REINFORCED ESOPHAGEAL HEAT TRANSFER DEVICES

Reinforced esophageal heat transfer devices are disclosed. An example reinforced esophageal heat transfer device includes a distal end configured for nasopharyngeal or oropharyngeal insertion into an esophagus of a subject, a proximal end including an inlet port and an outlet port, a heat transfer region between the distal end and the proximal end, one or more lumens configured for providing a fluid path for flow of a heat transfer medium to and from the heat transfer region, and one or more reinforcing elements configured for reinforcing the one or more lumens to enable the heat transfer medium to flow through the fluid path via negative pressure.

TECHNICAL FIELD

The present disclosure generally relates to heat transfer devices, more specifically, reinforced esophageal heat transfer devices; systems; and methods for managing temperature, particularly esophageal temperature and/or core body temperature, in a subject. In one aspect, the present technology relates to a reinforced esophageal heat transfer device for managing core body temperature in a subject. In one aspect, the present technology relates to a temperature management system including a reinforced esophageal heat transfer device for managing core body temperature in a subject. In one aspect, the present technology relates to a method of using a reinforced esophageal heat transfer device or temperature management system for managing core body temperature in a subject.

BACKGROUND

Active temperature management has been shown to be important for a number of conditions. In particular, adults who remain comatose after resuscitation from cardiac arrest, neonates suffering from hypoxic ischemic encephalopathy, and patients undergoing general surgical procedures longer than one hour in duration all have strong recommendations for temperature modulation. More broadly, active temperature management has been shown to be potentially beneficial for certain subsets of traumatic brain injury, including refractory fever in acutely brain injured patients; spinal cord injury; certain subsets of stroke; acute myocardial infarction; traumatic/hemorrhagic cardiac arrest; surgical operations lasting longer than one hour; hepatic encephalopathy; sepsis/septic shock; and raised intracranial pressure.

For example, temperature management in an operative setting may improve patient outcome and reduce adverse events. Oftentimes, a patient's body temperature is controlled while undergoing surgical procedures in an operating room. The patient's body temperature may be controlled to avoid perioperative hypothermia during operative procedures, which potentially may otherwise increases the incidence of wound infection, prolong hospitalization, increase the incidence of morbid cardiac events and ventricular tachycardia, and/or impair coagulation. In some instances, surface cooling (e.g., via blankets, external vests, cooling helmets, etc.), raised operating room temperatures, inhaled gases, balloon catheters, and/or intravenous fluids are utilized to control a patient's body temperature during surgery.

Circulation of heat transfer medium (e.g., water, saline, etc.) within an esophageal heat transfer device allows for management of core body temperature of a subject. External heat exchangers are used to monitor subject temperature and adjust the temperature of circulating heat transfer medium to warm the subject, cool the subject, and/or maintain the subject at a relatively constant temperature, such as in a state of normothermia. Available esophageal heat transfer devices are fabricated from relatively thin-walled silicone tubing, which has a desirable combination of heat transfer, manufacturability, and strength properties.

SUMMARY

In one aspect, the present technology pertains to a reinforced esophageal heat transfer device. An example disclosed reinforced esophageal heat transfer device includes a distal end configured for nasopharyngeal or oropharyngeal insertion into an esophagus of a subject, a proximal end including an inlet port and an outlet port, a heat transfer region between the distal end and the proximal end and configured for contacting esophageal epithelium of the subject, a flexible tube defining one or more lumens configured for providing a fluid path for flow of a heat transfer medium to and from the heat transfer region, and one or more reinforcing elements, such as a reinforcing wire (e.g., a coiled wire), configured for reinforcing the flexible tube to enable the heat transfer medium to flow through the fluid path via negative pressure.

In one aspect, the present technology pertains to an esophageal heat transfer device comprising at least one reinforced silicone tube. In certain embodiments, the reinforced silicone tube comprises at least one reinforcing element. In certain embodiments, the reinforcing element is a reinforcing wire. In certain embodiments, the reinforcing element is a reinforcing coil. In certain embodiments, the reinforcing coil is a metal spring, such as a stainless steel spring, a nylon spring, or a plastic spring. In certain embodiments, the reinforcing coil is coextruded with the silicone during the formation of the tube itself. In certain embodiments, the reinforcing coil has a substantially D-shaped cross section. In other embodiments, the reinforcing coil has a circular cross section such that the coil is substantially cylindrical. In certain embodiments, the reinforcing coil is a light weight, low stiffness compression spring. In certain embodiments, the reinforcing coil has a diameter of about 1 mm to about 5 mm, preferably about 3 mm.

DETAILED DESCRIPTION

Oftentimes, a patient's body temperature is controlled while undergoing surgical procedures in an operating room. The patient's body temperature may be controlled to avoid perioperative hypothermia during operative procedures, which potentially may otherwise increases the incidence of wound infection, prolong hospitalization, increase the incidence of morbid cardiac events and ventricular tachycardia, and/or impair coagulation. In some instances, surface cooling (e.g., via blankets, external vests, cooling helmets, etc.), raised operating room temperatures, inhaled gases, balloon catheters, and/or intravenous fluids are utilized to control a patient's body temperature during surgery.

In one aspect, the present technology pertains to a reinforced esophageal heat transfer device. Example reinforced esophageal heat transfer devices include a heat transfer region that is configured for contacting tissue (e.g., esophageal epithelium) of a subject and transferring heat to the esophageal epithelium to heat or cool the subject. In certain embodiments, the reinforced esophageal heat transfer devices include a distal end configured for nasopharyngeal or oropharyngeal insertion into an esophagus of the subject and a proximal end that includes an inlet port and an outlet port. In some such embodiments, the heat transfer region is located between the distal end and the proximal end. Further, an example reinforced esophageal heat transfer device includes a plurality of lumens (e.g., a heat transfer medium supply lumen, a heat transfer medium return lumen) that are configured for providing a fluid path for flow of a heat transfer medium to and from the heat transfer region. Example reinforced esophageal heat transfer devices include a reinforcing element. For example, a plurality of reinforcing wires are configured for reinforcing a flexible tube that defines the plurality of lumens to enable the heat transfer medium to flow through the fluid path via negative pressure. That is, the example reinforced esophageal heat transfer devices are reinforced with the plurality reinforcing wires to prevent the negative pressure from collapsing the flexible tube and, thus, maintain the patency of the fluid path.

In certain embodiments, the reinforcing element is integrated with the device and, in particular, the flexible tube(s) defining a lumen for flow of heat transfer medium. For example, the reinforcing element may be coextruded with the tubing during the formation of the tube itself. In certain embodiments, the reinforcing element is a separate component from the device. For example, the reinforcing element may be disposed within the lumen.

In certain embodiments disclosed herein, a reinforced esophageal heat transfer device is intended to control a subject's temperature, while simultaneously maintaining access to the stomach to allow gastric decompression and drainage. In some such embodiments, the esophageal heat transfer device comprises a silicone tube with three lumens. In some such embodiments, two parallel lumens (an inflow lumen and an outflow lumen) are in fluid communication with each other and an external heat exchanger to provide a fluid path for the flow of heat transfer medium to and from the external heat exchanger. In some such embodiments, a third lumen provides gastric access. The third lumen can be connected to wall suction and used for standard gastric decompression. In certain embodiments, the third lumen is in a co-axial arrangement with the inflow and outflow lumens. In some such embodiments, a web supports the inner gastric lumen and separates inflow and outflow lumens. Upon placement in a subject, an external portion of the silicone tube is in contact with the esophageal tissue of the subject. Modulation and control of subject temperature is intended to be achieved by connecting the device to an external heat exchanger and circulating temperature-controlled heat transfer medium (e.g., water) along the fluid path.

In one aspect, the present technology pertains to an esophageal heat transfer device comprising at least one reinforced silicone tube. In certain embodiments, the reinforced silicone tube comprises at least one reinforcing element. The reinforcing element enhances the radial stiffness of the tube sufficiently to prevent the collapsing of the tube when operating in a negative pressure environment and/or enhances longitudinal stiffness of the tube to enhance placement. In certain embodiments, the reinforcing element is a light weight, low stiffness compression spring. In certain embodiments, the spring is a metal spring. In certain embodiments, the metal is non-ferromagnetic metal. In certain embodiments, one or more such springs are disposed within at least one lumen of the esophageal heat transfer device (i.e., multiple springs may be present in each lumen). In certain embodiments, a single spring is coextruded to maintain the stiffness of the tube. In certain embodiments, an exemplary esophageal heat transfer device comprises three lumens: inflow lumen, outflow lumen, and central lumen. In some such embodiments, at least one reinforcing element is disposed within at least one of the lumens. In some such embodiments, the reinforcing element is a reinforcing wire, such as metal spring. In some such embodiments, a first metal spring is disposed within the inflow lumen and a second metal spring is disposed within the outflow lumen. In some such embodiments, a first set of metal springs are disposed within inflow lumen and a second set of metal springs are disposed within the outflow lumen. The first set of metal springs can be arranged in parallel to each other. Likewise, the second set of metal springs can be arranged in parallel to each other. In some such embodiments, extension tubes are provided to connect the heat transfer device to an external heat exchanger.

In certain embodiments, an esophageal heat transfer device comprising at least one reinforced silicone tube has an increased radio-opacity relative to existing esophageal heat transfer devices. As such, an esophageal heat transfer device comprising at least one reinforced silicone tube may be viewed using x-ray imaging.

In certain embodiments, the reinforcing element is integrated with the device and, in particular, the silicone tube. For example, the reinforcing element may be coextruded with the silicone during the formation of the tube itself. In certain embodiments, the reinforcing element is a separate component from the device. For example, the reinforcing element may be disposed within the lumen of the silicone tube.

In one aspect, the present technology pertains to a system to manage temperature in a subject, the system including: an esophageal heat transfer device comprising at least one reinforced silicone tube and a source of a heat transfer medium. The esophageal heat transfer device is capable of interconnection to the source of the heat transfer medium. The source of the heat transfer medium operates to circulate the heat transfer medium through the heat transfer device. In certain embodiments, the source of the heat transfer medium includes a reservoir. In certain embodiments, the reservoir is capable of storing the heat transfer medium. In certain embodiments, the system includes the esophageal heat transfer device comprising at least one reinforced silicone tube and a negative pressure chiller, such as the Arctic Sun Temperature Management System (Bard Medical) or equivalent unit

In certain embodiments, the esophageal heat transfer device comprising at least one reinforced silicone tube is used with a negative pressure chiller, such as the Arctic Sun Temperature Management System (Bard Medical) or equivalent unit. In certain other embodiments, the esophageal heat transfer device comprising at least one reinforced silicone tube is used with another source of heat transfer medium such as a Medi-Therm III Conductive Hyper/Hypothermia System (Gaymar/Stryker), a Blanketrol II or Blanketrol III Hyper-Hypothermia System (Cincinnati Sub-Zero) or equivalent unit.

In certain embodiments, the source of the heat transfer medium supplies temperature-controlled fluid, such as water or saline, through a connector hose to the heat transfer device. An accessory temperature probe may interface between the source and the subject to sense subject temperature, which may be displayed on the source's control panel. In certain embodiments, the source includes a circulating pump, heater, and refrigeration system.

In certain embodiments, the system further comprises a subject temperature probe. In certain embodiments, the source of the heat transfer medium interfaces with a subject temperature probe. The subject temperature probe can be a component of the heat transfer device or a separate device that is capable of being directly or indirectly coupled to the source. Subject temperature probes are commercially available from, for example, Smiths Medical. Subject temperature probes are available for rectal, oral, vaginal, esophageal, or bladder temperature measurement.

In certain embodiments, the system includes: (a) at least one processor; (b) at least one operator interface configured to provide input to the processor; and (c) at least one memory. The system is configured to: (1) receive an operator generated temperature setting and (2) control the temperature of the heat transfer medium and/or the flow rate of heat transfer medium through the heat transfer device.

In certain embodiments, the system senses a temperature of the subject (e.g., core body temperature of the subject) through a temperature probe and compares it to a user-selected target temperature, adjusting the temperature and/or flow rate of the heat transfer medium appropriately. For example, a temperature probe may convert subject temperature data into electronically readable signals that are transmitted to the source of the heat transfer medium, which then, if necessary, automatically adjusts the temperature and/or flow rate of the heat transfer medium to achieve target temperature.

In certain embodiments, the reinforcing element enhances radial stiffness of the tube sufficiently to prevent the collapsing of the tube when operating under negative pressure. In certain embodiments, the reinforcing element additionally provides longitudinal stiffness to the device. The additional longitudinal stiffness provided by the reinforcing element allows for easier placement of the device. In certain embodiments, the reinforcing element provides sufficient longitudinal stiffness to facilitate insertion and placement of the device, but also includes sufficient flexibility to facilitate traversal of the subject's pharynx and esophagus from an access point, such as the subject's mouth or nostril. In certain embodiments, the term “subject” includes a mammal in need of therapy for a condition, disease, or disorder or the symptoms associated therewith. The term “subject” includes dogs, cats, pigs, cows, sheep, goats, horses, rats, mice and humans. The term “subject” does not exclude an individual that is normal in all respects.

In certain embodiments, the subject is in need of targeted temperature management. In certain embodiments, the subject is febrile. In some such embodiments, the subject is in an intensive care unit. In certain embodiments, the subject is suffering from or is at risk of suffering an ischemia-reperfusion injury.

In certain embodiments, the subject presents with out-of-hospital cardiac arrest (OHCA). In certain embodiments, the subject presents with in-hospital cardiac arrest (IHCA). In certain embodiments, the subject has been resuscitated following cardiac arrest. In some such embodiments, the subject's core body temperature is maintained between about 33° C. and about 36° C., such as about 33° C., about 34° C., about 35° C., or about 36° C., for at least 12 hours. Alternatively, the subject's core body temperature is maintained between about 33° C. and about 36° C. for at least 24 hours, at least 36 hours, at least 48 hours, at least 60 hours, at least 72 hours, at least 84 hours, or at least 96 hours.

In certain embodiments, the subject has hypoxic ischemic encephalopathy. In some such embodiments, the subject's core body temperature is maintained between about 32° C. and about 34° C., such as about 32° C., about 33° C., or about 34° C., for at least 24 hours. Alternatively, the subject's core body temperature is maintained between about 32° C. and about 34° C. for at least 48 hours, at least 72 hours, or at least 96 hours.

In certain embodiments, the subject has suffered a neurological insult, such as a stroke, spinal cord injury, or traumatic brain injury. In some such embodiments, the subject's core body temperature is maintained at normothermia for at least 24 hours. Alternatively, the subject's core body temperature is maintained at normothermia for at least 48 hours, at least 72 hours, or at least 96 hours.

In certain embodiments, the subject has suffered an acute myocardial infarction. In some such embodiments, the subject's core body temperature is maintained between about 33° C. and about 36° C., such as about 33° C., about 34° C., about 35° C., or about 35° C., for at least 12 hours. Alternatively, the subject's core body temperature is maintained between about 33° C. and about 36° C. for at least 24 hours, at least 36 hours, at least 48 hours, at least 60 hours, at least 72 hours, at least 84 hours, or at least 96 hours.

In certain embodiments, the subject is a burn patient. In some such embodiments, the burn patient is undergoing a surgical procedure. In some such embodiments, the burn patient's core body temperature is maintained at normothermia for the duration of the surgical procedure. In some such embodiments, the burn patient's core body temperature is maintained within a target range for the duration of the surgical procedure.

In certain embodiments, the subject is a patient undergoing a surgical operation. In some such embodiments, the surgical operation is scheduled to last for more than one, two, three, four, five, six, seven, or eight hours. In a particular embodiment, the surgical operation is scheduled to last for at least one hour. In some such embodiments, the subject's core body temperature is maintained at normothermia for the duration of the surgical operation. In some such embodiments, the subject's core body temperature is maintained within a target range for the duration of the surgical operation.

Turning to the figures,FIGS. 1 and 2depict an exemplary reinforced heat transfer device100in accordance with the teachings herein. More specifically,FIG. 1is a cross-sectional side view of the reinforced heat transfer device100, andFIG. 2is a cross-sectional view of the heat transfer region of the reinforced heat transfer device100.

As illustrated inFIG. 1, the reinforced heat transfer device100includes a heat transfer region102, which includes an internal cavity104. The reinforced heat transfer device100includes a proximal end106and a distal end108. The heat transfer region102extends between the proximal end106and the distal end108. The reinforced heat transfer device100also includes an inlet port110and an outlet port112. The inlet port110is fluidly connected to a heat transfer medium supply lumen114of the reinforced heat transfer device100, and the outlet port112is fluidly connected to a heat transfer medium return lumen116of the reinforced heat transfer device100.

As illustrated inFIG. 2, the reinforced heat transfer device100includes a wall118that divides the internal cavity104into a multi-lumen cavity including the heat transfer medium supply lumen114and the heat transfer medium return lumen116. The heat transfer medium supply lumen114and the heat transfer medium return lumen116are in fluid communication with each other, thereby defining a fluid path for flow of a heat transfer medium through the reinforced heat transfer device100. For example, the wall118extends from the proximal end106and toward, but not to, the distal end108such that the heat transfer medium supply lumen114and the heat transfer medium return lumen116fluid connected toward the distal end108of the reinforced heat transfer device100.

Returning toFIG. 1, the inlet port110is configured to connect to an inflow tube120, and the outlet port112is configured to connect to an outflow tube122. For example, the inflow tube120and the outflow tube122are coupled to an external source (e.g., a heat exchanger configured to heat or chill a heat transfer medium). The inflow tube120defines an external supply lumen that provides a fluid path for flow of the heat transfer medium from the heat exchanger and to the heat transfer medium supply lumen114of the reinforced heat transfer device100. The outflow tube122defines an external return lumen that provides a fluid path for flow of the heat transfer medium from the heat transfer medium return lumen116of the reinforced heat transfer device100to the external source.

When the external source is a heat exchanger, the heat exchanger may be any of a variety of conventionally designed heat exchangers. For example, the heat exchanger may operate to provide the heat transfer medium via negative pressure. The heat transfer medium may be a gas, such as, for example, nitrous oxide, Freon, carbon dioxide, or nitrogen. Alternatively, the heat transfer medium may be a liquid, such as, for example, water, saline, propylene glycol, ethylene glycol, or mixtures thereof. In other embodiments, the heat transfer medium may be a slurry, such as, for example, a mixture of ice and salt. In still other embodiments, the heat transfer medium may be a gel, such as, for example, a refrigerant gel. Alternatively, the heat transfer medium may be a solid, such as, for example, ice or a heat conducting metal. In other embodiments, the heat transfer medium may be formed, for example, by mixing a powder with a liquid. Thus, it should be understood that combinations and/or mixtures of the above-mentioned media may be employed to achieve a heat transfer medium according to the present technology.

Thus, the inflow tube120and the outflow tube122fluidly connect the heat exchanger and the reinforced heat transfer device100to enable the heat transfer medium to flow between the heat exchanger and the reinforced heat transfer device100to heat or cool the reinforced heat transfer device100. For example, when the inflow tube120is coupled to the inlet port110and the outflow tube122is coupled to the outlet port112, the heat transfer medium flows from the heat exchanger, through the inflow tube120and into the heat transfer medium supply lumen114to heat or cool a subject via the heat transfer medium. Further, the heat transfer medium flows from the heat transfer medium supply lumen114, through the heat transfer medium return lumen116, and to the outflow tube122to circulate the heat transfer medium back to the heat exchanger.

Additionally, the reinforced heat transfer device100is configured for placement within an anatomical structure of a mammalian subject. The distal end108of the reinforced heat transfer device100is configured for insertion into a body orifice. For example, the distal end108of the reinforced heat transfer device100is configured for insertion into the nostrils, mouth, anus, or urethra of a subject. When properly inserted, the distal end108of the reinforced heat transfer device100may be ultimately positioned in the esophagus, rectum, colon, bladder, or other anatomical structure. Upon insertion of the reinforced heat transfer device100into a subject (e.g., via nostrils, mouth, anus, or urethra), a heat transfer region102of the reinforced heat transfer device100may directly contact an epithelial surface of the subject. For example, when the reinforced heat transfer device100is inserted into an esophagus of the subject, at least a portion of the heat transfer region102directly contacts the esophageal epithelium of the subject. For example, the heat transfer region102may comprise flexible tubing124and is generally located between the distal end108and the proximal end106. In other examples, the heat transfer region102is defined by the flexible tubing124and the distal end108of the reinforced heat transfer device100. The heat transfer medium is supplied to the reinforced heat transfer device100(e.g., from a heat exchanger) via the inlet port110and the inflow tube120connected to the inlet port110. The heat transfer medium circulates through the reinforced heat transfer device100to transfer heat (e.g., to heat, to cool, or to maintain temperature) between the subject and the heat transfer region102that contacts and/or is positioned adjacent to an inner surface (e.g., of the esophagus) of the subject. Further, the heat transfer medium exits the reinforced heat transfer device100through the outlet port112and the outflow tube122connected to the outlet port112.

As illustrated inFIGS. 1 and 2, the reinforced heat transfer device100also includes a gastric access tube126that defines a gastric access lumen128and extends to the distal end108of the reinforced heat transfer device100. Further, the reinforced heat transfer device100includes one or more ports130along the side of the gastric access tube126. In the illustrated example, the one or more ports130are located along the gastric access tube126at the distal end108of the reinforced heat transfer device100. The one or more ports130may provide for communication between the space exterior to the reinforced heat transfer device100and the gastric access lumen128. For example, the one or more ports130may act as a portal between the subject's stomach and the gastric access lumen128allowing the gastric contents to be suctioned from the subject's stomach out through the gastric access lumen128. The presence of one or more ports130provides reduced likelihood of blockage of the gastric access lumen128from semi-solid stomach contents. Alternatively, multiple gastric access lumens may be employed. The addition of one or more ports130may improve and enhance the removal of stomach contents, which, in turn, may improve contact between gastric mucosa and the heat transfer region102of the reinforced heat transfer device100. Such improved contact may enhance heat transfer between the reinforced heat transfer device100and the gastric mucosa and, thus, enhance heating or cooling of the subject. The configuration of the ports130shown inFIG. 1is oval. However, the ports130can be, for example, circular, rectangular, or any other shape that permits flow of gastric contents from the stomach to the gastric access lumen128.

The reinforced heat transfer device100is manufactured via, for example, extrusion. For example, utilizing extrusion processes to form the reinforced heat transfer device100may eliminate the need to seal junctions or affix end caps and reduce the points at which leaks may occur. In some examples, the flexible tubing124, the wall118, and the gastric access tube126are integrally formed via extrusion. In other examples, the flexible tubing124and the wall118are integrally formed via extrusion, the gastric access tube126is formed separately via extrusion, and the gastric access tube126is subsequently inserted into the internal cavity104defined by the flexible tubing124. In other examples, the flexible tubing124, the wall118, and the gastric access tube126are formed separately via extrusion, and the wall118and the gastric access tube126are inserted into the internal cavity104to assemble the reinforced heat transfer device100.

In some examples, components of the reinforced heat transfer device100(e.g., the flexible tubing124, the wall118, and the gastric access tube126) includes or is formed of a semi-rigid material such as a semi-rigid polymer. For example, the flexible tubing124, the wall118, and/or the gastric access tube126is formed of silicone to increase a flexibility and/or a thermal conductivity of the reinforced heat transfer device100. In some such examples, the components of the reinforced heat transfer device100are formed of biomedical grade extruded silicone rubber such as Dow Corning Q7 4765 silicone. When the flexible tubing124is formed of silicone, the heat transfer region102defined by the flexible tubing124more efficiently transfers heat from the heat transfer medium to the esophageal epithelium to heat or cool the subject due to the increased thermal conductivity of the material forming the reinforced heat transfer device100. In other examples, the components of the reinforced heat transfer device100are formed of other semi-rigid materials including semi-rigid plastics such as ethylene tetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), and fluorinated ethylene propylene (FEP).

In certain embodiments, the reinforced heat transfer device100of the illustrated example includes one or more reinforcing elements disposed within one or more lumens, such as an inflow lumen and/or an outflow lumen.

In certain embodiments, the reinforced heat transfer device100of the illustrated example includes one or more reinforcing elements, such as a reinforcing wire (e.g., mesh, coil), embedded into the flexible tubing124, the wall118, and/or the gastric access tube126of the reinforced heat transfer device100. For example, a reinforcing wire may be embedded into one or more of the components of the reinforced heat transfer device100during the extrusion process. The reinforcing wire may be a metallic wire that stiffens the reinforced heat transfer device100. In some such embodiments, the reinforcing wires form a mesh embedded in the flexible tubing124, a mesh embedded in the wall118, and/or a mesh embedded in the gastric access tube126of the to reinforce the semi-rigid material of the reinforced heat transfer device100. In other examples, the reinforcing wires may be springs (e.g., helical springs such as 5-millimeter helical springs, D-shaped springs) that are embedded in the flexible tubing124, the wall118, and/or the gastric access tube126to reinforce or stiffen the reinforced heat transfer device100.

In certain embodiments, the reinforced heat transfer device100includes a reinforcing element, such as a reinforcing wire, to prevent the fluid path from becoming blocked when a negative pressure is applied to the heat transfer medium supply lumen114and/or the heat transfer medium return lumen116.

For example, the heat transfer device100may be fluidly connected to a heat exchanger via the inlet port110and the outlet port112to enable the heat transfer device100to transfer heat to heat or cool the subject. In some examples, the heat exchanger provides the heat transfer medium to the heat transfer device100by creating a negative pressure. In some instances, when the flexible tubing124, the wall118, and/or the gastric access tube126defining the heat transfer medium supply lumen114and/or the heat transfer medium return lumen116are formed of silicone rubber and/or any other semi-rigid material without a reinforcing element, the negative pressure generated by the heat exchanger potentially may cause the flexible tubing that defines the heat transfer medium supply lumen114and/or the heat transfer medium return lumen116to collapse. In such instances, the heat transfer medium is unable to flow through the fluid path defined by the heat transfer medium supply lumen114and the heat transfer medium return lumen116and, thus, is unable to cause heat to transfer to the subject via the heat transfer region102.

The reinforcing element of the heat transfer device100serves to stiffen and/or otherwise reinforce the flexible tubing124, the wall118, and/or the gastric access tube126to prevent the heat transfer medium supply lumen114and the heat transfer medium return lumen116from collapsing when negative pressure is created by the heat exchanger fluidly connected to the heat transfer device100. That is, the reinforcing element facilitates flow of the heat transfer medium through the fluid path of the heat transfer device100when utilized with an external heat exchanger that provides heat transfer medium via negative pressure, thereby enabling the heat transfer device100to be utilized with such heat exchangers to warm or cool a subject.

In certain embodiments, a reinforcing element, such as one formed of metallic material(s), increases radio-opacity of the heat transfer device100. For example, the increased radio-opacity enables the heat transfer device100to be viewed via an x-ray when inserted into the esophagus of the subject. By enabling the heat transfer device100to be viewed via an x-ray, the reinforcing element enables an operator (e.g., a technician, a nurse, a doctor) to utilize an x-ray to determine a location of and/or to navigate the heat transfer device100when inserted into the subject.

FIGS. 3A, 3B, 4, and 5illustrate another example heat transfer device300in accordance with the teachings herein. More specifically,FIG. 3depicts the heat transfer device300when assembled,FIG. 4depicts a cross-sectional top view of the heat transfer device300,FIG. 5depicts a portion of the heat transfer device300when partially disassembled, andFIG. 6depicts a portion of the heat transfer device300when partially assembled.

As illustrated inFIGS. 3A and 3B, the heat transfer device300includes the heat transfer region102, the proximal end106, the distal end108, the inlet port110, the outlet port112, the wall118, and the gastric access tube126. Those components of the heat transfer device300are identical to or substantially similar to the heat transfer region102, the proximal end106, the distal end108, the inlet port110, the outlet port112, the wall118, and the gastric access tube126as disclosed in accordance withFIGS. 1-2. Accordingly, some features of those components of the heat transfer device300will not be described in further detail below.

The heat transfer device300includes one or more reinforcing elements302that extend through the internal cavity104to reinforce or stiffen the heat transfer device300. In certain embodiments, the reinforcing element(s)302are metallic wires that stiffen the reinforced heat transfer device300. As illustrated inFIG. 3A, one or more of the reinforcing elements302extend through the inlet port110and/or into the inflow tube120to reinforce at least a portion of the inflow tube120. One or more of the reinforcing elements302also extend through the outlet port112and/or into the outflow tube122to reinforce at least a portion of the outflow tube122.

As illustrated inFIG. 3B, one or more of the reinforcing elements302are inserted into the heat transfer medium supply lumen114to reinforce the heat transfer medium supply lumen114to prevent the heat transfer medium supply lumen114from collapsing when a negative pressure is applied. Further, one or more of the reinforcing elements302are inserted into the heat transfer medium return lumen116to reinforce the heat transfer medium return lumen116to prevent the heat transfer medium return lumen116from collapsing when a negative pressure is applied. In the illustrated example, two of the reinforcing elements302are inserted into the heat transfer medium supply lumen114, and two of the reinforcing elements302are inserted into the heat transfer medium return lumen116. In other examples, more or less of the reinforcing elements302may be inserted into the heat transfer medium supply lumen114and/or the heat transfer medium return lumen116to stiffen the heat transfer device300. Further, in some examples, one or more of the reinforcing elements302are inserted into the gastric access lumen128.

In the illustrated example, the reinforcing elements302are springs, such as helical springs (e.g., 5-millimeter helical springs) or D-shaped springs. In other examples, the reinforcing elements302are meshes that extend through the internal cavity104of the heat transfer device300. Further, in the illustrated example, the flexible tubing124, the wall118, and/or the gastric access tube126are not embedded with reinforcing wires such that the reinforcing elements302inserted into the internal cavity104to prevent the flexible tubing124, the wall118, and/or the gastric access tube126from collapsing. In other examples, other reinforcing elements (e.g., a reinforcing wire) are embedded into the flexible tubing124, the wall118, and/or the gastric access tube126such that the reinforcing element and the embedded reinforcing wires combine to reinforce the fluid path of the heat transfer device300.

FIG. 4illustrates a portion of the heat transfer device300when a port connector402of the heat transfer device300is decoupled from the flexible tubing124. As illustrated inFIG. 4, the port connector402includes the inlet port110, the outlet port112, an aperture404through which the gastric access tube126is to extend, and an end406that is to couple to the flexible tubing124. In the illustrated example, two reinforcing elements302extend through the heat transfer medium supply lumen114. Additionally, two reinforcing elements302extend through the heat transfer medium return lumen116.

FIG. 5illustrates a portion of the heat transfer device300when the port connector402is coupled to the flexible tubing124of the heat transfer device300. In the illustrated example, one reinforcing element302extends through the heat transfer medium return lumen116, through the outlet port112, and at least partially into the outflow tube122.

Additional Embodiments

In one aspect, the present disclosure provides an esophageal heat transfer device comprising at least one reinforced tube defining a lumen for flow of a heat transfer medium. In certain embodiments, the reinforced tube is a silicone tube.

In one aspect, the present disclosure provides an esophageal heat transfer device comprising a lumen for flow of a heat transfer medium and a reinforcing element disposed within said lumen. In certain embodiments, the reinforcing element is a coil, preferably a spring, and more preferably a metal spring.

In one aspect, the present disclosure provides an esophageal heat transfer device comprising a first reinforced tube defining an inflow lumen and a second reinforced tube defining an outflow lumen. In certain embodiments, the first and second reinforced tubes have sufficient radial strength to prevent collapse in a negative pressure environment.

In one aspect, the present disclosure provides an esophageal heat transfer device comprising an inflow lumen in fluid communication with an outflow lumen, and at least one reinforcing element disposed within said inflow lumen or said outflow lumen. In certain embodiments, at least one reinforcing element is disposed within each of said inflow lumen and said outflow lumen.

In one aspect, the present disclosure provides a reinforced esophageal heat transfer device comprising: (a) a distal end configured for nasopharyngeal or oropharyngeal insertion into an esophagus of a subject; (b) a proximal end including an inlet port and an outlet port; (c) a heat transfer region between the distal end and the proximal end; (d) one or more lumens configured for providing a fluid path for flow of a heat transfer medium to and from the heat transfer region; and (e) one or more reinforcing elements configured for reinforcing the one or more lumens to enable the heat transfer medium to flow through the fluid path via negative pressure.