A system for delivering cooling liquid to a nasal cavity, said system comprising a safety mechanism

Abstract

A system for delivering a fluid mixture to a nasal cavity is provided. The system comprises a gas delivery apparatus (200), comprising a gas inlet (201) and a pump (204) for pumping a flow of gas, wherein the flow of gas is divided into at least three sub-flows of gas in form of a safety gas flow, a liquid driving gas flow, and a carrier gas flow. The system comprises at least one nasal cannula (100) and a liquid reservoir (400). Further, the system comprises at least one safety gas conduit (301) for leading the safety gas flow to at least one first opening (104) in the nasal cannula (100), a tube (300) for leading the carrier gas flow to the nasal cannula (100) and for leading the liquid driving gas flow to the liquid reservoir (400), wherefrom a liquid conduit (304) is configured to lead a liquid from the liquid reservoir (400) to the nasal cannula (100). The carrier gas flow is mixed with the liquid in at least one second opening (106), to expel a fluid mixture comprising the gas and the liquid into the nasal cavity.

Description

[0001] A SYSTEM FOR DELIVERING COOLING LIQUID TO A NASAL CAVITY, SAID SYSTEM COMPRISING A SAFETY MECHANISM

[0002] FIELD OF THE INVENTION

[0003] The invention relates to cerebral and systemic cooling via the nasal cavity, oral cavity, and other parts of the body. More particularly, the invention relates to methods and devices for cerebral and systemic cooling using liquids or liquid mists with boiling points above body temperature and dry gases and for delivering the liquid mists and / or dry gases to the nasopharyngeal cavity.

[0004] BACKGROUND OF THE INVENTION

[0005] Patients experiencing cerebral ischemia often face a range of outcomes, from temporary neurological deficits to permanent damage, such as stroke, or even death. Cerebral ischemia, which refers to a reduction or complete cessation of blood flow to the central nervous system, can be classified as either global or focal. Global cerebral ischemia occurs when there is a reduction in blood flow throughout the brain, typically caused by systemic circulatory failure from conditions like shock, cardiac failure, or cardiac arrest. Within minutes of circulatory failure, tissues, especially in the heart and brain, begin to suffer from ischemia.

[0006] One of the most common causes of shock is cardiogenic shock, resulting from severe impairment of cardiac function. Myocardial infarction, where a significant portion of heart muscle is lost, is the leading cause of cardiogenic shock. Other factors, such as acute myocarditis or decreased myocardial contractility following cardiac arrest or prolonged cardiopulmonary bypass, can also contribute. Mechanical issues, such as severe valve stenosis, significant aortic or mitral regurgitation, or newly acquired ventricular septal defects, can reduce cardiac output and lead to cardiogenic shock. Additionally, cardiac arrhythmias, such as ventricular fibrillation, are also common causes. In the event of a sudden cessation of blood flow to the brain, complete loss of consciousness is inevitable in cardiac arrest. Without prompt intervention, including cardiopulmonary resuscitation (CPR), defibrillation, or the administration of inotropic agents and vasoconstrictors like dopamine, dobutamine, or epinephrine, cardiac arresttypically progresses to death within minutes. The most frequent cause of death in hospitalized patients after a resuscitated cardiac arrest is often due to severe ischemic injury to the central nervous system, such as anoxic encephalopathy. The success of resuscitation efforts depends on factors such as the timing of intervention, the underlying mechanism, and the patient’s clinical status prior to the arrest.

[0007] Focal cerebral ischemia, on the other hand, involves the reduction or cessation of blood flow in a specific area of the brain, leading to stroke. Stroke is a syndrome marked by the sudden onset of neurological deficits due to localized brain injury. The current standard of care for acute stroke and traumatic brain injury is primarily supportive.

[0008] In both stroke and cardiogenic shock, neurological deficits develop as a result of reduced cerebral blood flow. As such, treatments should focus on preserving neural tissue to extend the window of time available for intervention, while also minimizing brain damage during the period of ischemia. New techniques and devices are needed to improve outcomes for patients with stroke or cardiogenic shock, particularly those affected by reduced cerebral perfusion.

[0009] Recent research suggests that cooling the brain may help mitigate damage from diminished cerebral blood flow. Early studies focused on selective cerebral cooling using external cooling methods. Additionally, the anatomy of the nasal cavity plays a significant role in regulating brain temperature. Due to the close proximity between the roof of the nose and the anterior cranial fossa, the nasal cavity can significantly influence the temperature of the brain through respiratory evaporative heat loss or convection. Most of the warming of inhaled air occurs in the upper airways, making this an effective site for temperature modulation. While there are devices designed to cool the brain through the nasal and / or oral cavities, these often involve complex flow arrangements and lack sufficient control features. Therefore, there is a clear need for improved devices that can enhance the cooling effect and better regulate the mist of cooling fluids during treatment.

[0010] SUMMARY OF THE INVENTIONAccordingly, the present invention preferably seeks to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solves at least the above mentioned problems by providing a system for delivering a fluid mixture to a nasal cavity, said system comprising: a gas delivery apparatus, wherein the flow of gas is divided into at least three sub-flows of gas in form of a safety gas flow, a liquid driving gas flow, and a carrier gas flow; at least one nasal cannula; a liquid reservoir; at least one safety gas conduit for leading the safety gas flow to a plurality of first openings along the length of the nasal cannula; a tube for leading the carrier gas flow to the nasal cannula and for leading the liquid driving gas flow to the liquid reservoir, wherefrom a liquid conduit is configured to lead a liquid from the liquid reservoir to the nasal cannula; wherein the carrier gas flow is mixed with the liquid in at least one second opening, to expel a fluid mixture comprising the gas and the liquid into the nasal cavity.

[0011] Further advantageous embodiments are disclosed below and in the appended patent claims.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] These and other aspects, features and advantages of which the invention is capable will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which Fig. 1 is a schematic view of a system according to one embodiment of the present invention; and

[0014] Fig. 2 is a cross section of a cannula according to one embodiment of the present invention.

[0015] DETAILED DESCRIPTION

[0016] The invention relates to methods, devices, and compositions for cerebral cooling, preferably via the nasal and / or oral cavities. The cooling occurs by direct heat transfer through the nasopharynx as well as by hematogenous cooling through the carotids as they pass by the oropharynx and through the Circle of Willis, which lies millimetres away from the pharynx. The direct cooling will be obtained through evaporative heatloss of a nebulized liquid in the nasal cavity, oral cavity, and / or throat. Additionally, cooling may occur through convection in the nasal cavity. Such cerebral cooling may help to minimize neurologic deficits in treating patients with cither stroke or cardiogenic shock caused by reduced cerebral perfusion or in the treatment of migraines. In the following description, where a cooling assembly, device, or method is described for insertion into a nostril of a patient, a second cooling assembly or device can optionally also be inserted into the other nostril to maximize cooling.

[0017] Among the many important advantages of the present invention is patient safety by comparison with transpulmonary and intravascular cooling methods and devices.

[0018] The invention provides a method for cerebral cooling. Elongate members, in form of cannulas 100, can be inserted into a nasal cavity of a patient through the patient's nostrils. The cannula 100 has a proximal end and a distal end. The distal end is the end inserted into the nostril, i.e. closest to the patient, while the proximal end is closest to a gas delivery apparatus 200, which delivers gas, such as air or oxygen into the cannula 100, via a tube or catheter 300 and a liquid reservoir, such as a liquid bottle 400. The gas delivery apparatus 200 comprises a gas inlet 201, such as an air inlet 201. The gas delivery apparatus 202 also comprises a power supply 202 to drive operation and monitoring. The gas delivery apparatus 200 also comprises a pressure safety circuit 203. The cannula 100 comprises a first lumen 101 for leading a safety gas flow, a second lumen 102 for leading a carrier gas flow, and a third lumen 103 for leading a liquid. The first lumen 101 is integrated into a side wall of the cannula 100. In this way, the wall of the first lumen 101 delimits the first lumen 101 in a central direction from a central lumen, which in this embodiment is the second lumen 102. The wall of the first lumen 101 delimits the first lumen 101 in a lateral direction from the environment, i.e. the outer periphery of the cannula 100.

[0019] There are safety openings 104 along the length of the cannula 100 through which the first lumen 101 may communicate with the environment. These safety openings 104 ensures that an occlusion of the flow can be detected or pressure build up in the nasal cavity can be detected. As long as there is a flow out through the safety openings 104, the user of the system can be assured that there is no occlusion and / or that the gas delivery apparatus 200 works properly. Also, in this way the pressure in the nasal cavity can be monitored. The system monitors the pressure and if to high, switch of themain pressure valve and open a vent valve to avoid harming the patient. Alternatively, there is only one safety opening 104, but a plurality is preferred.

[0020] The second lumen 102 runs preferably centrally of the cannula 100. There are spray channels 105 from the second lumen 102 that opens up into spray openings 106 at regular intervals along the longitudinal length of the cannula 100 towards the environment, such as the nasal cavity. These spray channels 105 arc angled in relation to each other with an angle a to realize an optimized spray pattern. The angle a is preferably from 40 to 80 degrees, more preferably from 55 to 65 degrees, such as 60 degrees. Within the angle a the third lumen 103 is positioned. There are connecting channels 107 extending from the third lumen 103 to the spray channels 105. In this way the liquid led in the third lumen 103 will exit the third lumen 103 via the connecting channels 107 to enter into the spray channels 105. In the spray channels 105 the liquid can be nebulized when mixing with the flow of carrier gas flow from the second lumen 102, thereafter be expelled into the nasal cavity to reduce the cerebral temperature of the patient.

[0021] The cannulas 100 may preferably have a rounded sealed distal tip, which seals the distal end of lumens 101, 102, 103. The rounded sealed tip provides a smooth surface to avoid damaging sensitive tissues.

[0022] The two cannulas 100 are connected to the flows at a manifold 500. The cannulas 100 extend distally from the manifold 500, and at the proximal end of the manifold 500 the tube 300 extends. The tube 300 comprises a lumen 301. In the lumen 301 the carrier gas flow can be led. Within the lumen 301 two safety tubes 302, 303 run. At the manifold 500 these two safety tubes are connected to one first lumen 101 each. Also, within the lumen 301 there is a liquid tube 304. The liquid tube 304 is leads liquid to the manifold 500, wherein the liquid is divided into third lumens 103 of the two cannulas 100. The manifold may be marked to indicate in what direction the cannulas 100 should be inserted. Such marking may be a sign that indicates what is up, i.e. corresponding to a position in which the spray openings 106 of the cannulas 100, when located in the nostrils, are facing upwardly towards the brain and not towards the mouth. For example, it may be marked with an “R” and / or an “L” to show whichcannula 100 should be inserted in which nostril. In this way the spray pattern may be directed in the correct direction, i.e. substantially upwardly.

[0023] In between the manifold 500 and the gas delivery apparatus 200 there is a bottle connector 600. The bottle connector 600 is provided with a bottle cap 601 to be connected to the liquid bottle 400. The liquid tube 304 extends into the liquid bottle 400, cither directly or via a drainage pipe (not shown). Proximally of the bottle connector the gas in the tube 300 is led into the liquid bottle 400 to increase the pressure in the liquid bottle 400, such that liquid in the liquid bottle starts to flow into the liquid tube 304. The liquid in the liquid bottle 400 is a liquid coolant, such as water or perfluorocarbons, preferably perfluorocarbons. A preferred perfluorocarbon is perfluorohexane. Perfluorocarbons have been used extensively in medical products because they are both chemically and biologically nonreactive.

[0024] In the gas delivery apparatus 200 there is a control unit. The control unit performs control of the gas flow by first regulating the incoming gas supply. A suitable pressure in the tube 300 is 20 to 40 psi, such as 30 psi. This pressure ensures a good performance even with variable input gas pressures. The control unit also has an electronic circuit that monitors the pressure in each nasal cavity via two separate pressure sensors. In some embodiments, the control unit may be provided to allow an operator to activate switches to turn on or on the liquid flow from the liquid coolant source. The control unit may also include software and a processor which allow if to be used in conjunction with one or more temperature sensors to automatically control the cooling therapy received by the patient based on the feedback regarding the temperature of the patient and a pre-determined desired temperature or temperature range set by the operator. The pressurized gas flow in the tube / catheter 300 may be closed with a main switch. This stops both gas and liquid flow, since liquid is driven by the pressurized gas.

[0025] The gases used within the tube / catheter 300, driven by the gas delivery apparatus 200, include any gas capable of evaporating the liquid. The gas can include, but is not limited to, nitrogen, air, oxygen, argon, or mixtures thereof.In use, the cannulas 100 are intended to be placed through the patient's nostrils and extend through the nares of the nose to the nasopharyngeal region of the nasal cavity. The length of cannulas 100, which extends to the nasal pharyngeal region of the nasal cavity and the openings 106 located longitudinally and axially along the outer wall of the cannulas 100 to disperse the liquid spray perpendicular to the longitudinal axis of cannulas 100 and over the entire nasal cavity region. This is in contrast to simply directing the spray through a single spray nozzle at a cannula tip, which would have the spray limited to a particular area along the longitudinal axis of catheter. This distinction is critical in that dispersing the spray over a larger region permits greater cooling though evaporative heat loss. In addition, the ability to nebulize the liquid at each delivery opening ensures that the distribution of liquid particles will be uniform throughout the nasal cavity. Specifically, when a liquid is nebulized, a spray with liquid particles is created. If the liquid was nebulized at the proximal end of the nasal cannula or outside of the cannula and then transported as a nebulized liquid spray through the cannula lumen to the multiple delivery openings, the smaller liquid particles would flow through the proximal delivery openings while the larger liquid particles would be carried to the distal end of the cannulas and therefore being delivered to the nasal cavity via one of site delivery openings near the distal end of the cannulas. This would result in an uneven distribution of the liquid particles within the nasal cavity. Conversely, when the liquid is transported through the cannulas and nebulized separately at each delivery opening just prior to delivery, the site distribution of liquid particles distributed at any given point in the nasal cavity is uniform. This is important because an even distribution of the liquid particles provides for better evaporation of the liquid spray, which results in better cooling through evaporative heat loss and is more tolerable to the patient. Furthermore, since the liquid begins to evaporate immediately upon contact with the gas, mixing at the point of use in the patient will ensure efficient use of all available cooling.

[0026] The flow rate of the gas and liquid can be altered during the process according to the amount of cooling achieved. Feedback can be provided in the form of nose temperature sensor, body temperature sensor, brain temperature sensor, rectal temperature sensor, etc.Although the foregoing invention has, for the purposes of clarity and understanding, been described in some detail by way of illustration and example, it will be obvious that certain changes and modifications may be practiced which will still fall within the scope of the appended claims. Rather, the invention is limited only by the accompanying claims.

[0027] In the claims, the term “compriscs / comprising” docs not exclude the presence of other elements or steps. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and / or advantageous. In addition, singular references do not exclude a plurality. The terms “a”, “an”, “first”, “second” etc. do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.

Claims

CLAIMS1. A system for delivering a fluid mixture to a nasal cavity, said system comprising: a gas delivery apparatus (200), wherein the flow of gas is divided into at least three subflows of gas in form of a safety gas flow, a liquid driving gas flow, and a carrier gas flow; at least one cannula (100); a liquid reservoir (400); at least one safety gas conduit (301) for leading the safety gas flow to a plurality of first openings (104) along a length of the cannula (100); a tube (300) for leading the carrier gas flow to the cannula (100) and for leading the liquid driving gas flow to the liquid reservoir (400), wherefrom a liquid conduit (304) is configured to lead a liquid from the liquid reservoir (400) to the cannula (100); wherein the carrier gas flow is mixed with the liquid in at least one second opening (106), to expel a carrier comprising the gas and the liquid into the nasal cavity.

2. The system according to claim 1, wherein the cannula (100) comprise a proximal end and a distal end, wherein the distal end is the end configured to be inserted into a nostril.

3. The system according to claim 1 or 2, wherein the gas delivery apparatus (200) comprises a pressure safety circuit (203), connected to the at least one of the gas conduits (301, 302, 303).

4. The system according to any of the preceding claims, wherein the cannula (100) comprises a first lumen (101) for leading the safety gas flow, a second lumen (102) for leading the carrier gas flow, and a third lumen (103) for leading the liquid.

5. The system according to any of claim 4, wherein the second lumen (102) runs centrally of the cannula (100).

6. The system according to any of claim 4 or 5, comprising spray channels (105) from the second lumen (102) that opens up into spray openings (106) towards the environment.

7. The system according to any of claims 4 to 6, wherein the spray channels (105) are angled in relation to each other with an angle (a).

8. The system according to claim 7, wherein the angle (a) is from 40 to 80 degrees, more preferably from 55 to 65 degrees, such as 60 degrees.

9. The system according to claims 7 or 8, wherein the third lumen (103) is positioned within the angle (a).

10. The system according to any of claims 3 to 9, comprising connecting channels (107) extending from the third lumen (103) to the spray channels (105).

11. The system according to any of the preceding claims, comprising two cannulas (100).

12. The system according to claim 11, wherein the two cannulas (100) are connected to the flows at a manifold (500).

13. The system according to any of the preceding claims, comprising a tube (300), said tube (300) comprising a lumen (301), wherein the mixture flow gas can be led, wherein two safety tubes (302, 303) are located in the lumen (301) to lead the safety gas flow to the at least one first opening (104) in the cannula (100).

14. The system according to claim 13, wherein a liquid tube (304) is arranged in the tube (300) for leading liquid from the liquid reservoir (400) to the cannula (100).

15. The system according to any of claims 11 to 14, wherein the cannulas (100) and / or the manifold (500) are marked to indicate which of the cannulas (100) should be inserted in the right nostril of a user and / or which of the cannulas (100) should be inserted in the left nostril of a user.

16. A cannula (100) for insertion in a nostril of a human, comprising a first lumen (101) for leading a safety gas flow, a second lumen (102) for leading a carrier gasflow, and a third lumen (103) for leading a liquid, wherein at least one safety opening (104) connects the first lumen (101) to the environment.

17. The cannula (100) according to claim 16, wherein the at least one safety opening (104) is a plurality of safety openings (104).

18. The cannula (100) according to claim 16 or 17, comprising spray channels (105) from the second lumen (102) to the environment.

19. The cannula (100) according to claim 18, wherein the spray channels (105) are angled in relation to each other with an angle (a), wherein the angle (a) is from 40 to 80 degrees, preferably from 55 to 65 degrees, such as 60 degrees.

20. The cannula (100) according to claim 19, wherein the third lumen (103) is positioned within the angle (a).

21. The cannula according to any one of claims 18 to 20, comprising connecting channels (107) extending from the third lumen (103) to the spray channels (105).

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