Valve assembly with spool for proportional fluid flow control and respirator

Abstract

A valve assembly includes a conduit having a first end and a second end, and two control valves. Each valve includes three ports and a spool for selectively adjusting a proportion of fluid flow through two of the ports. A first port of the valve is for connection with an inlet port or an output port of the pump, respectively. The second port of the valve is connected to the second end of the conduit for drawing fluid from or supplying fluid to the conduit, respectively. A valve may be included in the respirator to control application of variable pressure to an outer surface of the lung in the sealed chamber to breathe the lung.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Patent Application Serial No. 63 / 412,664, filed on October 3, 2022, the entire contents of which are incorporated herein by reference.

[0003] Incorporated by reference

[0004] Any patent, patent publication, journal publication, or other document cited herein is expressly incorporated by reference in its entirety. Technical Field

[0005] The present disclosure relates generally to valve assemblies and ventilators, and in particular, to valve assemblies and ventilators for ventilating an isolated lung outside the body. Background Art

[0006] In order to use an excised donor lung for transplantation, it may be necessary to perfuse and ventilate the excised lung ex vivo to restore or preserve its function before the transplant procedure can proceed, or to assess or evaluate its quality or suitability for transplantation.

[0007] Various ventilation techniques have been proposed, including negative pressure ventilation (NPV) methods and related devices. In NPV methods, the lungs can be ventilated using an external negative pressure (i.e., below atmospheric pressure) surrounding the lungs to allow the lungs to naturally fill with air (or gas) at or near atmospheric pressure. For example, a gas, such as air, can be supplied to the airways of the lungs at a positive pressure (above atmospheric pressure), and a negative external pressure can be maintained around the lungs.

[0008] However, it would be desirable to provide improved devices and systems for achieving NPV and other ventilation methods or techniques. Summary of the invention

[0009] In one aspect of the present disclosure, a valve assembly is provided, which includes: a first conduit, the first conduit including a first end and a second end; and a first control valve and a second control valve, each control valve including a first port, a second port and a third port, and each control valve also includes a valve core, which is configured to selectively adjust the ratio of fluid flowing through the second port and the third port of the corresponding control valve, wherein the first port of the first valve is configured to be connected to an inlet port of a pump, the second port of the first control valve is configured to be connected to the second end of the first conduit for extracting fluid from the first conduit, the first port of the second control valve is configured to be connected to the output port of the pump, and the second port of the second control valve is configured to be connected to the second end of the first conduit for supplying fluid to the first conduit.

[0010] In various embodiments, the valve assembly described in the previous paragraphs may include one or any combination of the following features. The control valve may include an actuator for actuating a valve core of the corresponding control valve. The actuator may include a servo motor. The valve core of at least one of the first control valve and the second control valve is a sliding valve core, and the actuator of at least one control valve is a linear actuator. The valve core of at least one of the first control valve and the second control valve is a rotary valve core, and the actuator of at least one control valve is a rotary actuator. The linear actuator of at least one control valve includes a drive shaft, which is coupled to the sliding valve core of the corresponding control valve for positioning the sliding valve core. The linear actuator of at least one control valve includes a proximity sensor, which is used to determine the position of the drive shaft of the corresponding control valve. The actuator of at least one control valve includes a controller, which is used to control the movement of the drive shaft of the corresponding control valve based on the output signal of the proximity sensor from the corresponding control valve. The drive shaft of the linear actuator of at least one control valve and the sliding valve core of the corresponding control valve are axially aligned along the axis of the drive shaft. The drive shaft of the linear actuator of at least one control valve includes a guide rod configured to maintain axial alignment of the drive shaft of the corresponding control valve. The linear actuator of at least one control valve includes a connector connected to the drive shaft of the corresponding control valve and a sliding valve core. The drive shaft of the linear actuator of at least one control valve and the sliding valve core of the corresponding control valve are stacked vertically. At least one control valve includes a housing including opposite ends and a cylindrical bore extending between the opposite ends, a first port of the corresponding control valve is located on a first side of the bore, and a second port of the corresponding control valve and a third port of the corresponding control valve are located on a second side of the bore, and wherein the valve core of the corresponding control valve is capable of sliding in the bore and includes a transversely extending conduit, the conduit including a first opening facing the first side of the bore and a second opening facing the second side of the bore, the first opening is sized and positioned to allow fluid communication with the first port, and the second opening is sized and positioned to selectively allow fluid communication with the second port and the third port by sliding the valve core in the bore. The valve assembly may include a three-way connector at the second end of the first conduit, the three-way connector being used to connect the second end of the first conduit to the second port of the first valve and the second port of the second valve, respectively. The three-way connector may include a three-way valve, a T-shaped connector or a Y-shaped connector.

[0011] On the other hand, a ventilator is provided, the ventilator comprising: a sealed chamber for accommodating a lung in the sealed chamber, the sealed chamber comprising a pressure port; and a first fluid system for applying a variable first pressure to the outer surface of the lung in the sealed chamber through the pressure port to allow the lung to breathe. The first fluid system comprises a first pump, the first pump comprising an inlet port and an outlet port. The valve assembly described herein is connected to the inlet port and the outlet port of the first pump. The first end of the first conduit of the valve assembly is sealingly connected to the pressure port of the sealed chamber.

[0012] In various embodiments, the ventilator described in the previous paragraph may include one or any combination of the following features. The ventilator may also include a second fluid system for applying and maintaining a second pressure in the airway of the lung, wherein the second fluid system may include a second conduit having a first end and a second end, and the second end of the second conduit can be connected to the trachea of ​​the lung through a sealed chamber. The second fluid system may also include a second pump for supplying pressurized fluid to the second conduit and maintaining a second pressure in the second conduit. The ventilator may also include a control system configured and connected to control the first fluid system and the second fluid system to breathe the lung. The control system may include a sensor for sensing the pressure and fluid flow rate in the first conduit and the second conduit, and a processor for processing the sensed pressure and fluid flow rate and determining the pumping speed of each pump and the ratio of the fluid flow through the second port and the third port of the corresponding control valve. The ventilator may also include a third conduit connecting the third port of the second control valve of the first fluid system to the second conduit of the second fluid system, and a third control valve in the third conduit for regulating the fluid flow from the first control valve to the second conduit through the third conduit. Each of the first pump and the second pump may include a blower. The respirator may include a fluid filter located in each of the first conduit and the second conduit. The respirator may include a fluid filter coupled to a third port of at least one of the first control valve and the second control valve. The respirator may include a fluid filter coupled to an input port of the second pump.

[0013] Other aspects, features, and embodiments of the present disclosure will become apparent to those of ordinary skill in the art after reading the following description of the specific embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In the accompanying drawings illustrating example implementations:

[0015] Figure 1 is a schematic block diagram of an apparatus for ventilating a lung according to an example embodiment of the present disclosure;

[0016] Figure 2A is suitable for use in an exemplary embodiment according to the present disclosure Figure 1 A schematic diagram of a valve assembly used in an apparatus;

[0017] Figure 2B is suitable for use in an exemplary embodiment according to the present disclosure Figure 2A Valve assembly or Figure 1 A schematic diagram of a valve used in the device;

[0018] Figure 3 yes Figure 1 A schematic block diagram of an example implementation of a device;

[0019] Figure 4 yes Figure 3 A schematic diagram of a device showing air flow during inhalation;

[0020] Figure 5 yes Figure 3 A schematic diagram of a device showing air flow during exhalation;

[0021] Fig. 6A yes Figure 2B A more detailed schematic diagram of the valve;

[0022] Figure 6B yes Fig. 6A A schematic cross-sectional view of a valve body of an example embodiment of a valve of;

[0023] Figure 6C yes Fig. 6A A schematic cross-sectional view of a valve body of another example embodiment of a valve of;

[0024] Fig.6D yes Fig. 6A A schematic cross-sectional view of a valve body of yet another example embodiment of a valve of;

[0025] Fig. 7A is a front perspective view of a three-way proportional valve according to an example embodiment of the present disclosure;

[0026] Figure 7B yes Fig. 7A A rear perspective view of a valve;

[0027] Fig. 8A yes Fig. 7A A front exploded view of a valve;

[0028] Figure 8B yes Fig. 7A Rear exploded view of the valve;

[0029] Fig.9A , Fig. 9B and Fig. 9C It is taken along the axis when the valve core is in different positions Fig. 7A A top cross-sectional view of a valve;

[0030] Fig. 10A , Fig. 10B , Fig. 10C , Fig. 10D , Fig. 10E and Fig.10F It is taken along the axis when the valve core is in different positions Fig. 7A a right side cross-sectional view or a left side cross-sectional view of a valve;

[0031] Fig.11A is a front perspective view of another three-way proportional valve according to an embodiment of the present disclosure;

[0032] Fig. 11B yes Fig. 12A A front exploded view of a valve;

[0033] Fig. 12A It is cut along the axis Fig.11A A top cross-sectional view of a valve;

[0034] Fig. 12B It is cut along the axis Fig.11A A right side cross-sectional view of a valve;

[0035] Fig.13A Is alone Fig.11A A left side plan view of a valve core and an actuator of a valve;

[0036] Fig. 13B Is alone Fig.11A A rear view of a valve core and an actuator of a valve;

[0037] Fig.14 is a top perspective view of another three-way proportional valve according to another embodiment of the present disclosure;

[0038] Fig.15 yes Fig.14 Exploded view of the valve;

[0039] Fig.16A It is cut along the axis Fig.14 A top cross-sectional view of a valve;

[0040] Fig. 16B It is cut along the axis Fig.14 A left side cross-sectional view of a valve;

[0041] Fig. 16C It is cut along the axis Fig.14 A right side cross-sectional view of a valve;

[0042] Fig.16D yes Fig.15 an enlarged view of a portion of a valve;

[0043] Fig.17 is a top perspective view of another three-way proportional valve according to another embodiment of the present disclosure;

[0044] Fig.18A yes Fig.17 Exploded view of the valve;

[0045] Fig.18B yes Fig.17 A cross-sectional view of a valve;

[0046] Fig.19A It is cut along the axis Fig.17 A top cross-sectional view of a valve;

[0047] Fig.19B It is cut along the axis Fig.17 A right side cross-sectional view of a valve;

[0048] Fig. 20 is a front perspective view of another three-way proportional valve according to another embodiment of the present disclosure;

[0049] Fig.21 yes Fig. 20 A front exploded view of a valve;

[0050] Fig.22A , Fig. 22B and Fig. 22C Taken along line AA-AA with the valve core in different positions Fig. 20 A top cross-sectional view of a valve;

[0051] Fig.23 yes Fig. 20 a top view of the valve; and

[0052] Fig.24 Is alone Fig. 20 A three-dimensional diagram of a valve core of a valve;

[0053] Fig.25 is a line graph illustrating intrathoracic pressure (ITP) and airway pressure over time for a pair of ventilated lungs in accordance with an embodiment of the present disclosure;

[0054] Fig.26 It is a diagram for controlling Figure 3 A schematic diagram of the control logic for the valves and pumps of the equipment; and

[0055] Fig.27A and Fig.27B is a flow chart illustrating an algorithm executed by the computer device of FIG. 27 for controlling the apparatus of FIG. 27 . DETAILED DESCRIPTION

[0056] It has been recognized that when an isolated lung is ventilated in vitro by varying the pressure surrounding the lung to cause the lung to breathe, the lung may still benefit from the application of a regulated positive pressure in the airways to prevent alveolar collapse during exhalation. For example, application of a continuous positive airway pressure (CPAP) in combination with pressure oscillations around the outside of the lung to drive breathing may allow for convenient regulation of the transpulmonary pressure (TPP) gradient in the lung to allow for efficient recruitment of the alveolar segments of the lung parenchyma while reducing, minimizing, or even preventing overdistension of the recruited segments.

[0057] It has been further recognized that for practical application of the intended ventilation strategy, it is desirable to provide a portable ventilation system that has a relatively small footprint, is easy to maintain and operate, yet is reliable. For example, it is desirable to provide a compact and reliable fluid and pressure system for applying and controlling the pressure applied to the airways and the outer surface of the lungs. In particular, it has been recognized that a reliable and compact valve assembly is desirable for supplying and controlling the negative pressure applied to the exterior of the lungs.

[0058] Therefore, embodiments of the present disclosure relate to a device for ventilating an isolated lung, particularly a valve assembly for use in a ventilation system. The valve assembly may include a conduit and a valve configured and connected to conveniently control and regulate the pressure applied to the outside of the lung by a single pump, such as a centrifugal blower or a regenerative blower, and a relatively simple mechanism for guiding and proportionalizing the fluid flow in the conduit. Specifically, the valve used in the assembly may be a control valve including three or more input ports or output ports. The valve core is used to control the fluid flow between the ports. Specifically, the valve core is configured to selectively adjust the proportion of the fluid flowing through different ports. One or more first valves are used to control the fluid input to the inlet port of the pump. One or more second valves are used to control the fluid flowing out of the output port of the pump. The valve is also connected to the conduit for selectively supplying fluid to the conduit or extracting fluid from the conduit. The valve core can be actuated by a motor. The valve core can be a sliding valve core actuated by a linear actuator, or can be a rotating valve core actuated by a rotary motor. Conveniently, this assembly can be compact and reliable, as will be further described below.

[0059] Other embodiments relate to systems and methods for ventilating a lung extracorporeally.

[0060] In the example method, ventilation gas is supplied to the airway (e.g., trachea or bronchus) of the lung, and pressure is applied to the outer surface around the lung. External pressure can change (e.g., cycle) between a lower level and a higher level to allow the lung to breathe, and the pressure of the ventilation gas supplied to the airway can be adjusted to maintain a continuous positive airway pressure in the airway of the lung. In some applications, the airway pressure can be constant or continuously positive for a period of time during ventilation. Typically, external pressure can be cyclically changed between two different pressure levels. The level can remain substantially constant for a period of time, or one or both of the lower level and the higher level can be adjusted during ventilation. At least one of the two levels can be lower than 1atm, and when the external pressure level applied is lower than 1atm, a vacuum is formed around the lung. Before ventilation gas is supplied to the lung, it can be filtered with a microbial filter and a humidity-moisture exchanger (HME) filter. The lung can be placed in a sealed chamber, and pressure is formed around the lung in the chamber.

[0061] Embodiments of the devices described herein can be conveniently used for negative pressure ventilation in an extracorporeal lung perfusion (EVLP) process or system or an ex situ lung perfusion (ESLP) system. When combined with such negative pressure ventilation, applying positive pressure to the airways of the lungs allows for a higher TPP to be achieved without applying excessive negative pressure to the outside of the lungs.

[0062] The embodiments disclosed herein may also allow for the restoration of atelectatic alveoli, thereby facilitating a prolonged EVLP or ESLP.It is also convenient to measure and obtain functional properties of a ventilated lung in vitro using at least some of the embodiments described herein.

[0063] Figure 1 An example device 100 for ventilating an ex vivo lung according to an embodiment is schematically illustrated. As depicted, the device 100 includes a container 110, which includes a sealable chamber 120 for accommodating a lung 130. Within the container 110, the lung 130 can be supported on a flexible porous surface, such as a silicone mesh or a plastic mesh, or the lung can be made buoyant by being placed on a fluid surface covered with a soft plastic membrane (not shown). Alternatively, the lung can be supported on a semi-rigid plastic form similar to the shape of the posterior chest, so that the lung is located in an anatomically familiar position (not shown). Alternatively, the lung can be placed on a cushion formed of a material that is elastic enough to cushion the mechanical vibration and impact of the organ during transportation. In an embodiment, the cushion assembly is formed of silicone, which is biocompatible, liquid-tight, and can withstand sterilization processes (ETO, etc.). For clarity, it is noted that the term "lung" can refer to a single lung, multiple lungs, or a portion of a single lung or multiple lungs. The two lungs attached to the same trachea are sometimes collectively referred to herein as "the lungs" or "the lungs."

[0064] The apparatus 100 may include a first fluid system 140 connected to the chamber 120 by a first conduit 150 for applying a variable first pressure to the outer surface of the lung 130. The pressure in the chamber 120 may be positive or negative at a selected time. As used herein, unless otherwise expressly stated, a positive pressure refers to a pressure above the atmospheric pressure in the immediate environment of the lung and the ventilator. A negative pressure refers to a pressure below atmospheric pressure. That is, a positive pressure as used herein refers to a positive gauge pressure, and a negative pressure refers to a negative gauge pressure.

[0065] The device 100 may also include a second fluid system 160 for applying and maintaining a second pressure, which is applied to the airway 170 of the lung 130 and may be constant. The second fluid system 160 is connected by a second conduit 180, which extends through the wall of the container 110 and connects the second fluid system 160 to the airway 170 of the lung 130 for supplying a second pressure to the airway of the lung. The second conduit 180 is sealed to prevent communication with the internal space pressure in the chamber 120. The second pressure can be applied using a ventilation gas, such as air or any suitable gas mixture containing oxygen. The second fluid system 160 may include an air pump or a motor-driven turbine or other air supply mechanism ( Figure 1 The output port of the air pump (not shown) can be controlled. The operating speed of the air pump or turbine can be controlled to adjust the airway pressure in the lung. Alternatively or additionally, a valve (not shown) in the second fluid system 160 can be used to control or adjust the airway pressure.

[0066] The control system 190 can be coupled to the first fluid system 140 and the second fluid system 160. As will be described in more detail below, the control system 190 can be in communication with a control pressure sensor, a flow sensor, a flow regulating valve to vary the pressure in the chamber 120 between a lower vacuum level and a higher vacuum level to enable the lungs 130 to breathe, and to adjust the pressure of the ventilation gas supplied by the second fluid system 160 to maintain a continuous positive airway pressure in the airways 170 of the lungs 130.

[0067] Reference Figure 2A, a valve assembly 200 suitable for use in a fluid system 140 is shown. The valve assembly 200 is configured to supply fluid to and remove fluid from the chamber 120 through the conduit 150 using a pump 208, thereby applying a variable pressure to the outer surface of the lung 130. The fluid can be air or a suitable gas supplied from a gas source (not shown). In an embodiment, the fluid is air from the atmosphere. The valve assembly 200 includes a conduit 202 for connecting to the conduit 150 to remove the fluid from the conduit 150 and a conduit 203 for supplying the fluid to the conduit 150. The valve assembly 200 also includes two three-way control valves 204, 206, which have ports 216, 222 for connecting to the conduit 150 and ports 214 and 220 for connecting to the inlet port 210 and the output port 212 of the pump 208, respectively. The valve 204 also has an air inlet port 218, and the valve 206 has an outlet port 224.

[0068] In particular, port 214 of valve 204 is an output port and is connected to inlet port 210 of pump 208 through conduit 211. Port 216 of valve 204 is an input port and is connected to conduit 202 for removing fluid from chamber 120 through conduit 150. Port 220 of valve 206 is an input port and is connected to output port 212 of pump 208 through conduit 213. Port 222 is an output port and is connected to conduit 203 for supplying fluid to chamber 120 through conduit 150.

[0069] Each of the valves 204, 206 may have a Figure 2B The structure shown in Figure 2B A three-way control valve 700 is shown. The valve 700 has a port 702 located on a first side of the valve 700, and the port 702 is connected to a first side of the valve 700. Figure 2A 704 and 706 on a second side opposite to the first side as depicted in the figure are in fluid communication. A control member 205 is provided in the valve 700 to proportion the fluid flow between the two ports 704 and 706, as will be further described below. The fluid flow through the valve 700 can be in a direction from port 702 to ports 704 and 706, or can be in the opposite direction.

[0070] When valve 700 is used as or as Figure 2A When valve 204 is opened, control member 205 controls the ratio of fluid entering valve 204 through port 216 or 218. Fluid removed from chamber 120 via conduits 150, 202 can enter valve 204 through port 216. New fluid, such as air or oxygen-enriched air, can enter valve 204 through inlet port 218, thereby being added to the fluid flow.

[0071] When valve 700 is used as or as Figure 2A When valve 206 in is closed, control component 205 controls the ratio of fluid exiting through ports 222 and 224. By allowing fluid to exit through port 222, fluid is added to chamber 120 via conduits 203, 150. By allowing fluid to exit through exhaust port 224, fluid can be removed from the fluid stream. In the above manner, fluid can be supplied to and removed from chamber 120 by pump 208 without the need to change the pump speed or use multiple pumps.

[0072] When the pump 208 and the catheter 150 are as described above and as Figure 2A When connected to the valve assembly 200 as shown in FIG, the pump 208 can be used to control and regulate the pressure in the chamber 120, as will be described further below. The valve assembly 200 and the pump 208 thus form part of the fluid system 140. The fluid system 140 may include other components, such as sensors, filters, processors, and additional pumps.

[0073] 7 to Fig.24 Possible configurations and example implementations of valve 700 are described.

[0074] Figure 3 The device 300 is shown, which is Figure 1 An exemplary embodiment of the apparatus 100 is shown in FIG. 1 and illustrates the use of the valve assembly 200. The apparatus 300 includes a fluid system 400 having a plurality of fluids as described above. Figure 2A 200. The fluid system 400 also includes a three-way connector 426 that connects the conduit 150 to the ports 216 and 222 via the conduits 202 and 203 for removing fluid from the conduit 150 or adding fluid to the conduit 150. The three-way connector 426 may include a three-way valve, a T-shaped connector, a Y-shaped connector, or the like.

[0075] The fluid system 400 also includes a fluid filter 428 mounted at or connected to the port 218 of the valve 204 via a conduit 429 and a fluid filter 430 mounted at or connected to the port 224 of the valve 206 via a conduit 431. The filters 428, 430 may be high efficiency particulate air (HEPA) filters to filter particles from the incoming air. A filter 432 may also be positioned in the conduit 150 and may be a humidity and moisture exchanger (HME) filter to maintain humidity in the chamber 120 to prevent the lungs 130 from drying out.

[0076] Fluid system 400 may also include an integrated sensor 434 coupled to conduit 150. Sensor 434 may be configured to detect pressure, flow, humidity, gas content, etc. within conduit 150. Sensor 434 may be a Siargo TM Manufactured FS6122-250F250-100P100-TH1 sensor.

[0077] The device 300 also includes a second fluid system 500, which is an example embodiment of the fluid system 160 described above. The fluid system 500 is configured to apply and maintain airway pressure in the airway 170 of the lung 130. The fluid system 500 is connected to the airway 170 via the conduit 180 and includes a pump 506 connected as shown. Specifically, the pump 506 has an inlet port 508 and an outlet port 510. The inlet port 508 receives a fluid source from a conduit 531, and the conduit 531 may include a three-way connector 521, which may be a three-way valve, or a T-shaped connector or a Y-shaped connector. Fluid can be extracted from the atmosphere through the conduit 519 and enter the conduit 531 via the three-way connector 521. The conduit 519 may also include a valve 515 for controlling the fluid flow from the atmosphere. Alternatively, oxygen can be supplied to the conduit 531 from an oxygen source 529 via a conduit 527. The conduit 527 may also include a valve 525 for controlling the flow of oxygen from the oxygen source 529. The valves 515 and 525 may be two-way proportional solenoid valves and may be optionally controlled by the control system 600. By controlling the valve 525, the supply of air or a mixture of air and oxygen to the conduit 531 may be adjusted.

[0078] The fluid system 500 may also include fluid filters 518, 520. Fluid filter 518 may be mounted at or connected to conduit 519 to filter air entering pump 506. Fluid filter 520 may be positioned between conduit 511 and conduit 180 and may be a HME filter to retain moisture in the trachea and prevent moisture from entering the valve. This is important to prevent tissue drying of the lungs 130 and to avoid bacterial contamination within the fluid system 500. Filter 518 may be a HEPA filter to filter particles from the incoming air.

[0079] Any suitable microbial filter known to those skilled in the art, such as HEPA filters and HME filters, can be used as filters in embodiments herein. There are products on the market that have both HME and HEPA properties. In this embodiment, filters 428, 430, 432, 518, 520 are combined HEPA / HME filters.

[0080] The fluid system 500 may also include an integrated sensor 522 coupled to the conduit 511. The sensor 522 may be configured to detect pressure, flow, or humidity within the second fluid system 500. An oxygen sensor 523 may also be coupled to the output port 510 of the pump 506 for detecting oxygen content within the second fluid system 500.

[0081] Device 300 also includes a control system 600, which is an example implementation of control system 190. Control system 600 is in communication with valves 204, 206, pump 208, and sensor 434 of system 400, and is in communication with pump 506 and sensors 522, 523 of fluid system 500. In some embodiments, fluid system 400 and fluid system 500 may include separate or additional control systems or devices. Control system 600 is configured to control the operation of pumps and valves to adjust the direction and pressure of fluid flow within device 300.

[0082] Providing separate fluid systems 400, 500 with separate pumps in the device 300 allows each system 400 or 500 to be more compact and provides greater and simplified control of each system in the respective system. This configuration also reduces the risk associated with component failures in the device, because in the event of a failure in one of the fluid systems 400, 500, the other system can still function normally. The separate fluid systems 400 and 500 each include a dedicated pump, which further allows the use of smaller, quieter and more compact pumps in each system.

[0083] In operation, the device 300 may be operated as follows Figure 4 and Figure 5 The lungs are ventilated in vitro as shown in FIG. , as described below. Figure 4 and Figure 5 The lines with arrows in them indicate the direction of air flow.

[0084] Figure 4The flow of fluid in the device 300 during inspiration is illustrated. Valves 204 and 206 are configured under the control of controller 600 to allow fluid to flow between port 216 and port 214 in valve 204 and between port 220 and port 224 in valve 206, but prevent fluid from flowing between port 222 and port 220 in valve 206, so that air can flow from container 110 through filter 432, conduits 150, 202 and connector 426, enter valve 204 via port 216, but cannot enter valve 205 through port 222. For inspiration, pump 208 is operated to pump air from inlet port 210 toward output port 212 at a selected pumping speed or rate. As a result, air is drawn out of chamber 120 of container 110, and air received at port 216 of valve 204 is directed to flow through port 214 into inlet port 210 of pump 208. Air pumped to valve 206 through output port 212 is directed by valve 206 to port 224 and then released to the atmosphere through filter 430. In this way, the pressure inside chamber 120 of container 110 is reduced, and negative pressure is applied to the outside of lung 130. The pressure at conduit 150 can closely reflect the pressure in chamber 120 and can be measured using sensor 434. Controller 600 can be configured to monitor the pressure in container 110 (which can be measured by sensor 434) within a specified time range before adjusting valve 204 to stop removing fluid from container 110 through port 216. In some embodiments, the air flow rate through conduit 150 can be controlled by the pumping speed of pump 208. In some embodiments, the air flow rate through conduit 150 can be controlled by adjusting valve 204 while the pumping speed remains constant. For example, valve 204 may be adjusted to allow some outside air to enter the air flow to port 214 through port 218 , thereby reducing the amount of air drawn through conduits 202 and 150 .

[0085] Alternatively or additionally, valve 206 can be controlled to allow a selected proportion of the air flowing through port 220 to flow back to conduit 202 through port 222, conduit 203, and connector 426, which will also reduce the air flow rate from container 110 to connector 426 through conduit 150. In some embodiments, the fluid flow rate in conduit 150 can be controlled by adjusting two or more of valves 204, 206 and pump 208.

[0086] For example, in some applications, valve 204 can be controlled by state control, i.e., controlling the movement of the valve from a 0% (fully closed) position or state to a 100% (fully open) position or state, to control the breathing state; and valve 206 can be used to adjust the pressure in chamber 120 and the inspiratory rise time (T i ).

[0087] During the same inhalation period, the subsystem 500 provides air or oxygen-containing gas to the lungs 130 through the airway 170. For example, the pump 506 can be operated to pump air from the inlet port 508 to the output port 510 at a selected speed. Thus, external (e.g., ambient) air is drawn into the inlet port 508 of the pump 506 through the conduits 519, 531 and the filter 518, and is supplied to the airway 170 through the output port 510, the conduit 511, the filter 520 and the conduit 180. In this way, positive pressure is applied to the airway 170 of the lungs 130. In one mode of operation, the valve 525 can be closed. In a different mode of operation, the valve 525 can be opened so that the oxygen in the oxygen supply source 529 can be pumped through the conduit 527 and mixed with the air in the conduits 521 and 531 at the connector 521. Thus, the air supplied to the airway 170 is oxygen-enriched. The proportion of oxygen added to the air flow may be adjusted by adjusting valve 525 under the control of controller 600. Oxygen sensor 523 may be used to measure the oxygen content or level in the air in conduit 511, and valve 525 may be controlled by controller 600 based on the measured oxygen level.

[0088] The pressure differential between the positive pressure applied to the airway 170 and the negative pressure applied to the exterior of the lung 130 causes the lung to expand and, therefore, inhale air.

[0089] The combination of negative and positive pressures applied as described above also creates a pressure gradient from the airway 170 to the alveoli, which causes some air to flow into and through the alveoli. Some air can pass through the lungs 130 and into the chamber 120.

[0090] Figure 5The flow of air in the device 300 during exhalation in some cases is illustrated. Valves 204 and 206 are configured to allow fluid flow between port 218 and port 214 in valve 204 and between port 220 and port 222 in valve 206 under the control of controller 600, but prevent fluid flow between port 214 and port 216 in valve 204, so that air can flow from valve 206 through port 222, conduits 203 and 150, connector 426 and filter 432 to container 110, but cannot flow from port 216 to port 214. For exhalation, pump 208 is still operated to pump air from inlet port 210 toward output port 212 at a selected pumping speed. Therefore, external air is drawn into valve 204 through port 218 and filter 428, and then enters pump 208 through conduit 211 and inlet port 210. Air is pumped to valve 206 through output port 212 and conduit 213 and directed by valve 206 to port 222 and supplied back to container 110 through conduits 222, 150, connector 426 and filter 432. In this way, the pressure inside chamber 120 of container 110 increases, and the pressure applied to the outside of lung 130 increases. Note that during exhalation, the pressure in the airway may be negative, in which case the device 300 may operate in a manner similar to that during the inhalation period as described above.

[0091] During the exhalation period, the subsystem 500 may continue to supply air or oxygen-enriched air to the airways 170 of the lungs 130 and maintain a positive air pressure in the airways 170 of the lungs 130 as described in the inhalation period described above.

[0092] In any case, during exhalation, the increase in pressure outside the lungs 130 causes the pressure differential between the airways 170 and the chambers 120 to decrease, and thus causes the lungs to exhale and air to flow from the alveoli to the airways 170 and out of the lungs 130 .

[0093] By adjusting control component 205, valves 204 and 206 may be controlled by controller 600 to alternately add or remove fluid from conduit 150, thereby causing the pressure inside chamber 120 to fluctuate between a lower pressure level and a higher pressure level.

[0094] The control system 600 can function in a variety of different ways to control the inhalation and exhalation cycles of the device 300. In a first embodiment, the pump 208 can be constantly operated at a fixed speed throughout the inhalation and exhalation cycles, and the control system 600 adjusts the valves 204 and 206 to operate proportionally by adjusting the control component 205 so as to appropriately proportion the air flow. That is, the air flow can be directed from either of the ports 216 and 218 to the port 214 of the valve 204, or the ratio of the fluid entering the valve 204 through the ports 216 and 218 can be controlled. In a similar manner, the air flow can be directed from the port 220 of the valve 206 to either of the ports 222 and 224, or can be proportional between the ports 222 and 224.

[0095] In another embodiment, the control system 600 regulates and adjusts the speed of the pump 208 while adjusting the valves 204 and 206 as non-proportional three-way valves between multiple set point positions. As will be outlined in more detail below, the control system 600 can be operated to regulate and adjust the speed at which the valves move between the set point positions so as to control the time between the various stages of the breathing curve. That is, air flow can be directed to the port 214 of the valve 204 from any one of the ports 216 and 218, but it is not proportional from the ports 216 and 218 to the port 214. In a similar manner, the air flow can be directed from the port 220 of the valve 206 to any one of the ports 222 and 224, but it is not proportional between the ports 222 and 224.

[0096] As can be appreciated, the speed at which a valve moves between different set positions or open / closed states can have a significant impact on respiratory timing control. Thus, in embodiments disclosed herein, system 300 can be configured to vary the speed at which each valve moves between different valve positions based on a time set point, which can be set by an operator or user. Such speed control can be conveniently achieved with the example valve assemblies described herein.

[0097] In another embodiment, the control system 600 can regulate and adjust the speed of the pump 208 while also adjusting the valves 204 and 206 to operate proportionally through adjustments to the control component 205 in order to appropriately proportion the air flow. That is, the air flow can be directed from either of the ports 216 and 218 to the port 214 of the valve 204, or the ratio of fluid entering the valve 204 through the ports 216 and 218 can be controlled. In a similar manner, the air flow can be directed from the port 220 of the valve 206 to either of the ports 222 and 224, or can be proportioned between the ports 222 and 224.

[0098] The control system 600 can also be used to maintain a constant positive airway pressure (CPAP) within the airway 170 by regulating and adjusting the speed of the pump 506 while adjusting the valves 515 and 525 between multiple fixed positions. In an embodiment, the pump 506 can be constantly operated at a fixed speed, and the control system 600 adjusts the valves 515 and 525 so that fluid flows from the atmosphere through the conduits 519, 531, 511, 180 and into the airway 170. In another embodiment, the control system 600 adjusts the valves 515 and 525 so that oxygen from the oxygen supply can be mixed with air from the conduits 519 and 531 at the connection 521. The oxygen content or level in the air in the conduit 511 can be measured using an oxygen sensor 523, and the valve 525 can be controlled by the controller 600 based on the measured oxygen level. In some embodiments, when a pump, such as the pump 506, is used to control the pressure in the conduit 180, the valve 515 can be omitted.

[0099] Controller 600 may control pumps and valves in device 300 to provide a desired or selected breathing curve.

[0100] Fig.25 An example respiration curve is shown in FIG. 1 . In this example, ITP i The set point for the inspiratory intrathoracic pressure is -11 cmH2O, and the ITP e The set point for expiratory intrathoracic pressure is 1 cmH2O. i and ITP e corresponds to the minimum and maximum pressures within the container 110 as measured by the sensor 434 during inhalation and exhalation, respectively.

[0101] Expiratory rise time (T e ) is once ITP starts to rise after inspiration and ITP reaches ITP e Inspiratory rise time (T i ) is once ITP starts to decrease after exhalation and ITP reaches ITP i The time taken.

[0102] The expiratory time (ET) is the calculated time span that the lungs are in the expiratory state, while the inspiratory time (IT) is the calculated time span that the lungs are in the inspiratory state. ET can be calculated by ((1 / RR)×(E / I+E)). RR is the respiratory rate, which is the number of cycles per minute (BPM) in each minute of breathing. Similarly, IT can be calculated by ((1 / RR)×(I / I+E)). I and E are simplified integers used in the I:E ratio and are simplified forms of ET and IT in the ratio. For example, if IT=4 seconds and ET=2 seconds, then I:E=4:2=2:1.

[0103] Cycle time (T循环 ) is the sum of ET and IT. The inspiratory to expiratory time ratio ("I:E") is the ratio of IT to ET.

[0104] Fig.25 The diagram shows T i Two curves of T i (a) and T i (b) T i (a) corresponds to a short inspiratory rise time, while T i (b) corresponds to a complete inspiratory rise time, as measured by sensor 434. A short inspiratory time may be used, for example, when the lung is non-compliant or needs to be recruited. A non-compliant lung may refer to a lung with poor distensibility (or poor lung compliance). Lung recruitment refers to temporarily increasing airway pressure to open collapsed alveoli. In this case, a short inspiratory rise time followed by a short inspiratory rise time at ITP may be used. i A longer pause may be beneficial during ITP i A longer pause may help improve lung compliance and recruitment.

[0105] In some embodiments, ITP e The range can be from -10cmH2O to 10cmH2O, and ITP i The minimum value can be -30cmH2O.

[0106] Fig.25 Also illustrated is the applied constant positive airway pressure (CPAP) as measured by sensor 523. In some embodiments, CPAP can be maintained at 7.5 cmH2O. The desired pressure can be maintained by adjusting the speed of pump 506 via controller 600 based on the pressure in conduit 511 measured by sensor 523.

[0107] Fig.26 The control logic for controlling valves 204 and 206 and pump 208 is illustrated. The control may be implemented using a proportional-integral-derivative (PID) controller or any standard variation of PID control. As will be appreciated by those skilled in the art, a PID controller continuously calculates an error value as the difference between a desired set point (SP) and a process variable (PV) to obtain a control output (CO). The PID controller may attempt to reach a desired set point over time by continually reducing the error value by adjusting the control output. A control system may include one or more PID controllers for controlling one or more variables. Multiple PID controllers may attempt to reach multiple desired set points. In an embodiment, the set points may be pre-stored or manually entered by a user, and may include ITP i (I-PD control), ITP e(I-PD control), RR, I:E, T e (IP control) and Ti (IP control).

[0108] Fig.26 The PID control logic shown in FIG. 6 which may be followed by control system 600 may be used to control proportional fluid flow in valves 204 and 206 by adjusting the speed of control element 205 and pump 208. In this logic, the pressure ITP in conduit 150 measured by sensor 434 during inspiration is set to i or ITP during exhalation (as measured by sensor 434) e ITP with expected i and ITP e The difference between the actual value measured by sensor 434 and the set point is used as feedback to adjust only valves 204 and 206, only the speed of pump 208, or both valves 204 and 206 and the speed of pump 208.

[0109] During operation of fluid system 400, the configuration of valves 204 and 206 may depend on the ITP input by the user. e For ITP e ≤0, valves 204 and 206 can maintain the same configuration throughout the inhalation and exhalation states. This configuration is achieved by adjusting control component 205 to configure valve 204 to divert air through port 214 and into pump 208 and by adjusting control component 205 to configure valve 206 to release air to the atmosphere via port 224. During each inhalation state and exhalation state, the speed of pump 208 can be controlled by control system 600 based on the ITP measured by pressure sensor 434. i (during inspiration) or ITP e Adjusts (during exhalation) to achieve user-input target ITP during inspiration and exhalation, respectively i and ITP e .

[0110] For ITP e≥1, the configuration of valve 204 and valve 206 implemented by adjusting control component 205 depends on whether the system is operating in an inspiratory state or an expiratory state. During the inspiratory state, valve 204 is configured to divert air from port 216 through port 214 and into pump 208, and valve 206 is configured to release air to the atmosphere via port 224. During the expiratory state, valve 204 is configured to draw air from port 218 and into pump 208, and valve 206 is configured to divert air from port 222 and into conduit 150. During each inspiratory state and expiratory state, the speed of pump 208 can be controlled by control system 600 based on the ITP measured by pressure sensor 434. i (during inspiration) or ITP e Adjusts (during exhalation) to achieve user-input target ITP during inspiration and exhalation, respectively i and ITP e The manner in which the speed of pump 208 is regulated by control system 600 depends on T input by the user. i and T e For T i <2 seconds or T e <2 seconds, the speed of the pump 208 can be instantaneously pulsed or ramped at the beginning of the inspiration phase or the expiration phase, respectively, to accelerate the pressure in the container 110 to reach the set point ITP, respectively. i or ITP e .

[0111] The pulse / ramp waveform of the pump 208 may be controlled by a PID controller as described above with a user input T i or T e value as its set point, where the PID controller can be based on T i or T e The measured value of the (process variable) is attempted to reach the desired set point over time by continuously reducing the error value by adjusting the pump speed multiplier (control output) of the pump 208 while maintaining a constant pulse duration, which may be 0.5 seconds. The pump speed multiplier may range from 0 to 4. If the pump speed multiplier is <1, a ramp-up effect will occur. The ramp from pulse to steady speed may occur over 50% of the entire inspiratory or expiratory breath length.

[0112] When ITP e ≤0 cmH2O, the speed of pump 208 will always increase during inspiration and decrease during exhalation. i >2 seconds or T e >2 seconds and ITP e ≤0 cmH2O, the speed of pump 208 is varied at a calculated rate to achieve the pressure in container 110.i > 2 seconds, the speed of the pump 208 is increased at a rate calculated to achieve the user-entered ITP during inspiration i If Te > 2 seconds, the speed of the pump 208 is reduced at a rate calculated to achieve the user-entered ITP during exhalation e .

[0113] The speed of pump 208 can be controlled by equation (1),

[0114]

[0115] Where b is the percentage of the speed of the pump 208 in the entire range (b s and b f are the starting speed and the final speed of the pump 208, respectively), t is the time since the start of the switch between exhalation and inspiration (or since the start of the switch between inspiration and exhalation), and a and C are constants, where C is preferably 0.9.

[0116] The constant a can be calculated according to equation (2), where if b s >b f , then A=1.5, otherwise A=1,

[0117]

[0118] For T i >2 seconds or T e >2 seconds and ITP e >0 cmH2O, the speed of pump 208 is adjusted in the same manner as mentioned above. In addition, valves 204 and 206 are configured by control system 600 by adjusting control component 205 at a second calculated rate to achieve a pressure in container 110. If T i > 2 seconds, valves 204 and 206 are adjusted at a second calculated rate to achieve the user inputted ITP during inspiration i If T e >2, valves 204 and 206 are adjusted at a second calculated rate to achieve the user inputted ITP during exhalation e .

[0119] The adjustment rate of the control member 205 of valve 204 and valve 206 is controlled by equations (3) and (4):

[0120]

[0121] In equation (3) and equation (4), if the control section 205 and t0, t 0.5and t1 represent the start time, midpoint time and end time of the adjustment period of the control part 205, respectively. Then x0, x 0.5 and x1 represent the starting point, midpoint, and end point, respectively.

[0122] The parameters listed below in Table 1 are used to modify the values ​​in equations (3) and (4) to accommodate the behavior of the physical system at different set points. Note that during inspiration, the subscripts s and f (related to the start and end) refer to exhalation and inspiration, respectively; for exhalation, the subscripts s and f are swapped. With respect to nomenclature, b refers to the speed of the pump 208 and ITP refers to the set point for ITP (ITP e or ITP i ), v refers to the specified valve position reference of valve 204 and valve 206, and x refers to the valve position determined within the range of the controller.

[0123] Table 1

[0124]

[0125]

[0126] In Table 1, the valve position v s and v f is known. i / e and ITP s / f The value is the desired set point which is also known. The baseline valve stroke V is a specified constant (between 0 and 1) which indicates the baseline to which the valve moves immediately upon a breathing state switch.

[0127] P characterizes the difference in ramped blower speed between the starting state and the final state of the breath and is used to modify the baseline valve stroke V to determine the context-modified valve stroke x 冲程 This is necessary because the valve stroke is dependent on the change in speed of the pump 208 and when ramping down the valve stroke would make the ramp too steep.

[0128] M is the adjustment transition time t 0.5 and position x 0.5 A bounded modification is provided to account for the dynamic nature of the system pressure balance. It is found that M needs to be constrained around the intermediate valve position to prevent M from overcompensating the midpoint parameter.

[0129] Fig.27A When ITP e ≤0 can be executed by one or more controllers, processors or computers to control the device, such as Figure 3 Flowchart of algorithm S3100 of device 300 in FIG. 1 . In this example, the set point input by the user is ITP i =-10cmH2O, ITP e =-2cmH2O, Ti = 1 second, T e =3 seconds, RR=10 BPM and I:E=1:1.

[0130] At block S3102, the software is activated by a signal provided by the user or an automatic process. At block S3104, valve 204 is configured to divert air through port 214 and into pump 208 by adjusting control member 205, and valve 206 is configured to release air to atmosphere via port 224.

[0131] At block S3106, the inhalation state of the device begins, and at block S3108, a signal is sent to the pump 208 to pulse and ramp up to a certain speed in order to increase the air flow into the conduit 150. At block S3110, the pressure sensor 434 is sampled, and at block S3112, the algorithm determines that at the set T i Has the ITP been reached? i If you have not reached ITP i (This may be the case particularly in the first ventilation cycle), then the speed of the pump 208 is adjusted at block S3114 for the next ventilation cycle before proceeding to block S3116. i , then no adjustment is required and the algorithm proceeds directly to block S3116. Blocks S3112 and S3114 may include PID calculations, as described above with respect to Fig.26 discussed.

[0132] The exhalation state begins at block S3116. After the exhalation state begins, a signal is sent at block S3118 to reduce the speed of the pump 208 so as to reduce the air flow into the conduit 150 to the set T e Achieve the set ITP within e At block S3120, the pressure sensor 434 is sampled, and at block S3122, the algorithm determines that at the set T e Has the ITP been reached? e If you have not reached ITP e (This may be the case particularly in the first ventilation cycle), then the speed of the pump 208 is adjusted for the next ventilation cycle at block S3124 before proceeding to block S3116. e , then no adjustment is required and the algorithm proceeds directly to block S3126. Blocks S3122 and S3124 may include PID calculations, as described above with respect to Fig.26 discussed.

[0133] At box S3126, the algorithm checks for user input (e.g., a change in a set point). At box S3128, it is determined whether the operating settings should be reconfigured. Reconfiguration may be required when a different operating mode is desired. If the settings are not to be reconfigured, the software returns to box S3106 to repeat the inspiratory state. If the settings are to be reconfigured, such as when a new operating mode is started, ventilation is stopped at box S3130.

[0134] Fig.27B When ITP e ≥1, one or more processors may execute S3202 to control the device of the present disclosure, such as Figure 3 Flowchart of another algorithm S3200 of the device 300 in FIG. 1 . In this example, the set point input by the user is ITP i =-10cmH2O, ITP e =5cmH2O, T i = 1 second, T e =3 seconds, RR=10 BPM and I:E=1:1.

[0135] At block S3202, the software is initiated by a signal provided by the user or an automatic process. At block S3204, the inhalation state of the device begins, and at block S3204, valve 204 is configured to divert air from port 216 through port 214 and into pump 208 by adjusting control member 205, and valve 206 is configured to release air to the atmosphere via port 224.

[0136] At block S3208, a signal is sent to the pump 208 to pulse and ramp up to a certain speed in order to increase the air flow into the conduit 150. At block S3210, the pressure sensor 434 is sampled, and at block S3212, the algorithm determines whether the ITP has been reached within the set Ti. i If you have not reached ITP i (This may be the case particularly in the first ventilation cycle), then the speed of the pump 208 is adjusted at block S3214 for the next ventilation cycle before proceeding to block S3216. i , then no adjustment is required and the algorithm proceeds directly to block S3216. Blocks S3212 and S3214 may include PID calculations, as described above with respect to Fig.26 discussed.

[0137] The exhalation state begins at block S3216. After the exhalation state begins, at block S3220, valve 204 is configured to draw air from port 218 and into pump 208 via adjustment control 205, and valve 206 is configured to direct air through port 222 and into conduit 150 via adjustment control 205. The rate of adjustment control 205 will depend on the set point entered by the user. If ITP e <0cmH2O, the control component 205 is not adjusted. If ITP e >0cmH2O and T i / T e <2, the control component 205 will switch as fast as possible as described above. e >0cmH2O and T i / T e >2, then the control component 205 will move at the calculated rate (as described above).

[0138] At block S3220, a signal is sent to reduce the speed of pump 208 to reduce the air flow into conduit 150 to achieve the desired T e ITP e At block S3222, the pressure sensor 434 is sampled, and at block S3224, the software determines that at T e Has the ITP been reached at the set point? e If you have not reached ITP e (This may be the case particularly in the first ventilation cycle), then the speed of the pump 208 is adjusted for the next ventilation cycle at block S3226 before proceeding to block S3228. e , no adjustment is required and the algorithm proceeds directly to block S3228. Blocks S3224 and S3226 include PID calculations, as described above with respect to Fig.26 discussed.

[0139] At block S3228, the software checks for user input (e.g., a change in a set point). At block S3230, a determination is made as to whether the operating settings should be reconfigured, such as by loading a new configuration file. Reconfiguration may be required when a different operating mode is desired. If the settings are not to be reconfigured, the software returns to block S3204 to repeat the inspiratory state. If the settings are to be reconfigured, such as when a new operating mode is to be started, ventilation is stopped at block S3232.

[0140] In some embodiments, the necessary adjustments to the equipment at block S3226 may alternatively be performed immediately prior to block S3204.

[0141] The second fluid system is also controlled by the control system 200, but can be operated autonomously from the first fluid system to provide a constant positive airway pressure (CPAP) to the lungs 130. The pump 506 will operate at a specific speed to achieve and / or maintain a user-defined CPAP set point corresponding to a desired pressure in the airway 170. The regulation of the pump 506 is based on feedback from the sensor 522, which can be configured to detect the pressure within the conduit 511. Fig.25 In the example shown in the breathing waveform shown in , the pressure within airway 170 measured by sensor 522 may be 7.5 cmH2O.

[0142] Fig. 6A 2 is a schematic diagram illustrating additional components of a valve 700 suitable for use in any of the fluid systems 140, 160, 200 or 400 described above as a specific embodiment of valve 204 and valve 206. As described above, valve 700 has ports 702 grouped on one side of the valve, which are connected to a second group of ports 704 and 706 on the opposite side via a conduit 709. In order to perform the function of control component 205, valve 700 has a valve core 708 that can move within a conduit 709 to guide the fluid flow between the two groups of ports. By doing so, valve 700 can selectively adjust the ratio of fluid flowing through port 704 and port 706 to adjust the flow rate and pressure within any of the fluid systems described above without changing the pump speed. The valve core 708 is moved between at least two positions by an actuator 710. Actuator 710 includes a motor 712, a drive shaft 714, a connector 716, and a proximity sensor 718. The drive shaft 714 is coupled to the valve core 708 via a connector 716 and is used to position the valve core 708. A proximity sensor 718 determines the initial position of the drive shaft 714 and provides an output signal to a controller 720, which controls the position of the drive shaft 714 via the motor 712.

[0143] FIG. 6B to FIG. 6D Three general implementations of valve 700 are shown to illustrate the use of a movable spool to control fluid flow between two sets of ports.

[0144] Reference Figure 6B , valve 1600 includes three ports in communication with a cylindrical bore 1608: port 1602 grouped on one side and port 1604 and port 1606 grouped together on the opposite side. To selectively control flow between the two groups of ports, a valve core 1610 is received within the bore 1608. The valve core is linearly movable within the bore 1608 and is capable of blocking or allowing flow between the two groups of ports. Figure 6B1604 is blocked, while flow from port 1602 to port 1606 / from port 1606 to port 1602 through openings 1612 and 1614 in the valve core (as indicated by the directional arrows) is possible. As will be described in more detail below, the position of the valve core 1610 can be adjusted to precisely control the relative fluid flow into or out of each of the second port 838 and the third port 840.

[0145] Reference Figure 6C , depicts a valve 1700 that is similar in design and function to valve 1600. In this embodiment, port 1704 and port 1706 are combined together in a generally V-shaped arrangement. One advantage of this configuration is that the pressure drop across the valve is lower because the flow path exits at 45 degrees instead of 90 degrees. This will increase the efficiency of the valve when installed in a fluid system such as 300.

[0146] Reference Fig.6D , valve 1800 has three ports in communication with a cylindrical bore 1808: ports 1802 grouped on one side and ports 1804 and 1806 grouped together on the opposite side. In this embodiment, a valve core 1810 is received within the bore 1808 and is configured to move in a rotatable manner to block or allow flow between the two groups of ports. Fig.6D In the position shown in , flow through port 1804 is blocked, while flow from port 1802 to port 1806 / 1806 to port 1802 is possible through openings 1812 and 1814 in the valve core (as indicated by the directional arrows).

[0147] Of course, other positions of the valve core 1610 and the valve core 1810 are possible to open and close different paths of fluid flow, as will be outlined in more detail below.

[0148] exist FIG. 7A to FIG. 7B , FIG. 8A to FIG. 8B , 9A to 9C and FIG. 10A to FIG. 10F A first embodiment of a valve 800 suitable for use in any fluid system is shown in FIG.

[0149] Special reference FIG. 7A to FIG. 7B and FIG. 8A to FIG. 8B, the valve 800 has a generally rectangular valve base 802, to which a housing 804 is attached using a suitable method, such as screws, to a top surface 802a of the valve base 802. The housing 804 has a rectangular cuboid shape, including a recessed valve core opening 808 located on an end surface 804b of the housing 804. The housing 804 can be made of a suitable material, such as aluminum. A cover plate 810 is sized to fit within the valve core opening 808 and is secured in place using a suitable method, such as screws 812. An O-ring 809 located within a groove 811 of the valve core opening 808 provides a seal between the valve core opening 808 and the cover plate 810. The O-ring 809 can be made of rubber or any other suitable material.

[0150] The motor mount 814 is positioned on the top surface 804a of the housing 804. The motor mount 814 is generally flat and rectangular and provides a surface for mounting a motor 816. In this embodiment, the motor 816 may be a linear DC servo motor, such as that manufactured by MicroMo Electronics. TM LM1247-020-01 linear DC brushless micro motor manufactured by Panasonic. Motor 816 includes a drive shaft 820. The motor mount 814 also has a flanged protrusion 822 protruding perpendicular to the top surface 804a, and a proximity sensor 824 can be attached to the flanged protrusion 822. The proximity sensor can be any suitable sensor, such as the GX-F8A-P inductive proximity sensor manufactured by Panasonic. As will be explained in further detail below, the proximity switch is configured to detect the position of the drive shaft 820, in particular, the initial position of the drive shaft. The valve base 802, the housing 804, the cover plate 810 and the motor mount 814 can be made of any material of suitable strength, such as aluminum.

[0151] The electronics mount 826 is also secured to the top surface 802a of the valve base 802. The electronics mount 826 includes two feet 828 that contact the surface 802a of the valve base 802 and are secured by a suitable method, such as screws (not shown). The electronics mount 826 also includes two legs 830 that extend vertically upward from the feet 828 to a vertical rectangular back plate 832. A controller 834 is secured to the back plate 832. In this embodiment, the controller 834 may be a MicroMo Electronics TM MCLM3002SRS motor controller manufactured by . The electronics mount 826 may be made of any suitably strong material, such as acetyl plastic.

[0152] Special reference FIG. 8A to FIG. 8B and 9A to 9C, the housing 804 also includes a first port 836, a second port 838, and a third port 840. The first port 836 is located on the face 804c of the housing 804, while the second and third ports are located on the opposite face 804d of the housing 804. Ports 836, 838, and 840 are cylindrical passages that extend inwardly to the center of the housing 804 to communicate with a central cylindrical bore 842. The cylindrical bore 842 extends along the longitudinal axis of the housing 804, terminating at one end at the valve core opening 808. At the opposite end of the cylindrical bore 842 is a stem connector opening 844 that exits through the face 804e of the housing 804 ( Figure 8B ). The cross-section of the cylindrical hole 842 may not be completely circular, and may include a flat portion 843 located on the bottom surface.

[0153] In order to provide a fluid connection between the first port 836 and any tube or conduit for receiving fluid from or supplying fluid to the valve 800, a first port connector 846 (852) including a flange portion 848 and a tubular portion 852 is provided. Figure 8B ). The flange portion 848 of the first port connector 846 contacts the surface 804c of the housing 804 where the first port 836 exits the housing 804. To provide a seal, an O-ring 850 may be provided that follows the circumference of the port 836 on the surface 804c and is located in a groove 851 to seal between the housing 804 and the first port connector 846 when the housing 804 and the first port connector 846 are secured by screws 854. Figure 8B As shown in FIG. 8 , the tubular portion 852 of the first port connector 846 is sized to receive a tube of a tube fixture or catheter, such as tube 856. Tube 856 may be secured by any suitable means, such as by a tube clamp (not shown).

[0154] Similar to as described above, a second port connector 858 and a third port connector 860 are also provided to provide fluid connections between the respective second port 838 and the third port 840 and any tube or conduit for receiving fluid from or supplying fluid to the valve 800. The second port connector 858 is mounted to the face 804d of the housing 804 using screws 862 and is sealed with an O-ring 864, which is located in a circular groove 866 in the face 804d. Similarly, the third port connector 860 is mounted to the face 804d of the housing 804 using screws 868 and is sealed with an O-ring 870, which is located in a groove 872 in the face 804d, which follows the circumference of the port 860. The first port connector 846, the second port connector 858, and the third port connector 860 can be made of any suitable strength material, such as aluminum. The O-rings 850, 864, 870 can be rubber or any other suitable material.

[0155] In order to selectively adjust the ratio of fluid flow through the second port 838 and the third port 840, a valve core 874 is provided, which is installed in the cylindrical bore 842. The valve core 874 is hollow and generally cylindrical in shape with three openings on the surface of the cylindrical member, and the valve core 874 is sized to fit tightly in the cylindrical bore 842. The outer surface of the valve core 874 may include a flat area 875 that aligns with the flat portion 843 of the cylindrical bore 842, which ensures that the valve core is properly aligned in the cylindrical bore during assembly ( Fig. 8A ). A first opening 876, which is generally rectangular in shape, is located on the curved surface of the valve core 874. A second smaller, generally rectangular opening 878 is located on the curved surface opposite the first opening 876. A third opening 880 is located on the end of the valve core 874 near the cover plate 810. The valve core 874 can be made of any material of suitable strength, such as acetal plastic.

[0156] The valve core 874 may be sized such that the clearance between the outer surface of the valve core 874 and the cylindrical bore is approximately 0.15 mm. The valve core 874 may be made of a suitable material having a low coefficient of friction, such as acetyl plastic.

[0157] The closed end 886 of the valve core 874 may include a series of perforations ( Figure 8B ), the series of perforations being used to allow fluid to flow therethrough, thereby preventing trapped fluid from obstructing movement during actuation of the valve core 874. A cylindrical central shaft 882 having threaded holes at either end connects the valve core 886 to a connector 884, which in turn is connected to a drive shaft 820 for moving the valve core. The central shaft 882 is coupled to the closed end 886 of the valve core 874 by screws 889.

[0158] As will be explained below, the spool 874 is movable between a plurality of positions by linear motion along the longitudinal axis of the cylindrical bore 842 to proportionally control the fluid flowing through the valve 800. The actuation mechanism includes a motor 816, a proximity sensor 824, and a drive shaft 820 that connects the spool 874 to the motor 816. In this embodiment, the drive shaft 820 includes a cylindrical portion having a threaded hole at one end that is coupled to an upper connector 884 by a screw 887. The distal end of the central shaft 882 of the spool 874 is coupled to the lower end of the connector 884 by a screw 885 received in a threaded end hole of the central shaft 882.

[0159] The movement of the spool 874 is controlled by the motor 816. The motor 816 is operable to move the spool 874 in increments of 0.006 mm over a total stroke length of 17.3 mm. Activation of the motor 816 (via the controller 834) causes the drive shaft 820 to move along the Fig. 8A The linear motion is transmitted to the valve core 874 through the central shaft 882 and the connector 884, causing the valve core 874 to move along the same x-axis. The proximity sensor 824 is used to detect the initial position of the drive shaft 820 and generate an output signal for the controller 834, thereby allowing the valve core 874 to be positioned in any number of positions along the longitudinal axis of the cylindrical bore 842 to control the fluid flow through the valve 800.

[0160] Reference 9A to 9C and FIG. 10A to FIG. 10F , showing the three positions of the valve core 874. First go to Fig.9A and FIG. 10A to FIG. 10B , the valve core 874 is in a first position (also referred to as an initial position) in which the open end of the valve core 874 is adjacent to the cover plate 810. In this position, the first opening 876 is aligned with the first port 836 and the second opening 878 is aligned with the third port 840. Depending on the configuration of the system in which the valve 800 is installed, the fluid can flow through the second opening 878, through the valve core 874, into the third port 840, and flow through the first port 836 via the first opening 876. Alternatively, the fluid can flow through the first opening 876, through the valve core 874, into the first port 836, and flow through the third port 840 via the second opening 878.

[0161] As described above, the valve core 874 can be actuated to Fig. 9B and FIG. 10C to FIG. 10D 836 and the third port 840. In this position, the first opening 876 is still aligned with the first port 836 and the second opening 878 is aligned with the second port 838 and the third port 840. Depending on the configuration of the system in which the valve 800 is installed, the fluid can flow through the second opening 878, through the valve core 874, into both or either of the second port 838 and the third port 840, and out through the first port 836 via the first opening 876. Alternatively, the fluid can flow through the first opening 876, through the valve core 874, into the first port 836, and flow through the second port 838 and the third port 840 via the second opening 878.

[0162] The valve core 874 can be actuated to Fig. 9C and FIG. 10E to FIG. 10F836 and the second opening 878 is aligned with the second port 838. Depending on the configuration of the system in which the valve 800 is installed, fluid can flow through the second opening 878, through the valve core 874, into the second port 838, and flow through the first port 836 via the first opening 876. Alternatively, fluid can flow through the first opening 876, through the valve core 874, into the first port 836, and flow through the second port 838 via the second opening 878.

[0163] The position of the valve core 874 in the cylindrical hole 842 may not be limited to Fig.9A 8C. By controlling the position of the spool 874, the relative fluid flow into / out of each of the second port 838 and the third port 840 can be precisely controlled.

[0164] The first opening 876 can be sized such that regardless of the position of the valve core 874 within the cylindrical bore 842, fluid flow is always possible between the first port 836 and the first opening 876. The second opening 878 can be sized such that, depending on the position of the valve core 874 within the cylindrical bore 842, fluid flow is possible only between the second opening 878 and the second port 838, only between the second opening 878 and the third port 840, or between the second opening 878 and both the second port and the third port.

[0165] In some embodiments, the valve core 874 can have a length of 64.1 mm and a diameter of 24.8 mm. The first opening 876 can have a length of 32.6 mm and the second opening 878 can have a length of 25.5 mm. The first port 836, the second port 838, and the third port 840 can each have a diameter of 15.3 mm.

[0166] Go to FIG. 11A to FIG. 11B , FIG. 12A to FIG. 12B and FIG. 13A to FIG. 13B, another embodiment of a valve 900 suitable for use in any of the first and second fluid systems described above is shown. Similar to valve 800, valve 900 includes a valve base 802, a housing 804, a motor mount 814, a motor 816, and a proximity sensor 826. An electronics mount 926 is mounted to the top surface 802a of the valve base 802. In this embodiment, the electronics mount 926 includes four feet 928, which contact the surface 902a at each corner of the valve base 802 and are fixed with a suitable method, such as screws (not shown). Four legs 930 are connected to each of the four feet 928, and the four legs 930 extend vertically upward from the feet to a back plate 932. The back plate 932 includes two parallel plates 932a and 932b spaced apart. A controller 934 is fixed to the top surface of the back plate 932a.

[0167] Reference FIG. 12A to FIG. 12B , the housing 804 includes a first port 836, a second port 838, and a third port 840, which cooperate with the cylindrical bore 842 as described above for the valve 800. In order to provide a fluid connection between the first port 836 and any tube or conduit for receiving fluid from or supplying fluid to the valve 800, a first port connector 946 is provided. The first port connector 946 includes a first tubular portion 952 for receiving a tube or conduit and a second, narrower tubular portion 953 sized to fit within the first port 836 of the housing 804 by an interference fit.

[0168] Similarly, second and third port connectors 958 , 960 are also provided to provide fluid connections between the respective second and third ports 838 , 840 and any tubes or conduits for receiving fluid from or supplying fluid to the valve 900 .

[0169] To selectively adjust the ratio of fluid flowing through the second port 838 and the third port 840 , a valve spool 874 is provided that operates in a manner similar to that described above with respect to the valve 800 .

[0170] Fig.14 , Fig.15 and FIG. 16A to FIG. 16D Another embodiment of a valve 1000 suitable for use in any of the first and second fluid systems described above is shown in . The valve 1000 includes a valve base 1002 , a housing 1004 , a motor mount 1014 , and a guide rail 1088 .

[0171] Special reference Fig.14 and Fig.15, the valve base 1002 has a rectangular base 1090, the proximal end of which terminates in a flanged end 1092. Extending longitudinally downward along the center of the mounting base 1002 is a housing mount 1094 having a semi-cylindrical profile sized to receive the housing 1004. The semi-cylindrical shape of the housing mount 1094 is closed at the distal end and open at the proximal end.

[0172] The motor mount 1014 has a cross-sectional profile that is approximately inverted U-shaped, having a top surface 1096 extending longitudinally downwardly along the center and terminating in a flanged end 1102, and side surfaces 1098 and 1100. The outer surface of the flanged end 1098 contacts the outer surface of the flanged end 1092 of the valve base 1002. The motor 816, which is longitudinally oriented and aligned with the housing 1004, is mounted to the top surface 1096 of the motor mount 1014. In this embodiment, the motor 816 can be a linear DC servo motor, such as that manufactured by MicroMo Electronics. TM LM0830-015-01 linear DC brushless micro motor manufactured by.

[0173] The guide rail 1088 is coupled to the motor mount 1014. The guide rail 1088 includes a generally rectangular body 1108 at a distal end, with a first parallel arm 1110 and a second parallel arm 1112 extending longitudinally ( Fig.15 The motor mount 1014 extends from the first parallel arm 1110 to the second parallel arm 1112, and terminates at flanged brackets 1114 and 1116. When fitted to the valve 1000, the side surface 1098 of the motor mount 1014 and the side surface 1100 are tightly sandwiched by the first parallel arm 1110 and the second parallel arm 1112, as shown in FIG. Fig.14 . Flanged brackets 1114 and 1116 contact the inner face of the flanged end 1102, and the guide rail 1098, motor mount 1014 and valve base 1002 are secured by suitable means, such as bolts 1104 and nuts 1106. Extending longitudinally downwardly along the center of the top surface of the rectangular body 1108 is a guide channel 1118, which is a recessed channel extending to approximately half the depth of the body 1108.

[0174] The housing 1004 is mounted to the housing mount 1094 of the valve base 1002. Fig.15 and FIG. 16A to FIG. 16D , the housing 1004 has a cylindrical body 1120 that is open at the distal end with a cylindrical bore 1042 defined by an inner surface. The distal end is sealed with a removable end cap 1010, which may include a ring 1012 protruding from the outer end to facilitate removal. The housing 1004 may be made of a suitable material, such as aluminum. An O-ring 1011 ( Fig.15 ) provides a seal between the cylindrical body 1120 and the end cap 1010. The O-ring 1011 can be any suitable material, such as rubber. The cylindrical body 1120 has a first port 1036 extending vertically outward from the cylindrical body 1120, and the first port 1036 is located at a substantially midpoint along the length of the body 1120. The housing 1004 also includes a second port 1038 and a spaced third port 1040 on the side of the cylindrical body 1120 opposite the first port 1036. The housing 1004 also includes a central shaft opening 1044 ( Fig.15 ).

[0175] In order to provide fluid communication between the first port 1036, the second port 1038, and the third port 1040 and any tube or conduit for receiving fluid from or supplying fluid to the valve 1000, the first port connector 1046, the second port connector 1058, and the third port connector 1060 are formed as an integral part of the housing 1004. The second port connector 1058 and the third port connector 1060 are angled away from each other to reduce the pressure drop across the valve while providing sufficient clearance between the second port connector 1058 and the third port connector 1060 for attaching a tube or conduit. In one embodiment, Fig.17 The angle θ between the second port connector 1058 and the third port connector 1060 in A is between 43.5 degrees and 44.5 degrees and is optimally 44 degrees.

[0176] The lower half of the cylindrical body 1120 of the housing 1004 is sized to fit within the housing mount 1094, with the first port connector 1046, the second port connector 1058, and the third port connector 1060 positioned so that the first port connector 1046, the second port connector 1058, and the third port connector 1060 are located within the corresponding first cutout 1122, the second cutout 1124, and the third cutout 1126 of the housing mount 1094 ( Fig.15 ).

[0177] Similar to other valve embodiments, in order to selectively adjust the ratio of fluid flowing through the second port 1038 and the third port 1040, a valve core 1074 is provided that is mounted within the cylindrical bore 1042. Similar to the valve core 874, the valve core 1074 is hollow and cylindrical in shape with three openings on the surface of the cylindrical member, and the valve core 1074 is sized to fit tightly within the cylindrical bore 1042. A first opening 1076, which is generally rectangular in shape, is located on the curved surface of the valve core 1074. A second, smaller, generally rectangular opening 1078 is located on the curved surface opposite the first opening 1076. The third opening 1080 is located on the end of the valve core 1074 near the end cap 1010. Similar to the valve core 874, the closed end 1086 of the valve core 1074 may include a series of perforations. A central shaft 1082 protrudes from the center of the closed end 1086, and the central shaft 1082 includes a cylindrical portion having a threaded hole 1130 at the distal end. In this embodiment, the central shaft 1082 and the valve core 1074 are a single integral piece. When installed in the housing 1004, the central shaft 1082 protrudes through the open central shaft opening 1044 ( Fig.15 ).

[0178] Similar to the valve core 874 in the valve 800, the valve core 1074 can be positioned in a plurality of positions (similar to the valve core 874 in the valve 800) in substantially the same manner as described above. 9A to 9C 1074) to control the fluid flow through the valve 1000. The actuation mechanism of the valve 1000 includes a motor 816, a drive shaft 820 that couples the valve core 1074 to the motor 816 via a connector 1128. In this embodiment, the drive shaft 820 and the valve core 1074 are arranged along Fig.15 The z-axis shown in is aligned axially. Fig.16D 1082 and the drive shaft 820. The drive shaft 820 is secured with a screw 1129 which is received in a threaded opening in the drive shaft. To secure the valve core 1074 to the connector 1128, the connector 1128 may also include a hole located along the length of the connector 1128 which is aligned with a hole 1130 in the distal end of the central shaft 1082 for positioning a bolt 1132 therethrough. The bolt 1132 is secured with a nut 1134.

[0179] At the distal end of the drive shaft 820, a guide rod 1136 is secured by a screw 1138. The guide rod 1136 is generally rectangular with rounded ends and extends downwardly to be received by the guide channel 1118. The guide rod 1136 is sized to be located in the guide channel 1118 during a full range of actuation of the valve 1000 and is used to maintain alignment of the drive shaft 820, the connector 1128, the central shaft 1082, and the valve core 1074 during actuation.

[0180] The movement of the valve core 1074 is controlled by the motor 816. The activation of the controller (not shown) causes the drive shaft 820 to move in a direction controlled by the motor 816. Fig.16A The valve core 1074 moves linearly in the direction indicated by the arrow 1140 in FIG. The linear motion is transmitted to the valve core 1074 via the central shaft 1082 via the connector 1128, resulting in the linear motion of the valve core 1074.

[0181] exist Fig.17 , FIG. 18A to FIG. 18B and FIG. 19A to FIG. 19B Another embodiment of a valve 1200 similar to valve 1000 and suitable for use in any of the first and second fluid systems described above is shown in FIG. Fig.17 , the valve 1200 includes a housing 1204 formed as a single continuous valve body 1201, a motor mount 1214, and a guide track 1288. The motor mount 1214 is formed as a single rectangular piece between the proximal end of the housing 1204 and the guide track 1288. The motor mount 1214 has a flat upper surface for receiving the motor 816.

[0182] The valve body 1201 also includes a guide track 1288 formed at the distal end of the motor mount 1214 and coupled to the motor mount 1214. The guide track 1288 includes a central longitudinal direction ( Fig.17 The guide channel 1217 extends downwardly along the entire length of the drive shaft 820 (in the x-axis). The guide rail 1288 has a flanged protrusion 1222 protruding perpendicularly from the top surface of the guide rail 1288, and the proximity sensor 824 can be attached to the flanged protrusion 1222 using a mounting bracket 1223, a bolt 1225, a washer 1226, and a nut 1227. The proximity sensor 824 is configured to detect the position of the drive shaft 820.

[0183] Similar to the housing 1004 of the valve 1000 described above, the housing 1204 has a cylindrical body 1220 that is open at the distal end with a cylindrical bore 1242 defined by an inner surface. In this embodiment, the cylindrical bore 1242 has a circular cross-section with flat portions 1243 ( Fig.18B ). The distal end is sealed with a removable end cap 1010 and an O-ring 1011. The cylindrical body 1220 has a first port 1236 extending vertically outward from the cylindrical body 1220, and the first port 1236 is located at approximately the midpoint of the length of the body 1220. The housing 1204 also includes a second port 1238 and a spaced third port 1240 on the side of the cylindrical body 1220 opposite the first port 1236. The housing 1004 also includes a central shaft opening 1144 ( Fig.18A ).

[0184] In order to provide fluid communication between the first port 1236, the second port 1238 and the third port 1240 and any tube or conduit used to receive fluid from or supply fluid to the valve 1200, a first port connector 1246, a second port connector 1258 and a third port connector 1260 are provided, and the first port connector 1246, the second port connector 1258 and the third port connector 1260 are arranged and function in a manner similar to the first port connector 1046, the second port connector 1058 and the third port connector 1060 of the valve 1000 described above.

[0185] Similar to the other valve embodiments described above, in order to selectively adjust the ratio of fluid flowing through the second port 1238 and the third port 1240, a valve core 1274 is provided that is mounted within the cylindrical bore 1242. Similar to the valve core 1074, the valve core 1274 is hollow and cylindrical in shape with three openings on the surface, and the valve core 1274 is sized to fit tightly within the cylindrical bore 1242. A central shaft 1282 is coupled to the closed end 1286 of the valve core 1274 using a heat-set threaded insert 1283, and the central shaft 1282 includes a cylindrical portion with threads at each end. In this embodiment, the top and bottom surfaces of the valve core 1274 include flat portions 1275 that are sized to complement the flat areas 1243 of the cylindrical bore 1242 to ensure that the valve core is properly aligned within the cylindrical bore during assembly ( Fig.18A ). This arrangement eliminates any rotation of the valve core 1274 within the cylindrical bore during operation, thereby preventing the central shaft 1282 from being threadedly disconnected from the valve core 1274 or the drive shaft 820. A first opening 1276, which is generally rectangular in shape, is located on the curved surface of the valve core 1274, and a second smaller generally rectangular opening 1278 is located on the curved surface opposite the first opening 1276. The third opening 1280 is located on the end of the valve core 1274 near the end cap 1010. Similar to the valve core 874, the closed end 1286 of the valve core 1274 can include a series of perforations.

[0186] Similar to the valve core 874 in the valve 800, the valve core 1274 can be positioned in a plurality of positions (similar to 9A to 9C ) to control the fluid flow through the valve 1200. The actuation mechanism of the valve 1200 includes a motor 816 and a drive shaft 820 that couples the valve core 1274 to the motor 816. In this embodiment, the drive shaft 820 and the valve core 1274 are moved along Fig.18A The z-axis shown in is axially aligned. The distal threaded end of the central shaft 1282 is coupled to the threaded center of the drive shaft 820.

[0187] The actuation mechanism of the valve 1200 may also include a proximity sensor 824 for detecting the position of the drive shaft 820 (and therefore the valve core 1274) and generating an output signal for a controller (not shown) to allow the valve core 1274 to be positioned in any number of positions along the longitudinal axis of the cylindrical bore 1242 so as to control the flow of fluid through the valve 1200.

[0188] At the distal end of the drive shaft 820, a guide rod 1262 is secured by a screw 1264. The guide rod 1262 extends downwardly into the guide channel 1217. The guide rod 1262 is sized to be located in the guide channel 1217 during full range actuation of the valve 1200 and is used to maintain alignment of the drive shaft 820, the central shaft 1282, and the spool 1274 during actuation.

[0189] The movement of the valve core 1274 is controlled by the motor 816. The activation of the motor by the controller (not shown) causes the drive shaft 820 to move in the direction of the valve core 1274. Fig.19A The valve core 1274 moves linearly in the direction indicated by the arrow 1241 shown in the figure. The linear motion is transmitted to the valve core 1274 through the central shaft 1282, resulting in the linear motion of the valve core 1274.

[0190] Reference Fig. 20 , Fig.21 , FIG. 22A to FIG. 22C , Fig.23 and Fig.24 , depicts another embodiment of a valve 1300 suitable for use in any of the first fluid system or the second fluid system described above, the valve 1300 comprising a valve base 1302 , a motor 1316 , a housing support 1303 , a housing 1304 and a cover 1310 .

[0191] Specific reference Fig. 20 and Fig.21 , the valve base 1302 may include a rectangular plate 1302a and a motor mount 1314. The motor mount 1314 is a hollow cylindrical member protruding from the center of the rectangular plate 1302a, which is open at the upper end for receiving the motor 1326 therein. In this embodiment, the motor 1316 may be a brushless DC servo motor.

[0192] Reference Fig.21, the housing support 1303 is coupled to the motor 1316 and is secured by screws 1305 located in threaded holes on the top surface of the motor 1316. The housing support 1302 includes a lower housing mounting plate 1307 and an upper housing mounting plate 1309 connected by a pair of upwardly extending lower support arms 1321. The lower housing mounting plate 1307 is a circular plate with an opening in the center for the actuating mechanism to fit therethrough. Similarly, the upper housing mounting plate 1309 has a generally circular shape sized to follow the outer contour of the housing 1304 with a central opening. At opposite points along the circumference of the upper housing mounting plate 1309 are two upper support arms 1313 that rise vertically with horizontally outwardly projecting flanged bosses 1321 that contact corresponding flanges 1315 on the housing 1304 to provide additional support. The flanged end 1315 and flange 1315 are secured together using bolts 1317 and nuts 1319 .

[0193] In this embodiment, the housing 1304 can be cylindrical in shape with an opening at the upper end that can be reversibly sealed by a cap 1310 and an O-ring 1311. The cap 1310 can include a ring 1312 that protrudes from the upper surface to facilitate removal. The housing 1304 also includes a first port 1336, a second port 1338, and a third port 1340 positioned on the outer cylindrical surface. The second port 1338 and the third port 1340 are positioned adjacent to each other, while the first port 1336 is positioned on the opposite side of the housing 1304.

[0194] In order to provide fluid connection between the first port 1336, the second port 1338 and the third port 1340 and any tube or conduit for receiving fluid from the valve 1300 or supplying fluid to the valve 1300, a first port connector 1346, a second port connector 1358 and a third port connector 1360 are provided respectively, and the first port connector 1346, the second port connector 1358 and the third port connector 1360 are formed as an integral part of the housing 1304.

[0195] The inner surface of the housing 1304 defines a cylindrical bore 1342 through which fluid can flow between the first port 1336, the second port 1338, and the third port 1340. In order to selectively adjust the ratio of the fluid flowing through the second port 1338 and the third port 1340, a valve core 1374 is provided, which is sized to fit within the cylindrical bore 1342 and to be opened at the third port 1340. Fig.2413. The valve core 1374 has a hollow cylindrical body closed at one end 1386, with a first rectangular opening 1376 located on a curved surface and a second smaller rectangular opening 1378 located on the opposite curved surface of the valve core 1374. The third opening 1380 is located at the top end of the cylindrical member of the valve core 1374. An actuation mounting member 1379 protrudes from the center of the bottom surface of the closed end 1386, which provides a connection point for the actuation mechanism of the valve 1300.

[0196] The valve core 1374 is movable between a plurality of positions so as to be able to move the valve core 1374 between the plurality of positions by moving the valve core 1374 about the central vertical axis ( Fig.21 The rotational movement of the valve core 1374 (y-axis in the figure) selectively adjusts the ratio of the fluid flow between the first port 1336, the second port 1338 and the third port 1340. The actuation mechanism includes a motor 1316 and a drive shaft 1320, and the motor 1316 and the drive shaft 1320 are connected using a connector. In this embodiment, in order to provide a secure connection without gaps between the valve core 1374 and the motor 1316, the connector is a cross slider connector 1381, which includes a disk 1383 sandwiched by an upper connecting hub 1385 and a lower connecting hub 1387. Examples of cross slider connectors suitable for use in the valve 1300 are the MOST19-8-A connecting hub and the MOCT19-4-A connecting hub and the OD12 / 19-AT connecting disk manufactured by Rotoprecision Inc. The upper connecting hub 1385 is attached to the drive mount 1379 via a set screw (not shown) on the flat edge 1379a of the drive mount 1379. The lower coupling hub 1387 is attached via an integrated clamping mechanism (not shown).

[0197] The movement of the valve core 1374 is controlled by the motor 1316, which drives the valve core 1374 to rotate about its central axis via the cross slide connector 1381. FIG. 22A to FIG. 22C , showing three positions of the valve core 1374. First go to Fig.22A , the valve core 1374 is in the first position, wherein the first opening 1376 is aligned with the first port 1336 and the second opening 1378 is aligned with the second port 1338. Depending on the configuration of the system in which the valve 1300 is installed, fluid can flow through the second opening 1378, through the valve core 1374, into the second port 1338, and flow through the first port 1336 via the first opening 1376. Alternatively, fluid can flow through the first opening 1376, through the valve core 1374, into the first port 1336, and flow through the second port 1338 via the second opening 1378.

[0198] As described above, the valve core 1374 can be actuated to Fig. 22B1374. In this position, the first opening 1376 is aligned with the first port 1336 and the second opening 1378 is aligned with the second port 1338 and the third port 1340. Depending on the configuration of the system in which the valve 1300 is installed, the fluid can flow through the second opening 1378, through the valve core 1374, into the second port 1338 and the third port 1340, and flow through the first port 1336 via the first opening 1376. Alternatively, the fluid can flow through the first opening 1376, through the valve core 1374, into the first port 1336, and flow through the second port 1338 and the third port 1340 via the second opening 1378.

[0199] As described above, the valve core 1374 can be actuated to Fig. 22C 1374 and the third position shown in FIG. In this position, the first opening 1376 is aligned with the first port 1336 and the second opening 1378 is aligned with the third port 1340. Depending on the configuration of the system in which the valve 1300 is installed, fluid can flow into the third port 1340 through the second opening 1378, through the valve core 1374, and flow through the first port 1336 via the first opening 1376. Alternatively, fluid can flow into the first port 1336 through the first opening 1376, through the valve core 1374, and flow through the third port 1340 via the second opening 1378.

[0200] When introducing elements of the present invention or embodiments of the present invention, the articles "a," "an," "the," and "said" are intended to indicate that there are one or more elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0201] Of course, the above embodiments are illustrative rather than restrictive. The described embodiments for implementing the present invention are susceptible to many modifications in form, arrangement of parts, details and order of operation. Therefore, the present invention is intended to include all such modifications within its scope.

Claims

1. A valve assembly, comprising: a first conduit including a first end and a second end; as well as a first control valve and a second control valve, each control valve including a first port, a second port, and a third port, and each control valve further including a valve spool configured to selectively adjust a ratio of fluid flow through the second port and the third port of the corresponding control valve, wherein the first port of the first control valve is configured to be connected to an inlet port of a pump, the second port of the first control valve is configured to be connected to a second end of the first conduit for extracting fluid from the first conduit, the first port of the second control valve is configured to be connected to an outlet port of the pump, and the second port of the second control valve is configured to be connected to the second end of the first conduit for supplying fluid to the first conduit.

2. The valve assembly according to claim 1, wherein: Each control valve comprises an actuator for actuating a valve spool of the respective control valve.

3. The valve assembly according to claim 2, wherein: The actuator of each control valve includes a servomotor.

4. A valve assembly according to claim 2 or claim 3, wherein: A valve spool of at least one of the first control valve and the second control valve is a sliding valve spool, and an actuator of the at least one control valve is a linear actuator.

5. A valve assembly according to claim 2 or claim 3, wherein: The valve spool of at least one of the first control valve and the second control valve is a rotary valve spool, and the actuator of the at least one control valve is a rotary actuator.

6. The valve assembly according to claim 4, wherein: The linear actuator of the at least one control valve comprises a drive shaft coupled to a sliding spool of the corresponding control valve for positioning the sliding spool.

7. The valve assembly according to claim 6, wherein: The linear actuator of at least one of the control valves comprises a proximity sensor for determining a position of a drive shaft of the respective control valve.

8. The valve assembly according to claim 7, wherein: The actuator of the at least one control valve comprises a controller for controlling movement of a drive shaft of the corresponding control valve based on an output signal from a proximity sensor of the corresponding control valve.

9. A valve assembly according to any one of claims 6 to 8, wherein: A drive shaft of the linear actuator of the at least one control valve and a sliding spool of the corresponding control valve are axially aligned along an axis of the drive shaft.

10. The valve assembly according to claim 9, wherein: The drive shaft of the linear actuator of at least one control valve includes a guide rod configured to maintain axial alignment of the drive shaft of the corresponding control valve.

11. A valve assembly according to any one of claims 6 to 10, wherein: The linear actuator of the at least one control valve includes a connector coupled to a drive shaft and a sliding spool of the corresponding control valve.

12. The valve assembly according to claim 11, wherein: The drive shaft of the linear actuator of the at least one control valve and the sliding spool of the corresponding control valve are stacked vertically.

13. A valve assembly according to any one of claims 1 to 4 and 6 to 12, wherein: The at least one control valve comprises a housing including opposite ends and a cylindrical bore extending between the opposite ends, a first port of the respective control valve being located on a first side of the bore, and a second port of the respective control valve and a third port of the respective control valve being located on a second side of the bore, and wherein a spool of the respective control valve is slidable in the bore and comprises a transversely extending conduit including a first opening facing the first side of the bore and a second opening facing the second side of the bore, the first opening being sized and positioned to allow fluid communication with the first port, and the second opening being sized and positioned to selectively allow fluid communication with the second port and the third port by sliding the spool in the bore.

14. The valve assembly according to any one of claims 1 to 13, comprising a three-way connector at the second end of the first conduit, the three-way connector being used to connect the second end of the first conduit to the second port of the first control valve and the second port of the second control valve, respectively.

15. The valve assembly according to claim 14, wherein: The three-way connector includes a three-way valve, a T-shaped connector or a Y-shaped connector.

16. A respirator comprising: a sealed chamber for containing a lung therein, the sealed chamber comprising a pressure port; as well as A first fluid system for applying a variable first pressure to the outer surface of the lung in the sealed chamber through the pressure port to enable the lung to breathe, the first fluid system comprising: a first pump, the first pump comprising an inlet port and an outlet port, The valve assembly according to any one of claims 1 to 15, connected to the inlet port and the outlet port of the first pump, wherein the first end of the first conduit of the valve assembly is sealingly coupled to the pressure port of the sealing chamber.

17. The ventilator of claim 16 further comprising a second fluid system for applying and maintaining a second pressure in the airway of the lung, wherein: The second fluid system includes a second conduit having a first end and a second end, the second end of the second conduit being connectable to a trachea of ​​the lung through the sealing chamber.

18. The respirator of claim 17, wherein: The second fluid system further includes a second pump for supplying pressurized fluid to the second conduit and maintaining a second pressure in the second conduit.

19. A ventilator according to claim 17 or claim 18, further comprising a control system constructed and connected to control the first fluid system and the second fluid system to ventilate the lung.

20. The respirator of claim 19, wherein: The control system includes sensors for sensing pressure and fluid flow rate in the first and second conduits, and a processor for processing the sensed pressure and fluid flow rate and determining a pumping speed of each pump and a ratio of fluid flow through the second and third ports of the corresponding control valves.

21. The respirator of any one of claims 17 to 20, further comprising a third conduit connecting a third port of a second control valve of the first fluid system to a second conduit of the second fluid system, and a third control valve in the third conduit for regulating fluid flow through the third conduit from the first control valve to the second conduit.

22. The respirator of claim 18, wherein: Each of the first pump and the second pump includes a blower.

23. The respirator of any one of claims 16 to 22, comprising a fluid filter located in each of the first and second conduits.

24. The respirator of any one of claims 16 to 23, comprising a fluid filter coupled to a third port of at least one of the first control valve and the second control valve.

25. A respirator according to any one of claims 16 to 24, comprising a fluid filter coupled to an input port of the second pump.

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