Respiratory system for inhaling substances

Abstract

A respiratory system configured such that a patient breathes continuously and inhales a substance during breathing, the respiratory system comprising addition means for adding to the gas inhaled by the patient and control means for pressurizing the contained gas. The addition means includes a reservoir for containing a liquid substance and vaporization means for vaporizing the substance. The contained gas combines with the substance in the reservoir and moves the substance to the vaporization means. The control means includes pressure reducing means for allowing the pressurized gas to leak at a rate lower than the rate at which the control means can pressurize the gas. Alternatively or additionally, flow control means (122) are arranged to restrict the flow of the substance flowing between the substance reservoir and the vaporization means.

Description

Technical Field

[0001] The present invention relates to a respiratory system for a patient to inhale substances, in particular analgesics, anesthetics, and / or sedatives. The present invention also relates to a method of using such a device.

Background Art

[0002] The inventor of the present application has noted that there is no respiratory system that enables a patient to inhale anesthetics, analgesics, and / or sedatives and that can affect or control the amount of anesthetic, analgesic, and / or sedative administered to the patient and maintain a comfortable state without the intervention of a medical professional. In such a system, safety is an important issue to avoid the risk of overdose. Also, conventional pumps for reliably adding a small amount of substance, in the range of 10 to 150 microliters, to the gas inhaled by the patient can be expensive. The object of the present invention is to address all or part of these problems.

Summary of the Invention

Problems to be Solved by the Invention

[0003] According to a first aspect of the present invention, there is provided a respiratory system configured such that a patient breathes continuously and inhales a substance during breathing. The respiratory system includes addition means for adding a substance to the gas inhaled, the addition means including a reservoir for containing the liquid substance and vaporization means for vaporizing the substance, and control means for pressurizing the contained gas, the contained gas being combined with the substance in the reservoir and moving the substance to the vaporization means, the control means including decompression means for allowing the pressurized gas to leak at a rate lower than the rate at which the control means pressurizes the gas. Thus, the decompression means reduces the amount of substance added to the inhaled gas in accordance with the time until no more substance is added.

[0004] The control means further comprises a flow control means arranged to restrict the flow of the substance between the reservoir and the vaporizing means, and the contained gas combines with the substance in the reservoir and moves the substance to the vaporizing means by the flow control means.

[0005] According to a second aspect of the present invention, there is provided a respiratory system configured such that a patient breathes continuously and inhales a substance during breathing. This respiratory system includes an adding means for adding to the gas inhaled by the patient, the adding means including a reservoir for containing a liquid or gaseous substance and a vaporizing means for vaporizing the substance, and a control means for pressurizing the contained gas. The contained gas combines with the substance in the reservoir and moves the substance towards the vaporizing means, and the control means includes a flow control means arranged to restrict the flow of the substance between the reservoir and the vaporizing means.

[0006] The flow control means may be arranged in the tube through which the substance flows between the reservoir and the vaporizing means, or at one end of the tube.

[0007] The control means may further comprise a pressure reducing means for allowing the pressurized gas to leak at a rate lower than the rate at which the pressurizing means pressurizes the gas.

[0008] The following features are optional features and / or preferred features of the first and / or second aspects.

[0009] The pressure reducing means may include a speed control unit for adjusting the speed. For example, the pressure reducing means may be a needle valve that enables such control.

[0010] The control means may be a user control unit operable by the patient, and may include a user control unit that supplies an input to the control means in response to an operation by the patient. The user control unit may be operable by an action consciously performed by the patient, such as an action of a finger, hand, blink, or bite.

[0011] The decompression means is coupled to the control means, and the control means may be configured to adjust the rate at which pressurized gas leaks, at least depending on the input.

[0012] The control means may be configured to control the pressurization of the contained gas, at least depending on the input.

[0013] This input may be a pneumatic input, a mechanical input, or an electrical input.

[0014] The user control unit may be arranged remotely from the patient airway interface for holding or wearing, for example, by the patient's hand during use of the respiratory system. One or more further parts or the whole of the control means may be arranged remotely from the patient airway interface during use of the respiratory system. Additionally, the reservoir may be arranged remotely from the vaporization means and may be connected to the vaporization means by a conduit for supplying the substance to the vaporization means. The reservoir may be arranged together with the user control unit as part of a hand-held device.

[0015] The user control unit may be operable by the patient when in a first state (e.g., an inflated state where the input is a pneumatic input), and by its operation, the user control unit may transition to a second state (e.g., a deflated state where the input is a pneumatic input). In this case, the control means may include a return limiter configured to set the time for the user control unit to return from the second state to the first state.

[0016] The user control unit may be biased to the first state and may include means for biasing to the first state.

[0017] By the operation of the user control unit for the user control unit to transition from the first state to the second state, air can be removed from the chamber within the user control unit. In this case, the return limiter allows intake of air into the chamber at a rate such that the user control unit returns to the first state at the end of the time.

[0018] The control means may include an expandable member, and the gas is arranged in the expandable member by the operation of the user control unit to expand the expandable member. The expandable member is biased to a deflated state. In this case, the expandable member can act on the substance to move the substance to the vaporizing means.

[0019] Alternatively, the control means may further include a pressurizing means for pressurizing the gas, such as an air compressor, and a controller coupled to the pressurizing means to control the pressurizing means and control the pressurization of the gas. For example, the controller can provide a control command to the pressurizing means. The user control unit and the controller may be electrically connected, and the input received by the controller is an electrical input.

[0020] The contained gas is coupled to the substance in the reservoir through an intermediate member that is pressed against the substance by the contained gas, thereby moving the substance to the vaporizing means. The intermediate member may include an elastically deformable membrane that separates the gas and the substance. This membrane may be an expandable membrane that is sealably attached to the reservoir around the opening of the reservoir connecting the reservoir and the gas supply port, and when the gas pressure in the expandable membrane increases, the expandable member is arranged to expand into the substance.

[0021] The respiratory system may further include a patient airway interface attachable to the patient, and inhalation and exhalation may be performed repeatedly and continuously through the patient airway interface.

[0022] The patient airway interface is wearable by the patient and is held at a predetermined position indefinitely without using the patient's hands. For example, the patient airway interface may be worn on the patient by a strap that surrounds the patient's head.

[0023] When using the respiratory system, the vaporizing means or the additive unit may be fixedly attached to the patient airway interface. The additive means may not be portable depending on the patient airway interface.

[0024] Control means other than the user control unit may be fixedly attached to the patient airway interface.

[0025] The substance may be an analgesic, anesthetic, and / or a sedative.

[0026] The components required to make the respiratory system can be obtained and assembled at a reasonable cost. Although not essential, the respiratory system may be disposable.

[0027] Hereinafter, embodiments of the invention will be described only illustratively with reference to the accompanying drawings.

Brief Description of the Drawings

[0028]

Fig. 1A

Fig. 1B

Fig. 2A

Fig. 2B

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8A

Fig. 8B

Fig. 8C

[0029] Embodiments of the present invention relate to a breathing system for controllably adding a substance to an inhalation gas. Here, the "operator" should be understood to be the patient or another person such as a medical professional.

[0030] Referring to FIG. 1A, a respiratory system according to such an embodiment includes a housing 100 having a flow control valve, a patient airway interface (PAI) 102, an addition unit 104, and a control device 106. The control device 106 includes a user control unit 108 and a decompression component 110. In some embodiments, the control device 106 includes one or more sensors. This control device has a pressure generation function for supplying pressure to drive the addition of substances. Also referring to FIG. 1B, the addition unit 104 includes a substance reservoir 112, a first conduit 115, a gas reservoir 116, a vaporization unit 118, a second conduit 120, and flow control means in the form of a flow limiter 122. The control device includes a pump unit 119 shown by a dashed line. The dashed line indicates that in some embodiments, the pump unit 119 is not provided and the pressure generation function is included in the control unit 107, and in some of those embodiments, the user control unit 108 is also not provided.

[0031] The housing 100 provides a structure for mounting the PAI 102, the addition unit 104, and the control unit 107. The PAI 102 is separated from the housing 100 in the initial state and can be connected to the housing 100 for use. Although the clip system provided on the PAI 102 and the housing 100 is not shown in these figures, its position is indicated by 125. Alternatively, the PAI 102 and the housing 100 may be connected at the same position using corresponding threads. The embodiment is not limited to a specific method of connecting the PAI 102 and the housing 100. Because it is separated in the initial state, it is possible to select PAI of different shapes / sizes for different patients, and it is also possible to discard the PAI 102 after use and reuse the rest of the respiratory system. Alternatively, the PAI 102 and the housing 100 may be provided as a single component, that is, they may be permanently connected.

[0032] When the PAI 102 and the housing 10 are connected, they are fixedly arranged relative to each other. The addition unit 104 and the control device 106 are attached to and fixed to the housing 100. In a variant embodiment, such components can be flexibly attached. In some variant embodiments, one or more components of the addition unit 104 (for example, the substance reservoir and / or the gas reservoir 116), and / or one or more components of the control device 106 (for example, the user control unit 108) or all, instead of being attached to the housing 100, may be connected to other components attached to the housing 100, for example via a flexible cable. In particular, as will be described below, the user control unit 108 can be physically separated from the remaining components of the control device 107 and, for example, be made portable and connected to other components of the control device by such a cable. In some embodiments, the control device may be provided as a hand-held device operable by a patient. Such a device may comprise a substance reservoir 112 and / or a gas reservoir 116, in which case a second conduit extends between the hand-held device and the vaporization unit 118.

[0033] The flow control valve includes the first and second one-way intake valves 118, 112, and the one-way exhaust valve 114. The first intake valve 118 is arranged at the intake port 111 to the breathing system and prevents the gas containing the substance from escaping to the surroundings through the intake port 111. The second intake valve 112 is arranged to prevent the exhaled gas from entering the vaporization unit 118. In some embodiments, the second intake valve 112 is optional and may be omitted. The exhaust valve 114 is arranged to allow the exhaled gas to exit the breathing system and prevent the intrusion of air from the surroundings. In FIG. 1, arrows indicating the gas flow through the breathing system are shown. A filter (not shown), such as a charcoal filter, may be arranged together with the exhaust valve 114 to remove residual substances in the gas flowing out of the PAI 102.

[0034] Referring also to FIG. 1B, the substance reservoir 112 contains a liquid substance 113 and a gas present above the surface of the substance. The gas reservoir 116 also contains a gas. This gas is air, but in alternative embodiments, one or more other gases may be used additionally or alternatively. The substance reservoir 112 is operably coupled to the gas reservoir 116 by a first conduit 115. The pressure of the substance in the substance reservoir 112 is equal to the pressure of the gas in the gas reservoir 116. When the respiratory system is in use, the substance reservoir 112 is oriented such that the outlet of the conduit 115 to the substance reservoir 112 is located above the surface of the substance 113. The control device is operably coupled to the gas reservoir 116 to increase the pressure of the gas contained in the gas reservoir 116.

[0035] The substance reservoir 112 is coupled to the vaporization unit 118 by a second conduit 120 and a flow control unit 122. The substance flowing from the substance reservoir 112 to the vaporization unit 118 flows through the second conduit 120 and the flow control unit 122. Pressurized gas acts on the substance to cause the substance to pass through the second conduit 120 and the flow control unit 122. The flow control unit 122 is arranged to limit the flow rate of the substance discharged from the reservoir 112. For example, the flow rate can be limited by the flow control unit 122 to less than 10 microliters per second, or less than 5 microliters per second, or less than 2 microliters per second during use. The flow rate may depend on the pressure difference across the flow control unit, but it is possible to configure the device such that the flow rate does not exceed these limits.

[0036] The flow control unit 122 may be, for example, a hollow tube in the shape of a needle. Alternatively, the flow control unit may provide a labyrinthine flow path. Alternatively, the flow control unit may include a region of compressed or woven material such as a wick or a compression cloth. In alternative embodiments, the flow control unit 122 is not limited to these, and alternatives are provided that function to impede the free flow of the substance 113 to the vaporization unit 118, and a driving pressure may be required to generate a clinically significant substance flow.

[0037] In a modified embodiment in which the gas reservoir 116 and the substance reservoir 116 are adjacent to each other, the first conduit 115 may be in the form of an opening between the gas reservoir 116 and the substance reservoir 112. Further, in a modified embodiment in which the substance reservoir 116 and the vaporization unit 118 are adjacent to each other, the second conduit 120 may simply be composed of a flow restrictor 122 having openings to the substance reservoir 112 and the vaporization unit 118.

[0038] The control device includes a control unit 107 and a user control unit 108. The user control unit 108 is operable to provide an input to the control unit 107 in response to an operation of the user control unit 108 by an operator. The user control unit 108 is, for example, operable by a manual operation. The user control unit 108 may be attached to the housing 100, but in a preferred embodiment, the user control unit 108 is coupled to other control components of the control unit 107 by a flexible cable, and thus, the user control unit 108 can be placed on or held by the patient's hand so as to facilitate manual operation, that is, it can be handheld and / or wearable. In a modified embodiment, the user control unit 108 is operable in some physical action that the patient can consciously control, such as a biting action or a blinking action. Alternatively, the user control unit 108 may be arranged so that it can be operated by an operator other than the patient.

[0039] In some embodiments, the control unit 107 includes a microcontroller, and the pressure generation function includes a pump unit 119. In this case, the microcontroller is coupled to the user control unit 108, and the user control unit 108 is configured to supply an electrical signal to the microcontroller in response to an operation by the patient. The microcontroller may be coupled to one or more sensors and receive data from the one or more sensors. Further, the microcontroller is coupled to the pump unit 119 and controls the pressurization of the gas in the gas reservoir 116 by the addition unit.

[0040] The microcontroller includes a processor and a memory. The memory stores computer program code executable by the processor, and the computer program code is for determining control instructions for the pump unit 119 according to the received input and, if there are one or more sensors, the real-time data from the one or more sensors. In a variant embodiment, to execute this determination, the control unit 107 may comprise dedicated hardware, or a combination of dedicated hardware and software. In other embodiments, the control device does not include a microcontroller and may actually be merely mechanical and / or pneumatic, i.e., may simply have mechanical and / or pneumatic control components.

[0041] The pressure reducing component 110 allows gas to leak from the gas reservoir 116 to the surroundings at a rate lower than the rate at which the pump unit 119 can add gas. For example, the pump unit 119 can pressurize the gas in the gas reservoir in less than 1 second, but the pressure reducing component 110 causes sufficient pressure loss in the gas reservoir 116 so that, as a result, in more than 2 seconds but less than 60 seconds, or less than 30 seconds, or less than 15 seconds, or less than 10 seconds, the substance will be added to the gas being aspirated. Thus, the pressure reducing component 110 is configured to gradually reduce the gas pressure when the pump unit 119 is not operated to increase the gas pressure. The pressure reducing component 110 can be configured to let the contained gas escape to the surroundings until the remaining contained gas reaches the same pressure as the ambient pressure. Alternatively, the pressure reducing component 110 is configured to allow the pressure in the reservoir 112 to drop until it reaches a predetermined pressure that is lower than the pressure required for the substance to flow through the flow control unit 122 but higher than the ambient pressure. The pressure reducing component 110 may be in the form of a valve provided in the wall of the gas reservoir 116 connecting the inside and outside of the gas reservoir 116 and may also be called a "leak valve".

[0042] The decompression component 110 may be configured to allow gas to leak from inside the gas reservoir 116 at a constant rate. In one alternative embodiment, instead, the rate may depend on the pressure within the gas reservoir 116. In another alternative embodiment, the rate is settable by an operator, for example, the control device 106 may include a speed control section that enables this. In some embodiments, the rate may be based on an input generated by the operation of the user control section 108 by the patient. In such embodiments where the control unit 106 includes a microcontroller, the decompression component 110 is operably connected to the microcontroller, and the microcontroller is configured to dynamically control the rate using a predetermined algorithm of code that changes the rate depending on the input from the operation of the user control section 108. In other alternative embodiments where the control device also includes such a microcontroller, such a predetermined algorithm can change the rate in response to real-time information received from one or more sensors, additionally or alternatively, for such an input. In the absence of further pressurization by the pump unit 119, the higher the rate, the faster the addition of the substance to the inhaled gas is completed.

[0043] In one alternative embodiment, the decompression component 110 is disposed within the first conduit 115 rather than within the gas reservoir 116. In another alternative embodiment, instead, the decompression component 110 is disposed above the surface of the substance within the substance reservoir 112. In this case, the decompression component 110 is installed such that, during use of the respiratory system, gas impinges on the decompression component 110 rather than the substance, i.e., the decompression component 110 is installed above the surface of the substance 113.

[0044] PAI102 is shown in the form of a face mask. In alternative embodiments, the mask 10 may be replaced with another type of PAI. The PAI may be in the form of an invasive device such as, for example, a nasal clip, a nasal mask, a supraglottic airway device, etc. Such a nasal mask may be, for example, for special use in the dental field. Breathing through the mouth can be avoided by the patient or blocked by means known in the art. Embodiments of the present invention are not limited to any particular form as long as the PAI102 functions as a conduit for all inhaled and exhaled respiratory gases and requires the patient to perform repeated and continuous inhalation and exhalation through the respiratory system. For example, in many applications, the PAI may be worn on the patient such that inhalation and exhalation occur through the respiratory system only for at least 10 minutes. In many applications, the PAI may be worn in this manner for at least 30 minutes.

[0045] The vaporization unit 118 includes a material 123 into which the substance is administered after exiting the flow control unit 122. The vaporization unit may consist only of the material 123. The material 123 is mounted across the interior of the PAI102 and its ends are attached to the PAI102, so the inhaled gas must pass through it. The second conduit 120 extends into the PAI102 for the administration to the material 123. For this reason, when the housing 100 and the PAI102 are separated in the initial state, it may be necessary to insert the second conduit 120 through the opening of the PAI102. In an alternative embodiment, instead, the material is mounted throughout the interior of the housing 100 or includes a part of the housing 100. The position of the material in this case is indicated by the dashed line 123a. In some embodiments, the vaporization unit 118 may include a grid attached to the housing 100 in which the material 123 is disposed, or two grids between which the material 123 is sandwiched.

[0046] Material 123 is preferably configured, for example, to diffuse a substance by means of a wicking action and increase the surface area of the substance, thereby promoting evaporation into the passing air. The material is preferably absorbent, but embodiments are not limited thereto. Material 123 is arranged to extend perpendicular to the flow path of the captured gas. The captured gas needs to pass through Material 123, which exhibits low resistance to inhalation. In an alternative embodiment, Material 123 may extend only partially, rather than entirely, across the housing, or may extend longitudinally in the direction of the air flow such that the captured air passes over it. Embodiments are not limited to a particular arrangement of Material 123, whether Material 123 is located within housing 100 or within PAI 102. Material 123 may be in the form of, for example, a gauze piece or a cloth (e.g., cotton) pad. Embodiments are not limited to a particular form.

[0047] Vaporization unit 118 is configured to diffuse the substance such that the substance evaporates rapidly, taking into account the rate at which the substance flows into vaporization unit 118. For this reason, taking into account the breathing rate of the patient, the substance is prevented from being held on Material 123 for a long time, for example, longer than 10 seconds. Further, vaporization unit 118 is configured to promote rapid evaporation in order to avoid the substance accumulating within housing 100.

[0048] In use, the respiratory system enables the patient to breathe through the respiratory system and typically administers a substance in response to an input from an operator. First, the PAI 201 is worn by the patient, and the patient is forced to breathe through the respiratory system by repeated and continuous inhalation and exhalation. In some cases, the operator may be required to turn on the respiratory system. Thereafter, if further administration of a substance is desired, the patient operates (or attempts to operate in some of the following embodiments) the user control unit 108. The control device determines whether the gas in the gas reservoir 116 should be pressurized so that a further substance is added to the inhaled air, and if so, pressurizes the gas reservoir 116 accordingly. If the control device includes a control unit 107 including a microcontroller and a pump unit 119, the microcontroller makes this determination and provides a control command to the pump unit 119 accordingly, and the pump unit 119 acts to increase the pressure in the gas reservoir 116. If the control device is simply pneumatic and / or mechanical, this determination depends on the state of the control device.

[0049] The embodiments described below may be considered possible implementations of the many generalized embodiments described above. Components having the same or similar functions in different embodiments are shown with the same numbers incremented by 100 times the corresponding drawing number in one or more of the respective drawings showing the respective embodiments.

[0050] Referring to FIG. 2A, according to one embodiment, the control device is mechanical and pneumatic. The control device includes a control unit 207 and a user control unit 208. These components are operable to supply gas to the above-described substance reservoir 112 and move the substance to the vaporization unit 118.

[0051] The control unit 207 includes first and second one-way valves 230, 231, a pressure reducing component in the form of an adjustable first needle valve 232, a return time control component in the form of an adjustable second needle valve 233, and a plurality of tubes. The first needle valve 232 includes a first dial 234 for controlling the flow rate through the first needle valve 232. The second needle valve 233 includes a second dial 235 for controlling the flow rate through the second needle valve 233.

[0052] The first needle valve 232 is connected to the gas reservoir 216 and allows the contained gas to leak out gradually. The first needle valve 232 is operable by the first dial 234 and adjusts the rate at which the contained gas leaks out. This rate also depends on the pressure of the gas.

[0053] The user control unit 208 is in the form of a pump 236 and is preferably held in the patient's hand. The cable 222 is a tube connected to the pump 236 in a sealed state. The pump 236 has an internal chamber and is squeezable in a manual squeezing operation and is capable of providing an input in the form of air pumped to the control unit 207. The pump 236 is biased towards an inflated state. That is, for example, the pump 236 may be formed from a suitable elastic rubber essentially configured to move towards an inflated state. Alternatively, the pump 236 may be formed from a device such as a bellows that is biased towards an inflated state by an elastic member such as a spring.

[0054] The cable 222 is connected at one end to the first tube 237 by a first connector 241, and the first tube 237 is connected at the other end to the second one-way valve 231. The second tube 238 connects the second one-way valve 231 to the gas reservoir 216. The second one-way valve 231 allows the flow of air from the pump 236 to the gas reservoir 216, that is, from the first tube 237 to the second tube 238, and blocks the reverse flow.

[0055] The second needle valve 233 is connected to the first tube 237 by a third tube 239. The second needle valve 233 is also connected to the first one-way valve 230 by a fourth tube 240. The first one-way valve 230 allows ambient air to flow into the second needle valve 233 and blocks the air flow in the opposite direction. Thus, the control unit 207 is arranged such that for the pump 236 to expand from the squeezing state to the expanding state, the pump 236 must take in air via the second needle valve 233. Thus, the return time control unit limits the speed at which the patient can cause the pump to supply the control unit 207, thereby setting the maximum speed to the amount of substance administrable to the patient.

[0056] The first needle valve 232 is connected to the second tube 238 by a fifth tube 242. Air can flow from the gas reservoir 216 through the second needle valve 232 to the surroundings.

[0057] Referring further to FIG. 2B, these components are attached to the housing 200. Each component of the housing 200 is held in place by bolts 243.

[0058] In use, the patient operates the user control unit 208. That is, the patient squeezes the pump 236. By doing so, air is forced to flow through the cable 222 and through the second one-way valve 231, thus pressurizing the gas reservoir 216. The pressurized gas acts to move the substance towards the flow control unit 122. At the same time as the substance is driven in this way, air is discharged from the control unit 207 through the first needle valve 232, so the pressure in the gas reservoir 216 decreases. Also, since the pump 236 is biased towards the expanding state, the pump 236 acts such that air is inhaled through the second needle valve 233. The speed of returning to the expanding state depends on the speed at which the second needle valve 233 allows air to flow through it.

[0059] In one variant embodiment, the gas reservoir 216 may be elastically expandable. For example, the gas reservoir 216 may be formed from a deformable elastic material such as rubber or latex. Alternatively, the gas reservoir 216 may be formed from an expandable flexible material and can be biased to an initial volume. The gas reservoir 216 may be expanded by operation of the user control unit.

[0060] Referring to FIG. 3, the components are the same as those in the embodiment shown in FIG. 2 or a variant thereof, except that additionally an expandable member 343 is connected to the cable 222. In a variant embodiment, the expandable member 343 need not be connected to the cable 222 and may be connected anywhere as long as the interior of the expandable member 343 is in communication with the interior of the pump 236. For example, the expandable member 343 may be connected to the first tube 237 or the third tube 239, or may be directly connected to the pump 236 at its distal end or the like. The expandable member 343 can expand to an expanded state and is biased towards a deflated state. When the pump 236 operates, the air pressure rises within the cable 222 and thus within the expandable member 343, causing the expandable member 343 to expand. By providing the expandable member 343, a high peak pressure is prevented from occurring within the gas reservoir 216 after operation of the pump 236. As a result, the pressure within the gas reservoir 216 exceeds the pressure required for the substance to flow to the vaporization unit 118 for a longer period of time, and as a result, the pressure profile within the gas reservoir 216 is smoothed. The expandable member 343 is made of, for example, rubber or latex and is configured to essentially move to a deflated state. Alternatively, the expandable member 343 may consist of a device such as a bellows and may be biased to a deflated state by an elastic member such as a spring.

[0061] In use, these components function in the same way as the components in FIG. 2, except that additionally air flows into the expandable member 343, causing the expandable member 343 to expand. The expandable member 343 acts to return to a contracted state.

[0062] Referring to FIG. 4, in another embodiment, the pressure generating function in the form of pump unit 419 includes an air intake 445. The control unit 407 includes a microcontroller, and one or more sensors include a pressure sensor 443 electrically coupled to the microcontroller by cable 444. The user control 408, for example in the form of a button, is operable to provide an input in the form of an electrical signal to the microcontroller via cable 422 in response to an operation of the user control by an operator or a patient.

[0063] The pressure sensor 443 supplies data indicating the real-time pressure within the gas reservoir 416 to the microcontroller. The microcontroller is configured to control the pump unit 414 in response to the pressure within the gas reservoir 416, in response to the received input from the user control 408 generated by the operator, and in response to its stored algorithm. The pump unit 414 may be in the form of a compressor.

[0064] The substance reservoir 412 comprises a container 448 having a threaded opening at the bottom 449. The container 448 is used in an orientation where the opening is at the bottom of the container. The reservoir 412 includes a closure member 449 that is screwed onto the bottom 449, thereby closing the container 448 in a sealed state. The closure member includes a first opening through which the first conduit 415 extends in a sealed manner. The closure member 449 also includes a second opening to which one end of the second conduit 420 is connected. One end of the first conduit 415 is located within the container 448 and terminates near the top inside the container 448 so as to be located above the surface of the substance. The outflow of the substance from the container 448 is blocked by the flow control unit 422 and by the gas pressure within the gas reservoir 416. The flow control unit 422 allows the substance to flow from the container 448 when the pressure of the gas within the container 448 is greater than the gas pressure at one end of the second conduit 420 (material 446 in the illustrated embodiment) to which the substance is supplied to the vaporizing unit.

[0065] The control device includes a leak valve 410 that allows gas to gradually leak from the gas reservoir 416. The leak valve 410 extends from approximately the midpoint of the gas reservoir 416 and is designed to reduce the risk of substances reaching the leak valve and clogging it.

[0066] The container 448 may be a vial obtained from a supplier in a state containing the substance and with a seal (not shown) applied.

[0067] During use, the control unit 407 receives an input from the user control unit 408 in response to an operation of the user control unit by the patient. The control unit 407 determines whether to supply a control instruction to the pump unit 414 to add a substance to the inhaled gas. When the pump unit 414 is operated to increase the gas pressure, the substance flows through the second conduit 420 to the vaporization unit.

[0068] The leak valve 410 limits the time during which the gas reservoir 416 is pressurized sufficiently to cause the addition of the substance. The control unit 407 also receives real-time pressure data from the pressure sensor 416, and feedback is provided to the control unit 407. In this way, closed-loop control can be achieved.

[0069] Referring to FIG. 5, in another embodiment, the control device includes, in the user control unit 508, a main body 550, a cable 522, a recess 551 in the main body 550, a button 552, a spring 553, a return time control unit, a plunger 555, and a cylinder 556. The button 552 is movable by the patient to a position (or state) where it is pushed down into the recess 551 (or chamber) against a spring 553 that biases the button 552 to an extended position. The plunger 555 is slidably disposed within the cylinder 556. The plunger 555 is attached to the button 552 such that when the button 552 is pushed down into the recess 551, the plunger 555 moves into the cylinder 556. One end of the cable 522 is connected to the cylinder 556 in a sealed state, and the other end is connected to the gas reservoir in a sealed state. Thus, when the button is pressed, the air within the cylinder 556 is pushed out towards the gas reservoir, thereby pressurizing the gas within the gas reservoir 516.

[0070] The return time control unit includes a second needle valve 533 and a second adjustment dial 535. The second needle valve 533 is provided between the recess 551 and the surroundings. These function as the second needle valve 233 and the adjustment dial 235. The second needle valve 233 limits the speed at which ambient air can enter the recess 551, thereby limiting the speed at which the button 552 returns to the extended position, and thereby limiting the speed at which the patient supplies air to the gas reservoir 516.

[0071] The control device includes a leak valve 510 having a first needle valve with a needle 532, and a control unit 534. The leak valve 510 extends from approximately the midpoint of the gas reservoir 516. Similar to the leak valve 410, the leak valve 510 limits the time for which the gas reservoir 416 is pressurized sufficiently to cause the addition of substances.

[0072] Referring to FIG. 6, which is more simplified than FIG. 2A, in a variation of the embodiment described with reference to FIGS. 2A - 2B, the flow rates through the first needle valve 632 and the second needle valve 633 can be controlled by a single control unit such as a single dial 670. In this case, by the operation of the control unit, the air flow rates through both the first needle valve 632 and the second needle valve 633 either both decrease or both increase.

[0073] Referring to FIG. 7, a substance reservoir 712 is included in the face mask. A first conduit 715 extends from the face mask and is coupled to a control device for pressurizing a gas. The face mask includes a strap 771 for attaching the mask to the patient's head. The material 723 is held within a mesh (not shown), and the mesh is adhered to the inside of the face mask at its ends.

[0074] The first conduit 715 opens into the reservoir 712 near the top of the reservoir 712. This top is so defined based on the orientation of the reservoir 712 when the face mask is worn by the patient. A second conduit 720 opens into the reservoir 712 near the bottom of the reservoir 712. This bottom is so defined based on the orientation of the reservoir 712 when the face mask is worn by the patient.

[0075] In a preferred embodiment of the present invention, during use of the respiratory system, the substance reservoir is oriented such that the contained liquid is located at the bottom of the reservoir under the influence of gravity, regardless of whether the patient is in an upright position or a supine position. In some embodiments, the gas reservoir may include a drain valve. Thus, if some substance accidentally enters the gas reservoir, the substance is discharged through the drain valve.

[0076] In the above - described embodiment, the pressurized gas acts directly on the surface of the liquid substance to move the substance through a flow restrictor. In a variant embodiment, the gas may act on an intermediate member. Such an intermediate member allows the substance to be either gaseous or liquid.

[0077] Referring to FIG. 8A, in one such embodiment, the intermediate member is in the form of an elastic, flexible and / or deformable membrane 890 positioned between the gas and the substance. The membrane 890 is attached (e.g., by an adhesive) along the inner wall of the reservoir 812a and separates the gas from the substance. When the pressure of the gas increases as the gas enters the reservoir 812a through the first conduit 815a, the pressure of the gas presses the membrane 890 against the substance and moves the substance through the second conduit 820. The embodiment is not limited to a particular orientation of the membrane 890. The membrane 890 may be formed of, for example, rubber or latex.

[0078] Referring to FIG. 8B, in another such embodiment, the intermediate member is in the form of an expandable bag 891 sealed within the reservoir 812b around the opening of the first conduit 815b into the reservoir 812b. When the pressure of the gas increases within the bag, the expandable bag 891 expands against the substance. The embodiment is not limited to a particular arrangement of the bag within the reservoir 812b, although the bag is preferably at least partially immersed in the substance. The bag 891 may be formed of, for example, rubber or latex.

[0079] Referring to FIG. 8C, in another such embodiment, the intermediate member is in the form of a piston 892 and the reservoir 812c is at least partially a cylinder. The piston 892 is slidable within the reservoir. When the pressure of the gas increases, the gas presses the piston 892 against the substance, thereby moving the substance towards the second conduit 820. The piston 892 may be formed of, for example, a rigid plastic material. The plunger 555 described above is an example of a similar intermediate member in another embodiment.

[0080] The substance is a volatile liquid. This substance can be an analgesic, anesthetic, and / or sedative for imparting analgesic, anesthetic, and / or sedative effects to a patient. For example, the substance can be methoxyflurane, sevoflurane, or ketamine. In a variant embodiment, the substance may have alternative or additional effects.

[0081] In all embodiments, the substance reservoir of the embodiment may be in the form of a medical vial. In a variant embodiment, an alternative form of reservoir configured to replenish the substance may be provided.

[0082] In an alternative embodiment, the vaporization unit 118 is not limited to being a material. Alternative means for vaporizing the substance may be provided. In particular, in some embodiments where the substance used is highly volatile, the vaporization unit 118 need not diffuse the substance to promote evaporation. Rather, the vaporization unit 118 can simply be a space where the substance evaporates.

[0083] In an alternative embodiment, the vaporization means may include a heater for heating the substance. The heater may be disposed at the exhaust port of the second conduit 120. In such a case, the substance need not be a volatile liquid and can be any substance that can be evaporated by heating at a temperature according to the performance of the heater. When a heater is included, the control means includes a microcontroller and the heater is coupled to the microcontroller. The microcontroller controls the operation of the heater by determining control instructions and providing them to the heater. For example, the control instructions may include an "on instruction" and an "off instruction". The control instructions can control the degree of heating. The control means may include a temperature sensor for providing information indicating the temperature of the substance and / or the room temperature to the control means, and the control means can determine control instructions regarding the degree of heating based on the said information.

[0084] In an alternative embodiment, the vaporization unit 118 may include a nozzle spray disposed at the exhaust port of the second conduit 120. In this case, the substance need not be a volatile liquid and may be any liquid suitable for conversion by the nozzle spray into droplets that can be carried by the gas within the respiratory system and absorbed by the patient's inhalation.

[0085] The manufacturing process for manufacturing the respiratory system according to the above-described embodiments will be apparent to those skilled in the art. For example, the mask may be formed from a rigid plastic material or silicone, and the airway portion may be formed from a rigid plastic material. The embodiments are not limited to the use of specific materials.

[0086] Various modifications to the above-described embodiments will be apparent to those skilled in the art. In some embodiments, the gas reservoir in the embodiment may be omitted. Instead, the space above or adjacent to the substance in the substance reservoir may function as the gas reservoir.

[0087] As used in this specification and the claims, the terms "comprising" and "including" and their variants mean that a particular feature, step, or integer is included. This term is not to be construed as excluding the presence of other features, steps, or components.

[0088] Unless otherwise stated, all individual features and / or steps of all embodiments described herein are disclosed separately, and combinations of two or more such features, such combinations of such features or steps, or features and / or steps, whether or not they solve the problems disclosed herein, are disclosed to the extent that they are practicable based on the general common knowledge of those skilled in the art and based on the entire disclosure herein.

Claims

1. A respiratory system configured for a patient to breathe continuously and inhale analgesic, anesthetic, and / or sedative substances during respiration, An additive means for adding the substance to an inhaled gas, A reservoir for containing the liquid substance, A vaporization means for vaporizing the substance and Addition means including, Control means for pressurizing the contained gas, Equipped with, A breathing system in which the contained gas combines with a substance in the reservoir, transfers the substance to the vaporization means, and the control means includes a depressurization means for allowing the pressurized gas to be gradually depressurized at a rate lower than the rate at which the control means can pressurize the gas.

2. The breathing system according to claim 1, wherein the control means further comprises a flow control means arranged to restrict the flow of the substance between the reservoir and the vaporization means, and the contained gas combines with the substance in the reservoir and moves the substance to the vaporization means.

3. A respiratory system configured for a patient to breathe continuously and inhale analgesic, anesthetic, and / or sedative substances during respiration, An additive means for adding the substance to an inhaled gas, A reservoir for containing the substance in liquid or gaseous form, A vaporization means for vaporizing the substance, Addition means including, Control means for pressurizing the contained gas, Equipped with, A respiratory system in which the contained gas combines with the substance in the reservoir, pressing the substance from the reservoir toward the vaporization means, and the control means includes flow control means arranged to allow the substance to flow between the reservoir and the vaporization means and to restrict the flow, and a driving pressure is required to generate a clinically significant substance flow.

4. The breathing system according to claim 3, wherein the flow rate control means is located in a tube through which the substance flows between the reservoir and the vaporization means, or at one end of the tube.

5. The breathing system according to claim 3, wherein the control means further comprises a depressurization means for enabling the pressurized gas to leak out at a rate lower than the rate at which the pressurizing means pressurizes the gas.

6. The breathing system according to claim 5, wherein the decompression means includes a speed control unit for adjusting the speed.

7. The respiratory system according to any one of claims 1 to 6, wherein the control means includes a user control unit that can be operated by a patient and which supplies input to the control means in response to the patient's operation.

8. The control means includes a patient-operable user control unit that provides input to the control means in response to operations by the patient, the depressurization means is coupled to the control means, and the control means, depending at least on input from the user control unit, pressurized gas The breathing system according to claim 6, configured to adjust the rate of decompression.

9. The breathing system according to claim 7, wherein the control means is configured to control the pressurization of the contained gas, at least depending on the input.

10. The breathing system according to claim 7, wherein the input is a pneumatic input, a mechanical input, or an electrical input.

11. The respiratory system according to claim 7, wherein the user control unit is for manual operation and is located away from the patient airway interface.

12. The respiratory system according to claim 11, wherein the control means is positioned away from the patient airway interface when the respiratory system is in use.

13. The breathing system according to claim 12, wherein the reservoir is located apart from the vaporization means, and the reservoir is connected to the vaporization means by a conduit for supplying the substance to the vaporization means.

14. The respiratory system according to claim 7, wherein the user control unit is operable by the patient when it is in a first state, and the operation of the user control unit causes the user control unit to transition to a second state, and the control means includes a return limiter configured to set a time for the user control unit to return from the second state to the first state.

15. The breathing system according to claim 14, wherein the operation of the user control unit causes air to be removed from the chamber within the user control unit by an operation of the user control unit to transition from the first state to the second state, and the return limiter allows air to be drawn into the chamber at a rate such that the user control unit returns to the first state at the end of the time.

16. The breathing system according to claim 15, wherein the control means includes an expandable member, and the operation of the user control unit causes gas to be placed inside the expandable member, causing the expandable member to expand, and the expandable member acts on the substance to move the substance in the flow rate control means.

17. The breathing system according to claim 14, wherein the user control unit is biased to the first state.

18. The breathing system according to claim 7, wherein the contained gas combines with the substance in the reservoir via an intermediate member that is pressed against the substance by the contained gas, thereby transferring the substance to the vaporization means.

19. The breathing system according to claim 7, further comprising a patient airway interface that can be attached to the patient, wherein inspiration and exhalation are performed repeatedly and continuously through the patient airway interface.

20. The respiratory system according to claim 19, wherein the patient airway interface is attachable to the patient and can be held in a predetermined position indefinitely without the use of the patient's hands.

21. The respiratory system according to claim 19, wherein the additive unit is fixedly attached to the patient airway interface when the respiratory system is in use.

22. The respiratory system according to claim 19, wherein the control means other than the user control unit is fixedly attached to the patient airway interface when the respiratory system is in use.

23. The breathing system according to claim 7, wherein the control means further comprises pressurizing means for pressurizing the gas and a controller, the controller being coupled to the pressurizing means and configured to control the pressurizing means to control the pressurizing of the gas.

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