Systems and methods for volatile anesthetic delivery

Abstract

Various methods and systems are provided for an anesthesia system that can include a cartridge pump assembly including a cartridge containing a liquid anesthetic and a pump adapted to pressurize the liquid anesthetic through a pressure line and a reservoir. An ejector can deliver the liquid anesthetic into a heater assembly. The system also includes a liquid flow valve configured to fluidly couple and decouple the cartridge and the ejector.

Description

Technical Field

[0001] The implementation schemes of the subject matter disclosed herein relate to the delivery of volatile anesthesia using an anesthetic vaporizer. Background Technology

[0002] An anesthetic system vaporizes volatile anesthetic liquids to deliver anesthetic vapors to the patient. Volatile anesthetics, such as isoflurane and sevoflurane, have pharmacological properties that allow for well-tolerated and titratable mild to deep sedation. The use of volatile anesthetics can be helpful in both operating room and intensive care unit (ICU) settings. For example, volatile anesthetics are cleared from the patient's system more quickly than intravenously delivered sedatives, better allowing for regular monitoring of sedated patients in the ICU. Summary of the Invention

[0003] In one example, the anesthesia system includes a cartridge containing liquid and a pump adapted to pressurize the liquid; an injector configured to deliver the liquid to a heater assembly; a liquid flow valve configured to fluidly connect and disconnect the cartridge and the injector; and a pressure line and a reservoir fluidly positioned between the liquid flow valve and the injector. In this way, the liquid flow valve can be closed when the cartridge is being replaced by a new cartridge, thus preventing exposure of the user and the environment to liquid anesthesia. Furthermore, the reservoir can store a volume of liquid anesthesia such that the supply of liquid anesthesia to the injector is uninterrupted during the period when the liquid flow valve is closed, allowing for uninterrupted delivery of the anesthetic to the patient during cartridge replacement. Further still, this cartridge-based pressurized anesthesia system is compatible with a variety of anesthetics with different properties, such as boiling point and vapor pressure.

[0004] It should be understood that the above brief description is provided to introduce some concepts further described in the detailed embodiments in a simplified form. This is not intended to identify key or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims following the detailed embodiments. Furthermore, the claimed subject matter is not limited to specific implementations that address any shortcomings pointed out above or in any part of this disclosure. Attached Figure Description

[0005] This disclosure will be better understood by referring to the following description of non-limiting embodiments, in which:

[0006] Figure 1 A block diagram of a cylindrical pressure anesthesia system is shown.

[0007] Figure 2 An example of a tubular pressure anesthesia system including an internal cartridge is shown.

[0008] Figure 3 A diagram of a cylindrical pressure anesthesia system including an internal cartridge is shown.

[0009] Figure 4 A diagram of a tubular pressure anesthesia system including an external cartridge is shown.

[0010] Figure 5 An example of a heater assembly for a cylindrical pressurized anesthesia system is shown.

[0011] Figure 6 A flowchart is shown for a method of controlling the pressure of a cylindrical pressurized anesthesia system.

[0012] Figure 7 A flowchart is shown for a method of controlling the injector of a tubular pressurized anesthesia system.

[0013] Figure 8 An example of a cylindrical pressure anesthesia system connected to a ventilator is shown.

[0014] Figure 9 A detailed view of the interface between the ventilator and the cylindrical pressure anesthesia system is shown.

[0015] Figure 10 A flowchart is shown for a method of operating a cylindrical pressure anesthesia system. Detailed Implementation

[0016] The following description relates to systems and methods for use with cylindrical pressurized anesthesia systems. Conventionally, the anesthesia system is coupled to a reservoir that holds liquid anesthetic. During operation, the reservoir may need to be manually refilled from the liquid anesthetic bottle, exposing technicians and the environment to uncontrolled doses of anesthetic vapor. Furthermore, coupling a volatile anesthesia system to a vaporizer in an intensive care unit (ICU) setting may require the use of a closed-loop system in which exhaled vapor is washed away of CO2 and returned to the patient, in addition to being coupled to a suction system available in the ICU. Further still, conventional anesthesia systems may not be able to simultaneously deliver treatment and refill the reservoir, thus interrupting the delivery of anesthesia to the patient.

[0017] The inventors thus recognized the drawbacks discussed above and attempted to address these drawbacks using a cartridge-type pressurized anesthesia system. By introducing liquid anesthetic into a cartridge (such as a syringe), the need for technicians to discard the liquid anesthetic is eliminated. Instead, the cartridge can be pre-filled in a controlled environment before technicians handle it in an ICU or operating room setting. Furthermore, the cartridge-type pressurized anesthesia system can be configured for use in circulatory anesthesia systems and may include an integrated CO2 removal system suitable for patients with varying tidal volumes (e.g., including low lung flow) and / or adapted to the use of a humidifier. Additionally, the cartridge can be replaced with a full cartridge to replenish the supply of anesthesia without interrupting the delivery of anesthesia to the patient.

[0018] like Figure 1 As shown, a cylindrical pressurized anesthesia system can be configured to receive a gas mixture, vaporize the liquid anesthetic, and output fresh gas. The cylindrical pressurized anesthesia system can be further configured to remove CO2 from the gas mixture. In one example, the cylindrical pressurized anesthesia system can be a self-contained system including a display and an inlet / outlet configured to be connected to the source and destination of the gas mixture and fresh gas, respectively. Figure 2 As shown. Figures 3 to 4 The diagram shows the flow of anesthetic liquids and gases, in addition to the sensors and actuators for cartridge-type pressurized anesthesia. Figure 5 An example of the heating system of a cylindrical pressure anesthesia system is shown. The administration of anesthetic agents can be precisely controlled by the actuator of the cylindrical pressure anesthesia system. Figures 6 to 7 The diagram shows a flowchart of a method for controlling actuators based on feedback from sensors in a cylindrical pressurized anesthesia system. As an example, the gas can be supplied by, for instance... Figures 8 to 9 The ventilator cycle shown is via a tubular pressurized anesthesia system. Figure 10 The diagram shows a flowchart of a method for operating a cylindrical pressure anesthesia system.

[0019] Now go to Figure 1 A block diagram of a cylinder-type pressurized anesthesia system 100 is shown. The cylinder-type pressurized anesthesia system 100 may include a cartridge-pump assembly 102. The cartridge-pump assembly 102 may include a cartridge and a pump configured to deliver a volatile liquid anesthetic to a vaporizer at a predetermined desired pressure. The cartridge may include an internal volume configured to retain the volatile liquid anesthetic and prevent vapor escape. Furthermore, the cartridge may be mechanically coupled to the pump, which is configured to adjust the internal volume of the cartridge to pressurize the volatile liquid anesthetic. As an example further described below, the cartridge may be a syringe, and the pump may be a linear infusion pump.

[0020] The cartridge pump assembly 102 is fluidly connected to the heater assembly 104 via an injector 106. The injector 106 receives pressurized volatile liquid anesthetic from the cartridge pump assembly 102 and disperses droplets of the pressurized volatile liquid anesthetic into the heater assembly 104. The heater assembly 104 is configured to vaporize the liquid reagent from the cartridge pump assembly 102 and mix it with an incoming mixed gas 118. The mixed gas 118 (e.g., an O2 / N2 mixture) can be combined with vaporized anesthetic within the heater assembly 104, and the heater assembly 104 can output fresh gas 120 (e.g., a mixture of the mixed gas and the anesthetic).

[0021] The cylinder pressurized anesthesia system 100 may also include a controller 108 communicatively coupled to sensors 110 and actuators 112 of the cylinder pressurized anesthesia system 100. Sensors 110 may include one or more of the following: a pressure sensor, a flow sensor, a temperature sensor, and a sensor (e.g., a non-dispersive infrared (NDIR) sensor) configured to detect the concentration of anesthetic in fresh gas 120. Actuators 112 may include injector 106 and a pump of the cartridge pump assembly 102. Controller 108 may be a microcomputer including a microprocessor, input / output ports, and non-volatile electronic storage media for executing programs and calibration values. Controller 108 may be programmed with computer-readable data representing instructions capable of being executed to perform the methods further described below, as well as other methods.

[0022] The cylindrical pressure anesthesia system 100 may also include a user interface 124 communicatively coupled to a controller 108. The user interface 124 may be configured for a user to input operating parameters to the controller 108. In one example, the user interface 124 may be integrated into the housing of the cylindrical pressure anesthesia system 100. Additionally or alternatively, the user interface 124 may include an input device, such as a keyboard, touchscreen, etc., located externally to the housing and communicatively coupled to the controller 108. In some examples, the user interface 124 may be incorporated into portable devices such as tablets, laptops, smartphones, etc., including options for input via wired or wireless (e.g., WiFi or Bluetooth). ® Instructions for communication with controller 108.

[0023] The cylindrical pressure anesthesia system 100 may include a display 126 communicatively connected to a controller 108. The display 126 may be configured to show the user the operating status of the cylindrical pressure anesthesia system 100. In some examples, the display 126 may be integrated into the housing of the cylindrical pressure anesthesia system 100. Alternatively or additionally, the display 126 may be located externally to the housing and communicatively connected to the controller 108. For example, a tablet computer, laptop computer, external monitor, etc., may be configured as the display 126 and may be communicatively connected to the controller 108 via wired or wireless communication. In some examples, a single external computing device (such as a tablet computer, laptop computer, smartphone, etc.) may include the display 126 and a user interface 124.

[0024] Optionally, the cylindrical pressurized anesthesia system 100 may include a CO2 removal system 114. The CO2 removal system 114 may be positioned upstream of the heater assembly 104 relative to the flow of gas. The CO2 removal system 114 may be configured to receive a mixture of gases 128 exhaled by the patient (which may also include CO2 in addition to an anesthetic agent) and output a mixture of gases 118 having reduced CO2 (e.g., no CO2). The CO2 removal system 114 may include a CO2 filtration system, such as a membrane filtration system, as referenced below. Figure 8 Further description.

[0025] Optionally, the cylindrical pressurized anesthesia system 100 may also include a scavenging system 116. The scavenging system 116 may be configured to receive excess mixed gas and waste anesthetic gas 122 that has not been delivered to the patient. The scavenging system 116 may include reagents for isolating waste anesthetic gas 122 for removal and proper disposal.

[0026] Now go to Figure 2 A non-limiting example of the housing 202 of a cylinder pressure anesthesia system 100 is illustrated in perspective view 200. The housing 202 may enclose various components of the cylinder pressure anesthesia system 100, including an injector 106, a heater assembly 104, and a controller 108. In at least some examples, the housing 202 may further enclose a cartridge pump assembly 102. The housing 202 may include a door 204. In examples where the cartridge pump assembly 102 is housed by the housing 202, the door 204 may be configured to open, allowing a user selective access to the cartridges of the cartridge pump assembly 102. The user may not be able to access other components of the cartridge pump assembly 102, the injector 106, and the heater assembly 104, and these components may be automatically controlled by the controller 108. In this way, the cylinder pressure anesthesia system 100 can be easily used by a technician with minimal training.

[0027] The housing 202 may include a gas inlet 206 and a gas outlet 208. The gas inlet 206 may be configured to receive a gas mixture. For example, the gas inlet 206 may be coupled to a ventilator and may receive a gas mixture output by the ventilator and / or a recirculated gas mixture exhaled by the patient (e.g., Figure 1 The mixed gas 128). In an example where the mixed gas is exhaled gas (e.g., gas exhaled by the patient), the CO2 removal system (e.g., Figure 1 The CO2 removal system 114 can be fluidly connected to the gas inlet 206. The gas outlet 208 can be configured to deliver fresh gas. For example, the gas outlet 208 can be fluidly connected to a ventilator and can deliver fresh gas to the ventilator's inspiratory line.

[0028] The cylinder pressure anesthesia system 100 may also include an adjustable pressure limiting valve 210 fluidly coupled to a gas outlet 208. The adjustable pressure limiting valve 210 may be fluidly coupled to the ventilator's expiratory line upstream of the gas inlet 206. Therefore, the adjustable pressure limiting valve 210 can limit the pressure in the expiratory line to prevent the patient's lungs from being subjected to pressure exceeding a threshold pressure, above which the lungs may be compressed. For example, the threshold pressure may be adjusted according to the patient's characteristics. The adjustable pressure limiting valve 210 may automatically release pressure in response to experiencing pressure at or above the threshold, thereby preventing overpressure in the expiratory line. Therefore, the adjustable pressure limiting valve 210 may be a pressure reducing valve. For example, when the pressure in the expiratory line exceeds the threshold, the adjustable pressure limiting valve 210 may divert gas out of the expiratory line. In such examples, the gas diverted from the expiratory line may be directed to a clearance system, as further described below. In one example, using... Figure 1 For reference, in response to the pressure sensor detecting a pressure exceeding a threshold... Figure 1 The controller 108 can transmit a command signal to adjust the pressure relief valve 210, causing gas to be diverted from the exhalation line. Alternatively, the pressure relief valve 210 can be self-actuated. For example, the pressure relief valve 210 may include a mechanical mechanism (e.g., including a spring) that, when overcome by pressure exceeding a threshold pressure, causes the pressure relief valve 210 to adjust, causing gas to be diverted from the exhalation line. In this way, the pressure relief valve 210 can automatically reduce the pressure in the exhalation line to or below the threshold pressure. Figure 2 In this example, the pressure relief valve 210 is schematically shown as being positioned outside the housing 202, but in other examples, the pressure relief valve 210 may be enclosed within the housing 202.

[0029] The housing 202 may include an integrated display 212. The integrated display 212 may be as described above relative to... Figure 1Examples of displays 126 discussed. Integrated display 212 may display a graphical user interface (GUI) output by controller 108. In some examples, integrated display 212 may be a touchscreen display, and may also be an example of user interface 124. Housing 202 may additionally include physical interface 214. Physical interface 214 may include buttons that can be pressed by a user to actuate actuators of the cylindrical pressure anesthesia system 100. Furthermore, physical interface 214 may be configured for user interaction with the GUI displayed on integrated display 212.

[0030] Now go to Figure 3 Figure 300 shows an example of a cylindrical pressurized anesthesia system 100, which includes a cartridge pump assembly 102, an injector 106, and a heater assembly 104.

[0031] The cartridge pump assembly 102 may include a cartridge 302 mechanically coupled to the pump 304. In one example, such as Figure 3 As shown, cartridge 302 can be a syringe, and pump 304 can be a syringe pump, although as described above relative to... Figure 1 Other variable-volume cartridges and corresponding pumps are also considered in the discussion. Cartridge 302 can be self-sealing. For example, cartridge 302 can be configured to automatically seal to isolate from the environment in response to separation from pump 304. Cartridge 302 can be configured to be stable (e.g., non-degradable) under operating and storage pressures and temperatures. For example, the material forming the cartridge can be chemically compatible with and impermeable to volatile liquid anesthetics within the required pressure and storage temperature range. Pump 304 can be communicatively coupled to controller 108. Cartridge 302 can be reversibly mechanically coupled to pump 304. In this document, reversibly mechanically coupled components can be coupled and disengaged without component degradation and without the use of special tools or equipment.

[0032] Cartridge 302 may be fluidly connected to pressure line 306. A liquid flow valve 308 (e.g., a pneumatic valve) may be positioned between cartridge 302 and pressure line 306 relative to the flow of liquid anesthetic. Cartridge 302 may be selectively fluidly connected to pressure line 306 via liquid flow valve 308. Liquid flow valve 308 may be communicatively connected to controller 108. Controller 108 may include instructions to close liquid flow valve 308 in response to cartridge 302 being emptied or nearly emptied of liquid anesthetic, thereby fluidly separating cartridge 302 from pressure line 306. Closing liquid flow valve 308 maintains liquid pressure within pressure line 306 and prevents liquid anesthetic leakage into the environment while replacing the current cartridge (e.g., an empty or nearly empty cartridge) with a new cartridge (e.g., a full cartridge).

[0033] Pressure line 306 fluidly connects cartridge 302 to injector 106. Pressure sensor 310 can be configured to sense the liquid pressure within pressure line 306. Pressure sensor 310 can be communicatively coupled to controller 108. The pressure within pressure line 306 may be affected by liquid from cartridge 302 being forced into pressure line 306 by pump 304 changing the volume of cartridge 302. As an example, the pressure within pressure line 306 can be maintained in the range between 20 psi and 30 psi. Therefore, the pressure within pressure line 306 can be regulated by adjusting (e.g., operating) pump 304. In this way, cartridge-based pressurized anesthesia system 100 (specifically cartridge pump assembly 102) is suitable for use with a variety of different volatile liquid anesthetics, each with a different boiling point / vapor pressure and requiring different pressures within pressure line 306. In one example, cartridge 302 may include an identifier specific to the volatile liquid anesthetic contained therein, and pump 304 may be configured to read the identifier and communicate the identity of the volatile liquid anesthetic to controller 108 to automatically adjust the target pressure of pressure line 306 accordingly. For example, the identifier may be a radio frequency identification (RFID) tag. Controller 108 may actuate pump 304 based on sensor feedback to maintain the target pressure within pressure line 306, as referenced below. Figure 6 Further description.

[0034] Reservoir 312 is fluidly connected to pressure line 306. Reservoir 312 is fluidly positioned between liquid flow valve 308 and injector 106. Reservoir 312 stores a non-zero volume of pressurized liquid anesthetic. Therefore, when liquid flow valve 308 is closed and cartridge 302 is replaced with a full cartridge, reservoir 312 can supply pressurized liquid anesthetic to injector 106. By doing so, anesthetic is actively delivered to the patient while cartridge 302 is being replaced. In this way, the supply of liquid anesthetic can be replenished without interrupting the patient's sedation, which could occur when using other systems that do not include replaceable cartridges that are selectively fluidly connected to a reservoir. Reservoir 312 can be positioned anywhere along pressure line 306 between liquid flow valve 308 and injector 106.

[0035] Injector 106 is fluidly positioned between pressure line 306 and heater assembly 104. Injector 106 may be configured to receive pressurized liquid anesthetic from pressure line 306 and inject droplets of liquid anesthetic into a gas mixture flowing through heater assembly 104. As an example, injector 106 may be the same as or similar to an automotive fuel injector. Injector 106 may be communicatively coupled to controller 108. Controller 108 may actuate injector 106 at a rate (e.g., at a duty cycle) and for a duration to control the amount (e.g., concentration) of anesthetic in the fresh gas 120 output by cartridge pressurized anesthesia system 100. Controller 108 may control the duty cycle of injector 106. Controller 108 may actuate injector 106 based on the identifier of the cartridge of cartridge pump assembly 102. Controller 108 may further actuate injector 106 based on sensor feedback, as referenced below. Figure 7 Further description. Therefore, the cylindrical pressurized anesthesia system 100 is suitable for use with a variety of different volatile liquid anesthetics, each of which requires a different concentration in the fresh gas 120.

[0036] The heater assembly 104 may include a heating element 316 thermally coupled to the heating channel 314. The heating element 316 may be communicatively coupled to a controller 108. The heating element 316 may provide heat energy to cause the liquid anesthetic to evaporate (e.g., vaporize). In one example, the heating element 316 may be a self-regulating heater. In some examples, the heating element 316 may be a ceramic positive temperature coefficient (PTC) heating element. The heater assembly 104 may be controlled by the controller 108. For example, the controller 108 may regulate the amount of heat energy output by the heating element 316. In this way, the cylindrical pressurized anesthesia system 100 may be adapted for use with a variety of different volatile liquid anesthetics, each with a different boiling point, and therefore requiring different temperatures within the heater assembly 104.

[0037] The heating channel 314 may be a hollow chamber having at least a first end configured to receive the mixed gas 118 and a second end configured to output fresh gas 120. The heating channel 314 may be configured to transfer thermal energy from the heating element 316 to droplets of liquid anesthetic output by the injector 106. The heating channel 314 may be formed of a thermally conductive material. The heating channel 314 may include a gas inlet configured to receive the mixed gas 118 and a gas outlet configured to output fresh gas 120. In some examples, the injector 106 may disperse droplets of liquid anesthetic into the gas inlet in a direction tangential to the flow of the mixed gas 118. In another example, the heating channel 314 may include an opening configured to receive the dispersed droplets of liquid anesthetic at a non-zero angle relative to the flow of the mixed gas 118 through the heating channel 314. (The following is a repetition of the previous paragraph.) Figure 5 An example of heater assembly 104 is further described.

[0038] The cylindrical pressurized anesthesia system 100 may include an input gas valve 318 and an output gas valve 320. In one example, the input gas valve 318 and the output gas valve 320 may be pneumatic valves. The input gas valve 318 may be positioned relative to the flow of gas at the mixed gas inlet (e.g., Figure 2 The gas inlet 206 is located between the gas inlet of the heater assembly 104 and the gas inlet of the heater assembly 104. The output gas valve 320 is positioned relative to the gas flow between the gas outlet of the heater assembly 104 and the fresh gas outlet (e.g., Figure 2 Between the gas outlet 208). In this way, the input gas valve 318 and the output gas valve 320 can be positioned upstream and downstream of the heater assembly 104, respectively. The input gas valve 318 and the output gas valve 320 can each be communicatively coupled to the controller 108. In one example, when the gas source and gas destination (such as a ventilator) are fluidly connected to the cylinder pressure anesthesia system 100, the controller 108 can open the input gas valve 318 and the output gas valve 320. As another example, when the cylinder pressure anesthesia system 100 is not fluidly connected to the gas source and gas destination, the controller 108 can close the input gas valve 318 and the output gas valve 320 to prevent gaseous anesthetic from leaving the heater assembly 104. The input gas valve 318 can be positioned between the gas outlet 208 and the output gas outlet 208. Figure 2 Downstream of the adjustable pressure relief valve 210.

[0039] The cylindrical pressurized anesthesia system 100 may include an anesthetic sensor 322. The anesthetic sensor 322 may be configured to determine the amount (e.g., concentration) of anesthetic in the fresh gas 120 output from the cylindrical pressurized anesthesia system 100 and may be communicatively coupled to a controller 108. In one example, the anesthetic sensor 322 may be an NDIR detector configured for absorption in an infrared spectral region by the anesthetic. The anesthetic sensor 322 may be configured to determine the concentration of various anesthetics, each absorbing a different wavelength. The anesthetic sensor 322 may be calibrated to determine the concentration of the anesthetic in the fresh gas 120. The anesthetic sensor 322 may be used as part of a feedback loop to control the injector 106 and thus control the amount of anesthetic delivered to the patient. Specifically, the controller 108 may actuate the injector 106 based on signals received from the anesthetic sensor 322, as described below regarding... Figure 7 Further description.

[0040] The cylindrical pressure anesthesia system 100 may include a user interface and a display 328. In one example, the user interface and display 328 may be an integrated device configured to display and receive user input. For example, the user interface and display 328 may be one or more of a personal computer, laptop computer, tablet computer, smartphone, etc. In one example, the user interface and display may be integrated into a device such as... Figure 2 The illustrated cylindrical pressurized anesthesia system 100 is housed within a housing. A user interface and display 328 are communicatively connected to a controller 108. In some examples, the user interface and display 328 are wirelessly communicatively connected to the controller 108. Alternatively, the user interface and display 328 may be communicatively connected to the controller 108 via one or more conductive wires.

[0041] The cartridge pump assembly 102 may be positioned internally, such as within a housing (e.g., housing 202) that further encloses the heater assembly 104, controller 108, injector 106, and reservoir 312. Therefore, the pump 304 may be integrally constructed within the cartridge pressurized anesthesia system 100, making the pump 304 non-removable from the housing. Aside from the openings for inserting and removing the cartridge 302, the pump 304 may not be directly accessible to the user. Alternatively, as per [reference to...] Figure 4 Further described, the cartridge pump assembly 102 may be positioned externally, outside the housing. In such an example, the cartridge pump assembly 102 may be further removably coupled to the pressure line 306, thereby allowing the cartridge pressurized anesthesia system 100 to be compatible with conventional pumps.

[0042] Go to Figure 4 Figure 400 shows another example of a cylindrical pressurized anesthesia system 100, which includes a cartridge pump assembly 102, an injector 106, and a heater assembly 104. Figure 400 includes the above-mentioned... Figure 3 The various components described in Figure 300 are referenced and do not need to be reintroduced.

[0043] The cartridge pump assembly 102 may include a cartridge 402 and a pump 404. The cartridge 402 may have the features described above. Figure 3 Similar characteristics are described in cartridge 302, including self-sealing capability, variable volume, and stability under operating and storage pressures and temperatures (e.g., no degradation). Similarly, pump 404 may have characteristics similar to those described above. Figure 3Similar characteristics are described for pump 304, including the ability to detect the identifier of cartridge 402 and change the volume of cartridge 402. However, cartridge 402 and pump 404 may be positioned externally (e.g., outside housing 202). Housing 202 may include a port configured to removably fluidly connect pressure line 306 to cartridge 402. Pump 404 may be communicatively coupled to controller 108 via wired and / or wireless connections. The externally positioned cartridge 402 and pump 404 allow a user-supplied pump to deliver the pressurized liquid flow contained in cartridge 402 to injector 106 via a control loop controlled by controller 108. Figure 4 In this example, the cartridge pump assembly 102 may be physically and removably coupled to the pressure line 306 and selectively communicatively coupled to the controller 108, rather than being integrated with the components housed within the housing 202. For example, the communicative connection between the pump 404 and the controller 108 may be formed as needed (e.g., by forming a physical wired connection or establishing a wireless connection). However, the pump 404 may be removed from the housing 202, and the communication between the pump 404 and the controller 108 may be discontinued, allowing the pump 404 to be used in other systems when the cartridge pressure anesthesia system 100 is not in use.

[0044] In this way, the cartridge-type pressurized anesthesia system 100 can be compatible with various configurations of the cartridge pump assembly 102 when it is externally located, thus allowing selection according to user preferences. For example, a user may desire a larger capacity cartridge, resulting in a lower frequency of cartridge replacements. Therefore, it is compatible with configurations such as... Figure 3 Compared to the internal configuration shown, in such as Figure 4 The external configuration shown allows for greater flexibility in cartridge volume. However, an internal configuration where the pump is integrated (e.g., non-removable) may be easier for the user to operate (e.g., by eliminating the need for a manual pump connection). Therefore, there are two configurations available (e.g., internal pump and external pump).

[0045] The cartridge-type pressurized anesthesia system 100 may also include a liquid flow sensor 406. The liquid flow sensor 406 may be configured to measure the flow rate of the anesthetic liquid through the pressure line 306. The liquid flow sensor 406 may be located upstream or downstream of the reservoir 312. The liquid flow sensor 406 may be located upstream or downstream of the pressure sensor 310. In some examples, the liquid flow sensor 406 is omitted because the flow rate through the pressure line 306 can be derived (e.g., approximated) from other variables communicated to the controller 108, such as pressure monitored by the pressure sensor 310, pipe diameter, and / or operation of the pump 404 (e.g., rate of change of cartridge volume). In some examples, the liquid flow sensor 406 may be included... Figure 3 In the internal configuration shown.

[0046] For example, the flow rate of the anesthetic liquid through the pressure line 306 can be calculated based on Poiseuille's law (Equation 1) for laminar flow.

[0047] (1)

[0048] In Equation 1, Q is the volumetric flow rate, π is a mathematical constant (e.g., ≈3.14159…), r is the pipe radius (e.g., pipe radius), ΔP is the pressure difference, μ is the dynamic viscosity of the fluid (e.g., anesthetic liquid), and L is the length of the pipe (e.g., pipe length). If a differential pressure sensor (e.g., pressure sensor 310 may be a differential pressure sensor including sensors P1 and P2) is used to monitor the pressure difference across a fixed section of a pressure line, and the inner diameter of the pressure line is known (e.g., by design and fixed and stored in the controller's non-volatile memory), and the pipe length between differential pressure sensors P1 and P2 is known (e.g., by design and fixed and stored in the controller's non-volatile memory), and the dynamic viscosity of a particular liquid anesthetic can be known and stored in the controller 108's non-volatile memory, then the flow rate of the liquid anesthetic entering the injector valve 106 can be calculated.

[0049] Go to Figure 5 An example of heater assembly 104 is shown. Heater assembly 104 may include heating element 316 and heating channel 314 as described above.

[0050] A first end 502 of the heating element 316 may be configured to receive gas (e.g., mixed gas 118), and a second end 504 of the heating element 316 may be configured to output gas (e.g., fresh gas 120). A heating channel 314 may be positioned within the heating element 316 such that the received gas flows through the heating channel 314 before exiting the heating element 316 at the second end 504. That is, the received gas may be forced through the heating channel 314 together with droplets of liquid anesthetic injected into the heater assembly 104 (e.g., by injector 106). For example, the inlet 506 and outlet 508 of the heating element 316 may be positioned close to the first end 502 and the second end 504, respectively.

[0051] Heating channel 314 can be configured to transfer thermal energy from heating element 316 to droplets of liquid anesthetic. Therefore, heating channel 314 can be made of a thermally conductive material, such as metal. Heating channel 314 can be further configured to mix the received gas with the liquid anesthetic droplets. For example, the geometry of heating channel 314 can form a non-linear path through it, such that anesthetic vapor mixes with the received gas as the liquid anesthetic droplets vaporize. Such geometry can also increase the surface area of ​​the heat transfer interface in which the droplets contact the heating channel 314, thereby improving the space efficiency and energy efficiency of heating channel 314. For example, heating channel 314 may include a static mixer. Therefore, heater assembly 104 can be configured for both heating and mixing (e.g., active heating and passive mixing).

[0052] Heating channel 314 is shown as having cutouts for visibility of its interior 510, which includes an example of a heating channel geometry that passively induces a gas flow pattern resulting in an increased area for mixing and expanding heat transfer interfaces. An outer wall 512 may surround the interior 510. For example, the outer wall 512 may be a hollow cylindrical shape, with open ends forming an inlet 506 and an outlet 508. Within the interior 510, multiple guide walls 514 may be present. The guide walls 514 may be shaped and positioned to guide the gaseous and liquid materials in a path that facilitates mixing. For example, the guide walls 514 may be curved to define a helical path. The guide walls 514 can further increase heat transfer from the heating element 316 to the liquid anesthetic droplets in the interior 510 by increasing the surface area of ​​the conductive material exposed to the liquid anesthetic droplets. Thus, the liquid anesthetic droplets can be vaporized and thoroughly mixed with the received gas due to their travel through the heating channel 314.

[0053] In this way, the gas output from heater assembly 104 may include vaporized anesthetic and may not include liquid anesthetic. Furthermore, the output gas may include a homogeneous mixture of vaporized anesthetic and received gas mixtures. Additionally or alternatively, heating element 316 may include an induction heater. An induction heater can provide near-instantaneous heating. Heating element 316 may include an induction heater in configurations where there is a large (e.g., above a Δ threshold) abrupt change in the volume of the liquid anesthetic injected therein and / or if the inlet gas is cold (e.g., below a threshold gas temperature). All received gases may be included in the output gas. By heating the liquid anesthetic and gas via heater assembly 104, the liquid anesthetic can be heated and mixed more efficiently compared to other heating systems that do not include similar heating channels.

[0054] Go to Figure 6 This illustrates a cylindrical pressure anesthesia system (such as...) for controlling the present disclosure. Figures 1 to 4 , Figure 8 and Figure 9 A flowchart of a method 600 for applying pressure to a cylindrical pressure anesthesia system 100. The pressure stored in a controller (e.g., Figure 1 Instructions in the non-volatile memory of the controller 108 can be executable to respond to a sensor (e.g., Figure 1 The feedback received by the sensor 110 is sent to the actuator (e.g., Figure 1 The actuator 112) transmits command signals to execute method 600.

[0055] At 602, method 600 includes a cartridge pump assembly via a cartridge-type pressurized anesthesia system (e.g., Figure 1 , Figure 3 and Figure 4 The cartridge pump assembly 102) directs the fuel into the injector (e.g., Figure 1 , Figure 3 and Figure 4 The injector 106 supplies pressurized liquid anesthetic. The controller can supply pumps (e.g., for the cylindrical pressurized anesthesia system) to the pumps of the system. Figure 3 and Figure 4 The pump (304 or 404) transmits a command signal to the cartridge (e.g., respectively) to control the cartridge. Figure 3 and Figure 4 The liquid anesthetic in cartridge 302 or 402 is pressurized, thereby forcing the liquid anesthetic along the pressure line between the pump and the injector (e.g., Figure 3 and Figure 4 The pressure line 306) is directed downwards. In some examples, the liquid anesthetic accumulates in a reservoir (e.g., upstream of the injector) that is fluidly connected to the pressure line. Figure 3 and Figure 4 In the storage device 312).

[0056] At 604, method 600 includes measuring the pressure in the pressure line between the cartridge pump assembly and the injector. The measurement may include a controller connected from a gauge pressure sensor or differential pressure sensor (e.g., fluid coupling to the pressure line) to the pressure line. Figure 3 and Figure 4 The pressure sensor 310 receives electrical signals indicating a pressure drop in the pressure line at both ends of the pressure line and / or at fixed limits (e.g., internal pipe resistance, orifice, and / or the injector valve itself). The controller can respond automatically to the signals as described below.

[0057] At 606, method 600 includes determining whether the measured pressure is equal to a target pressure. If the measured pressure is within the range of the target pressure, the method determines that the measured pressures are equal. This range can be + / - 5%. In the example, this range can be within + / - 5% of the nominal pressure required to reliably operate the injector (e.g., injector 106). The liquid injector (such as injector 106) may have a characteristic minimum pressure specification, a nominal pressure specification, and a maximum inlet pressure specification. The characteristic minimum pressure may be the minimum pressure required for normal operation of the liquid injector. The nominal pressure, minimum pressure, and maximum pressure may each depend on the ambient temperature of the anesthetic liquid. The target pressure may be specific to one or more of the type of anesthetic pumped through the cartridge pressurization anesthesia system, the ambient temperature of the anesthetic, and the characteristics of the injector. For example, the controller may detect the cartridge identifier (e.g., RFID) and set the target pressure accordingly. Additionally or alternatively, the controller may set the target pressure based on the input of a temperature sensor measuring the ambient temperature of the anesthetic and / or the minimum pressure, nominal pressure, and maximum pressure of the injector stored in the controller's non-volatile memory. In this way, a cylindrical pressure anesthesia system can be equipped to deliver various anesthetics with different properties.

[0058] If the measured pressure equals the target pressure ("Yes" at 606), then method 600 proceeds to 608. At 608, method 600 includes continuing to supply pressurized liquid anesthetic to the injector (e.g., without adjusting the pressure).

[0059] Alternatively, if the measured pressure is not equal to the target pressure ("No" at 606), method 600 proceeds to 610. At 610, method 600 includes adjusting the operation of the pump in the cartridge pump assembly until the measured pressure equals the target pressure. For example, if the measured pressure is lower than the target pressure, the controller may send a command signal to the pump to increase the force applied to the liquid in the cartridge (e.g., by reducing the cartridge volume at a faster rate). Conversely, if the measured pressure is higher than the target pressure, the controller may send a command signal to the pump to decrease the force applied to the liquid in the cartridge (e.g., by pausing or slowing the reduction of the cartridge volume).

[0060] Method 600 returns after 608 or 610. By performing method 600 during operation of the cylindrical pressure anesthesia system of this disclosure, the feedback loop maintains the target pressure in the pressure line. Control of the feedback loop described herein (e.g., regarding...) Figure 6 and Figure 7 Methods 600 and 700 can utilize scaling, derivative and / or integration operations to optimize stability (e.g., minimize overshoot) and reduce latency.

[0061] Go to Figure 7This illustrates a cylindrical pressure anesthesia system (such as...) for controlling the present disclosure. Figures 1 to 4 , Figure 8 and Figure 9 A flowchart of a method for using the injector in a cylindrical pressurized anesthesia system 100. The data is stored in a controller (e.g., Figure 1 Instructions in the non-volatile memory of the controller 108 can be executable to respond to a sensor (e.g., Figure 1 The feedback received by the sensor 110 is sent to the actuator (e.g., Figure 1 The actuator 112 transmits command signals to execute method 700.

[0062] At 702, method 700 includes via an injector (e.g., Figure 1 , Figure 3 and Figure 4 The injector 106) delivers pressurized liquid anesthetic to the heater assembly (e.g., Figure 1 , Figure 3 and Figure 4 The heater assembly 104). The injector can operate at a duty cycle in response to a command signal generated by the controller. That is, the injector can inject a fixed amount of pressurized liquid anesthetic (e.g., dropwise) into the heater assembly at a frequency equal to the duty cycle.

[0063] At 704, method 700 includes measuring the fresh gas output from the heater assembly (e.g., Figure 1 , Figure 3 and Figure 4 The concentration of the anesthetic in the fresh gas 120. For example, the controller can detect the concentration from an NDIR sensor (e.g., a fresh gas 120). Figure 3 and Figure 4 The anesthetic sensor 322 receives an electrical signal. Fresh gas can flow through the ventilator's inspiratory line, as further described below. The controller can automatically respond to the electrical signal generated by the sensor, as described below.

[0064] At 706, method 700 includes determining whether the measured concentration is equal to the target concentration. If the measured concentration is within the range of the target concentration, the method determines that the measured concentrations are equal. This range can be + / - 5%. As another example, the accuracy (e.g., range) can be + / - 0.15 volume% + 5% of the measured concentration. The target concentration can depend on the type of anesthetic pumped through the cylinder pressurization anesthesia system. For example, the target concentration of sevoflurane can be in the range of greater than 0 volume% to 8 volume%, the target concentration of desflurane can be in the range of greater than 0 volume% to 18 volume%, and the target concentration of isoflurane can be in the range of greater than 0 volume% to 5 volume%. Furthermore, the response time for measuring the target concentration can be less than 160 milliseconds. The target concentration can further depend on the characteristics of the patient inhaling fresh gas, such as age, weight, etc. Therefore, the target concentration can be set by the user. For example, the user can determine the target concentration and via, such as Figure 1 The user interface 124 and other user interfaces input the desired target concentration into the controller.

[0065] If the measured concentration equals the target concentration ("Yes" at 706), the method proceeds to 708. At 708, the method includes continuing to deliver pressurized liquid anesthetic (e.g., without adjusting the injector duty cycle).

[0066] Alternatively, if the measured concentration is not equal to the target concentration ("No" at 706), method 700 proceeds to 710. At 710, method 700 includes adjusting the operation of the injector until the measured concentration equals the target concentration. For example, if the measured concentration is below the target concentration, the controller may send a command signal to the injector to increase the flow rate of the liquid anesthetic entering the heater assembly (e.g., by increasing the frequency and / or duration of the injector's duty cycle). Conversely, if the measured concentration is above the target concentration, the controller may send a command signal to the injector to decrease the flow rate of the liquid anesthetic entering the heater assembly (e.g., by decreasing the frequency and / or duration of the injector's duty cycle).

[0067] Method 700 returns after 708 or 710. By performing method 700 during operation of the cylindrical pressure anesthesia system of this disclosure, the feedback loop maintains a target concentration of vaporized anesthetic in the fresh gas supplied to the patient.

[0068] Go to Figure 8An example of a system 800 including a cylinder-type pressurized anesthesia system 100 coupled to a ventilator 802 is illustrated. The ventilator 802 may be a non-limiting example of a conventional ventilator typically used in operating rooms, ICUs, or other medical settings. The cylinder-type pressurized anesthesia system 100 adapts a ventilator system, such as the ventilator 802, to deliver vaporized anesthetic agents to the respiratory system of a patient 804. The system 800 can deliver various anesthetic agents to the patient 804 based on their characteristics without manual adjustment. The system 800 further eliminates user exposure to the anesthetic agent during refilling. Furthermore, the system 800 eliminates interruptions in anesthesia delivery during refilling.

[0069] The ventilator 802 may include an inspiratory line 808 and an expiratory line 810. Gases inhaled and exhaled by the patient 804 may flow into and out of the patient 804 via the inspiratory line 808 and expiratory line 810, respectively. The inspiratory line 808 may be connected to a humidifier 812 adapted to provide an appropriate level of water vapor in the gas inhaled by the patient 804. The humidifier 812 may be fluidly connected to an inspiratory port 814 of the ventilator 802, from which inhaled gas is delivered to the inspiratory line 808. An expiratory port 816 of the ventilator 802 may receive exhaled gas from the expiratory line 810. The inspiratory line 808 and expiratory line 810 may be fluidly connected to one or more patient lines 840 that directly interface with the patient 804. The patient lines 840 may include a nasogastric tube, an endotracheal tube, etc.

[0070] The cylindrical pressure anesthesia system 100 can be fluidly connected to the exhalation port 816 via a mixed gas line 818. The mixed gas can flow into the cylindrical pressure anesthesia system 100 through the mixed gas line 818. The mixed gas can be delivered via an inlet (such as...) Figure 2 (Entrance 206) enters the cylindrical pressure anesthesia system 100.

[0071] Since the gas mixture exhaled by the patient 804 contains CO2 to be removed before inhalation, the cylindrical pressure anesthesia system 100 may include a CO2 removal system 114. The CO2 removal system 114 may include a membrane separator configured to passively separate the gaseous mixture into two or more output streams via a membrane, wherein one or more of the output streams include CO2, and at least one of the output streams does not contain CO2. Although described herein as a membrane separator, in other examples, an absorber or other non-membrane separator may be used. The CO2 removal system 114 may receive the gas mixture and a flushing gas 822 via a gas mixing line 818. The flushing gas 822 may include O2. In some examples, the flushing gas 822 may also include one or more other gases, such as N2. The flushing gas 822 may flush out CO2 that has diffused across the membrane. The flushing gas 822 may be mixed with CO2 pre-contained in the gas mixture in the gas mixing line 818 and exit the cylindrical pressure anesthesia system 100 as exhaust gas 824. Therefore, in addition to any gases present in the flushing gas 822 (such as O2 and / or N2), the exhaust gas 824 may also include CO2. The exhaust gas 824 may be released into the environment or conveyed to the purging system 116. The exhaust gas 824 may not include anesthetic gases.

[0072] Any remaining mixed gas that is not flushed away by flushing gas 822 may be supplied to vaporization system 826. Vaporization system 826 may include components of cylindrical pressurized anesthesia system 100, such as those adapted to supply gas to an injector (e.g., Figure 1 , Figure 3 and Figure 4 The injector 106) provides a cartridge and pump (e.g., internally constructed, such as) for pressurized liquid anesthetic. Figure 3 The cartridge 302 and pump 304, or externally constructed, such as Figure 4 The cartridge 402 and pump 404), the injector sprays droplets of liquid anesthetic onto the heater assembly (e.g., Figure 1 , Figure 3 and Figure 4 The anesthetic is vaporized in the heater assembly 104. The mixed gas flowing through the mixed gas line 818 can be... Figure 1 The mixed gas 128, and the CO2-free filtered (e.g., membrane-separated) mixed gas supplied to the gasification system 826 may be... Figure 1 118.

[0073] Pressure limiting valve 836 can be configured to limit pressure within expiratory line 810 to protect the lungs of patient 804. Pressure limiting valve 836 can be... Figure 2An example of pressure limiting valve 210. Pressure limiting valve 836 is fluidly coupled to expiratory line 810 and mixed gas line 818. Pressure limiting valve 836 may selectively connect expiratory line 810 to clearance line 838 leading to clearance system 116. For example, when the pressure in expiratory line 810 exceeds a threshold pressure, gas can be released into clearance line 838 by adjusting pressure limiting valve 836 to reduce the pressure below the threshold pressure. Therefore, the pressure in mixed gas line 818 may also be reduced. When the pressure in expiratory line 810 is below the threshold, gas may not flow through clearance line 838. Pressure limiting valve 836 may be part of ventilator 802 and / or cylinder pressure anesthesia system 100. In an example where both ventilator 802 and cylinder pressure anesthesia system 100 include pressure limiting valves (e.g., adjustable pressure limiting valves) within the patient's exhaled airflow, the two pressure limiting valves may be used as backups for each other in a dual-tolerance configuration. The clearance system 116 may include a container encapsulating charcoal and / or one or more other materials configured to facilitate the adsorption or absorption of vaporized anesthetics present in the patient's exhaled gas. As an example, the container may be periodically replaced as it becomes full, as indicated by an increase in its weight, thereby allowing for the proper disposal of the material collected therein.

[0074] Fresh gas (e.g., fresh gas 120) may be supplied from the cylinder pressure anesthesia system 100 via fresh gas line 820. Fresh gas line 820 may be supplied via an outlet (such as...) Figure 2 The outlet 208 is fluidly connected to the cylindrical pressurized anesthesia system 100. The fresh gas may include a vaporized anesthetic. The fresh gas may not include CO2. The fresh gas may not include a liquid anesthetic. The fresh gas line 820 may be fluidly connected to the inhalation line 808, so that the patient 804 inhales the gas from the inhalation line 808 and the fresh gas line 820.

[0075] The gas arriving at the scavenging system 116 may not be recirculated to the patient 804. Instead, the scavenging system 116 may remove volatile anesthetics from the gas and output exhaust gas 122. For example, the scavenging system 116 may include a container encapsulating charcoal and / or other materials capable of promoting the adsorption or absorption of volatile anesthetics. The container may be replaced periodically, for example, when the amount of weight increase in the container indicates that the maximum amount of anesthetic has accumulated therein. In this way, any anesthetic that has not been metabolized by the patient 804 or recirculated back to the patient 804 can be disposed of without releasing anesthetic vapors into the atmosphere. In some examples, exhaust gas 824 output by the CO2 removal system 114 may also be transferred to the scavenging system 116 to collect any trace amounts of volatile anesthetic present that were not captured by the vaporization system 826.

[0076] The ventilator 802 may also include a controller 832. The controller 832 may be communicatively coupled to the controller of the cylindrical pressure anesthesia system 100 (e.g., Figure 1 (Controller 108). Therefore, controller 832 and the controller of the cylindrical pressure anesthesia system 100 can operate collaboratively to control system 800. Communication between controllers can occur wirelessly or via one or more wires. In some examples, the cylindrical pressure anesthesia system 100 may further receive power from ventilator 802 via one or more wires.

[0077] The ventilator 802 may also include a display 834. The display 834 may show user parameters monitored by sensors of the ventilator 802. Since the controller 832 communicates with the controller of the cylinder pressure anesthesia system 100, the display 834 may further display parameters monitored by sensors of the cylinder pressure anesthesia system 100, such as the concentration of anesthetic flowing through the fresh gas line 820. That is, the display 834 may be included in... Figure 1 The display 126 of the cylindrical pressure anesthesia system 100 shown.

[0078] In this way, the tubular pressure anesthesia system 100 can be configured to inhale gas exhaled by the patient 804 and provide gas prepared for inhalation, such that the tubular pressure anesthesia system 100 is incorporated into the system 800 in a closed-loop configuration. By doing so, gas can circulate simultaneously through the ventilator 802 and the tubular pressure anesthesia system 100. Furthermore, connecting the tubular pressure anesthesia system 100 to the ventilator 802 in this manner allows the ventilator 802 to be adapted to deliver various anesthetics with different inherent properties. Further still, due to the configuration of the tubular pressure anesthesia system 100 (e.g., including…), Figure 3 and Figure 4 The patient 804 can continue to receive anesthesia even when the cartridge of the cylinder pressure anesthesia system 100 is replaced (the storage device 312), thereby eliminating the interruption of sedation to the patient 804.

[0079] Go to Figure 9 A detailed view 900 shows the interface between the ventilator 802 and the cylindrical pressure anesthesia system 100. The direction of the circulating airflow between the ventilator 802, the cylindrical pressure anesthesia system 100, and the patient 804 is also shown.

[0080] Inspiratory port 814 may be fluidly connected to the inspiratory line of ventilator 802 as described above. Gas (e.g., oxygen-containing gas) may flow from inspiratory port 814 to patient 804, as indicated by arrow 912. Gas output from ventilator 802 via inspiratory port 814 as indicated by arrow 912 and fresh gas output from cylinder pressure anesthesia system 100 via outlet 208 as indicated by arrow 914 may be combined (e.g., mixed) into a gas mixture inhaled by patient 804.

[0081] The expiratory port 816 may include an inlet 902 and an outlet 904. The inlet 902 may be fluidly connected to an expiratory line of the ventilator 802 as described above. The outlet 904 may be fluidly connected to a mixed gas line of the ventilator 802 leading to the cylindrical pressure anesthesia system 100. Therefore, gas may flow through the expiratory port 816 in the direction indicated by arrow 908. The expiratory port 816 may direct all gas exhaled by the patient 804 to the cylindrical pressure anesthesia system 100. In the event of excessive pressure in the expiratory line, some gas may be directed to a scavenging system instead of being recirculated into the cylindrical pressure anesthesia system 100. For example, a pressure-limiting valve 836 may be integrated with the expiratory port 816 such that the pressure-limiting valve 836 selectively allows gas to flow through a second outlet 906 of the expiratory port 816. The second outlet 906 may be, for example, via… Figure 8 Cleaning pipeline 838 and Figure 1 and Figure 8 The purging system 116 is fluidly connected. When the pressure in the expiratory line exceeds a threshold pressure, gas can flow out of the expiratory port 816 through the second outlet 906. In this way, the cylinder pressure anesthesia system 100 can utilize the pressure limiting valve of the ventilator 802 to limit the pressure in the expiratory line. Alternatively, the pressure limiting valve 836 may not be integrated with the ventilator 802. For example, the pressure limiting valve 836 may be included closer to the inlet 206 than the outlet 904, or it may be included inside the cylinder pressure anesthesia system 100. That is, a pressure limiting valve configured to reduce the pressure in the expiratory line by delivering gas to the purging system can be located anywhere downstream of the patient 804 and upstream of the cylinder pressure anesthesia system 100.

[0082] The ventilator 802 may also include one or more additional ports, such as port 910, which can be fluidly connected to the inspiratory and / or expiratory lines of the ventilator 802 for additional therapeutic purposes.

[0083] In this way, a closed loop is formed between the ventilator 802, the patient 804, and the tubular pressurized anesthesia system 100. The closed loop configuration allows for the recirculation of anesthesia exhaled by the patient 804 (e.g., anesthesia delivered to the patient and not metabolized), thereby reducing the amount of wasted anesthetic.

[0084] In the alternative configuration, now refer to Figure 8The cylindrical pressurized anesthesia system 100 may be fluidly coupled to the inhalation line 808. For example, the cylindrical pressurized anesthesia system 100 may be located downstream of a humidifier 812, such that humidified gas output from the humidifier 812 is introduced into the cylindrical pressurized anesthesia system 100. The cylindrical pressurized anesthesia system 100 may mix the humidified gas with vaporized anesthetic. The gas output from the cylindrical pressurized anesthesia system 100 may flow directly into the inhalation line 808 to reach the patient 804. In such an example, a humidity sensor may be positioned to read the humidity of the fresh gas output from the cylindrical pressurized anesthesia system 100. The humidity of the fresh gas measured by the humidity sensor may be used to adjust the reading of the anesthetic sensor 322. For example, without using a humidity-based correction factor, the NDIR concentration measurement in the presence of water vapor may be erroneous. The effect of humidity on the output anesthetic sensor 322 may be empirically mapped and stored in the non-volatile memory of the controller 108 as a correction factor for the measured anesthetic concentration. Additionally or alternatively, it can be transmitted through water vapor pipes (e.g., Nafion). ™ A sample pump and / or dryer may be positioned between the sampling pump and the anesthetic sensor 322 to reduce the relative humidity of the fresh gas before it reaches the anesthetic sensor 322. In this way, an accurate measurement of the anesthetic concentration in the fresh gas can be determined.

[0085] Because the humidified gas has an acceptable CO2 level due to the function of the ventilator 802, the cylinder pressure anesthesia system 100 may not include a CO2 removal system 114 in this example. However, the anesthetic vapor exhaled by the patient 804 may not be recirculated. Instead, all exhaled gas can be directed to the scavenging system 116, as in the routine operation of the ventilator 802, without being connected to the cylinder pressure anesthesia system 100. Therefore, although fewer components may be required in this example, reducing the resource requirements and packaging volume of the cylinder pressure anesthesia system 100, while providing the effect of vaporizing anesthetics with different properties such as boiling point, it is still possible to achieve the same effect as... Figure 8 and Figure 9 Compared to the configuration shown, this configuration can increase the amount of wasted anesthetic that accumulates in the clearance system 116.

[0086] Go to Figure 10 It shows the operation of including a ventilator (e.g., Figure 8 and Figure 9 The ventilator 802) and the cylindrical pressure anesthesia system of this disclosure (e.g., Figures 1 to 4 , Figure 8 and Figure 9A flowchart of a method 1000 for a cylindrical pressure anesthesia system (100). Method 1000 can be stored as instructions in the non-volatile memory of the ventilator controller and / or the cylindrical pressure anesthesia system controller. The controllers can be communicatively coupled to jointly execute method 1000. Additionally, one or more steps of method 1000 can occur passively. One or more steps of method 1000 can be manually performed by the system user.

[0087] At 1002, method 1000 includes a tubular pressure anesthesia system receiving an expiratory line from a ventilator (e.g., Figure 8 The mixed gas (exhalation line 810) is exhaled by the patient. Therefore, the mixed gas may include carbon dioxide mixed with one or more other gases.

[0088] At 1004, method 1000 optionally includes directing gas from the expiratory line to a clearance system (e.g., when the pressure in the expiratory line exceeds a threshold pressure). Figure 1 and Figure 8 The purging system 116). For example, pressure relief valves (e.g., respectively). Figure 2 or Figure 8 The pressure limiting valve 210 or 836 can selectively fluidly connect the expiratory line to a clearance line leading to a clearance system. The clearance system removes the anesthetic before the exhaust gas is released. The threshold pressure can be a pressure above which the patient's lungs may be compressed during exhalation. If the pressure does not exceed the threshold pressure, method 1000 may not include 1004.

[0089] At 1006, method 1000 includes a removal system via a tubular pressure anesthesia system (e.g., Figure 1 and Figure 8 The CO2 removal system 114 filters carbon dioxide from the mixed gas. In one example, the removal system may include a membrane separator. A flushing gas may flow through the membrane separator to flush away carbon dioxide that has accumulated along the membrane. Carbon dioxide may be passively filtered from the mixed gas. While the flushing gas with increased CO2 is released (e.g., depleted), the remaining filtered mixed gas with reduced CO2 or no CO2 may continue to flow through the tubular pressurized anesthesia system.

[0090] At 1008, method 1000 includes combining a filtered mixed gas with an anesthetic agent vaporized via a cylindrical pressurized anesthesia system to produce fresh gas. Vaporizing the anesthetic agent and combining the filtered mixed gas with the anesthetic agent via a cylindrical pressurized anesthesia system may include using a pump (e.g., respectively) Figure 3 and Figure 4 Pump 302 or 402) for use with cartridges (e.g., respectively) Figure 3 and Figure 4The liquid anesthetic in the cartridge (304 or 404) is pressurized, and (e.g., via...) Figure 1 , Figure 3 and Figure 4 The injector 106) sprays droplets of pressurized liquid anesthetic onto the heater assembly (e.g., Figure 1 and Figures 3 to 5 In the heater assembly 104), liquid anesthetic droplets are vaporized and transmitted via heating channels (e.g., Figure 1 and Figures 3 to 5 The heating channel 314) mixes with the filtered mixed gas. The feedback loop can be used to control the operation of the injector and pump, as per [specific parameters]. Figure 6 and Figure 7 As described. Therefore, 1008 may include, respectively Figure 6 and Figure 7 Method 600 and / or 700, one or more steps.

[0091] At 1010, method 1000 includes allowing fresh gas to flow into the inspiratory line of a ventilator to deliver a vaporized anesthetic to the patient. The fresh gas may be mixed with oxygenated gas and humidified gas from the ventilator before reaching the patient.

[0092] At 1012, method 1000 includes determining whether the cartridge of the cartridge pump assembly is empty or nearly empty. For example, if the volume of the cartridge is below a threshold volume, it can be determined that the cartridge is empty or nearly empty. The volume of the cartridge can be related to the position of the pump. For example, the position of a pump that can be linearly actuated as described above can be any position along a linear path of a certain length. The position, which can be expressed as a percentage of length, can be used to determine the remaining cartridge volume as a percentage of the maximum volume. Thus, the pump can communicate the pump's position to a controller. When the position reaches or exceeds a threshold position, the controller can automatically determine that the cartridge is empty or nearly empty. As another example, when the threshold position is reached or exceeded, the pump can automatically send an alarm signal to the controller, prompting the controller to determine that the cartridge is empty or nearly empty. Alternative methods for determining whether the cartridge is empty or nearly empty are also possible. It may be advantageous to replace the cartridge with a full cartridge before the current cartridge is completely empty (e.g., when it is nearly empty) to prevent (e.g., avoid) the depletion of the anesthetic fluid supply. However, due to the reservoir of the tubular pressurized anesthesia system (e.g., Figure 3 and Figure 4 The reservoir 312 is configured to maintain a certain volume of pressurized liquid anesthetic, so that anesthesia can continue to be delivered to the patient without interruption during the period when the cartridge is empty. Therefore, in order to minimize wasted anesthesia, it may be desirable to wait until the cartridge is empty (e.g., when the pump is actuated to the end of a length).

[0093] If it is determined that the cartridge is not empty or nearly empty ("No" at 1012), then method 1000 includes continuing to deliver the vaporized anesthetic to the patient at 1014.

[0094] Alternatively, if it is determined that the cartridge is empty or nearly empty ("Yes" at 1012), method 1000 includes replacing the cartridge at 1016 when the vaporized anesthetic is delivered to the patient. For example, the controller may automatically generate an alarm that is communicated to the user via a visual and / or auditory format, indicating that the cartridge is empty or nearly empty. The controller may close a fluid flow valve fluidly positioned between the cartridge and the injector (e.g., ...). Figure 3 and Figure 4 A liquid flow valve 308 automatically disconnects the cartridge from the injector fluid. In response to this alarm, the user can remove the cartridge and insert a new one when the liquid flow valve is closed. Because the liquid flow valve is closed and the new cartridge completely encapsulates the anesthetic fluid, the user is not exposed to anesthesia during replacement. Furthermore, because the reservoir, which is fluidly connected to the injector regardless of the liquid flow valve's position, is configured to maintain a volume of pressurized anesthetic fluid, vaporized anesthetic can continue to be delivered to the patient even when the cartridge is not fluidly connected to the injector. When the new cartridge is in the appropriate position (e.g., mechanically connected to the pump), the controller can automatically fluidly connect the new cartridge to the injector by opening the liquid flow valve. Method 1000 returns.

[0095] The technical advantage of the system and method disclosed herein is that it provides vaporized anesthesia to a patient's respiratory system via a cylinder pressurized anesthesia system compatible with various anesthetics having different properties (e.g., boiling point, vapor pressure, etc.), and does not cause interruption in anesthetic delivery when replenishing the supply of liquid anesthetic by replacing empty or nearly empty cartridges with full cartridges. Specifically, since a certain volume of pressurized anesthetic is stored in a reservoir upstream of the injector, the injector can continue to inject liquid anesthetic into a heater assembly where the liquid anesthetic is vaporized as the cartridge is fluidly separated from the injector via a liquid flow valve. Therefore, vaporized anesthetic can continue to be vaporized and subsequently delivered to the patient while replacing the cartridge without exposing the user to the anesthetic. Furthermore, a feedback loop allows for adjustment of operation based on the delivery of anesthetic in a given application. As an example, the pressure of the liquid anesthetic delivered to the injector can be controlled in a first feedback loop. The concentration of vaporized anesthetic in the fresh gas output from the cylinder pressurized anesthesia system can be controlled in a second feedback loop.

[0096] This disclosure also provides support for a cylinder-type pressurized anesthesia system comprising: a cartridge pump assembly including a cartridge containing a liquid anesthetic agent, the cartridge being configured to be mechanically coupled to a pump; a pressure line fluidly coupled to the cartridge, wherein the pressure line is configured to retain pressurized liquid anesthetic agent from the cartridge; a heater assembly fluidly coupled to the pressure line via an injector, wherein the injector disperses liquid anesthetic agent from the pressure line into the heater assembly; and a liquid flow valve configured to fluidly connect and disconnect the cartridge and the injector. In a first embodiment of the system, the system further comprises: a carbon dioxide removal system configured to remove carbon dioxide from a mixed gas entering the heater assembly. In a second embodiment of the system, optionally including the first embodiment, the heater assembly includes a ceramic positive temperature coefficient heating element and a heating channel. In a third embodiment of the system, optionally including one or both of the first and second embodiments, the cartridge is a syringe and the pump is an infusion pump. In a fourth embodiment of the system, which optionally includes one or more of the first to third embodiments, the system further includes a pressure relief valve located upstream of the heater assembly relative to the flow of fresh gas from the cylindrical pressurized anesthesia system. In a fifth embodiment of the system, which optionally includes one or more of the first to fourth embodiments, the system further includes: an anesthetic sensor and a controller, the anesthetic sensor being positioned at the output of the heater assembly, the controller including instructions stored in non-volatile memory and executable to: measure the concentration of fresh gas output from the heater assembly via the anesthetic sensor; and adjust the output of the injector until the measured concentration is substantially equal to a target concentration. In a sixth example, which optionally includes one or more of the first to fifth embodiments, the system further includes: a pressure sensor and a controller, the pressure sensor being fluidly coupled to the pressure line, the controller including instructions stored in non-volatile memory and executable to: supply pressurized liquid anesthetic to the injector via the cartridge pump assembly; measure the pressure of the pressure line via the pressure sensor; and regulate the operation of the pump until the measured pressure is substantially equal to the target pressure.

[0097] This disclosure also provides support for a method of operating a cylinder pressure anesthesia system, the method comprising: receiving a mixed gas from the expiratory line of a ventilator into the cylinder pressure anesthesia system; combining the mixed gas with an anesthetic agent vaporized via a heater assembly of the cylinder pressure anesthesia system to generate fresh gas; allowing the fresh gas to flow into the inspiratory line of the ventilator to deliver the vaporized anesthetic agent to a patient; and replacing the cartridge of the cylinder pressure anesthesia system while delivering the vaporized anesthetic agent to the patient. In a first embodiment of the method, the anesthetic agent is supplied as a pressurized liquid to the heater assembly via a cartridge pump assembly and an injector of the cylinder pressure anesthesia system, wherein the injector is selectively fluidly coupled to the cartridge. In a second embodiment of the method, which optionally includes the first embodiment, the combination of the mixed gas with the vaporized anesthetic agent occurs passively within the heater assembly. In a third embodiment of the method, which optionally includes one or both of the first and second embodiments, the method further includes: filtering carbon dioxide from the gas mixture via a removal system of the cylinder pressure anesthesia system before combining the gas mixture with the anesthetic. In a fourth embodiment of the method, which optionally includes one or more of the first to third embodiments, replacing the cartridge while delivering the vaporized anesthetic to the patient includes closing a liquid flow valve to separate the cartridge from the injector fluid. In a fifth embodiment of the method, which optionally includes one or more of the first to fourth embodiments, the method further includes: directing gas from the expiratory line to a clearance system when the pressure in the expiratory line exceeds a threshold pressure.

[0098] This disclosure also provides support for a cylindrical pressure anesthesia system comprising: a heater assembly including a gas inlet and a gas outlet, wherein the gas inlet is configured to be fluidly connected to an expiratory line of a ventilator, and the gas outlet is configured to be fluidly connected to an inspiratory line of the ventilator; a cartridge pump assembly including a cartridge containing a liquid anesthetic, wherein the cartridge is mechanically connected to a pump; a pressure line fluidly connecting the cartridge to the heater assembly via an injector; and a carbon dioxide removal system positioned between the expiratory line and the gas inlet. In a first embodiment of the system, the carbon dioxide removal system includes a membrane separator. In a second embodiment of the system, optionally including the first embodiment, the system further includes: a reservoir fluidly located between the cartridge and the injector. In a third embodiment of the system, optionally including one or both of the first and second embodiments, the system further includes: a liquid flow valve capable of closing to fluidly separate the cartridge from the injector. In a fourth embodiment of the system, which optionally includes one or more of the first to third embodiments, the cartridge pump assembly is positioned within a housing enclosing the injector and the heater assembly. In a fifth embodiment of the system, which optionally includes one or more of the first to fourth embodiments, the system further includes a non-dispersive infrared sensor fluidly coupled to the gas outlet. In a sixth embodiment of the system, which optionally includes one or more of the first to fifth embodiments, the system further includes a controller communicatively coupled to the injector, the pump, the heater assembly, the pressure sensor, and the anesthetic sensor.

[0099] Figures 1 to 5 and Figures 8 to 9Example configurations with the relative positioning of various components are shown. If liquid and / or airflow is shown as flowing directly from one component to another, then in at least one example, such elements may be referred to as flowing directly between components. In at least one example, if shown as being in direct contact or directly connected to each other, such elements may be referred to as being in direct contact or directly connected, respectively. Similarly, in at least one example, elements shown as being adjacent to or next to each other may be referred to as being adjacent to or next to each other, respectively. For example, components placed in coplanar contact with each other may be referred to as being in coplanar contact. As another example, in at least one example, elements positioned as spaced apart from each other and having only space between them without other components may be described as such. As yet another example, elements shown as being above / below each other, on opposite sides of each other, or on the left / right side of each other may be described as such relative to each other. Furthermore, as shown, in at least one example, the topmost element or point of the element may be referred to as the "top" of the component, and the bottommost element or point of the element may be referred to as the "bottom" of the component. As used herein, top / bottom, upper / lower, and above / below can be relative to the vertical axis of the figure and can be used to describe the positioning of elements in the figure relative to each other. Thus, in one example, an element shown above other elements is vertically positioned above the other elements. Similarly, the shape of the elements depicted in the figure can be described as having those shapes (e.g., such as circular, straight, planar, curved, rounded, chamfered, angled, etc.). Furthermore, in at least one example, elements shown intersecting each other can be described as intersecting elements or intersecting each other. Additionally, in one example, an element shown as being inside or outside another element can be described as such.

[0100] As used herein, elements or steps listed in the singular and beginning with the word "a" or "an" should be understood to not exclude a plurality of said elements or steps unless such exclusion is explicitly stated. Furthermore, references to "one embodiment" of the invention are not intended to be construed as excluding the existence of additional embodiments that also include the referenced features. Moreover, unless explicitly stated to the contrary, embodiments that "comprise," "include," or "have" elements or multiple elements having a particular characteristic may include additional such elements that do not have that characteristic. The terms "comprise" and "in" are used as concise linguistic equivalents to the corresponding terms "comprising" and "wherein". Furthermore, the terms "first," "second," and "third," etc., are used merely as notations and are not intended to impose numerical requirements or a particular order of position on their objects.

[0101] This written description uses examples to disclose the invention, including the best mode, and also enables those skilled in the art to practice the invention, including making and using any device or system and performing any included methods. The scope of patentability of the invention is defined by the claims, but may include other examples that would occur to those skilled in the art. Such other examples are intended to fall within the scope of the claims if they have structural elements that are not indistinguishable from the literal language of the claims, or if they include equivalent structural elements that have minor differences from the literal language of the claims.

Claims

1. A cylindrical pressure anesthesia system (100), the cylindrical pressure anesthesia system comprising: A cartridge pump assembly (102) comprising a cartridge (302) containing a liquid anesthetic, the cartridge being configured to be mechanically coupled to a pump (304). A pressure line (306) is fluidly connected to the cartridge (302), wherein the pressure line is configured to hold pressurized liquid anesthetic from the cartridge (302); A heater assembly (104) fluidly connected to the pressure line via an injector (106), wherein the injector (106) disperses liquid anesthetic from the pressure line (306) into the heater assembly (104); and A liquid flow valve (308) is configured to fluidly connect and disconnect the cartridge (302) and the injector (106).

2. The cylindrical pressurized anesthesia system of claim 1, further comprising a carbon dioxide removal system configured to remove carbon dioxide from the mixed gas entering the heater assembly.

3. The cylindrical pressure anesthesia system according to claim 1, wherein the heater assembly includes a ceramic positive temperature coefficient heating element and a heating channel.

4. The cartridge-type pressure anesthesia system according to claim 1, wherein the cartridge is a syringe and the pump is an injection pump.

5. The cylindrical pressurized anesthesia system of claim 1, further comprising a pressure limiting valve located upstream of the heater assembly relative to the flow of fresh gas from the cylindrical pressurized anesthesia system.

6. The cylindrical pressurized anesthesia system of claim 1, further comprising an anesthetic agent sensor and a controller, the anesthetic agent sensor being positioned at the output end of the heater assembly, the controller comprising instructions stored in non-volatile memory and executable to perform the following operations: The concentration of fresh gas output from the heater assembly is measured via the anesthetic sensor; and Adjust the output of the injector until the measured concentration is substantially equal to the target concentration.

7. The cylindrical pressure anesthesia system of claim 1, further comprising a pressure sensor and a controller, the pressure sensor being fluidly connected to the pressure line, the controller comprising instructions stored in non-volatile memory and executable to perform the following operations: Pressurized liquid anesthetic is supplied to the injector via the cartridge pump assembly; The pressure in the pressure line is measured via the pressure sensor; and Adjust the operation of the pump until the measured pressure is substantially equal to the target pressure.

8. The tubular pressurized anesthesia system according to claim 1, wherein the tubular pressurized anesthesia system further comprises a reservoir fluidly located between the cartridge and the injector.

9. The cylindrical pressure anesthesia system according to claim 1, further comprising a liquid flow valve capable of being closed to separate the cartridge from the injector fluid.

10. A method for operating a cylindrical pressure anesthesia system (100), the method comprising: The mixed gas (118) from the expiratory line (810) of the ventilator (802) is received (1002) into the tubular pressurized anesthesia system (100); The mixed gas (118) is combined (1008) with an anesthetic agent vaporized via a heater assembly (104) of the cylindrical pressurized anesthesia system (100) to produce fresh gas (120). The fresh gas (120) is introduced into the inspiratory line (808) of the ventilator (802) (1010) to deliver the vaporized anesthetic to the patient (804); and The cartridge (302) of the cylinder pressure anesthesia system (100) is replaced (1016) while the vaporized anesthetic is delivered to the patient (804).

11. The method of claim 8, wherein the anesthetic is supplied as a pressurized liquid to the heater assembly via the cartridge pump assembly and the injector of the cartridge pressurized anesthesia system, wherein the injector is selectively fluidly connected to the cartridge.

12. The method of claim 8, wherein the combination of the mixed gas with the vaporized anesthetic occurs passively within the heater assembly.

13. The method of claim 8, further comprising filtering carbon dioxide from the gas mixture via a removal system of the cylindrical pressurized anesthesia system before combining the gas mixture with the anesthetic.

14. The method of claim 8, wherein replacing the cartridge while delivering the vaporized anesthetic to the patient comprises closing the liquid flow valve to separate the cartridge from the injector fluid.

15. The method of claim 8, further comprising directing gas from the exhalation line to a clearance system when the pressure in the exhalation line exceeds a threshold pressure.

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