WO2021191580A1 - Système d'écoulement d'air - Google Patents

Système d'écoulement d'air Download PDF

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Publication number
WO2021191580A1
WO2021191580A1 PCT/GB2021/050327 GB2021050327W WO2021191580A1 WO 2021191580 A1 WO2021191580 A1 WO 2021191580A1 GB 2021050327 W GB2021050327 W GB 2021050327W WO 2021191580 A1 WO2021191580 A1 WO 2021191580A1
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WO
WIPO (PCT)
Prior art keywords
piston
cylinder
downstroke
drive
air
Prior art date
Application number
PCT/GB2021/050327
Other languages
English (en)
Inventor
Oliver John BECKETT
Original Assignee
Johnson Matthey Public Limited Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Johnson Matthey Public Limited Company filed Critical Johnson Matthey Public Limited Company
Publication of WO2021191580A1 publication Critical patent/WO2021191580A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/0057—Pumps therefor
    • A61M16/0072—Tidal volume piston pumps
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/20—Valves specially adapted to medical respiratory devices
    • A61M16/201—Controlled valves
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/20—Valves specially adapted to medical respiratory devices
    • A61M16/208—Non-controlled one-way valves, e.g. exhalation, check, pop-off non-rebreathing valves
    • A61M16/209—Relief valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B31/00—Free-piston pumps specially adapted for elastic fluids; Systems incorporating such pumps
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/021—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes operated by electrical means
    • A61M16/022—Control means therefor
    • A61M16/024—Control means therefor including calculation means, e.g. using a processor
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
    • A61M2016/0027—Accessories therefor, e.g. sensors, vibrators, negative pressure pressure meter
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2205/00—General characteristics of the apparatus
    • A61M2205/07—General characteristics of the apparatus having air pumping means

Definitions

  • the present specification relates to an air flow system and particularly to a ventilator system to aid human respiration in the event of respiratory illness. This may be as a result of acute respiratory distress syndrome (ARDS) or in the event of any other medical condition where a patient is struggling to breath unaided.
  • ARDS acute respiratory distress syndrome
  • the present specification is particularly directed to a simplified, optionally portable, ventilator system to aid human respiration in the situation where more complex ventilator systems are not available and where continuous respiratory ventilation may be required over a prolonged time period such that manually operated respirator systems are not suitable.
  • Respirator systems are a well-known for use in aiding human respiration in the event of a medical condition which results in a patient struggling to breath unaided.
  • Respirator systems are usually located within a hospital environment and comprise a dedicated power supply configured to power an electro-mechanical device for providing a regular, periodic air flow to a patient's lungs to mimic the air flow into a person's lungs under normal breathing conditions.
  • Portable respiratory systems are also known in the art for use in the field. These can be manually operated devices. For example, they may comprise a mouth-piece for placing over a patient's mouth and a compressible bulb made of a resilient material which can be squeezed by a paramedic to compress the bulb and force air into the patient's lungs and then released to enable air to flow out of the patient's lungs. Since such simple respirator systems require continual manual operation, they are only intended for temporary use until the patient can be transferred to a powered respirator system.
  • Battery powered portable respirator systems are also known in the art. Flowever, these are relatively complex systems with a dedicated electrical power supply system.
  • complex ventilator systems may not be available. This may be the case, for example, in remote environments, poor countries, or in the event of extreme medical emergencies when the number of patients exceeds the number of available respirators, e.g. in an epidemic or global pandemic which causes respiratory problems in a large number of people.
  • the present specification provides a ventilator system to aid human or animal respiration comprising: a cylinder orientated in a substantially vertical direction with a top end and a bottom end; a piston disposed within the cylinder and slidable up and down the cylinder to provide an upstroke and a downstroke respectively; a drive coupling configured to be connected to a drive mechanism to drive the upstroke of the piston by drawing the piston up the cylinder; a control system configured to release the piston at the top of the upstroke enabling the piston to move down the cylinder under its own weight for the downstroke such that during the downstroke of the piston air is forced out of the cylinder below the piston through an outlet coupling and into the patient's lungs, the control system being configured to re-engage the drive mechanism at the bottom of the downstroke to drive the upstroke of the piston and draw air into the cylinder below the piston from outside the cylinder, wherein the piston has a size and weight sufficient to drive the downstroke delivering air to the patient on the downstroke.
  • Such a ventilator system is based on a vertically orientated, weighted free piston concept in which the weight of the piston drives the air flow to a patient on a downstroke of the piston and a drive mechanism lifts the weighted piston on an upstroke.
  • a control system in the form of a valve, switching, latching or coupling system is provided in order to couple and de-couple the drive mechanism and the piston in a periodic manner to switch between upstroke and downstroke at a rate which mimics the breathing rate of a patient.
  • Such a weighted free piston ventilator configuration can have one or more of the advantages as outlined below.
  • the ventilator system can be couple to a standard domestic vacuum cleaner as the drive mechanism with suction from the vacuum cleaner raising the piston and a valve system releasing the suction at the top of the upstroke thus enabling the piston to fall downwards under its own weight for the downstroke.
  • the valve system can be configured to move back to the suction position at the bottom of the downstroke such that the piston is then sucked back up the piston cylinder.
  • the drive mechanism can be a mechanical drive mechanism.
  • the drive mechanism may be a manually actuated drive mechanism.
  • the configuration is inherently safe for the patient.
  • the maximum pressure of air which can be delivered to a patient is limited by the weight of the piston.
  • the system is not reliant on regulating a high-pressure air flow in a direction towards the patient, which could be hazardous in the event of a failure in the air flow regulating system.
  • the pressure and volume of air delivered to the patient is not reliant on the specific power of the drive mechanism but rather is controlled only by the size and weight of the piston.
  • the ventilator system can be driven off a range of driving mechanisms with varying power ratings without any variation in the flow pressure and volume delivered to the patient.
  • the system is simple, quick, and cheap to manufacture and does not require complex parts made to precise tolerances.
  • the system can be actuated and controlled using electrical components, it is also possible to provide a purely mechanical ventilator system using the weighted free piston concept.
  • the system can be manufactured easily and quickly, e.g. using 3D printing techniques.
  • the system can be made to be robust without delicate parts which could be damaged during transport and use.
  • the system can be used in a variety of environments including outdoors and in wet conditions without problems of electrical faults.
  • the ventilator systems as described herein can be used to aid respiration of a human or animal patient in medical and veterinary applications.
  • a method of aiding human or animal respiration is thus provided, the method comprising: coupling a ventilator system as described herein to the airway of a human or animal patient; and operating the ventilator system to deliver air to the patient to aid respiration.
  • ventilator systems as described herein may be configured to be operated off a blowing device rather than a suction device.
  • a blowing device can be coupled to a vertically orientated, weighted free piston with the system re-configured such that air is blown into the cylinder below the piston to raise the piston and then de-coupled to enable the piston to drop to deliver the air to the patient.
  • the ventilator systems as described herein may be powered by a mechanical drive mechanism rather than a suction or blowing device.
  • a mechanical drive mechanism may be provided for a vertically orientated, weighted free piston system which is re-configured such that piston is mechanical lifted (rather than sucked upwards or blown upwards) and then released to enable the piston to drop to deliver air to the patient.
  • a ventilator system may be based on a biased piston concept rather than a weighted free piston concept while still retaining several of the benefits as described above.
  • a ventilator system can be provided to aid human or animal respiration comprising: a cylinder; a piston disposed within the cylinder and slidable along the cylinder to provide an outstroke and an instroke respectively; a drive coupling configured to be connected to a drive mechanism to drive the outstroke of the piston by drawing the piston along the cylinder; a biasing means, such as a spring or equivalent, to bias the piston to drive the instroke; and a control system configured to release the piston at the end of the outstroke enabling the piston to move along the cylinder under biasing force from the biasing means for the instroke such that during the instroke of the piston air is forced out of the cylinder through an outlet coupling and into the patient's lungs, the control system being configured to re-engage the drive mechanism at the end of the instroke to drive the outstroke of the piston and draw air into the
  • the biasing means drives air delivery rather than the weight of the piston.
  • the configuration still has the advantage that the pressure and volume of air delivered to the patient is controlled by the configuration of the system and not the power of the drive mechanism.
  • operational parameters such as pressure, volume and cadence can be safely selected and controlled by selection of a suitable biasing means and selection of a piston configuration having a piston size, weight, and stroke length to achieve the desired air delivery.
  • Figure 1 shows a schematic cross-sectional view of the core components of a ventilator system according to one embodiment described herein;
  • Figure 2 shows another schematic cross-sectional view of the ventilator system, orientated at a 90° angle relative to the cross-sectional view shown in Figure 1.
  • valve system configuration is just one example of a configuration implementing the inventive concepts as described herein and it is possible to implement the invention in a variety of different ways.
  • valve system configuration is illustrated, the required functionality of the valve system can be achieved using a variety of mechanical or electromechanical configurations based on conventional engineering components.
  • the present specification provides a ventilator system based on a vertically orientated, weighted free piston concept in which the weight of the piston drives the air flow to a patient on a downstroke of the piston and a drive mechanism lifts the weighted piston on an upstroke.
  • Such a ventilator system comprises: a cylinder orientated in a substantially vertical direction with a top end and a bottom end; a piston disposed within the cylinder and slidable up and down the cylinder to provide an upstroke and a downstroke respectively; a drive coupling configured to be connected to a drive mechanism to drive the upstroke of the piston by drawing the piston up the cylinder; a control system configured to release the piston at the top of the upstroke enabling the piston to move down the cylinder under its own weight for the downstroke such that during the downstroke of the piston air is forced out of the cylinder below the piston through an outlet coupling and into the patient's lungs, the control system being configured to re-engage the drive mechanism at the bottom of the downstroke to drive the upstroke of the piston and draw air into the cylinder below the piston from outside the cylinder, wherein the piston has a size and weight sufficient to drive the downstroke delivering air to the patient on the downstroke.
  • the cylinder and piston arrangement is not necessarily required to be orientated in a precisely vertical fashion.
  • the cylinder may be oriented within an angle of +/- 45°, 35°, 25°, 15°, 10°, or 5° to vertical. It is sufficient that the orientation is such as to allow the piston to fall under its own weight in this example.
  • tilting the cylinder and piston orientation can be used as a means of moderating the output pressure of the system.
  • the system may comprise a tilting mechanism for controllably tilting the orientation of the piston and cylinder configuration.
  • the drive mechanism can be an integral part of the ventilator system.
  • the drive mechanism may be housed within the ventilator system in a common housing with the cylinder and piston components.
  • the drive mechanism can be a separate device which is detachably couplable to the drive coupling of the ventilator system, e.g. a domestic vacuum cleaner, industrial suction pump, hair dryer, or other air flow or mechanical driving device.
  • the drive mechanism is a suction device (e.g. a vacuum cleaner) and the drive coupling is configured to be connected to the suction device to drive the upstroke of the piston by sucking air out of the cylinder above the piston thus drawing the piston up the cylinder.
  • the control system may comprise a valve system which is configured to couple suction from the suction device to the piston to drive the upstroke of the piston and decouple suction from the piston enabling the piston to move down the cylinder under its own weight for the downstroke.
  • the piston has a size and weight such that the suction from the suction device is sufficient to drive the upstroke and the weight of the piston is sufficient to drive the downstroke delivering air to the patient on the downstroke.
  • the suction device may be configured to provide a continuous suction to the drive coupling and the valve system is configured to couple the continuous suction from the suction device to the piston to drive the upstroke of the piston and then release the piston from the continuous suction of the suction device such that the piston is free to move down the cylinder under its own weight for the downstroke.
  • the suction device may be configured to turn on and off the suction to the drive coupling.
  • the control system can be a mechanically actuated control system or may comprise an electrical switching system.
  • the control system can be configured to be actuated by the piston at the bottom of the downstroke to engage the drive mechanism and configured to be actuated by the piston at the top of the upstroke to disengage the drive mechanism.
  • the ventilator system can be configured such that the cylinder comprises two one-way ports located below the piston including a first one-way port which enables air to flow out of the cylinder during the downstroke to the patient and a second one-way port which enables air to flow into the cylinder below the piston during the upstroke.
  • the cylinder may comprise a port located above the piston which enables air to flow into the cylinder above the piston during the downstroke thus allowing the piston to move down the cylinder under its own weight during the downstroke without generating a negative pressure above the piston which would otherwise impede the downward motion of the piston.
  • the control system is configured to close the upper port during the upstroke thus sealing the upper chamber of the cylinder above the piston to enable the suction device to suck the piston up the cylinder.
  • the control device is then configured to open the upper port during the downstroke.
  • the cylinder thus comprises at least two upper ports: one connected to the suction device; and another connecting to outside the cylinder allowing air to flow in to reduce or eliminate the pressure differential on the piston and allowing the piston to drop down the cylinder.
  • the system components are configured to achieve operational parameters suitable for aiding respiration of a human or animal patient.
  • the size and weight of the piston is selected to generate an outlet air pressure in a range 50 to 1000 mm of water.
  • the outlet air pressure may be: at least 50, 100, 200, or 250 mm of water; no more than 1000, 800, 600, or 400 mm of water; or within a range defined by any combination of the aforementioned lower and upper limits.
  • the size of the cylinder and the stroke length of the piston can be selected to deliver a volume of air to the patient on the downstroke in a range 50 ml to 1.5 litres.
  • the volume of air delivered to the patient may be: at least 50, 100, 200, 300, 400, or 500 ml; no more than 1500, 1000, 800, or 700 ml; or within a range defined by any combination of the aforementioned lower and upper limits.
  • the size of the cylinder and the stroke length of the piston can selected to deliver a volume of air to the patient on the downstroke in a range 1 to 15 ml per Kg body weight of the patient.
  • the volume of air delivered to the patient may be: at least 1, 2, 3, 4, or 5 ml per Kg body weight of the patient; no more than 15, 10, 8, or 7 ml per Kg body weight of the patient; or within a range defined by any combination of the aforementioned lower and upper limits.
  • the ventilator system can be configured to have a cadence in a range 5 to 40 breaths per minute.
  • the ventilator system can have a cadence of: at least 5, 8, 10 or 12 breaths per minute; no more than 40, 30, 25, or 20 breaths per minute; or within a range defined by any combination of the aforementioned lower and upper limits.
  • a single drive mechanism can be provided for each ventilator or alternatively more than one ventilator can be coupled to a single drive mechanism.
  • FIG. 1 and 2 show cross-sectional views of an example of such a ventilator system.
  • parts are labelled according to the following key:
  • a weighted free piston 4 is placed in an air filled, vertically orientated, open ended cylinder 3.
  • the piston 4 is sealed against the cylinder walls 3 with relatively low friction seals 5. If the pressure above the piston is lowered such that the pressure differential causes a net force on the piston exceeding its weight, the piston will rise against gravity. If the pressures above and below the piston are allowed to equalize, the piston will fall under its own weight, driving air out through the bottom of the cylinder. If air flow out of the bottom of the cylinder is restricted, the air below the piston will reach a maximum gauge pressure of Piston weight / Piston Cross Sectional Area.
  • a vacuum valve housing 1 including a vacuum valve 2.
  • the vacuum valve housing 1 includes an atmospheric air port 17 for releasing pressure for the downstroke and a vacuum port 18 (Low pressure air, not actually vacuum) for connection to the suction device.
  • valve retaining plate 10 Also provided at the top of the cylinder are valve retaining plate 10, a magnet 11, and a magnet anchor 12. These components function to hold the vacuum valve 2 in position during the downstroke of the piston with the atmospheric air port 17 open.
  • a valve actuator 6 which is actuated by the piston at the bottom of its downstoke.
  • a valve actuator tie rod 8 pulls down on the vacuum valve 2 switching to close the atmospheric air port 17 and engage suction through the vacuum port 18 to raise the piston.
  • Part 7 is the breathing air valve housing with sealing rings 9 disposed around various parts of the apparatus for sealing (these are optional depending on the precision and fit of the components.
  • breathing air output port 13 to patient on downstroke
  • breathing air inlet port 16 for drawing air in on the upstroke
  • one-way valve plate 14 and one-way valve seal 15 for ensuring that ports 13 and 16 function in one direction only as required.
  • the World Health Organization recommend a pressure of 300 mm of H O equivalent to support patients with Acute Respiratory Distress Syndrome.
  • Continuous positive airway pressure (CPAP) machines typically operate at around 100 mm H O equivalent pressure.
  • the air pressure may be moderated by adjusting the weight of the piston or using a pressure modulator to suit the patient and the condition being treated.
  • Ventilators are typically set to a "tidal volume" of 5-7ml per kg of ideal body weight, although this may be altered to suit the patient and the condition.
  • a simple adjustable stopper system can be located within the cylinder to limit the stroke length of the piston and thus adjust the tidal volume of air.
  • the bottom of the cylinder may be capped off and a pair of opposing one-way valves sealed into openings in the cap. If the pressure above the piston is alternated between "low” and atmospheric pressure, the piston will repeatedly rise and fall. As the piston rises, it will draw air into the bottom of the cylinder from outside through one of the one-way valves. As the piston it falls it will push air out through the other of the one-way valves towards the patient. The volume of air drawn in and pushed out of the cylinder will be proportional to the travel distance of the piston.
  • the air above the piston may also be controlled to be above or below atmospheric pressure to moderate output pressure.
  • a breathing circuit may be connected to the air out port to allow a patient to be ventilated by such a device.
  • Additional gases may be fed into the intake port, or directly into the breathing loop to modify the gas mixture received by the patient.
  • air should not be interpreted to be limited to only the standard gas composition of air, but rather should be understood to include modified gas compositions.
  • additional oxygen may be incorporated into the gas mixture to aid the patient.
  • Other gases may alternatively or additionally be introduced such as nitrous oxide to alleviate pain.
  • An additional valve may be configured to control the pressure at the top of the cylinder, switching between a supply of low-pressure air and one of atmospheric pressure. If this valve is switched to low pressure when the piston is at, or near to, the bottom of its stroke and to atmospheric at the top, the piston will cycle between the top and bottom of the cylinder. Valve actuation may be performed mechanically or electromechanically by means of sensors and actuators, solenoids motors, etc. Alternatively, this effect may also be achieved by switching on and off a vacuum pump or other supply accordingly.
  • the ventilator may be configured to support a breathing patient, by releasing the piston when a drop in pressure due to the patient inhaling is detected at the intake port or in the breathing circuit.
  • the cadence or cycle time for the ventilator system is controlled by a number of factors.
  • the acceleration, maximum velocity, and therefore upstroke time are determined by low pressure supply pressure, low pressure flow rate, and air inlet flow rate.
  • the aforementioned variables may be readily adjusted individually or collectively to control breathing rate.
  • a typical ventilator cadence range is 12-20 breaths per minute.
  • a pulse oximeter or similar device may be used to measure the patient's blood oxygen concentration and used in a feedback loop to control cadence or additional gas supply.
  • a ventilator system as described herein may be powered as an individual stand-alone system, e.g. by a vacuum pump such as a vacuum cleaner or industrial vacuum pump.
  • a vacuum pump such as a vacuum cleaner or industrial vacuum pump.
  • several (two or more) ventilators may be powered from a single power source.
  • a manifold can be provided to link two or more ventilator systems to a single power source.
  • a vacuum pump may be coupled to more than one ventilator.
  • the example described herein is such that at least two systems can be powered by a single domestic vacuum cleaner.
  • a vacuum lifts a free piston, drawing air into the bottom of the cylinder.
  • the piston gets to the top, it actuates a valve which closes the vacuum port and opens an air port.
  • the piston then falls under its own weight, driving air out of the bottom of the piston through a one-way valve into a breathing loop.
  • the piston opens the vacuum valve and is lifted back up.
  • Pressure is set by piston weight, tidal volume is set by stroke length, and cadence is controlled by several factors including vacuum/suction level.
  • Sensing the piston position is not necessary but can be desirable in certain configurations.
  • a simple switching system can be provided which switched the driving mechanism (e.g. suction device) on and off at set intervals.
  • additional sensors can be provided to monitor performance.
  • a pressure sensor can be provided to measure output air pressure.
  • air flow can be moderated.
  • vacuum/suction can be moderated either by partially occluding (obstructing/closing) the suction pipework or by opening a hole in the suction pipework or upper portion of the cylinder.
  • the illustrated embodiment was constructed using a cylinder having an outer diameter of 68 mm and an inner diameter in a range 64.3 - 65.1 mm.
  • tidal volume is 33.2 cm 3 per 1 cm of stroke, and can be adjusted to suit the patient.
  • guidelines suggest 5-7 ml tidal volume per kg of ideal body weight. For example, an 80 kg man might require 560 ml tidal volume.
  • the WHO suggest treating ARDS with pressure of 300 mm of H O.
  • Pressure is set by the weight of the piston, with 300mm of H O equating to 996g assuming no friction (so the weight needs to be adjusted upwards to account for friction).
  • the piston seals don't have to be perfect, but they do have to be low friction.
  • a ventilator system based on a biased piston.
  • a ventilator system comprises: a cylinder; a piston disposed within the cylinder and slidable along the cylinder to provide an outstroke and an instroke respectively; a drive coupling configured to be connected to a drive mechanism to drive the outstroke of the piston by drawing the piston along the cylinder; a biasing means, such as a spring or equivalent, to bias the piston to drive the instroke; and a control system configured to release the piston at the end of the outstroke enabling the piston to move along the cylinder under biasing force from the biasing means for the instroke such that during the instroke of the piston air is forced out of the cylinder through an outlet coupling and into the patient's lungs, the control system being configured to re-engage the drive mechanism at the end of the instroke to drive the outstroke of the piston and draw air into the cylinder from outside the cylinder, wherein
  • the biasing means drives air delivery rather than the weight of the piston.
  • the configuration still has the advantage that the pressure and volume of air delivered to the patient is controlled by the configuration of the system and not the power of the drive mechanism.
  • operational parameters such as pressure, volume and cadence can be safely selected and controlled by selection of a suitable biasing means and selection of a piston configuration having a piston size, weight, and stroke length to achieve the desired air delivery.
  • aspects of the previously described system can also be applied to this biased piston system. It is also envisaged that elements of both systems may be combined.
  • a vertical configuration may be provided with a biasing means such that the piston drives the air flow by a combination of weight and biasing force.
  • the direction of the drive mechanism and biasing means can be reversed so that the drive mechanism drives the instroke and the biasing means drives the outstroke.
  • This has the advantage that the air parameters (pressure, volume) delivered to the patient can be controlled by controlling the drive mechanism.
  • this arrangement will be more sensitive to variations in the power of the drive mechanism and so will depend on the reliability of the drive mechanism to deliver the desired power.
  • the drive mechanism may be a manually actuated drive mechanism.
  • manual actuation can be used to drive the upstroke or outstroke with the piston weight or biasing means used to provide a controlled instroke/downstroke to controllably deliver air to a patient with the correct pressure and volume.

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  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Pulmonology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Emergency Medicine (AREA)
  • Anesthesiology (AREA)
  • Biomedical Technology (AREA)
  • Hematology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Abstract

Un système de ventilateur pour aider à la respiration humaine ou animale comprend : un cylindre orienté dans une direction sensiblement verticale avec une extrémité supérieure et une extrémité inférieure ; un piston disposé à l'intérieur du cylindre et pouvant coulisser vers le haut et vers le bas dans le cylindre pour fournir une course ascendante et une course descendante respectivement ; un accouplement d'entraînement conçu pour être relié à un mécanisme d'entraînement pour entraîner la course ascendante du piston en tirant le piston vers le haut du cylindre ; un système de commande conçu pour libérer le piston au sommet de la course ascendante permettant au piston de se déplacer vers le bas du cylindre sous son propre poids pour la course descendante de telle sorte que, pendant la course descendante du piston, l'air est poussé hors du cylindre sous le piston par l'intermédiaire d'une sortie accouplée et dans les poumons du patient, le système de commande étant conçu pour réenclencher le mécanisme d'entraînement au fond de la course descendante pour entraîner la course ascendante du piston et aspirer de l'air dans le cylindre sous le piston depuis l'extérieur du cylindre, le piston ayant une taille et un poids suffisants pour entraîner la course descendante et apportant de l'air au patient sur la course descendante.
PCT/GB2021/050327 2020-03-27 2021-02-11 Système d'écoulement d'air WO2021191580A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GBGB2004482.2A GB202004482D0 (en) 2020-03-27 2020-03-27 Air flow system
GB2004482.2 2020-03-27

Publications (1)

Publication Number Publication Date
WO2021191580A1 true WO2021191580A1 (fr) 2021-09-30

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1489563A (en) * 1973-10-02 1977-10-19 Chemetron Corp Fluid delivery apparatus
US4182599A (en) * 1973-10-02 1980-01-08 Chemetron Corporation Volume-rate respirator system and method
GB1561261A (en) * 1977-10-12 1980-02-20 Purvis D Hydraulically operated accumulator turbine system
WO1989000872A1 (fr) * 1987-07-27 1989-02-09 Gates William M Dispositif de ventilation portatif
EP1410821A2 (fr) * 2002-10-16 2004-04-21 Resmed Limited Dispositif d'alimentation en gaz respiratoire

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1489563A (en) * 1973-10-02 1977-10-19 Chemetron Corp Fluid delivery apparatus
US4182599A (en) * 1973-10-02 1980-01-08 Chemetron Corporation Volume-rate respirator system and method
GB1561261A (en) * 1977-10-12 1980-02-20 Purvis D Hydraulically operated accumulator turbine system
WO1989000872A1 (fr) * 1987-07-27 1989-02-09 Gates William M Dispositif de ventilation portatif
EP1410821A2 (fr) * 2002-10-16 2004-04-21 Resmed Limited Dispositif d'alimentation en gaz respiratoire

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GB2593586A (en) 2021-09-29
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