VENTILATION APPARATUS

Abstract: The invention relates to a portable apparatus for ventilation support to persons with respiratory distress. The apparatus is provided with a compressed air pump which may be connected to the mouth or the nose via tube means (8) for generation of pressure pulses with an individually adaptable air volume. The pump comprises a rigid container consisting of two symmetrical halves (4) and with a flexible membrane (5) which is located as a laterally reciprocating diaphragm between the two container halves. These are provided with check valves permitting ambient air to be fed into the pump and from the pump into the tube means while the membrane wall is moved, for generation of a pressure pulse. The pump is provided with flexible pull means (6) for reciprocating operation of the membrane (5) in the container. The pull means extend via pulley wheels (1) to a driving device (9) located substantially in the same plane as the container and beside it.

Description: TITLE Ventilation apparatus TECHNICAL FIELD The present invention relates to a portable apparatus for ventilation support to persons with respiratory distress, with a compressed air pump which may be connected to the mouth or the nose via tube means for generation of pressure pulses with an individually adaptable air volume, which pump comprises a rigid container consisting of two symmetrical halves and with a flexible membrane which is located as a laterally reciprocating diaphragm between the two container halves, that are provided with check valves permitting ambient air to be fed into the pump and from the pump into the tube means while the membrane wall is moved, for generation of a pressure pulse. STATE OF THE ART Prior art in the field of breathing aids, comprises portable units and non-portable units that, if required, may be moved inside a hospital or be used within an ambulance, but may not be comfortably carried when travelling, thereby fulfilling the criteria of being classed as portable. For example, apparatuses are available that provide oscillatory pulse types, IPPV, which apparatuses are heavy and expensive. Conventional breathing aids for the above described area of use, often comprise a fan which creates a static overpressure, which is aimed to open and to ventilate the respiratory system of the user. However, this method, CPAP (Continuous Positive Air Pressure) lead to other drawbacks as noise, desiccation of the respiratory system and a high consumption of energy. Also, this method only works if the brain controls the diaphragm. It is also known to use a piston or accordion pump for providing pressure pulses. However, these pump units are more bulky than fans and are normally combined with comparatively complicated electronics for synchronisation of the pump function to the user breathing rhythm. Accordingly, also these apparatuses have become energy demanding as well as expensive and unwieldy. So far, membrane pumps have particularly been used on stationary apparatuses for spray painting, because they are normally very space consuming in comparison with fans and piston or accordion pumps. Normally, the air requirement during sleep for the age of 18-80 years is about 7 litres per minute, for example the equivalent to 1 respiration of 0,6 litre every fifth second, while small children may respire about 30 times per minute with a corresponding smaller tidal volume. Accordingly, a breathing apparatus must have a relative wide capacity for adjustment, in order to cover occurring needs. This is difficult to achieve for single-action pumps. OBJECT OF THE INVENTION Therefore the object of the present invention is to provide a space-saving and simple apparatus which solves or at least reduces the above described problems . THE SOLUTION For this object, the invention is characterized in that the pump is provided with flexible pull means for reciprocating operation of the membrane in the container, said pull means extending via pulley wheels to a driving device located substantially in the same plane as the container and beside it . Because of this configuration of the invention, it is possible to use an efficient operating and power saving double action membrane pump. Advantageous embodiments of the invention are disclosed by the accompanying claims . BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further described in the following with reference to the accompanying drawing which schematically shows a section through a respiration apparatus according to the invention. DETAILED DESCRIPTION OF THE INVENTION The respiration apparatus according to the invention provides for a comprehensive ventilation support wherever the patient is, owing to that it is designed for fulfilling the following demands: a) low weight b) small dimensions, to be able to fit inside cabin luggage c) low power consumption d) be equipped with internal, chargable storage battery, e) possibility to operate from 220 V 50 Hz AC-mains f) alternatively 12/24 V direct-current battery g) simple to adjust and use h) dependable in service i) low sound level j ) low manufacturing cost The apparatus comprises a pump with a rigid container consisting of two symmetrical container halves 4 manufactured from plastic or aluminium. A membrane 5 of a flexible material is mounted between the two container halves and is provided with a central stiffener 11. The thus formed pump housing is rigidly attached to the base plate 16 which also carries a drive motor 9 and pendulum barrel 7 via a bearing bracket 2. Pull means 6 are mounted at the respective side of the stiffener 11, in such a manner that each pull means extends through an opening in the respective container half 4, to which opening a guide-rail 10 connects sealingly. The pull means may for example comprise toothed belts extending via pulley wheels 1 to openings at the outer ends of the guide-rails. These openings have substantially the same shape as the cross section of the toothed belt forming sealing segments having a certain length, for providing sealing against the toothed belt along a corresponding longitudinal section. The drive motor 9 turns the pendulum barrel 7 in a reciprocating motion, and the length of these movements is defined by adjustably arranged limit switches 12 that reverses the current supply of the drive motor via a relay 14. The frequency of the movement is defined by an adjustable time relay 15. Each container half 4 is provided with check valve controlled air inlets 18 and outlets 17 respectively, where the outlets 17 are interconnected at 8 to a mutual inspiration tube 8 (expiration from pump - inspiration to patient) . The above described, compact built ventilator is preferably positioned below the bed and is connected to the electricity supply network via a 12 V DC battery eliminator, alternatively , 12 V socket when staying in a caravan/mobile home etc. A standard patient mask with expiration valve is preferably positioned over the mouth and is connected to the air outlet 8. After a switch is closed, a pre-set air volume is provided with a frequency which can be adapted to the age and weight of the patient. The amplitude of the membrane depends upon the pre-set rotation angle of the pendulum barrel. A double action is achieved due to that a corresponding air volume which is delivered when the membrane moves in one direction, is at the same time drawn in at the opposite side of the membrane. As a consequence, separate intake phase is eliminated with an accompanying saving of energy, wear and time. The last point is important for high frequencies. As an alternative to the above described adjustable operation of the pendulum barrel 7, this may be connected to the drive motor 9 via a simple crankshaft for conversion of a rotating motion into a reciprocating motion. For this, no limit switches and no relay for polarity reversal of the drive motor power supply will be needed. In this case, the transmission, i.e. the speed and transmission ratio of the drive motor determines the working frequency of the respiration apparatus. It has been found that the respiration rate of the human body can easily adapt to such a suitable working frequency . The invention is not limited to the above described embodiment, but several variants are imaginable within the scope of the following claims.

Claims: CLAIMS 1. A portable apparatus for ventilation support to persons with respiratory distress, with a compressed air pump which may be connected to the mouth or the nose via tube means (8) for generation of pressure pulses with an individually adaptable air volume, which pump comprises a rigid container consisting of two symmetrical halves (4) and with a flexible membrane (5) which is located as a laterally reciprocating diaphragm between the two container halves (4) that are provided with check valves permitting ambient air to be fed into the pump and from the pump into the tube means while the membrane wall is moved, for generation of a pressure pulse, c h a r a c t e r i z e d in that the pump is provided with flexible pull means (6) for reciprocating operation of the membrane (5) in the container, said pull means extending via pulley wheels (1) to a driving device (9) located substantially in the same plane as the container and beside it. 2. An apparatus according to claim 1, c h a r a c t e r i z e d in that each pull means (6) extends through an opening at the centre of the respective container half (4) , and that a guide-rail (10) is arranged at the respective opening, which guide-rail forms a sealing towards the surrounding atmosphere. 3. An apparatus according to claim 2, c h a r a c t e r i z e d in that the pull means (6) comprises a toothed belt, and that the guide-rail (10) is provided with an aperture segment for the toothed belt, which segment substantially corresponds to the cross section of the toothed belt for sealing against said belt. 4. An apparatus according to claim 3, c h a r a c t e r i z e d in that the sealing segment has a certain length, in order to provide a sealing against the toothed belt along a corresponding longitudinal section. 5. An apparatus according to any one of claims 1 to 5, c h a r a c t e r i z e d in that the pull means (6) are attached to the centre of the membrane (5) , and that the respective ends of the pull means are mounted to a pendulum barrel (7) which is rotatable around an axis which is substantially parallel to the plane of the membrane. 6. An apparatus according to claim 5, c h a r a c t e r i z e d in that the pendulum barrel (7) is attached to the driving device (9) via a crankshaft for conversion of a rotating movement to a reciprocating movement. 7. An apparatus according to claim 5, c h a r a c t e r i z e d in that the driving device (9) is connected to the pendulum barrel (7) via a belt or toothed belt transmission. 8. An apparatus according to claim 7 , c h a r a c t e r i z e d in that the pendulum barrel (7) is operated by polarity reversal (14) of a DC motor (9) , via limit switches (12) and time relay (15) , in order to provide rapid membrane movements and pump action by absence of a separate intake stroke. 9. An apparatus according to claim 8 , c h a r a c t e r i z e d in that the limit switches (12) easily may be repositioned in order to determine the volume of each separate intake stroke . 10. An apparatus according to any one of the preceding claims, c h a r a c t e r i z e d in that the shape of the membrane (5) corresponds to the shape of the container halves (4) .

Inventors: SVENSSON ROLF, WENNERHOLM BJOERN, SVENSSON, ROLF, WENNERHOLM, BJOERN
Applicants: BARNWELL INVESTMENTS SA, SVENSSON ROLF, WENNERHOLM BJOERN, BARNWELL INVESTMENTS S.A., SVENSSON, ROLF, WENNERHOLM, BJOERN
Application year: 1999
Main classification: A61M16
IPC codes: A61M16, F04B45