US2071215A - Artificial respiration apparatus - Google Patents

Description

Feb. 16,1937. RPE ER EN 2,071,215

ARTIFIC IAL RESPIRATION APPARATUS Filed Sept. 14, 1935 2 Sheets-Sheet 1 Feb. 16, 1937. PETERSEN 2,071,215

ARTIFICIAL RESPIRA'IION APPARATUS Filed Sept. 14, 1955 2 Sheets-Sheet 2 5 E 69 56 g g 50 o a g a? 7 I v a? :P/ 59/ 45 z 7 A9 8* l 7 PEJP/VI/Vf/YW Man 753 J M 4 0M W 4 Patented Feb. 16, 1937 UNITED STATES PATENT OFFICE Application September 14, 1935, Serial No. 40,644 In Sweden October 15, 1934 12 Claims. (Cl. 128--28) This invention relates to apparatus for producing artificial respiration by imparting inspiratory and expiratory movements to the respiratory system of the patient.

The chief object of the invention is to provide an eflicient and simple apparatus of this kind. Another object of the invention is to provide an apparatus of this kind which can be driven by a compressed gas such as carbogen (a mixture of about 93% oxygen and 7% carbon dioxyd) which then can be used for inhalation purpose.

The invention is based on the idea of producing the respiratory movements by the combined action of two operating devices which are driven both by the same pressure impulses in a liquid or gaseous working fluid and of which one acts to compress the thorax and the other acts to cause flexion of the thoracic vertebral column alternately with the compression of the thorax.

In order that the invention may be fully under stood, reference is made to the accompanying drawings giving a schematic illustration of a preferred embodiment of the invention.

In the drawings:

Fig. 1 shows the apparatus in the position attained at the end of the compression of the thorax, i. e. at the end of the expiration.

Fig. 2 shows the apparatus in the position at the end of the inspiration.

Fig. 3 shows an oscillating valve in section.

In the drawings, I designates a girdle, preferably having a width of about 4 inches and adjusted around the thorax 2 of a patient resting on his back. The back portion of the girdle is provided with an oval rubber bladder 3 or the like reinforced by fabric, which bladder is positioned under the back of the patient, approximately under the middle of the thoracic region. The ends of the girdle are detachably and adjustably secured to a pair of holders 4, preferably provided with rollers 5 in order to be easily movable on the breast of the patient. One of the holders 4 is flexibly connected to a cylinder 6, and the other holder is flexibly connected to the projecting end of the piston rod 1 of a piston 8 which is movable in the cylinder 6. The holders 4 are also interconnected by means of tension springs 9 or the like. The bladder 3 and the cylinder 6 are connected through a conduit It to the oscillatory pressure chamber l I (Fig. 3) of an oscillating valve l2 (Fig. 1) connected by means of a conduit l3 and a pressure reducing valve l4 to a gas container 15 charged with a compressed gas, preferably carbogen. In addition to the inlet l6 and the outlet I! which are alternately closed and opened by a valve tongue l8 (Fig. 3), the valve chamber H is provided with a third opening or stud l9 to which the operating devices (that is the bladder 3 and the cylinder 6) of the respiration apparatus are connected so that these devices are in constant communication with the oscillatory pressure chamber H and are filled and emptied simultaneously with the said chamber through the action of the oscillating valve which operates automatically at a suitable frequency, as will be more fully described in the following.

During the filling of the cylinder 6 the piston 8 is moved outwards (that is, to the right in Fig. 1), whereby the springs 9 are tensioned and the girdle expanded to release compression of the thorax. Almost simultaneously, as the compression of the thorax is released, the back bladder 3 is filled (expanded), thereby causing 2. raising of the back of the patient and, as a result thereof, a flexion of the thoracic vertebral column. These movements give, as a result, inspiration in two co-operating steps: firstly through the release of the compression of the thorax so that the thorax passively expands and increases its volume, and secondly through the flexion of the vertebral column, whereby the ribs are forced to separate on the front of the thorax so as to further increase the volume of the thorax. The cylinder 6 and the bladder 3 are thereafter emptied again, thereby doing away with the previously effected flexion of the vertebral column and causing the springs 9 to tighten the girdle around the thorax, whereby expiration is effected in two co-operating steps by movements which are reversed in relation to the inspiratory movements just described. Thus it will be seen that artificial respiration will be produced, if the filling and emptying of the cylinder and the bladder is made rhythmical and a proper pressure range is used for the purpose.

The periodical filling and emptying of the cylinder 6 and the bladder 3 may be effected by means of a piston working in a cylinder in which the piston is reciprocated in order to force air or a similar gas periodically into and out of the cylinder E5 and the bladder 3. Preferably the piston should be able to be operated at a variable stroke and at a variable speed or frequency, and preferably the cylinder should be provided with valves opening at the desired maximum and minimum pressures. The piston stroke is adjusted for a somewhat larger stroke volume than is required for filling the cylinder 5 and the bladder 3 to the desired end pressure during the expiration period. When this end pressure is attained, the excess gas forced forward by the piston during its continued compression stroke is discharged to the atmosphere through the maximum pressure valve. During the reversed stroke of the piston, the cylinder and the bladder on the girdle are first emptied and then the piston is sucking in an additional amount of gas through the minimum pressure valve, the maximum pressure valve being adjusted to act at the desired highest working pressure used, while the minimum pressure valve is adjusted to act at a pressure which, for instance, is slightly below the pressure of the atmosphere when the working medium consists of air. By means of this arrangement with valves and excess stroke of the piston or the like effecting the pressure impulses for driving the operating devices 3 and 6, the advantage is obtained that the operating system within certain limits is unaffected by leakage, and further it is possible to control the time during which the girdle remains in its end positions after inspiration and expiration, respectively, at a given frequency of operation.

It is preferred, however, to efiect filling and emptying of the operating devices of the girdle by connecting the same to a gas container charged with compressed gas, preferably carbogen, through a reduction valve and an oscillating valve as is shown in Fig. 1, and in this case the advantage is gained that the discharge gas from the girdle can be used for inhalation. For this purpose there is connected to the outlet I! (Fig. 3) of the oscillating valve an inhalation cap, an inhalation nozzle or an inhalation mask which is placed over the face of the patient. Such a mask is preferably made from a yielding material in order to accumulate the amount of gas received when the operating devices of the girdle and the lungs simultaneously discharge their contents into the mask. The resulting contamination of the carbogen gas with the exhaled air is not objectionable, since the continuously renewed supply of carbogen prevents an accumulation of carbon dioxid in the inhalation gas or a reduction of the content of oxygen in the same.

It is desirable that the devices 3, 6 during their filling and emptying through the oscillating valve, as indicated in Fig. 1, be in uninterrupted communication with the oscillatory pressure chamber ll (Fig. 3) of the Valve so as to form a variable enlargement of the said chamber. In order to enable an easy and exact predestination or control of a time interval desired after discharge of the working devices through the oscillatory pressure chamber H in the oscillating valve and before the outlet of this valve is closed and its inlet is opened, the valve according to the present invention is constructed in a somewhat modified way when compared with known types of oscillating valves. As usual the pressure chamber H is closed on one side by means of a membrane 20 for actuating the valve tongue l8 which is pivoted-on an ear El and urged into its respective positions in which it closes the inlet l6 and the outlet 52', respectively, by means of the arms 22 and 23 of a permanent magnet. The tongue 18 is connected to the membrane 20 by means of a rod 24 having a loop or eye through which the tongue extends. According to the invention a tightly fitting cap or cover 25 is provided outside the membrane 20, said cover being equipped with a valve 26 opening to the outside and an adjustable leakage 27. The valve is also provided with a spring 29 which acts on the membrane 20 and is adjustable by means of a screw plug 28.

The general operation of the oscillating valve for securing the alterations of compression and release in the operating devices 3 and 6 is as follows. With the valve tongue E8 in its lower position in which it closes the outlet 11 and the inlet is open, gas flows from the container I5 to the chamber H and to the devices 3 and 6 which communicate with said chamber ll through the stud l9 and the conduit ID. The gas builds up a pressure in the chamber H and the devices 3 and 6 communicating therewith, and this pressure lifts the membrane 29 which in turn, after the pressure has attained at certain value, lifts the tongue is by means of the rod 24, whereby the valve tongue i8 is shifted to the position in which it closes the inlet it and the outlet H is open. The gas under pressure in the chamber H and the devices 3 and 6 communicating therewith now escapes through the open outlet l1, and as the pressure in the chamber H falls the membrane 28 is pressed down by the spring 29, whereby the tongue l8, after the pressure has fallen substantially to the atmospheric pressure, is shifted again to its lower position by means of the rod 24.

The modification hereinbefore described enables the desired timing of the operation by ad justing the period after decrease of the pressure in the valve chamber to the atmospheric pressure and before switching of the valve tongue through its actuating device. Fig. 3 shows the valve in the position at which the chamber ll and the operating devices 3, 6 connected at I 9 to the chamber II have been completely or almost completely emptied through the outlet On this occasion the spring 29, however, has not been able to press down the membrane 26 in accordance with the pressure fall in the valve chamber H, because the pressing down of the membrane by means of the spring is only possible in accordance with the flow of air from the atmosphere through the adjustable leakage 21 into the space between the membrane 20 and the cover 25. Thus, the movement of the membrane is dependent upon the speed by which the air is flowing in under the cover 25. The flow of the incoming air can be easily and exactly controlled by the adjustable air leakage 21. On the other hand the air entrapped under the cover 25 has a free escape during the filling period through the valve 26 opening to the outside.

In the embodiment hereinbefore described, the

spring 29 and the screw 28 may be omitted and,

within a certain pressure range, substituted by the action of the pressure of the air volume between the membrane 20 and the cover or cap 25, the upper pressure limit of this air being regulated by a maximum pressure valve opening to the outside as the valve 26 and substituted for the latter.

It is obvious that the rhythmical filling and emptying of the operating devices 3, 6 can be efiected solely by means of the simple oscillating valve for the reason that said devices 3, 6 are connected to the chamber II by means of a connection l9 arranged independently of the outlet l1, whereby the operating devices 3, 6 receive an uninterrupted connection with the pressure chamber H and are emptied through the outlet l! of this chamber. The construction of the oscillating valve is such that a desired control of the different periods of the operation can be performed in a very simple and feasible manner.

While the invention has been described with reference to a preferred embodiment of the same, the invention is not limited to the embodiment shown and described but can be varied and modified in different ways without departing from the general principle thereof. As an example, instead of a bladder as back raising device a piston or the like can be used which is movable in a cylinder. The device for operating the girdle can also be modified in a number of different ways. And furthermore, the construction of the girdle may be varied within wide limits. The term girdle is intended to mean any device that can be adjusted around the thorax and effect compression of the thorax when being tightened.

What I claim and desire to secure by Letters Patent, is:-

1. An apparatus for producing artificial respiration, comprising in combination a girdle adapted to be adjusted around the thorax of a patient, means operable by pressure impulses in a working fluid for expanding and tightening the girdle, and means operable by the same pressure impulses in the same working fluid for raising the back of the patient while resting on his back, in the region of the thorax in order to cause flexion of the vertebral column of the patient in that region alternately with compression of the thorax through tightening of the girdle.

2. An apparatus for producing artificial respiration, comprising in combination, a girdle adapted to be adjusted around the thorax of a patient, means connected to said girdle and operable by pressure impulses in a working fluid for expanding and tightening the girdle to allow for expansion and cause compression of the thorax, respectively, means on the back of the girdle for raising the thoracic region of the back of the patient, while resting on his back, in order to cause flexion of the thoracic vertebral column of the patient, said last mentioned means being operable by the same pressure impulses as the first mentioned means in such a Way that compression of the thorax and flexion of the vertebral column are performed alternately.

3. An apparatus as claimed in claim 2, in which the means for expanding and tightening the girdle through the driving pressure impulses comprises a cylinder and a piston movable therein and springs, the arrangement being such that the piston is moved under the action of the pressure impulses against the action of the springs which effect the tightening of the girdle.

4. An apparatus as claimed in claim 2, in which the means for raising the back of the patient comprises a rubber bladder on the back of the girdle.

5. An apparatus as claimed in claim 1, in which the pressure operable means are connected to a container for compressed gas through an oscillating valve through which the said operating means are periodically filled with pressure gas and again emptied.

6. An apparatus as claimed in claim 1, in which the pressure operable means are connected to a cylinder having a reciprocable piston for periodically forcing a gas into and allowing it to escape from the said operating means.

'7. An apparatus for producing artificial respiration, comprising in combination a girdle adapted to be adjusted around the thorax of a patient, a pair of holders to which the ends of the girdle are detachably and adjustably secured, a cylinder connected to one of said holders, a piston working in said cylinder and having a projecting piston rod connected to the other holder, tension springs interconnecting said holders, a rubber bladder on the back of the girdle, a source of gas pressure impulses, and means for connecting said cylinder and said bladder to said source.

8. An apparatus as claimed in claim 7, in which said holders are provided with rollers to allow for easy movement of said holders over the breast of the patient.

9. An apparatus as claimed in claim '7, in which the cylinder and the piston rod are flexibly connected to the respective holders.

10. An apparatus as claimed in claim l,in which the gas pressure operable means are connected to a container for compressed gas such as carbogen through an automatic valve having an oscillatory pressure chamber having an inlet and an outlet, which are alternately closed and opened by a valve member actuated in dependence upon the oscillating pressure in said chamber, said chamber having a connection to the said gas operable means, which is independent of said inlet and outlet so that said means are in constant communication with said chamber, and said oscillating valve being provided with means for controlling the frequency of the operation thereof.

11. An apparatus as claimed in claim 2, in which the pressure operable means are connected to a cylinder having a reciprocable piston for periodically forcing air into and allowing it to escape fromv said operating means, valves being provided for producing an upper and a lower limit for the air pressure in said means and cylinder.

12. An apparatus as claimed in claim 2, in which the pressure operable means are connected to a compressed gas container through an oscillating valve for periodically filling and emptying said means, said valve having an outlet for the discharge gas, a mask and means for connecting said mask to said outlet.

PETER PETERSEN.

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