US3106204A - Respiratory apparatus - Google Patents

Description

Oct. 1963 B. PARAMELLE RESPIRATORY APPARATUS Filed Nov. 28, 1960 United States Patent Ofilice 3,166,204 Patented Oct. 8, 1963 3,106,204 RESPRATORY APPARATUS Bernard Paramelle, Grenoble, Isere, France, assignor to Electronique Medicale Serdal, Paris, France Filed Nov. 28, 1960, Ser. No. 72,087 Claims priority, application France Dec. 2, 1959 1 Claim. (Cl. 128-29) My invention has for its object a respiratory apparatus controlling directly at a predetermined rhythm the artificial inhalation and expiration of air, oxygen or the like suitable gasifo-rm mixture into and out of the respiratory ducts of a human being or of an animal on which experiments are being made through the agency of application means such as a respirator, a cannula or an intratracheal probe.

Said apparatus may be of a portable type and be actuated by the operators muscles or else, chiefly in the case of a laboratory apparatus, the apparatus may be fitted without any modifications in its structure with driving means which ensure its automatic operation. There is obtained thereby, whatever type of control is used and under the best conditions possible, a ventilation of the lungs under the desired values of pressure and depression. Further-more, the weight and bulk of the apparatus are comparatively small and its simplicity and reliable operation allow its control by unskilled operators.

My improved apparatus includes chiefly tWo independent bellows mounted in a common casing and controlled in a manner such that they may execute simultaneously their expansion followed by a compression, said bellows being provided with valves arranged in a reversed relationship on the two bellows so as to open respectively during the compression stroke and during the expansion stroke of the bellows While a common connection leading to the application means communicates with the two bellows through the agency of corresponding flaps arranged in opposite relationship on the two bellows so as to open when the valve carried by the same bellows closes and reversely. Thus the common expansion of the two bellows provides for the suction of the breathing gas into those bellows of which the valve opens at this moment and simultaneously for the suction of the air blown out of the lungs of the patient into the other bellows of which the flap opens also at this moment, while the following compression stroke delivers the gas out of the first bellows considered into the application means and the vitiated air from the lungs contained in the second bellows into the outer atmosphere.

I have illustrated by way of example in the accompanying drawings a preferred embodiment of my invention. In said drawings:

FIG. 1 illustrates the arrangement of the two bellows in the position corresponding to the breathing out stage at the end of the expansion stroke of said bellows,

FIG. 2 is a similar view corresponding to the blowing of the breathing gas into the application means at the beginning of the compression stroke of the bellows.

It is apparent from inspection of the drawings that the two bellows 1 and 2 are arranged in parallel and side by side. The expansible wall of said bellows are made preferably of an antistatic rubber, that is, a rubber which is rendered conductive through incorporation of carbon for instance and, in all cases, the material forming said bellows should satisfy the requirements of resistance to the heat or hygrometric conditions which may be met in practice, while allowing its storage even when it is subjected to heat and moisture without any risk of damage thereto. The cross-section of said bellows is irrelevant and it may be advantageously of a rectangular shape with rounded angles so as to provide a maximum useful Volume within a minimum bulk, but it may be possible as well to provide a circular, oval or the like cross-section for the bellows. The size of each of the bellows is such that the useful volume, that is the difference between its volume when at its maximtun expansion and its volume when in its position of maximum compression may be equal to about 1200 ch. cm. The bellows are closed at their two ends by common rigid plates 3 and 4 made of metal or the like material ensuring an excellent fluidtightness along its line of contact with the lateral rubber wall of the bellows.

The bellows may furthermore be arranged no longer side by side but coaxially or in any other suitable manner and they may be designed in any desired manner; in fact, the plates closing each of the two bellows may be independent but in all cases, the compression and the expansion of the two bellows should be ensured synchronously. Furthermore, springs are provided to return automatically the bellows into one of their extreme positions. Said springs may be arranged helically inside each of the bellows or else, as illustrated, a single spring R urges the two plates 3 and 4 apart to a maximum extent.

It is also possible to pivotally secure in a removable manner to one of the plates the end of an elastic blade or of a telescopic tube including a spacing spring, the other end of said blade or tube being pivotally secured round a stationary point, so as to move the plate considered away from the other plate, whereby the two bellows are urged into their relative position of maximum expansion.

Each of the bellows is associated with an opening extending through the plate 3 and controlled by a valve; the valve shown at 5 opens towards the inside of the bellows 1 while the other valve shown at 6 opens towards the outside of the corresponding bellows 2, the larger surfaces of said valves lying inwardly of the bellows in the case of the valve 5 and outwardly in the case of the valve 6 so as to further the shifting of said valves respectively inwardly and outwardly of the corresponding bellows.

Said valves may be constituted by a frusto-conical blade made of a plastic material such as that available under the registered name Plexiglas, said valves being of a circular cross-section and resting on a seat made of aluminum or plastic material for instance, plastic material showing the advantage of cutting out to a large extent the risk of freezing. The pressure returning each valve onto its seat is provided by a gauged helical spring shown at 5 or 6' as engaging the larger surface of the valve, said springs being held in position by corresponding straps shown respectively at 7 or 8, said preferably cross-shaped straps being secured to the face of the plate coplanar with the larger surface of the corresponding valve. Said springs are thus arranged, in the case of the valve 5, that is in the case of the spring 5, inside the bellows 1, while the spring 6 corresponding to the valve 6 is located outside the bellows.

The valve 5 serving as an admission valve as illustrated by the arrows of FIG. 1 is gauged so as to operate for a depression equal to about 7 cm., of water and it is provided either, as illustrated, in the outer plate carrying the bellows or else, at any other suitable point according to the requirements of mechanical assembly or of control to be considered. As to the exhaust valve 6, it is gauged so as to open for a pressure of about 17 cm. of water, and it is provided similarly either in the outer plate 3 as illustrated, or else at any other suitable point of the outer surface of the bellows 2.

'In the inner plate 4 common to the two bellows are provided two ports 1 and 2 serving respectively for the output of the air or gas contained in the bellows 1 and for the input of the air breathed out into the bellows 2. Said ports communicate with preferably yielding pipes, h and 16 respectively, which latter may be given a length of say one meter and which lead each to a nozzle opening into a common connection S extending between said pipes 9 and it said T- or Y-shaped connection feeding the application means. In the nozzles terminating the yielding pipes 9 and 10 are fitted the flaps showing a very small inertia, 11 and 12 respectively, said flaps being held in the same manner and in the same direction as the valves and 6 in the same bellows l and 2, with the diiference however that said flaps are adapted to open for extremely small pressures of say one to two centimeters of water column. The flaps and the valves corresponding to the same bellows are thus subjected to a pressure facing the same direction so that they can never under normal operation be opened or closed simultaneously. The valves 5-6 and the flaps ll12 are adapted to provide a throughput of gas of about 20 to 30' litres per minute. The apparatus described may be located advantageously to the front of a portable metal case for instance, the plates carrying the bellows being then rigid respectively with the body of the casing and with its cover, which latter is pivotally secured to the body of the casing through a strong hinge. The control of the cover between its open and closed position at the rhythm of the breathing to be furthered produces the desired alternate expansion and compression of the bellows.

It is possible to secure to the front edge of said cover of the casing, a handle which allows the manual operation of the bellows or else it is possible to locate a pedal on the upper surface of the cover, which allows the apparatus to be controlled by the operators foot. It is also possible to provide on the apparatus securing lugs for a belt, so as to allow its easy transportation on ones back.

It is also possible to provide an automatic drive constituted by a wheeled suitably ventilated casing carrying an electric motor rotating at a variable or adjustable speed: said motor may drive the bellows in their reciprocatory movement through the agency of a suitable speed reducer and of a cam engaging a rail fitted on the upper surface of the cover of the casing referred to hereinabove, with a view to constraining said cover to execute movements which it has been assumed hereinabove are executed by human energy.

The operation of the apparatus described will be readily understood. As a matter of fact, the bellows are subjected simultaneously to an alternating shifting between their compressed and expanded positions at a predetermined rhythm which is generally equal to 16 to 18 reciprocations per minute. During the expansion period, the valve 5 opens and allows air or the like breathing gas to enter the bellows i as illustrated by the arrows drawn in solid lines in FIG. 1, while the corresponding flap 1-11 is urged against its seat to be held in its closed position. At the same time, the vitiated air passing out of the lungs enters as also illustrated by the arrows drawn in solid lines in FIG. 1 inside the bellows 2 through the flap 12 which opens under the pressure of said vitiated air against the expanded gases inside the bellows 2, the valve 6 of which is necessarily closed under the pressure of the atmosphere which is added to that exerted by the spring 6'.

During the next stage of operation, that is during the compressional stage for the bellows, the gas or air which has just filled the bellows 1 is delivered into the patients lungs, the valve 5 being closed and the flap 11 opening as shown in FIG. 2 under the action of the pressure of the air contained in the bellows while in contradistinction the vitiated air which has been precedingly sucked inside the bellows 2 is delivered into the outer atmosphere by the valve 6 which opens to this end, the flap 12 closing under the action of the compression produced inside the bellows 2; the circulation of the gases thus disclosed is illustrated by the arrows drawn in solid lines in FIG. 2. The arrows drawn in dotted lines show the direction which cannot be followed in each case by the stream of air or gas by reason of the closing of the corresponding flap.

When during the expansion stroke (FIG. 1) the pressure in the respirator or the like application means rises to a value which is higher by more than 17 cm. of a water column than atmospheric pressure, air leaks of necessity through the open valve 12 and the bellows 2 into the outer atmosphere through the valve '6 which opens then under the action of said exaggerated pressure.

Similarly in the case of a pressure which is lower by more than 7 cm. of a water column than atmospheric pressure during the compression stroke shown in FIG. 2, external pressure enters the bellows 1 through the valve 5 which opens for such a relative pressure above 7 cm. of water and on which this exaggerated reduction in pressure prevailing inside the respirator, acts at such a moment.

Any risk of an over-pressure in the respiratory tracts above 17 cm. and any risk of a reduction in pressure beyond 7 cm; with reference to atmospheric pressure are thus prevented through the arrangement which has just been described.

Thus safety in the case of an excessive pressure or depression in one of the bellows is ensured by the valve carried by the other bellows.

Of course it should be mentioned that the gas breathed in by the bellows 1 may be obtained out of the atmosphere or of any suitable container while the bellows 2 communicate always with the outer atmosphere when the valve 6 opens.

Obviously, and as already mentioned, numerous modifications may be provided with reference to the arrangement described without unduly widening thereby the scope of the invention as defined in the accompanying claim.

What we claim is:

Ina respiratory apparatus comprising two parallel carrier plates provided each with two ports the spacing of which is the same in both plates and bellows fitted between and opening into corresponding ports of said two plates, and adapted to be urged towards and away from each other to produce in succession and repeatedly a common compression and a common expansion of the two bellows, and valves controlling the ports in one of the plates and adapted to open respectively inwardly and outwardly of the corresponding bellows, the larger surfaces of said valves facing respectively the inside of one of the bellows and the outside of the other bellows, the combination of pipes opening into the ports formed in the other plate and communicating with the corresponding bellows, the outer ends of said pipes facing each other at a short distance from each other, a flap of a reduced inertia mounted at the outer end of each of said pipes, said flaps controlling the passage of gas through the outer ends of said pipes and facing the same direction as the valve in the corresponding bellows to open the passage through the corresponding pipe when spectively inwardly for a pressure lower than atmos- 5 pheric pressure by about 7 cm. of water column and outwardly for a pressure higher than atmospheric pressure by about 17 cm. of water column respectively, further light springs urging said flaps onto their seat and gauged to open for pressures below and above atmospheric pressure of less than 2 cm. of-water column,

and a chamber adapted to communicate with the patients lungs and the inner end of which is fitted between and communicates with the flap-controlled outer ends of the two pipes.

References Cited in the file of this patent UNITED STATES PATENTS 1,202,125 Tullar Oct. 24, 1916 2,428,451 I Emerson Oct. 7, 1947 2,902,992 Renvall Sept. '8, 1959 10 3,009,459 Ruben Nov. 21, 1961 FOREIGN PATENTS 463,948 France Dec. 31, 1913

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