US2593774A - Apparatus for no-effort inhalation anesthesia - Google Patents

Description

April 22, 1952 M. A. LOREDO APPARATUS FOR NO-EFFORT INHALATION ANESTHESIA Filed Jan. 19, 1949 1 m l ml m. wa W Jr m m HI n W N H N l NM H TM R Q H d W .8 1 aw Q m Ma v m ax PW. Q r J N I H Ti A s Q mm a Q A a W Patented Apr. 22, 1952 APPARATUS FOR NO -EFFORT INHALATION AN ESTHESIA Miguel Angel Loredo, Habana, Cuba Application January 19, 1949, Serial N 0. 71,697 V In Cuba March 18, 1948 1 Claim.

This invention relates to apparatus for ad'- ministering gases employed in the application of inhalatory anesthesia, by the closed or confined method. The invention is characterized and distinguished in that it eliminates mechanical obstacles which heretofore have been interposed in the respiratory circuit of the apparatus. The invention, therefore, provides a no-effort inhalation method and apparatus in which the patient needs only the kind of respiratory force of a person in normal repose and forced respiration is eliminated.

One object of this invention is to provide means whereby the patient is enabled to breathe, freely and directly, the anesthetic mixture within the breathing bag of the apparatus while conserving the vital functions of oxygenation and elimination of carbon dioxide. The patient is entirely relieved of the strain imposed in the use of prior apparatus which necessitated the patient forcing the gases to circulate over soda lime, for example, and through lengthy tubes, pipes, valves and other parts of the apparatus.

Another object of this invention isto provide a novel and improved breathing bag having three communicating passages, namely an inlet passage for the admission into the bag of the purified gases from the absorber unit together with the gases from the standard gas supply unit. Secondly, an outlet passage for the exit of the gases from the breathing bag to the absorber unit. Third, a passage connecting the breathing bag with the face mask. The patient breathes the gases in the bag through this third passage.

It is a feature of this invention that the inlet and outlet passages of the breathingbag are located on opposite sides of the bag or spaced as far apart as possible, while the breathing passage to the face mask is located between the said inlet and outlet passages and in a position to intercept the gas current established within the bag from inlet to outlet thereof. Another object is to include, in the absorption circuit of the apparatus, mechanical means for circulating the gases.

The invention is embodied in a no-eifort inhalation apparatus consisting of a closed circuit from which the external atmosphere is excluded and which comprises three intercommunicating circuits, namely the respiratory circuit including the patients respiratory system and the breathing bag with the face mask. Second, an absorption circuit which includes a mechanical gas circulating device and the absorber which con- -or tube 5.

tains the carbon dioxide absorption material. Third, a gas supply or feeder circuit which includes apparatus of known character and function for supply anesthetizing gases.

Other objects, features and advantages of this invention willbe apparent from the following detailed discussion read together with the accompanying drawing in which Fig. 1 is a diagrammatic illustration of an apparatus embodying the invention, with parts in section.

Fig. 2 is a view of the breathing bag.

In the drawing the reference numeral I denotes the breathing bag which is made of the same material as now used for standard breathing bags in anesthesia apparatus. The bag has a gas inlet passage at 2 and a gas outlet passage at 3. The passages are spaced as far apart as is convenient or practicable in the manufacture of the bag. In the preferred construction illustrated the two passages. 2 and 3 are on opposite sides of the bag I. The bag is also formed with a face mask or attached to a face mask 4 to be placed over the face of the patient as shown. The face mask communicates directly with the interior of the bag through a nipple The latter is located between the inlet and outlet passages 2 and 3, respectively, in such a position that it intercepts the gas current passing through the bag. In Fig. l the breathing passage 5 is located close to the inlet passage 2 and almost diametrically opposite the outlet passage 3.

The anesthetizing gases are supplied from a source of'supply comprising gas mixing cylinders 6 and 1 provided with control devices and interconnecting passages as shown at 8 and 9 respectively. Inasmuch as the gas supply unit is of known construction and function, no further description is deemed necessary. The gases pass from the supply unit to the breathing bag by way of a connecting tube Ill and a second tube ll. At the point l2 the gas supply circuit is connected to the absorption circuit by a tube I3.

The absorption circuit comprises an absorber ,M which contains carbon dioxide absorbing material indicated at IS. The exhaled gases from the breathing bag I pass to the absorber M by way of a tube I 6. 'I he gases then pass through the material I5 and are drawn therefrom by a suction-impulse device in the form of a double pump having two bellows l1 and I8 which are, alternately compressed and expanded by the operation of connecting rods 19 and 20, which in turn are reciprocated by cranks 2i and 22 mounted upon a shaft 23 180 degrees apart as shown. The shaft 23 is rotated by a motor 24 which drives a small pulley 25 which is in driving engagement with a large pulley 26 secured to the shaft 23.

The space Within the bellows I1 is connected by a forked tube 28 to two valve chambers 29 and 30 which contain valves 3i and 32. The space within the other bellows I8 is connected by a forked tube 34 to two other valve chambers 35 and 36 which contain valves 38 and 39. The valve chambers and valves are connected to the outlet side of the absorber M by a suction tube 40. The valve chambers 29 and "36 are connected by a tube 42 which communicates with the aforesaid tube 13.

Thus the suction side of the valve mechanism 28-39 is connected to the absorber It by the tube 40. The supply side or outlet side of the valve mechanism is connected to the breathing bag by the tubes 42,13 and H. The gas circuits are indicated by arrows in the drawing.

The operation of the system is as follows: Gas flowing from the supply unite-1 passes :to the breathing bag I through the tubes 10 and Hand inlet :passage 2. The gas flows out of the bag through outlet passage 3 and tube It: to the absorber 14. If new the motor 24 is started, the connecting rods (9 and 20 will be operated and reciprocated to alternately compress and expand the pump bellows; li and it. Thus a vacuum is created in the tube 40 and the exhaled gases are drawn through the material l in the absorber N where they are freed from carbon dioxide and thereafter circulated through the valve mechanism 28-39 and through the outlettube '42 and 13 into the gas supply circuit from the unit 3-1. The purified gases from the absorber mingle with the gases from the supply unit and pass through the tube 1 I into the bag.

The valves in the valve chambers are shown in open and closed positions corresponding to the operations of the pump bellows I1 and 18. When the bellows ii are expanded, gas fiows'from the absorber l4 through open valve 32 and forked tube 28 into the bellows ,l'i, valves 31 and 35 being then closed. On the other side, the impelling movement of the bellows it forces the gas which had previously passed into the bellows l8 out of the valve mechanism through forked tube 34,

' open valve 39 and tube d2. So that, by the ex clusive operation of the pump |1,l8 the purified gases are drawn from the absorber l4 and circulated back into the breathing bag, the withd'rawal and circulating requiring no effort what- 's'oever from the breathing efforts of the patient. -yIn the operation of the apparatus of the invention as herein disclosed the anesthetic gases and oxygen are administered as in the known closed standard systems. The absorber of the carbonic gas which forms the greatest obstacle has been separated from the respiratory circuit;

and placed inconnection with an aspirating and tion thereof may be changed. The pump may be connected in the absorber circuit between the bag and the absorber, or between two absorbers, if such be used. The breathing bag may consist of more than one bag.

From the foregoing description and the drawing it will be clear that the invention includes two'ess'ential elements, namely mechanical means for forcibly circulating the gases through the absorberand entirely independentof the breathing efforts of the patient, and the use of a bag-mask of suitablesize and provided with communicating passages so interrelated that the patient. is .provided with a breathing space and atmosphere which allow him to breathe without effort.

I claim:

An apparatus for administering anesthetic gases in a closed'circuit from which the atmosphere is excluded, comprising an ,ela'sticibreathing bag-having an inlet, an outlet and a breathing passage, a carbon dioxide absorber having an inlet and an outlet, ,a tube connecting said breathing bag outletwith theinlei; of said carbon dioxide absorber, a pumping device having :an inlet and a discharge port, a second tube connecting the outlet of said carbondioxideabsorber with the'inlet'of saidpumping device, athird'tube connecting said'discharge port of said pumping device with the inlet of said breathing bag, an

anesthetic gas supply source, a fourth tube connecting'said anesthetic gas supplyintosa'id third tube connecting said .pumping device with the breathing bag inlet, "said fourth .tube "discharging the anesthetic gases coming'fromisaidgas supply source into said third tube at a pointin the latter between the. discharge :port of said pumping device and said breathing bag inlet, and means for actuating said pumping device.

. MIGUEL ANGEL LOREDO.

REFERENCES CITED The rfollowing references are of record in the file of this patent:

UNITED STATES PATENTS

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