BREATHING AID APPARATUS
The present invention relates to a breathing aid apparatus and concerns an apparatus suitable for ensuring the inhaling phase of the pulmonary breathing of a user whose breathing out phase is controlled by his respiratory muscles as well as an apparatus which, while ensuring the enhaling phase of the pulmonary respiration, assists the breathing out phase of said breathing.
Such apparatus as the operating power of which is provided by a source of compressed gas, advantageously the source of the gas to be blown into the patient's lungs, are already known. In these apparatus, means are provided for controlling the breathing cycle, i.e. the sequence of fresh gas insufflation and of ventilation of the breathing system ventilation periods, by means of pneumatic logic circuits.
However, owing to the relatively large number of components required for constituting the logic circuits, such as valves, fluid throttle means, etc., a relatively large apparatus is required and which is consequently difficult to transport, particularly in the case of first aid to the injured persons. In addition, the large number of components increases the cost of the equipment without increasing their reliability.
One general aim of the invention is to provide a breathing aid apparatus of particularly simple design, with a reduced number of components, and consequently of low cost, which remedies the drawbacks of known apparatus as particularly an apparatus of reduced dimensions which is thus well suited to a plurality of operating conditions.
It is also a purpose of the invention to provide such an apparatus for simply and reliably humidifying gases or a mixture of gases blown into the lungs of a user, as is for example necessary in the case of anaesthesia, and whose working parameters particularly frequency, flow rate and the ratio of the fresh gas insufflation time to the breathing out time of stale air in an elementary cycle, can be adjusted easily.
The breathing aid apparatus according to the invention, comprising an end piece suitable for connection to a source of pressurized gas to be blown into a patient's lungs, and means deriving their operating power from the gas source and a circuit in derivation form a said source in which is inserted an adjustable throttling means, for periodically connecting the gas source to the output of the device suitable for connection to the patient's pulmonary system, is characterised in that said means are constituted by a single automatic servocontrolled valve, the mobile member of which is subjected to an elastic force applied in the same direction as that of the pressure in the circuit in derivation.
The invention will be fully understood by means of the following description given for the purposes of example and with reference to the attached drawings wherein:
FIG. 1 represents a longitudinal cross-section of a first embodiment of a device according to the invention;
FIG. 2 is a part view analogous to that of FIG. 1 but for an alternative embodiment;
FIG. 3 is a view analogous to that of FIG. 1, but for another embodiment;
FIG. 4 is a graph;
FIG. 5 is a view analogous to that of FIG. 1, but for yet another embodiment;
FIG. 6 is a larger scale view of a part of the device represented in FIG. 5 for a first state;
FIG. 7 is a view analogous to that of FIG. 6 but for another state of the device; 5 FIG. 8 illustrates the functioning of means for humidifying gas blown by a device according to the invention;
FIG. 9 is a view analogous to that of FIG. 8, but for an alternative embodiment;
FIG. 10 is a view analogous to that of FIG. 1, but for 10 yet another embodiment;
FIG. 11 is a top view on a large scale of a member of the device represented in FIG. 10;
FIG. 12 is a cross-section along line 12—12 of FIG. ll;
15 FIG. 13 is a top view of another member of the device represented in FIG. 10;
FIG. 14 is a cross-section view along line 14—14 of FIG. 13;
FIG. 15 is a part longitudinal cross-section of another
20 embodiment of a device according to the invention. First, referring to FIG. 1, the breathing aid apparatus according to the invention comprises a first end piece 11 with a longitudinal bore 12 the althrough having a cross-sectional area s and whose mouthpiece 13 is suit
25 able for connection to a source of pressurized gas to be blown into the lungs of a patient, for example oxygen or a mixture of oxygen and another gas. At its end opposite that connected to the gas source, end piece 11 is shaped into a collar 46, or valve seat, surrounding
30 bore 12 which emerges in a chamber 14 provided in body IS, screwed to piece 11 with a seal 16 interposed between pieces 11 and body 15. The central portion of body 15 comprises a cavity 17, extending from chamber 14, in which is mounted a piston 19 with a working
35 face 47 having an area S, a seal 18 being interposed, the piston being biased by a spring 20 bearing against the bottom of cavity 17. A channel 21 emerges in the cavity and connects it to a radial chamber 22 of body 15 housing an element 23 causing a considerable pressure
40 drop, such as a pellet of porous polyurethane foam or analogous material, acted upon by a compression piston 24 bearing a seal 25 and displaceable by the operation of a screw 26. A channel 27 connects the chamber 14 to chamber
45 22 and a longitudinal through bore 30 of body 15 connects chamber 14 to a chamber 31 provided in a body 32, screwed onto body 15, and shaped to form a venturi with a neck 33 and flared portion downstream from chamber 31 in the direction taken by the gas (arrow f) flowing from the pressurized gas source towards the patient.
A sleeve 38 is attached to the wall of body 32 by means of an internal thread 37 and a screw 35 having
^ a longitudinal through bore 36; a mouthpiece 39 is integral with said sleeve and possesses a longitudinal bore 40 suitable for connection to a source of gas different from that introduced through mouthpiece 13, for example air or anaesthizing gas. A needle type device 41
^ is rotatably mounted in sleeve 38 for interconnecting chamber 31, as desired with the gas source suitable for connection to mouthpiece 39.
The lower portion of needle device 41 is provided with a non return valve 42 opening outwardly for decompressing chamber 31 if necessary by discharge into the atmosphere.
The device according to the invention functions as follows: