WO2021224894A1

WO2021224894A1 - Ventilator and method of ventilation

Info

Publication number: WO2021224894A1
Application number: PCT/IB2021/053952
Authority: WO
Inventors: Erich KERSTEN
Original assignee: Kersten Erich
Priority date: 2020-05-08
Filing date: 2021-05-10
Publication date: 2021-11-11
Also published as: ZA202212693B

Abstract

This invention relates to a ventilator (1) and method of ventilation. The ventilator (1) has a flow path defined between a fluid source and a delivery device, a fluid control valve (11) regulating pressure in the flow path, and control means controlling the fluid control valve (11) between an open position and a closed position.

Description

VENTILATOR AND METHOD OF VENTILATION

FIELD OF INVENTION

This invention relates to a ventilator and method of ventilation.

BACKGROUND TO THE INVENTION

Mechanical ventilation is termed "invasive" if it involves any instrument inside the trachea through the mouth, such as an endotracheal tube or the skin, such as a tracheostomy tube. Face or nasal masks are used for non-invasive ventilation in appropriately selected conscious patients.

Ventilators are well known and widely used. Some examples of ventilators include the following:

US patent number 5,452,714 entitled “Human lung ventilator system” in the name of Infrasonics, Inc., discloses a patient ventilator system which provides a controllable flow and volume of a mixed inhalation gas to a patient, and receives exhaled gas from the patient. The ventilator system includes gas flow controllers that mix air and oxygen and provide the mixture to the patient with a controllable inhalation cycle. The ventilator system monitors the resulting patient pressures and volume of gas exhaled by the patient, as necessary. Compressed air is provided to the gas controller in the event of an absence of an external gas supply by a compressor. A controller permits the user of the ventilator system to control ventilation mode, gas pressure, composition, and flow rate of the mixed gas with a single control knob. US patent application number US20130239968A1 entitled “Lung ventilator and/or anesthesia machine” in the name of IMT Information Management Technology AG, discloses a lung ventilator (14) and/or anesthesia machine with a blender for mixing a pressurized medical gas, e.g. oxygen, with air drawn in by a blower (1), comprising a gas line (10) for the medical gas, and an air line (11), which open into a common breathing gas line (12), whereby the opening of the gas line (10) into the common gas line (12) is downstream of the blower (1) and in the gas line (10) a regulating valve (8) is provided for variable adjustment of the gas flow and in the common breathing gas line (12) a regulating valve (4) is provided for dosing the breathing gas, and whereby in the breathing gas line (12) a flow sensor (3) is provided for measuring the breathing gas flow and in the gas line (10) a flow sensor (9) is provided for measuring the gas flow.

US patent application number US8230857B2 entitled “Expiratory pressure regulation in a ventilator” in the name of RIC Investments, LLC., discloses a ventilator that delivers a flow of gas to an airway of a user, and to communicate a flow of gas from the airway of the user in a controlled manner. The ventilator includes a conduit (1, 3) that carries a flow of gas from the airway of a patient, a first valve (7) coupled to the conduit and adapted to control a pressure or rate of the flow of gas exhausted from the conduit, a first sensor (10) coupled to the conduit and adapted to monitor a pressure of the gas in the conduit, and a controller (12) adapted to control the first valve based on an output of the first sensor. A restrictor (8) is provided in the conduit between the pressure sensor and the patient such that a first volume is defined in the conduit between the first valve and the restrictor and a second volume is defined in the conduit between the patient and the restrictor. The controller controls actuation of the first valve based on a pressure of the first volume monitored by the first sensor. International patent application publication number W02000032261A9 entitled “Variable flow and pressure ventilation system” in the name of Bunnell, Incorporated, discloses a ventilation system which supplies a gas mixture that is humidified and heated through a proportional valve (22) which is a fail closed and normally closed servo control valve positioned proximate a patient. The proportional valve (22) is operated by a controller that regulates the pressure and the mode (e.g., high frequency, normal respiration, combinations) gas is delivered to the patient through a nozzle (30) connected to the endotracheal tube (42). The nozzle (30) has an exhaust connected to it and a pressure sensor (44) through a pressure sensing port. The exhaust is a capped corrugated tube that is heated and perforated to allow air to escape, to muffle gas and respiration noises, and to trap moisture.

OBJECT OF THE INVENTION

It is an object of this invention to provide a ventilator of the type described above. SUMMARY OF THE INVENTION

In accordance with this invention there is provided a ventilator comprising a flow path defined between a fluid source and a delivery device, a fluid control valve regulating pressure in the flow path, and control means controlling the valve between an open position and a closed position. The fluid source is a fluid pressure source.

There is provided for the fluid pressure source to be a blower motor. There is provided for the delivery device to define a delivery end having a delivery opening of the flow path leading thereto. The blower motor has an inlet to receive ambient air and/or gas supply such as oxygen supply.

There is provided for the valve to be a body with a passage therethrough, and a rotatable closure means located in part of the passage, the rotatable closure means having a cut out in a part thereof to close or open the passage by rotation of the rotatable closure means.

There is provided for the body to be a block of material.

There is provided for the rotatable closure means to be a rod. There is provided for the rotatable closure means to rotate between a first position in which fluid may flowthrough the passage and a second position in which flowthrough the passage is limited.

There is provided for the control means to be a motor. There is further provided for the motor to be a servo motor. In accordance with this invention there is provided a ventilator comprising a first and a second regulators in flow communication with a fluid source, a first delivery flow path from the first regulator to a delivery device and a second delivery flow path from the second regulator to the delivery device.

The fluid source is a fluid pressure source.

There is provided for the fluid pressure source to be a blower motor. There is provided for the delivery device to define a delivery end having a delivery opening of the flow path or paths leading thereto.

The blower motor has an inlet to receive ambient air and/or gas supply such as oxygen supply. There is further provided for the first and second regulators to be adjustable to restrict flow therethrough as required.

Preferably, the first and second regulators are adjustable to a desired setting for the duration of operation of the ventilator. A further feature of the invention provides for a shut-off valve to be included in the second delivery flow path, between the second regulator and the delivery device.

A still further feature of the invention provides for the shut-off valve to be a butterfly valve.

There is yet further provided for a pressure sensor to be in the flow path, preferably in the delivery device.

A control means controls the blower motor and butterfly valve and is connected to the pressure sensor.

The control means may also control the first and second regulators.

This invention extends to a method of patient ventilation comprising the steps of: - connecting a fluid pressure source in flow communication with inlets of a first and second regulators; connecting outlets of the regulators to an inlet of a delivery device; ensuring that the regulators are set at different flow control settings and remain at these settings for the duration of the operation of the ventilation; and - providing a switch to selectively allow or prevent flow through the second regulator. A further step includes sensing pressure between the outlets of the regulators and the delivery device all in the delivery device and adjusting the pressure source in response thereto as required.

These and other features of the invention are described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described below by way of example only and with reference to the drawings in which: Figure 1 shows a schematic diagram of a first embodiment of the ventilator;

Figure 2 shows a graph of pressure over time during the use of the ventilator of figure 1 ; Figure 3 shows a front right perspective view of a valve;

Figure 4 shows a right sectional view of the valve with a rotating means in a closed position; Figure 5 shows a right sectional view of the valve with a rotating means in an open position; and Figure 6 shows a schematic diagram of a second embodiment of the ventilator; DETAILED DESCRIPTION OF THE DRAWINGS

With reference to figure 1 , a ventilator is generally indicated by reference numeral 1.

A first embodiment of the ventilator is shown in figures 1 to 5. The ventilator 1 has a flow path defined between a fluid pressure source 2 and a delivery device 7. The fluid pressure source 2 is a blower motor. The delivery device 7 is a mask with a circumferential seal that fits on a patient’s face as is known in the art.

A fluid control valve 11 , regulating pressure in the flow path, is located in the flow path between the blower motor 2 and the mash 7. A motor, in this case a servo motor, switches the valve 11 between an open position and a closed position.

A pressure sensor 12 is in the flow path, in this embodiment, inside the mask 7. The flow direction of fluid (air or an air and gas, such as oxygen, mixture) is indicated by the arrows 6. The blower motor 2 has an ambient air inlet with auxiliary inlet connections such as for the connection of an optional oxygen source for. The facemask 7 has an atmospheric or ambient mask outlet nozzle 8 as is known in the art. Filters and/or other devices may be connected to this outlet nozzle 8, as is known in the art. The connection of such other devices to the outlet 8 may cause a certain amount of back pressure. This can be compensated for as explained below. A flow path defined by the piping 5 thus extends from an ambient air inlet 3 to an inlet of the blower motor 2. Optional gas sources such as an oxygen source 4 may feed into the section of the flow path. The blower motor thus receives ambient air and/or additional gas from additional gas sources and then forces the air and/or air and gas mixture through its outlet into a further section of the flow path. For ease of reference, further referencing the specification to “air” may include ambient air or an air and gas mixture such as an air and oxygen mixture. A delivery flow path part of the flow path extends from the outlet of the valve to an inlet of the mask 7. The mask 7 defines the delivery end of the flow path with a seal of the mask defining a delivery opening.

The mask has an outlet in the form of the nozzle outlet 8. Control means including a microprocessor or other programmable logic controller (PLC) controls the operation of the and the motor 2. The controller may also control the operation of the first and second regulators and the optional oxygen source or other gas sources. The control means also receives an input from the pressure sensor 12. The valve 11 has a body 19. A passage 23 extend operatively horisontally through the body. A hole extends vertically centrally through the body 19, including part of the passage 23. A rod 20, in this case a dowel stick, locates in the hole. The hole has a cut out extending through part of the dowel stick. The cut out aligns with the passage 23

In use, when a patient is ventilated, using the first embodiment of the ventilator, the mask is placed over a patient’s face to cover its nose and mouth. The mask includes a seal around its circumference, as is known in the art, to provide an almost airtight seal on the patient’s face. The valve is closed off. In the closed position the rod of the valve is rotated so that the cut out of the rod face towards an end of the passage. The motor is started to allow airflow from the inlet. Limited fluid flows past the rod. After a certain predetermined time interval, when the patient breathes in and the pressure will drop as indicated by numeral 13. As soon as the pressure drops the valve 11 may be opened completely to allow an increase of airflow to the mask 7. To open the valve, the rod of the valve rotates to a second position in which the cut out is perpendicular with an opening of the passage. As soon as the flow control valve is closed, the pressure recorded by the pressure sensor rises as indicated by numeral 14 and once the pressure reaches a 15 cm H₂0 point, the patient continues breathing at this point as indicated by the broken lines 16. The flow control valve acts as an on-off switch and, again, a cost-effective valve can thus be employed. The speed of the motor is controlled by the control means to account for variations such as for different patients, masks that do not seal properly and the like. In other words, only the motor needs to be controlled and adjusted during operation and the regulators can remain at their preset settings. A second embodiment of the invention is shown in figures 2 and 6.

A first and a second regulators (9 and 10) are in flow communication with a fluid pressure source, a blower motor 2, through flow paths defined by piping 5. A pipe from outlet of the blower motor splits to the inlet of each regulators (9 and 10). A first delivery flow path extends from an outlet of the first regulator to a delivery device. The delivery device is a mask 7 with a circumferential seal that fits on a patient’s face as is known in the art. A second delivery flow path extends from an outlet of the second regulator to the mask. In this embodiment, the second delivery flow path joins the first delivery flow path at a T-section to form a combined flow path to the mask 7.

A pressure sensor 12 is in the flow path, in this embodiment, inside the mask 7.

The flow direction of fluid (air or an air and gas, such as oxygen, mixture) is indicated by the arrows 6.

The blower motor 2 has an ambient air inlet with auxiliary inlet connections such as for the connection of an optional oxygen source for. A throttle valve in the form of a butterfly valve 11 is included in the second delivery flow path between the second regulator 10 anti-flow path leading to the facemask 7.

The facemask 7 has an atmospheric or ambient mask outlet nozzle 8 as is known in the art. Filters and/or other devices may be connected to this outlet nozzle 8, as is known in the art. The connection of such other devices to the outlet 8 may cause a certain amount of back pressure. This can be compensated as explained below.

A flow path defined by the piping 5 thus extends from an ambient air inlet 3 to an inlet of the blower motor 2. Optional gas sources such as an oxygen source 4 may feed into the section of the flow path. The blower motor thus receives ambient air and/or additional gas from additional gas sources and then forces the air and/or air and gas mixture through its outlet into a further section of the flow path. This second section of the flow path splits into a first and second regulator flow paths to feed the pressurised air and/or gas mixture to the inlets of the first and second regulators. For ease of reference, further referencing the specification to “air” may include ambient air or an air and gas mixture such as an air and oxygen mixture. A first delivery flow path part of the flow path extends from the outlet of the first regulator to an inlet of the mask 7. A second delivery flow path part of the flow path extends from the outlet of the second regulator to a T-connector in the first delivery flow path part or section. In this manner, the second delivery flow path joins the first delivery flow path. The butterfly valve is connected in the second delivery flow path between the second regulator and the first delivery flow path, thus effectively between the second regulator and the mask 7. The mask 7 defines the delivery end of the flow path with the seal of the mask defining a delivery opening. The mask has an outlet in the form of the nozzle outlet 8. Control means including a microprocessor or other programmable logic controller (PLC) controls the operation of the butterfly valve 11 and the motor 2. The controller may also control the operation of the first and second regulators and the optional oxygen source or other gas sources. The control means also receives an input from the pressure sensor 12.

In use, when a patient is ventilated, the mask is placed over a patient’s face to cover its nose and mouth. The mask includes a seal around its circumference, as is known in the art, to provide an almost airtight seal on the patient’s face. The butterfly valve is closed off and the motor is started to allow airflow from the inlet end through the first regulator to the mask. The first regulator is set to restrict flow such that the pressure sensor returns a reading of 5 cm H20 shown in the graph of figure 2. At this pressure, the patients breathing may be represented by the broken lines 15. After a certain predetermined time interval, when the patient breathes in the pressure will drop as indicated by numeral 13. As soon as the pressure drops the butterfly valve 11 may be opened completely to allow airflow through both regulators to the mask 7. The second regulator has been preset so that in combination with the first regulator and the motor speed, depression recorded by the pressure sensing the mask is around 15 cm H20. This point is also indicated in figure 2. As soon as the butterfly valve is closed, the pressure recorded by the pressure sensor rises as indicated by numeral 14 and once the pressure reaches the 15 cm H20 point, the patient continues breathing at this point as indicated by the broken lines 16. After a further time interval as may be desired or prescribed when the patient breathes out thus increasing the pressure as indicated by numeral 17 the butterfly valve can be closed off completely so that the pressure drops back to the 5 cm H20 mark with air flowing only through the first regulator. During the process described above the first and second regulators remained at their settings and were not adjusted. In other words, mechanical valves such as gate valves can be used and adjusted and set as required. This feature enables the ventilator of the invention to be made of cost-effective regulator valves instead of more expensive active regulators which may include feedback control and the like. In addition, the throttle all butterfly valve acts as an on-off switch and, again, a cost-effective valve can thus be employed. The speed of the motor is controlled by the control means to account for variations such as for different patients, masks that do not seal properly and the like. In other words, only the motor needs to be controlled and adjusted during operation and the regulators can remain at their preset settings.

It is envisaged that the ventilator described herein will provide a cost-effective alternative to existing ventilators. The ventilator described herein uses lower cost regulators as well as the inexpensive switch in the form of a flow control valve. The system as described also lends itself to the use of a more generic and possibly less expensive motor.

The invention is not limited to the precise details as described herein. The above description is but one embodiment of the invention and various other embodiments are possible without departing from the scope of the invention. For example, amongst others, an endotracheal or tracheostomy tube may be used instead of the mask. A throttle valve in the form of a butterfly valve may be included in the second delivery flow path between the second regulator anti-flow path leading to the facemask. Furthermore, the butterfly valve may be located in the flow path in front of the second regulator as this will have the identical effect.

Claims

1. A ventilator comprising a flow path defined between a fluid source and a delivery device, a fluid control valve regulating pressure in the flow path, and control means controlling the valve between an open position and a closed position.

2. A ventilator as claimed in claim 1 in which the fluid source is a fluid pressure source.

3. A ventilator as claimed in any one of claims 1 or 2 in which the fluid pressure source is a blower motor.

4. A ventilator as claimed in claim 1 in which the delivery device defines a delivery end having a delivery opening of the flow path leading thereto.

5. A ventilator as claimed in claim 3 in which the blower motor has an inlet to receive ambient air.

6. A ventilator as claimed in any one of claims claim 3 or 5 in which the blower motor has an inlet to receive gas supply such as oxygen supply.

7. A ventilator as claimed in claim 1 in which the valve has a body with a passage therethrough, and a rotatable closure means located in part of the passage, the rotatable closure means having a cut out in a part thereof to close or open the passage by rotation of the rotatable closure means.

8. A ventilator as claimed in claim 7 in which the body is a block of material.

9. A ventilator as claimed in claim 7 in which the rotatable closure means is a rod.

10. A ventilator as claimed in any one of claims 7 or 9 in which the rotatable closure means rotates between a first position in which fluid flow through the passage and a second position in which flow through the passage is limited.

11. A ventilator as claimed in claim 1 in which the control means is a motor.

12. A ventilator as claimed in claim 11 in which the motor is a servo motor.

13. A ventilator comprising a first and a second regulators in flow communication with a fluid source, a first delivery flow path from the first regulator to a delivery device and a second delivery flow path from the second regulator to the delivery device.

14. A ventilator as claimed in claim 13 in which the fluid source is a fluid pressure source.

15. A ventilator as claimed in claim 14 in which the fluid pressure source is a blower motor.

16. A ventilator as claimed in any one of claims 13 to 15 in which the delivery device defines a delivery end having a delivery opening of the flow path or paths leading thereto.

17. A ventilator as claimed in any one of claims 16 or 17 in which the blower motor has an inlet to receive ambient air supply such as oxygen supply.

18. A ventilator as claimed in any one of claims 16 to 17 in which the blower motor has an inlet to receive gas supply such as oxygen supply.

19. A ventilator as claimed in any one of claims 13 to 18 in which the first regulator is adjustable to restrict flow therethrough as required.

20. A ventilator as claimed in any one of claims 13 to 19 in which the second regulator is adjustable to restrict flow therethrough as required.

21. A ventilator as claimed in any one claims 13 to 20 in which the first regulator is adjustable to a desired setting for the duration of operation of the ventilator.

22. A ventilator as claimed in any one of claims 13 to 21 in which the second regulator is adjustable to a desired setting for the duration of operation of the ventilator.

23. A ventilator as claimed in claim 13 in which a flow control valve is included in the flow path.

24. A ventilator as claimed in any one of claims 13 or 23 in which the flow control valve regulates flow in the first flow path and in the second flow path.

25. A ventilator as claimed in any one of claims 13 or 14 in which the flow control valve is a servo motor.

26. A ventilator as claimed in claim 1 in which a shut-off valve is included in the second delivery flow path.

27. A ventilator as claimed in claim 26 in which the shut-off valve is included in the second delivery flow path, between the second regulator and the delivery device.

28. A ventilator as claimed in any one of claims 26 or 27 in which the shut-off valve is a butterfly valve.

29. A ventilator as claimed in any one of claims 13, 16, 26 or 28 in which a pressure sensor is in the flow path.

30. A ventilator as claimed in claim 29 in which the pressure sensor is in the delivery device.

31. A ventilator as claimed in any one claims 15, 17 or 18 in which a control means controls the blower motor.

32. A ventilator as claimed in any one of claims 28 or 31 in which the control means controls the butterfly valve.

33. A ventilator as claimed in any one of claims 29, 31 or 32 in which the control means is connected to the pressure sensor.

34. A ventilator as claimed in any one of claims 31 to 33 in which the control means control the first and second regulators.

35. A method of patient ventilation comprising the steps of: connecting a fluid pressure source in flow communication with inlets of a first and second regulators; connecting outlets of the regulators to an inlet of a delivery device; ensuring that the regulators are set at different flow control settings and remain at these settings for the duration of the operation of the ventilation; and providing a switch to selectively allow or prevent flow through the second regulator.

36. A method of patient ventilation as claimed in claim 35 in which a further step includes sensing pressure between the outlets of the regulators and the delivery device all in the delivery device.

37. A method of patient ventilation as claimed in claim 36 in which a further step includes adjusting the pressure source in response to pressure sensed between the outlets of the regulators and the delivery device all in the delivery device as required.