional view, an arrangement of the liquid evaporator assembly ofFIG. 8A during liquid evaporation.
• FIG. 8C depicts, in transverse cross sectional view, an arrangement of the liquid evaporator assembly ofFIG. 8A in a storage configuration.
• FIG. 9 depicts, in cross sectional view, the operation of the cooling mechanism of the cooling cap or cooling helmet liner showing the inner wall, the outer wall, the liquid evaporator, and the convective heat transfer liquid space between the inner wall, and the outer wall.
• FIG. 10 depicts, in cross sectional view, the manual control valve assembly of the cooling-cap, or the cooling helmet liner.
DETAILED DESCRIPTION
• Embodiments of the present invention provide techniques for reducing temperature in a subject. A cooling system includes a pressurized liquid refrigerant source having a liquid refrigerant and a cooling garment coupled to the liquid refrigerant source. The cooling garment defines chambers containing a heat transfer fluid. During operation, a user places the cooling garment in thermal communication with a body portion of a subject. As the cooling garment receives the liquid refrigerant from the pressurized source, the liquid refrigerant thermally contacts the heat transfer fluid and evaporates, thereby reducing the temperature of the heat transfer fluid. The heat transfer fluid, in turn, reduces the temperature of the body portion in thermal communication with the cooling garment. The heat transfer fluid acts to substantially evenly distribute cooling, as provided by the evaporation of the liquid refrigerant, to the body portion contacting the cooling garment to minimize localized “cold spots” within the chamber.
• In one arrangement, the heat transfer fluid has a freezing point configured such that the surface of the cooling garment (e.g., the surface of a wall forming the chamber) in thermal communication with the body portion and in thermal communication with the heat transfer fluid maintains a temperature above approximately zero degrees centigrade (0° C.). In such an arrangement, with the surface of the cooling garment in contact with the body portion at a temperature above approximately 0° C., the heat transfer fluid provides heat transfer with the body portion (e.g., a maximal level of heat transfer) while minimizing injury, such as frostbite) to the body portion.
• FIG. 1 depicts acooling system100 including a cooling source1 and acooling assembly110. The coolingassembly110 includes a cooling garment, such ascooling cap2, (or helmet with cooling liner) having a fluid inlet coupled to the cooling source via umbilical3.Cooling cap2 includescontrol valve assembly4, and coolingcontrol knob5. Umbilical3 consists of a single liquid conduit, and a connector or conduit to connect to cooling source1 and controlvalve assembly4 ofcooling cap2, and provides liquid communication between cooling source1 and controlvalve assembly4. Cooling source (e.g., pressurized liquid refrigerant source)1 consists of a passively pressurized container of cooling fluid or liquid refrigerant, such as a gas held under pressure in a liquid phase, a connector or conduit to connect umbilical3 to the container of liquid refrigerant, and optionally a carrying case (as shown). In one embodiment, the liquid refrigerant is nitrogen, however, the apparatus can be configured to operate on alternative liquid refrigerants such as argon, freon, or others. Nitrogen is preferred due to its nature as being the main component of air, and therefore does not present an environmental hazard, its high heat of vaporization (199 KJ/Kg), and the fact that it is readily available at a low cost. Liquid refrigerant is supplied to controlvalve assembly4 under pressure.Control valve4 controls the flow of liquid refrigerant into cooling cap1, and also controls the gas pressure inside cooling cap1. Cooling is accomplished by evaporation of the liquid refrigerant within the walls of the cooling cap, and the resulting gas is vented throughcontrol valve assembly4 into the atmosphere. Cooling control knob (e.g., flow control valve)5 controls the rate at which liquid refrigerant enters the cooling cap, and therefore, the cooling rate.Chin strap6 secures the cooling cap to the worker's or patient's head.
• FIG. 2 depicts an arrangement of a resuscitation apparatus having a smallportable resuscitation console7, resuscitation-cooling cap8,temperature sensor assembly9, and umbilical10.Resuscitation console7 includes an internal container containing passively pressurized liquid refrigerant (not shown), electronic control circuits (not shown), an electrical battery (not shown), user control and display interface (not shown),temperature sensor connector14,umbilical connector15, carryinghandle16. Resuscitation-cooling cap8 includes umbilical10, electrically actuatedcontrol valve assembly13,chinstrap6, and cap assembly17. Umbilical10 includesliquid conduit11,electrical conduit12 andconsole connector18. A physiological sensor assembly, such as atemperature sensor assembly9, includes a physiological sensor, such as atemperature sensor19, catheter/electrical lead20, andconsole connector21.
• The user control and display interface (not shown) provides allows the user to set operational parameters including set point temperature (temperature to which the patient's body temperature is to be lowered to and then maintained at), and to view operation parameters including actual patient body temperature, and to activate and deactivate patient cooling. Internal container of liquid refrigerant (not shown) is connected to electrically actuated control valve byliquid conduit11 andconnectors15 &18. The container of liquid refrigerant may be permanently installed withinresuscitation console7 and be re-filled upon exhaustion, or replaceable after exhaustion.Temperature sensor19 is connected to electronic control circuits (not shown) by catheter/electrical lead20 andconnectors14 &21. Electrically actuatedcontrol valve13 is connected to electronic control circuits (not shown) byelectrical conduit12, and byconnectors15 &18. Cap assembly17 (seeFIGS. 5, 6, &9 for construction details) includes electrically actuatedcontrol valve13, at least one evaporator assembly (not shown—seeFIG. 8A-8C for construction details), inner wall and outer wall, and space between inner wall and outer wall containing convective heat transfer liquid (not shown—seeFIG. 9 for construction details),chinstrap6, and optionally outer liner or helmet (not shown). Electrically actuated control valve includes a liquid inlet flow control valve (not shown) and an electrical motor (not shown) that actuates the liquid inlet control valve to regulate inlet flow of liquid refrigerant, a gas outlet port and gas outlet pressure regulator (not shown) that allows evaporated refrigerant to be vented to the atmosphere, or scavenged by a gas scavenger (not shown) under a constant predetermined pressure, and a conduit or connector to communicate liquid refrigerant fromconsole7 into liquid evaporator(s) within cap assembly17, and a conduit to communicate evaporated refrigerant to gas outlet port and outlet pressure regulator (not shown), and optionally a temperature sensor and a electrical circuit (not shown) that measures the temperature of the evaporated refrigerant as it leaves thecap assembly7 as an indication of cooling rate, where the flow rate of liquid refrigerant into cap assembly is adjusted by the liquid inlet flow control valve, motor, and electrical circuit according to predetermined algorithms and signals received by the temperature sensor.
• The apparatus is used for resuscitation in the following manner: 1.) Thecooling cap8,temperature sensor assembly9, andresuscitation console7 is hand carrier to a stricken patient. 2.) Thecooling cap assembly8 is placed onto the patient's head and secured withchinstrap6. 3.)Temperature sensor19 is placed on or into the patient's body. 4.)Temperature sensor assembly9 is connected to console7 byconnector14 &21. 5.) Coolingcap assembly8 is connected to console7 byconnectors15 &18. 6.) The user selects operational parameters and then activates the system using the user control and display interface (not shown). 7.) Upon activation of the system, passively pressurized liquid refrigerant flows from the liquid refrigerant container withinconsole7 intocooling cap assembly8. Liquid refrigerant is evaporated within the walls of coolingcap8 into a gaseous state, and absorbs heat from the patient's body as a result of said evaporation. Flow of refrigerant is continuously maintained until either the user deactivates the system, or the patient's body temperature is lowered to the body set point temperature, at which time the system enters a temperature maintenance phase of operation. During the temperature maintenance phase, liquid refrigerant flow into cooling cap assembly is modulated by the control circuit (not shown), of the control console for example, and the electrically actuatedcontrol valve assembly13 according to signals received fromtemperature sensor19 to adjust cooling of the patient to maintain patient body temperature at said set point. The system is deactivated upon completion of hypothermia therapy.
• FIG. 3 depicts another arrangement of a resuscitation apparatus having small resuscitation console22, resuscitation-cooling cap8,temperature sensor assembly9, umbilical10, a second cooling-garment23 (a cooling collar as depicted), and second cooling-garment umbilical24. Resuscitation-cooling cap8,temperature sensor assembly9, and umbilical10 are described above in the description ofFIG. 2. Resuscitation console22 is as described above inFIG. 2 with the addition of a controller to provide refrigeration liquid to and to control operation of second cooling-garment23. Second cooling-garment is similar toresuscitation cooling cap8 in construction and operation and includes umbilical24, electrically actuatedcontrol valve assembly25, andgarment assembly26. Second cooling garment assembly includes electrically actuatedcontrol valve25, at least one evaporator assembly (not shown—seeFIGS. 8A-8C for construction details), inner wall and outer wall, and space between inner wall and outer wall containing convective heat transfer liquid (not shown—seeFIG. 9 for representative construction details). The operation and construction of electrically actuatedcontrol valve assembly25 is equivalent to electrically actuatedcontrol valve assembly13 inFIG. 2. Second cooling garment may be configured as a collar as depicted, but may also be configured as a vest, trouser, blanket, or any other garment configuration. In one arrangement, when configured as a collar, the cooling garment is configured to cover or contact a shoulder area of a patient, such as the clavicle or axilla area of a patient. Second garment umbilical24 is equivalent to umbilical10 ofFIG. 2 and includesliquid conduit27,electrical conduit28, and console connector29.Resuscitation console23 is equivalent toresuscitation console7 inFIG. 2 with the additional capability of operating two cooling devices concurrently or separately.Resuscitation console23 has additionalumbilical connector30 for connecting and operating a second cooling-garment. The resuscitation console may be constructed to operated resuscitation cooling-cap8 or a second cooling-garment23 simultaneously or independently, or may be constructed to operate two cooling garments where neither cooling garment is a cooling-cap. The user control and display interface (not shown) ofresuscitation console23 may provide a controller to set operating parameters for each cooling device independently.
• FIG. 4 depicts an arrangement of a resuscitation apparatus having a treatment device, such as a defibrillation apparatus to defibrillate a patient and a hypothermia apparatus to induce hypothermia in a patient, including a smallportable resuscitation console31, resuscitation-cooling cap8,temperature sensor assembly9, and defibrillation electrode handles32. In another arrangement, the resuscitation apparatus includes atreatment apparatus112, such as a chest compression apparatus, or an intravenous fluid infusion device. For example, in a case where a worker suffers heat exhaustion and is dehydrated, the worker can suffer a cardiac arrest. In such a case the chest compression apparatus and intravenous fluid infusion device of the resuscitation apparatus can be used to resuscitate the patient.Resuscitation console31 is equivalent toresuscitation console7 inFIG. 2 with the addition of components for defibrillation, a larger battery sufficient to provide both cooling and defibrillation, a defibrillatorelectrode paddle connector33, and the user control and display interface (not shown) may be configured to include controls and display for defibrillation. Defibrillation, both manual and automated is thoroughly disclosed in the art, and requires no further teaching. Defibrillator electrode paddles33 are of standard configuration for defibrillator electrode paddles and connect to console31 byconsole connector34.Resuscitation cooling cap8, andtemperature sensor assembly9 as described inFIG. 2. The apparatus is used to resuscitate a patient stricken with cardiac arrest in the following manner: 1.) Thecooling cap8,temperature sensor assembly9, andresuscitation console31, and defibrillation electrode paddles32 are hand carrier to a patient stricken with cardiac arrest. 2.) The patient is then defibrillated using a defibrillator withinconsole31 and defibrillation electrode paddles32. 3.) Thecooling cap assembly8 is then placed onto the patient's head and secured withchinstrap6. 4.)Temperature sensor19 is placed on or into the patient's body. 5.)Temperature sensor assembly9 is connected to console7 by connector means14 &21. 6.) Coolingcap assembly8 is connected to console7 byconnector15 &18. 7.) The user selects cooling operational parameters and then activates the system using the user control and display interface (not shown). Cooling is as described above inFIG. 2.
• FIG. 5 depicts cooling-cap inner liner or helmet cooling-liner assembly35 with manualcontrol valve assembly4 including coolingcontrol knob5, umbilical3 andgas outlet port37. Outer liner (not shown) includes insulative foam, or a helmet with a foam insulated inner wall. Finger shaped structures (e.g., chambers)38 depict convective liquid filled space between inner wall (not shown) andouter wall40 of cooling capinner liner assembly35.Bond area39 depicts where the inner wall (not shown)outer wall40 is bonded together to form said convective liquid filled space. Cooling cap inner liner is sized and shaped to cover the cranium of a worker and a patient, and functions to remove heat from a worker to provide comfort, or remove heat from a patient to provide hypothermia therapy. Further construction details and embodiments of cooling-capinner liner assembly35 are described below.
• FIG. 6 depicts in cross sectional view cooling capinner liner assembly35. Depicted is manualflow control valve4, umbilical3, coolingcontrol knob5, a first orouter wall40, a second orinner wall41,evaporator manifold44, convective heattransfer liquid space43 having evaporator assembly(s)42, and convectiveheat transfer liquid46. Cooling capinner liner assembly35 removes heat from a worker or a patient in the following manner: 1.) Liquid refrigerant enterscontrol valve assembly4 through umbilical3. 2.) The liquid refrigerant flows throughcontrol valve assembly4 intoevaporator manifold44 at a rate that is adjustable by coolingcontrol knob5. 3.)Evaporator manifold44 distributes liquid refrigerant into one or more evaporator assemblies42 (as shown). 4.) The liquid refrigerant entersevaporator assemblies42 and evaporates due to heat absorption from surrounding convectiveheat transfer liquid46 through the walls ofevaporator assembly42. 5.) As heat is absorbed from surrounding convectiveheat transfer liquid46 the temperature of theheat transfer liquid46 is lowered to a temperature lower than the body temperature of the worker or the patient, thereby causing heat to be transferred from the worker's or patient's head into the convective heat transfer liquid thoughinner wall41 which, thereby results in a heat flux between the head of the worker or the patient and the liquid refrigerant causing evaporation of the liquid refrigerant. Theheat transfer fluid46 acts to substantially evenly distribute cooling, as provided by the evaporation of the liquid refrigerant, to the head of the worker (e.g., the portion contacting the cooling garment) to minimize localized “cold spots” within the chamber. 6.) Evaporated refrigerant is vented into the atmosphere thoughtevaporator manifold44,control valve assembly4, and gas outlet port (e.g., vent)37. Convectiveheat transfer liquid46 may include water, or some other liquid. Convectiveheat transfer liquid46 may include water and an anti-freeze agent such as ethylene glycol and be formulated such that convectiveheat transfer liquid46 freezes at a temperature below zero degrees centigrade whereby the temperature of convectiveheat transfer liquid46 will not drop below said freezing point while said convectiveheat transfer liquid46 is at least in part in a liquid state. The heat transfer fluid, in turn, reduces the temperature of the body portion in thermal communication with the cooling garment.
• The freezing point of convectiveheat transfer liquid46 in one arrangement is formulated such that the surface ofinner wall41 in contact with the worker's or patient's skin is just above zero degrees centigrade. With the surface ofinner wall41 in contact with the worker's or patient's skin at just above zero degrees centigrade, heat transfer will be at a maximal level possible while minimizing frostbite injury to the worker's or patient's skin. The flow rate of the liquid refrigerant may be limited by the design and construction ofcontrol valve assembly4 such that freezing of all of the convectiveheat transfer liquid46 will not be possible during normal use.
• FIG. 7 depicts an alternate embodiment of the cooling-cap inner liner assembly whereby an evaporator assembly is not required. Inner cooling-cap liner assembly47 includesinner wall48,outer wall49, convective heattransfer liquid space51 formed betweeninner wall48 andouter wall49, convectiveheat transfer liquid52, and controlvalve assembly50 havingcooling control knob54, umbilical55, and liquidrefrigerant port53.Inner wall48 is constructed from a polymer such as polyethylene.Outer wall49 is constructed from a gas permeable membrane such as Tyvek® During operation, liquid refrigerant flows intocontrol valve assembly50 from umbilical55, and into convective heattransfer liquid space51 containing convectiveheat transfer liquid52 through liquidrefrigerant port53. Liquid refrigerant is evaporated by direct contact with, and heat absorption from convectiveheat transfer liquid52. Direct evaporation of liquid refrigerant within convectiveheat transfer liquid52 causes a boiling like effect and enhanced convection within convective heattransfer liquid space51. Gas resulting from evaporation of liquid refrigerant is vented into the atmosphere thoughouter wall49 where the outer wall is formed of a gas permeable membrane. In such an arrangement, the gas permeable membrane acts as vent for the cooling assembly.
• FIGS.8A-C depictsevaporator assembly42.FIG. 8A depicts the front view ofevaporator assembly42.FIG. 8B depicts a transverse sectional side view ofevaporator assembly42 during operation depicting the evaporation process ofliquid refrigerant56.FIG. 8C depicts a transverse sectional view ofevaporator42 in a pre-use or storage configuration.Evaporator assembly42 includeswalls57 fabricated from a metal foil such as aluminum or titanium and are welded together atweld seam60;liquid feed tube58 having a flexible polymer or metallic tube with an inside diameter of 0.5 to 1.5 mm, and amanifold ferrule59.Ferrule tube59 includesgas port62.Liquid refrigerant56 entersevaporator assembly42 throughliquid feed tube58. Evaporated refrigerant leavesevaporator assembly42 throughgas port62. Prior to use, or after use evaporator assembly may be folded into a compact shape as depicted inFIG. 8C. Manifold ferrule may be machined out the same material asevaporator assembly walls57 and welded into place as shown.Liquid feed tube58 may be held in place with an adhesive, or if metallic, welded in place as shown.Distal end63 ofliquid feed tube58 may have an open end as shown, where liquid refrigerant56 enters evaporator assembly throughdistal end63. Alternatively,liquid feed tube58 may be configured withdistal end63 closed and liquidfeed tube wall64 includes a series of small hoes between 0.05 and 0.15 mm in diameter where liquid refrigerant56 entersevaporator assembly42 through said holes.
• FIG. 9 depicts in cross sectional view the operation of the cooling mechanism of cooling cap8 (or cooling helmet liner) showing inner cooling-cap liner assembly35,inner wall41,outer wall40,evaporator assembly42, convective heattransfer liquid space43, convectiveheat transfer liquid46,liquid refrigerant56, evaporatedrefrigerant61,ice formation65, and heat transfer liquid orgel66.Liquid refrigerant56 boils at a cryogenic temperature determined by the physical properties of the refrigerant, and the pressure withinevaporator assembly42. The pressure withinevaporator assembly42 is controlled bypressure relief valve67 ofcontrol valve assembly4 at a value between 1 and 40 PSIG (FIG. 10). At an operating pressure between 1 and 40 PSIG, liquid nitrogen will boil (or evaporate) at a temperature near minus 190 degrees centigrade. Convectiveheat transfer liquid46 includes water and an antifreeze agent and is formulated to have a freezing point between zero and minus thirty degrees centigrade. Due to the cryogenic temperature generated by said boiling withinevaporator assembly42,outer surface69 ofevaporator assembly42 will also be at a cryogenic temperature.Ice formation65 develops at outer surface70 ofevaporator assembly42 as shown. The temperature atouter layer68 ofice formation65 is very near the freezing point of convectiveheat transfer liquid46. The temperature atinner layer69 ofice formation65 is very near the temperature of outer wall70 ofevaporator assembly42. Heat transfer liquid orgel66 is placed into the hair of the worker or patient, or is placed ontoinner wall41 prior to placing cooling-cap8 onto the head as shown. Heat transfer liquid orgel66 provides a heat transfer medium between the worker's or the patient's scalp, for example, andinner wall41, and greatly diminishes the insulating effect of hair. Arrows indicate convective heat transfer betweeninner wall41 andice formation65 andevaporator assembly42.
• FIG. 10 depicts in sectional viewcontrol valve assembly4,evaporator manifold assembly44,evaporator assemblies42, andouter wall40 of cooling-capinner liner assembly35.Control valve assembly4 includesvalve housing79,needle valve assembly80, umbilical3,liquid passage73,gas passage74 and pressurerelief valve assembly67.Evaporator manifold assembly44 includesmanifold housing87,gas passage82,evaporator receptacles83, liquid feed tube o-rings84, inner gas passage o-ring85, and outer gas pressure o-ring86. Evaporator assemblies42 (seeFIG. 8) includeevaporator walls57,liquid feed tube58, andmanifold ferrule59.Needle valve assembly80 includesneedle valve71, needlevalve adjustment screw75, and coolingcontrol knob5. Pressurerelief valve assembly67 includesball76,spring77, andspring ferrule78.Valve housing79,manifold housing87,needle valve71, and needlevalve adjustment screw75 may be machined from stainless steel as shown. Pressurized liquid refrigerant56 enters control valve assembly though umbilical3.Needle valve71 controls the flow rate of liquid refrigerant56 intoliquid passage73.Control knob5, and needlevalve adjustment screw75 control the position ofneedle valve71 whereby, movement ofneedle valve71 down reduces the flow rate of liquid refrigerant56, and movement ofneedle valve71 up increases the flow rate ofliquid refrigerant56. Liquid refrigerant flows throughliquid passages73 and81 and intoliquid feed tube58 ofliquid evaporator assemblies42 as shown. Liquid feed tube o-rings84 isolateliquid passage81 fromgas passage82. Evaporated refrigerant61leaves evaporator assembly42 throughgas passage82 and74, and exits control valve assembly through pressurerelief valve assembly67 as shown.Gas pressurization port72 allows pressurization of convective heat transfer liquid space at the pressure of the evaporator operating pressure to provide inward expansion of inner wall41 (FIG. 9) and a snug fit of coolingcap8 with the head which provides enhanced heat transfer between the head andinner wall41.Evaporator assemblies42 may be welded to evaporatormanifold housing87 as shown, or may be fastened by some other fastener.Manifold housing87 may be bolted tovalve housing79. Inner o-ring85, and outer o-ring86 provide isolation ofliquid passages73 and81, fromgas passages74 and82, and from the atmosphere.Outer wall40 may be bonded or fastened tovalve housing79 by a fastener appropriate based of specific material considerations.
• While this invention has been particularly shown and described with references to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
• The body temperature sensor may be in the form of a Foley catheter, or an esophageal catheter, or a rectal probe, or a tympanic temperature sensor, or a scalp temperature sensor.
• The liquid flow control valve may be constructed to automatically control liquid refrigerant flow into the cooling helmet using valves similar to thermostatic expansion valves used in commercial refrigeration systems.
• Returning toFIG. 1, in one arrangement, the cooling-cap or garment includes aniontophoresis assembly90 that delivers a medication to a patient. During the process of iontophoresis, electric current passes through a solution containing ions, usually the ionic form of a drug or therapeutic agent. The current forces the medication to enter the patient's bloodstream through the skin.
• As illustrated inFIG. 1, for example, the coolinggarment2 includes theiontophoresis assembly90 that includes ananode92, acathode94, and apower source96 to provide a direct current voltage to theanode92 andcathode94. In one arrangement, theiontophoresis assembly90 delivers a anesthetic agent, such as a topical contained withingel66, as illustrated inFIG. 9, to minimize cold sensation in the scalp during operation of the cooling assembly.
• The heat transfer liquid or gel may include a suspension of metal powder to enhance heat transfer from the head to the inner wall, or a topical anesthetic to minimize cold sensation in the scalp.
• Professional or amateur athletes may use embodiments of the invention during an athletic event for comfort or to prevent or recover from heat exhaustion.
• A means other than convective heat transfer liquid may be used to transfer heat from the inner wall to the evaporator assembly.
• The cooling source may be mounted in a vehicle. The cooling source may also be a refrigeration system mounted in a vehicle.
• The liquid flow control valve may be located at the cooling source.

Claims (20)

1-21. (canceled)

22. A cooling assembly, comprising:

a garment having a chamber configured to receive a liquid refrigerant, the chamber having a vent configured to release evaporated liquid refrigerant; and

a thermal transfer fluid disposed within the chamber, the thermal transfer fluid configured to exchange heat between the liquid refrigerant and a body portion in thermal contact with the garment.

23. The cooling assembly ofclaim 22, wherein the chamber comprises a pressure relief valve configured to maintain a pressure within the chamber.

24. The cooling assembly ofclaim 22, wherein the vent comprises a gas permeable membrane forming at least a portion of a wall of the chamber.

25. The cooling assembly ofclaim 22, wherein the garment comprises an iontophoresis assembly configured to deliver an electric current to a therapeutic agent.

26. The cooling assembly ofclaim 25, wherein the iontophoresis assembly comprises an anode, a cathode, and a power source in electrical communication with the anode and the cathode.

27. A thermal exchange assembly, comprising

a chamber containing a thermal transfer fluid; and

an evaporator assembly in thermal communication with the thermal transfer fluid, the evaporator assembly having an evaporator chamber configured to receive a liquid refrigerant and having a vent configured to release evaporated liquid refrigerant from the evaporator chamber.

28. The thermal exchange assembly ofclaim 27, wherein the evaporator assembly a pressure relief valve configured to maintain a pressure within the evaporator chamber.

29. The thermal exchange assembly ofclaim 27, wherein the vent comprises a gas permeable membrane forming at least a portion of a wall of the evaporator chamber.

30. A cooling system, comprising:

a console containing a liquid refrigerant source;

a garment coupled to the console, the garment having a chamber configured to receive the liquid refrigerant, the chamber having a vent configured to release evaporated liquid refrigerant; and

a thermal transfer fluid disposed within the chamber, the thermal transfer fluid configured to exchange heat between the liquid refrigerant and a body portion in thermal contact with the garment.

31. The cooling system ofclaim 30, wherein the chamber comprises a pressure relief valve configured to maintain a pressure within the chamber.

32. The cooling system ofclaim 30, wherein the vent comprises a gas permeable membrane forming at least a portion of a wall of the chamber.

33. The cooling system ofclaim 30, wherein the garment comprises an iontophoresis assembly configured to deliver an electric current to a therapeutic agent.

34. The cooling system ofclaim 33, wherein the iontophoresis assembly comprises an anode, a cathode, and a power source in electrical communication with the anode and the cathode.

35. The cooling system ofclaim 30, further comprising a gel in thermal communication with the garment and configured to thermally contact the body portion.

36. The cooling system ofclaim 35, wherein the gel includes an anesthetic agent.

37. The cooling system ofclaim 35, wherein the gel includes a suspension of metal powder disposed therein.

38. The cooling system ofclaim 30, comprising a flow control valve in fluid communication with the chamber.

39. The cooling system ofclaim 38, wherein the consol comprises a physiological sensor configured to contact a subject, the control console coupled to the flow control valve and configured adjust the flow control valve based upon a signal received from the physiological sensor.

40. The cooling system ofclaim 30, wherein the console comprises a treatment device chosen from the group consisting of a defibrillation device, a chest compression apparatus, and an intravenous fluid infusion device.

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