Apparatus and method for controlling brain temperature

Abstract

A device (1) for indirectly regulating the temperature of a brain of a person via the nasal cavity of the person, the device comprising: a membrane (2) having a membrane surface area (A0), a length (L), a centre point (C1) relative to the length (L), a width (W), and a centre point (C2) relative to the width, said membrane (2) being adapted to be arranged in contact with a surface of the nasal cavity, said membrane (2) defining an enclosed volume (V) and having the shape of the nasal cavity such that, in use, the membrane expands and conforms to the nasal cavity; a first conduit (3); a second conduit (4); and circulating means for circulating said fluid into said volume (V) via said first conduit (3) and out of said volume (V) via said second conduit (4).

Description

Technical Field

[0001] This invention relates to an apparatus and method for indirectly regulating brain temperature. The apparatus and method are particularly suitable for humans. Background Technology

[0002] In pathological conditions, body temperature or the temperature of a body part affects the healing process and the risk of permanent damage. For example, cancer cells are heat-sensitive, and for some types of cancer, local heating of the blood flow around the cancerous tumor can constitute a treatment that inhibits tumor growth or, in some cases, even shrinks the tumor. In other cases, cooling of body parts can be important for reducing adverse secondary symptoms of pathological conditions, primarily for treating cerebral ischemia. In the case of a stroke, blood flow to the brain is reduced (ischemia) due to hemorrhage or vascular blockage. This condition will lead to permanent functional impairment (such as paralysis) unless treatment to restore blood flow and protect nerve cells is initiated early, minimizing the loss of bodily function. It is well known that cooling the brain effectively prevents the development of cell damage after an ischemic attack. Systemic cooling of patients with temporary circulatory arrest in the brain alleviates symptoms of neurological dysfunction. However, there are some problems associated with systemic cooling. One problem is that cooling is not rapid enough to effectively utilize its protective potential. Another problem is that systemic cooling must be performed under close control of physiological parameters or under anesthesia. There is also the risk of cardiovascular complications. In cases of circulatory arrest, if the cessation of circulation lasts for more than approximately 5 to 15 minutes, permanent brain damage may occur. However, lowering brain temperature before, during, or after circulatory arrest can reduce brain damage. In cases of traumatic brain injury, such as open or closed concussions, hypothermia has been shown to reduce traumatic brain injury.

[0003] Therefore, improvements are needed in the field of brain temperature regulation. Summary of the Invention

[0004] The object of the present invention is to provide an improved and effective apparatus and method for regulating brain temperature via the nasal cavity without substantially altering the temperature of the rest of the body.

[0005] According to a first aspect of the invention, a device comprising a membrane is provided, the membrane having a membrane surface area, a length, a center point relative to the length, a width, and a center point relative to the width. The membrane is adapted to be arranged in contact with a surface of a nasal cavity and to define an enclosed volume. The membrane has a nasal cavity shape such that, in use, the membrane expands and conforms to the nasal cavity. The device further comprises a first conduit extending along a distal-proximal axis and having a first distal portion for introducing fluid into the enclosed volume. The first conduit has a first end portion, and the distal portion has at least one cranially located orifice having an area. The device further comprises a second conduit extending along a distal-proximal axis, wherein the second conduit has a second distal portion for removing fluid from the enclosed volume. The second conduit has a second end portion, and the distal portion has at least one cranially located orifice having a total area, a distal oblique opening having an area, and a distal slit. The distal portion of the first catheter protrudes more into the closed volume than the distal portion of the second catheter, and the combined area of ​​the plurality of orifices on the first catheter is smaller than the total area of ​​the combined area of ​​the plurality of orifices on the second catheter. Furthermore, the membrane length extends along a portion of the distal-proximal axis such that the membrane surface area distal to the center point is larger than the membrane surface area proximal to the center point. The device further includes a circulation device for circulating fluid into the volume via at least one cranial-side orifice on the distal portion of the first catheter and out of the volume via at least one cranial-side orifice and a distal opening on the distal portion of the second catheter.

[0006] One advantage of having orifices on the cranial side of the first and second catheters is that this allows for the formation of a favorable flow pattern within the membrane. This flow pattern provides a more comfortable experience for the patient and ensures optimal treatment of the fluid flowing within the membrane. Another advantage of having at least one orifice on the second catheter that is not located cranially is that this allows air to escape. One advantage of having a smaller total area of ​​openings on the first catheter than on the second catheter is that this ensures lower flow resistance when removing fluid from the membrane than when introducing fluid. This helps maintain the correct pressure level within the membrane, thus increasing patient comfort. This advantage is further enhanced by a distal slit and a distal oblique opening on the distal portion of the second catheter, which provides an opening for removing fluid from the membrane, allowing the opening to be larger than the diameter of the catheter. Another advantage of having a distal slit on the distal portion of the second catheter is that if the membrane comes into contact with tissue in the nasal cavity, causing the cranial orifice to be blocked by the membrane, the slit still allows fluid removal. This ensures that the pressure within the membrane does not become too high. This is particularly useful for patients with abnormal nasal anatomy. One advantage of having a membrane surface area distal to the center point larger than that proximal to the center point is that it improves the flow pattern within the membrane when fluid is circulated. This is achieved by increasing the area of ​​the membrane for introducing fluid and decreasing the area for removing fluid. This membrane shape reduces the risk of stagnant circulating fluid within the membrane. Consequently, pressure and circulation of the fluid within the membrane are maintained, allowing for effective and continuous cooling of the brain.

[0007] According to another aspect of the invention, the center point is located at an equidistant distance from the first end portion and the second end portion. This has the advantage that the flow pattern within the membrane is optimal for heat exchange between the fluid and its surrounding environment.

[0008] According to another aspect of the invention, the center point is positioned closer to the first end portion than to the second end portion. This has the advantage that the flow pattern within the membrane is optimal for heat exchange between the fluid and its surrounding environment.

[0009] According to another aspect of the invention, the membrane surface area on one side of the center point is greater than the membrane surface area on the other side of the center point, such that at least one pore located on the cranial side faces the larger side. This has the advantage that the flow pattern in the membrane is optimal for heat exchange between the fluid and its surrounding environment. Another advantage is that the fluid is less likely to stagnate in the membrane.

[0010] According to another aspect of the invention, the individual area of ​​each of the at least one cranial-side opening on the first conduit is 0.1 mm. 2 Up to 1.5mm 2 between.

[0011] According to another aspect of the invention, the individual area of ​​each of the at least one cranial-side openings on the second conduit is 0.1 mm. 2 Up to 1.5mm 2 between.

[0012] According to another aspect of the invention, the number of holes on the first conduit is equal to or greater than the number of holes on the second conduit.

[0013] According to another aspect of the invention, the number of holes on the second conduit is equal to or greater than the number of holes on the first conduit. This has the advantage that the flow resistance to fluid leaving the membrane can be lower, thus ensuring that the pressure within the membrane does not become too high.

[0014] According to another aspect of the invention, the number of at least two cranial-side holes on the first catheter is provided. This has the advantage of ensuring membrane filling, allowing the membrane to inflate like a balloon. Another advantage is that fluid can enter the membrane at a satisfactory rate, making fluid circulation both effective and comfortable for the patient.

[0015] According to another aspect of the invention, the number of at least two cranial-side holes on the second catheter is provided. This has the advantage of low flow resistance as the fluid exits the membrane. Another advantage is that the fluid can exit the membrane at a satisfactory rate, making fluid circulation both effective and comfortable for the patient.

[0016] According to another aspect of the invention, the center point relative to the length is positioned such that the distance from the first end portion is 1 / 1.5 of the distance from the second end portion. This has the advantage that the flow pattern within the membrane is optimal for heat exchange between the fluid and its surrounding environment. Another advantage is that the fluid is less likely to stagnate within the membrane.

[0017] According to another aspect of the invention, the center point relative to the length is positioned such that the distance from the first end portion is half the distance from the second end portion. This has the advantage that the flow pattern within the membrane is optimal for heat exchange between the fluid and its surroundings. Another advantage is that the fluid is less likely to stagnate within the membrane.

[0018] According to another aspect of the invention, the membrane surface area on the side facing at least one pore located on the cranial side of the center point is twice the membrane surface area on the other side of the center point. This has the advantage that the flow pattern within the membrane is optimal for heat exchange between the fluid and its surrounding environment. Another advantage is that the fluid is less likely to stagnate within the membrane.

[0019] According to another aspect of the invention, a method for indirectly regulating the temperature of a human brain via a human nasal cavity is provided, the method comprising the steps of: introducing a membrane into the nasal cavity, the membrane having a membrane surface area, a length, a center point relative to the length, a width, and a center point relative to the width. The membrane is adapted to be arranged in contact with a surface of the nasal cavity and defining a closed volume. The membrane has a shape of the nasal cavity such that, in use, the membrane expands and conforms to the nasal cavity. The device further includes a first conduit extending along a distal-proximal axis and having a first distal portion for introducing fluid into the closed volume. The first conduit has a first end portion, and the distal portion has at least one cranially located orifice having an area. The device further includes a second conduit extending along a distal-proximal axis, wherein the second conduit has a second distal portion for removing fluid from the closed volume. The second conduit has a second end portion, and the distal portion has at least one cranially located orifice having an area, a distal oblique opening having an area, and a distal slit. The distal portion of the first conduit protrudes more than the distal portion of the second conduit within the closed volume, and the combined area of ​​the plurality of orifices on the first conduit is smaller than the total area of ​​the combined area of ​​the plurality of orifices on the second conduit. Furthermore, the membrane length extends along a portion of the distal-proximal axis, such that the membrane surface area distal to the center point is larger than the membrane surface area proximal to the center point. The device further includes a circulation device for circulating fluid into the volume via the plurality of cranial-side orifices on the distal portion of the first conduit and out of the volume via cranial-side orifices and a distal opening on the distal portion of the second conduit. The method further includes circulating fluid into the volume via the plurality of cranial-side orifices on the distal portion of the first conduit and out of the volume via cranial-side orifices and a distal opening on the distal portion of the second conduit by suction. The method further includes regulating the fluid by comparing the kinetics of the fluid introduced into the membrane with the kinetics of the fluid leaving the membrane using a flow meter.

[0020] The advantage of circulating fluid by aspirating it from the second conduit is that it is a safe and easy way to control the pressure within the membrane. Aspirating fluid from the second conduit also allows for the assessment of membrane pressure by observing the vibrations of a small, externally visible portion of the membrane. No vibration indicates excessive pressure, and healthcare professionals can adjust the flow rate accordingly. Conversely, excessive vibration suggests insufficient membrane pressure.

[0021] The advantage of using a flow meter to compare the heat flow of the fluid introduced into and out of the membrane is that it provides an indication of temperature changes in the brain. When the dynamic difference between the fluid introduced into and out of the membrane is zero, the brain temperature has been successfully altered. This provides a non-invasive way to indicate changes in brain temperature. Another advantage of using a flow meter to sense the heat flow rate in the fluid leaving and entering the membrane is that it provides a rapid indication of temperature changes in the brain without requiring temperature sensor feedback. Therefore, when connected to a temperature regulator, this method of sensing heat flow provides rapid feedback and enables very rapid temperature regulation.

[0022] According to another aspect of the invention, the method further includes the step of sensing brain temperature by using a temperature sensor adapted to be positioned near the corner of the eye. The advantage of sensing temperature is that, combined with a flow meter, it improves feedback on the efficiency of temperature regulation.

[0023] Preferred embodiments are described in the claims and specification. It should be noted that, unless otherwise expressly stated, the invention relates to all possible combinations of features. Attached Figure Description

[0024] The invention will be described in more detail by way of example with reference to the accompanying schematic diagrams, which illustrate the presently preferred embodiments of the invention.

[0025] Figure 1 A schematic elevation view of a device for indirectly regulating brain temperature according to the present invention is shown.

[0026] Figure 2 A side perspective view of the device according to the invention in a patient's nasal cavity is shown.

[0027] Figure 3 A schematic diagram of a system including the apparatus according to the invention is shown.

[0028] Figure 4 A flowchart of a method for indirectly regulating brain temperature according to the present invention is shown. Detailed Implementation

[0029] It is contemplated that many modifications may be made to the embodiments described herein, which still remain within the scope of the invention as defined by the appended claims.

[0030] Figure 1A schematic elevation view of a device 1 for indirectly regulating temperature according to the present invention is shown. The device includes a membrane 2. The membrane 2 has a membrane surface A0, and a length L and a width W. The length L and width W can vary depending on the patient, as the nasal cavity is individualized. Preferably, the length is 100 mm to 200 mm, and the width is 50 mm to 200 mm. Figure 1 As can be seen, membrane 2 has a center point C1 relative to its length L and a center point C2 relative to its width. Figure 1 In the diagram, center points C1 and C2 are located at the midpoints of length L and width W, respectively. Membrane 2 is adapted for insertion through the patient's nostril to contact the surface of the nasal cavity. When membrane 2 is inserted, it deflates. During use, membrane 2 is filled with fluid, causing it to inflate like an air sac. The membrane defines a closed volume V. Figure 1 As can be seen, the shape of membrane 2 mimics the shape of the nasal cavity. Therefore, during use, membrane 2 expands and conforms to the nasal cavity. Device 2 also includes two catheters 3 and 4. The first catheter 3 extends along a distal-proximal axis such that the distal portion D1 of catheter 3 is inserted into the nasal cavity. Catheter 3 has an end portion E1, which constitutes the distal portion of catheter 3. The distal portion D1 has at least one orifice 5 for introducing fluid into a closed volume V. The fluid is preferably a saline solution or any other fluid with suitable properties that are harmless to the patient in the event of fluid leakage. Figure 1 In the middle, the distal portion D1 includes three holes 5; however, one, two, four, or more holes may also be present. Preferably, eight holes 5 are present. Figure 1 The orifice 5 is located on the cranial side. "Located on the cranial side" means that when fluid from the conduit 3 enters the membrane 2 through the orifice 5, the flow direction is towards the skull. Each orifice 5 located on the cranial side has an individual area A11 and a combined area A1. The individual area A11 of the (multiple) orifices 5 is preferably 1 mm. 2 However, it seems reasonable that, depending on the size of the patient's nasal cavity and therefore the length of the distal portion D1 and the number of orifices 5, the area A11 can be smaller or larger, for example, 0.5 mm. 2 Or 1.5mm 2 The device 1 further includes a second conduit 4 for removing fluid from the volume V. The first conduit 3 and the second conduit 4 are in fluid communication and are preferably made of a flexible material (such as plastic, synthetic latex, silicone, or Gore-tex). The material may be coated with a substance that creates a hydrophilic surface or an anesthetic. The first and second conduits are connected to an external pump 13, which is referenced herein. Figure 3Further description is provided. Pump 13, conduits 3 and 4, and membrane 2 form a closed system in which membrane 2 serves as a reservoir. Pump 13 is further connected to a temperature regulator 15 for regulating the temperature of the fluid entering the system. Temperature regulator 15 may also include software for automatically adjusting the temperature in response to measured parameters (such as heat flux). To reduce the pressure in volume V, the flow rate of pump 13 is increased, causing fluid to be drawn from and removed from volume V through second conduit 4. Similarly, to increase the pressure in volume V, the flow rate of pump 13 is decreased. Second conduit 4 also extends along a distal-proximal axis, such that the distal portion D2 of conduit 4 is inserted into the nostril. Figure 1 As can be seen, the distal portion D1 of the first catheter 3 protrudes more within the closed volume V of the membrane 2 than the distal portion D2 of the second catheter 4. Figure 1 In this design, the distal portion D2 of the second conduit 4 protrudes into the closed volume V by approximately one-third of its length L. However, it would seem reasonable for the distal portion D2 to protrude even more or less into the volume V. The second conduit 4 has an end portion E2, which is a distal oblique opening 7. The distal oblique opening 7 has an area A3. When the opening is a distal oblique opening, the area A3 can be increased because it is no longer limited by the diameter of the conduit 4. By increasing the area A3, the flow resistance of fluid entering the opening 7 (i.e., removed from the volume V) is reduced. The distal portion D2 includes at least one cranial orifice 6, which has a total combined area A2. The individual area A22 of the (multiple) orifices 6 is preferably 1.2 mm. 2 However, it seems reasonable that, depending on the size of the patient's nasal cavity and therefore the length of the distal portion D2 and the number of orifices 6, the area A22 could be smaller or larger, for example, 0.5 mm. 2 Or 1.5mm 2 .exist Figure 1Two orifices 6 located on the cranial side can be seen. It would also seem reasonable for more or fewer orifices to be present. Preferably, six orifices 6 are present; however, any number of orifices 5, 6 would seem reasonable, as long as the total areas A2, A3, and A4 exceed the total area A1. The distal portion D2 further includes a distal slit 8. The distal slit is preferably 1 mm to 2 mm in size. Fluid in volume V is removed from membrane 2 through the orifices 6, openings 7, and slit 8 of catheter 4. To ensure that the pressure in the membrane does not become too high, i.e., to cause patient discomfort, the total area A2 of the orifices 6, oblique openings 7, and slit 8 on the second catheter 4 exceeds the total area A1 of the orifices 6 on the first catheter 3. Slit 8 ensures that the pressure in membrane 2 does not become too high when fluid is removed from volume V by aspiration through the orifices and openings 6, 7, even if the anatomy of the nasal cavity prevents fluid from leaving through the orifices 6 located on the cranial side. The membrane length L extends along a portion of the distal-proximal axis, and the membrane 2 has an opening 10 through which the first catheter 3 and the second catheter 4 are introduced. The diameter of the opening 10 is slightly smaller than the combined diameter of the first and second catheters, such that the membrane 2 is held tightly in place without leakage. The opening 10 is further secured to the catheters by an adhesive connector 11. The distal portion D2 of the second catheter 4 further includes holes 9 positioned immediately adjacent to the adhesive connector 11. These holes 9 ensure that air can exit the membrane 2 during fluid aspiration. When the membrane 2 is inserted into the patient's nasal cavity, the adhesive connector 11, and therefore the holes 9, become the highest point of the device 1. Figure 1 The image shows two holes (9), but there can also be more or fewer holes, such as one, three, four, or five. For example... Figure 1 It can also be seen that the membrane surface area A0 on the distal side of the center point C1 is greater than the membrane surface area A0 on the proximal side of the center point. The center point C1 is... Figure 1 The center is located at an equidistant point from the first end portion E1 and the second end portion E2. However, C1 can also be positioned closer to the first end portion E1 than to the second end portion E2, or vice versa. Figure 1As can be seen, the membrane surface area A0 on one side of the center point C2 relative to the width W is greater than the membrane surface area A0 on the other side of the center point C2, such that the orifices 5 and 6 on the cranial side face the larger side of the membrane 2. Fluid is removed from the closed volume V by suction through the orifices 6, openings 7 and slits 8 in the second conduit 4. Since the device is part of a closed system, fluid is correspondingly introduced into the volume V through the orifice 5 on the first conduit 3. When the membrane surface area A0 is larger on one side of the center points C1 and C2, such that the orifices 5 and 6 on the cranial side face the larger side, the fluid flowing in the membrane is less likely to become stagnant in the membrane. Smooth and continuous flow in the membrane is crucial for achieving optimal brain cooling. Furthermore, the device 1 may include a flow meter (not shown) for measuring the heat flow rate of the fluid introduced into the membrane 2 through the first conduit 3 and the fluid leaving the membrane 2 through the second conduit 4. If the flow meter shows that the heat flow of the fluid entering the membrane 2 is equal to the heat flow of the fluid leaving the membrane 2, this indicates that the brain temperature has been successfully altered. The device 1 may further include a temperature sensor 12 disposed near the corner of the eye. This temperature sensor 12 may be connected wirelessly or via a wire 16 to a temperature regulator 15, thereby allowing the temperature of the fluid in the membrane 2 to be regulated or maintained.

[0031] although Figure 1 Only a single device 1 is disclosed, but preferably, the patient has two devices 1, one for each nasal cavity.

[0032] Figure 2 A side perspective view of the device according to the invention in a patient's nasal cavity is shown. Figure 2 As can be seen, the shape of membrane 2 corresponds to the anatomical structure of the patient's nasal cavity. Figure 2 The device 1 shown also includes a temperature sensor 12 disposed on the skin near the patient's eyes. The sensor 12 senses brain temperature and is connected to a temperature regulator 15. By continuously measuring the temperature with the temperature sensor 12, the cooling effect of the fluid circulating in the membrane 2 can be monitored, and the temperature regulator 15 can be adjusted accordingly.

[0033] Figure 3 A schematic diagram of the system including the membrane 2 is shown when the membrane 2 is inserted into the patient. Figure 3 In the middle, the patient lies supine, with membrane 2 inserted into one of the nasal cavities. Figure 3The arrows indicate the flow direction of fluid introduced into membrane 2 through first conduit 3 and removed through second conduit 4. Pump 13 circulates the fluid in the system by acting as a suction device and draws fluid from second conduit 4, rather than pumping fluid into first conduit 3. Pump 13 is connected to temperature regulator 15. Temperature regulator 15 includes a heat exchange device that controls the temperature of the cooling fluid entering the system. Temperature regulator 15 can be manually controlled by a medical professional or includes software that automatically adjusts the temperature of the cooling fluid entering the system. Temperature regulator 15 can be connected to temperature sensor 12, which is placed on the skin near the patient's eyes to sense brain temperature. Sensor 12 can be connected directly to regulator 15 via wire 16 or wirelessly. By continuously measuring the temperature with temperature sensor 12, the cooling effect of the fluid circulating in membrane 2 can be monitored, and temperature regulator 15 can be adjusted accordingly. Figure 3 The embodiments described include two flow meters 14. It should be understood that not all embodiments of the invention include these flow meters. The flow meters 14 measure the heat flow rates entering and leaving the membrane 2. By comparing the results, an indication of temperature changes in the brain is given. When the difference between the fluid entering and leaving the membrane 2 is small, it indicates that the temperature in the brain has changed. Figure 3 In this embodiment, the patient is disclosed as having one device 1; however, preferably, during treatment, the patient has two devices 1, one in each nasal cavity, to optimize the cooling effect. When the device 1 is combined with a flow meter 14 and a temperature sensor 14, an effective device for monitoring and adjusting brain temperature can be realized.

[0034] Figure 4 A flowchart of a method for indirectly regulating brain temperature according to the present invention is shown. The method includes introducing a membrane 2 into the patient's nasal cavity (S1). When the membrane 2 is inserted into the nasal cavity, cooling fluid circulates into the membrane 2 through a hole 5 on the distal portion D1 of a first conduit 3 (S2) and exits the membrane 2 through a hole 6, an oblique opening 7, and a slit 8 on the distal portion D2 of a second conduit 4. The fluid is circulated in the system by suction using a pump 13. The temperature of the fluid is regulated (S3) by a temperature regulator 15. Regulation (S3) is controlled by a flow meter 14. The flow meter 14 compares the heat flow of the cooling fluid entering the membrane 2 with the heat flow of the cooling fluid leaving the membrane 2. If the difference between the fluid entering and leaving the membrane 2 is very small, the brain temperature has been successfully reduced. Preferably, the method further includes sensing the brain temperature (S4) by using a temperature sensor 12 adapted to be positioned near the corner of the eye.

[0035] In some embodiments, a method is provided for indirectly regulating the temperature of a person's brain via the nasal cavity, the method comprising the steps of: introducing a membrane 2 into the nasal cavity S1, the membrane comprising: a membrane surface area A0, a length L, a center point C1 relative to the length L, a width W, and a center point C2 relative to the width; the membrane 2 being adapted to be arranged in contact with the surface of the nasal cavity; the membrane 2 defining a closed volume V and having a shape of the nasal cavity such that, in use, the membrane expands and conforms to the nasal cavity; and a first conduit 3 extending along a distal-proximal axis, the first conduit 3 having a first distal portion D1 for introducing fluid into the closed volume V, and a first end portion E1, the distal portion D1 having at least one cranially located orifice 5 having an area A1; and a second conduit 4 extending along a distal-proximal axis, the second conduit 4 having a second distal portion D2 for removing fluid from the closed volume V; and... The second end portion E2, the distal portion D2 has at least one cranial-side hole 6 with area A2 and a distal oblique opening 7 with area A3, and a distal slit 8, wherein the distal portion D1 protrudes more than the distal portion D2 in the closed volume V, and wherein the combined area A1 is smaller than the total area of ​​the combined area A2 and the distal opening area A3, and wherein the membrane length L extends along a portion of the distal-proximal axis such that the membrane surface area A0 distal to the center point C1 is greater than the membrane surface area A0 proximal to the center point C1; fluid is circulated into the volume V via the plurality of cranial-side holes 5 on the distal portion D1 of the first conduit 3 by suction and exits the volume V via the cranial-side holes 6 and the distal opening 7 on the distal portion D2 of the second conduit 4; the fluid in S3 is regulated by comparing the heat flow of the fluid introduced into the membrane with the heat flow of the fluid leaving the membrane using a flow meter 14. According to some embodiments, the method may further include the step of sensing brain temperature S4 by using a temperature sensor 12 adapted to be positioned near the corner of the eye.

Claims

1. A device for indirectly regulating the temperature of a human brain via the nasal cavity, the device comprising: A membrane (2) having a surface area (A0), a length (L), a center point (C1) relative to the length (L), a width (W), and a center point (C2) relative to the width, the membrane (2) being adapted to be arranged in contact with the surface of the nasal cavity, the membrane (2) defining a closed volume (V) and having the shape of the nasal cavity such that, in use, the membrane expands and conforms to the nasal cavity. A first catheter (3) extending along a distal-proximal axis has a first distal portion (D1) for introducing fluid into the closed volume (V) and a first end portion (E1), the first distal portion (D1) having at least one first opening (5) with a first total area (A1) located on the cranial side. A second catheter (4) extending along the distal-proximal axis has a second distal portion (D2) and a second end portion (E2) for removing fluid from the closed volume (V). The second distal portion (D2) has at least one cranially located second opening (6) with a second area (A2) and a distal oblique opening (7) with a third area (A3), at least one third opening (9) with a fourth area (A4), and a distal slit (8). The first distal portion (D1) protrudes further into the closed volume (V) than the second distal portion (D2). The first total area (A1) of the at least one cranially located first opening (5) is smaller than the sum of the second area (A2), the third area (A3), and the fourth area (A4). The length (L) of the membrane extends along a portion of the distal-proximal axis such that the membrane surface area distal to the center point (C1) of the length is greater than the membrane surface area proximal to the center point (C1) of the length. The device is used to allow the fluid to circulate into the closed volume (V) via at least one cranial first hole (5) on the first distal portion (D1) of the first conduit (3) and to circulate out of the closed volume (V) via at least one cranial second hole (6) and a distal oblique opening (7) on the second distal portion (D2) of the second conduit (4).

2. The apparatus according to claim 1, wherein, The center point (C1) relative to the length is located at an equal distance from the first end portion (E1) and the second end portion (E2).

3. The apparatus according to claim 1, wherein, The center point (C1) relative to the length is positioned closer to the first end portion (E1) than to the second end portion (E2).

4. The apparatus according to any one of claims 1 to 3, wherein, The membrane surface area on one side of the center point (C2) of the width is greater than the membrane surface area on the other side of the center point (C2) of the width, such that the at least one first hole (5) located on the cranial side faces the side with the larger membrane surface area relative to the center point (C2) of the width.

5. The apparatus according to any one of claims 1 to 3, wherein, The at least one first hole (5) located on the side of the skull has a diameter of 0.1 mm. 2 Up to 1 mm 2 The first individual area between (A11).

6. The apparatus according to any one of claims 1 to 3, wherein, The at least one second hole (6) located on the side of the skull has a diameter of 0.1 mm. 2 Up to 1 mm 2 The second separate area (A22) between.

7. The apparatus according to any one of claims 1 to 3, wherein, The number of at least one first hole (5) on the first catheter (3) located on the cranial side is equal to or greater than the number of at least one second hole (6) on the second catheter (4) located on the cranial side.

8. The apparatus according to any one of claims 1 to 3, wherein, The number of at least one second hole (6) on the second catheter (4) located on the cranial side is equal to or greater than the number of at least one first hole (5) on the first catheter (3) located on the cranial side.

9. The apparatus according to any one of claims 1 to 3, wherein, The number of at least one first orifice (5) located on the side of the skull is at least 2.

10. The apparatus according to any one of claims 1 to 3, wherein, The number of at least one second hole (6) located on the side of the skull is at least 2.

11. The apparatus according to claim 3, wherein, The center point (C1) relative to the length is positioned such that the distance from the first end portion (E1) is 1 / 1.5 of the distance from the second end portion (E2).

12. The apparatus according to claim 3, wherein, The center point (C1) relative to the length is positioned such that the distance from the first end portion (E1) is 1 / 2 the distance from the second end portion (E2).

13. The apparatus according to claim 4, wherein, The surface area of ​​the membrane on the side of the first orifice (5) located on the cranial side facing the center point (C2) of the width is twice the surface area of ​​the membrane on the other side of the center point (C2) of the width.

14. The apparatus according to claim 4, wherein, The membrane surface area on the side of the first orifice (5) located on the cranial side facing the center point (C2) of the width is 3 times the membrane surface area on the other side of the center point (C2) of the width.

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