Category Archives: Diagram

1910s, Diagram, Gas Analyzer

Alveolar air sampler, 1910

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Alveolar_Air_Sampler_1910

From: Practical Physiology, Edited by M.S. Pembrey, Published by Longmans, Green  and Co., NY, 1910, page 183

“The composition of the alveolar air is determined, according to the method introduced by Haldane and Priestley, by an analysis of the last portion of the air expired in an ordinary expiration. The experiment may be performed in the following way.  An anaesthetic mask is connected by a T-piece to a piece of tubing 80 cm long and 1.8 cm internal diameter; to the free end of the T-piece is connected (Fig. 181) a gas sampler with a capacity of 50 cubic centimeters.  The subject of the experiment fits the mask to his face and makes an ordinary expiration; as soon as the expiration ceases, the tap of the gas-sampler, the air of which has previously been removed be a vacuum-pump or gas-pump, is opened and a sample of the last portion of the expired air is collected before the mask is removed from the face. The analysis of the air is performed in the manner already described.  The percentage composition is about 5.5 carbon dioxide, 14.5 oxygen and 80 nitrogen.

1920s, Diagram, Mask

Mask for respiratory measurements, 1921

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Mask_1921

From: Notes on the apparatus used in determining the respiratory exchange in man: I. an adaptation of the French gas max for use in respiratory work, by Cameron Bailey, J. Biol Chem 1921; 47:277-279.

“The rubber gas mask used in the French army is admirably suited to this work. It is made of thick rubber, covers the whole face, and presents broad surfaces which closely engage the forehead, sides of the face, and jaw. The tissues in these regions are well supported by the bony framework of the face and the mask readily adapts itself to these fixed surfaces. It is held in place by elastic straps passing around the head. In emaciated subjects, leaks may occur above of below the zygoma, in the area the pull of the straps is in the same plane as the surface of the face. In such rare instances the leaks are overcome by placing 6 inch rubber sponges over these areas of the mask and binding them firmly in place with a 3 inch bandage. In this mask, the incoming air is directed upwards towards the windows, the opening of the expiratory tube being opposite the nose and mouth. In this way the space is perfectly ventilated and no discomfort results. Rubber flutter valves are eminently satisfactory for use with these masks. They are conveniently enclosed in flattened glass tubes introduced as near the mask as practicable. A satisfactory arrangement of mask valves for the Tissot method is shown in Fig. 1. The subject reclines in a wheel chair in the rest room, the tubes pass through the wall into the laboratory where the valves are mounted, the tubes then lead directly to the air supply and to the gasometer. A window permits the operator in the laboratory to observe the subject, while at the same time he can follow the respirations by watching the movement of the valve and start and stop the test by turning the 3-way valve on the gasometer.”

1940s, Diagram, Valve

Valve, Low resistance, 1946

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Valve_Low_Resistance_1946

From: A low resistance valve and indicating flowmeter for respiratory measurements.  By Leslie Silverman and Robert C. Lee.  Science 1946; 103: p537.

“It can be noted that the valve flap angle is very low (20 degrees), and thus very little change in direction is necessary in permitting air to pass, once the valve begins to open.  The area of the valve flap surface is large, and hence a low pressure will exert enough force to open it.  The weight of the valve flap is offset by the counterweight.  This counterweight (4 grams) was proportioned to give a low opening pressure and yet allow an adequate amount of of positional movement in the complete valve.  The seating surface of the valve is limited to the small longitudinal braces and edges of the seat periphery.  In order to reduce the adhesive effect of the rubber membrane when wet, the seating surfaces are dusted with talcum powder.  This powder prevents the rubber membrane and Lucite seating surfaces from wetting and also helps preserve the membrane.”

1920s, Diagram, Valve

Rosling Valve, 1922

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Rosling_Valve_1921

The Rosling valve was originally patented in England prior to World War I and was used in mining and gas masks.  This drawing is from Cecil Rosling’s American patent application. The valve had low resistance and unlike many valves of the time, the rubber diaphragms themselves provided the spring action.  The Rosling valve was used extensively in physiological research from the 1920’s to the 1950’s.

1900s, Carbon Dioxide, Diagram, Gas Analyzer

Balance Chemograph, 1905

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1905_Balance_Chemograph

From: A balance-chemograph and the excretion of carbon dioxide during rest and work, by George Oswin Higley, University of Michigan PhD Dissertation, 1905, page 6.

Before the infrared absorption CO2 analyzer was invented CO2 was analyzed by being absorbed chemically and the change in weight measured.

“The apparatus for absorbing carbon dioxide and recording on a blackened paper its rate of flow, is constructed as follows: (Fig. 1, Elevation). It consists of a Ruprecth lecture-room balance, capable of carrying a load of 6 kilograms in each pan and of turning to 5 milligrams. To the beam there was attached a copper tube one and one-hal centimeters in diameter as shown by figure 2. Dry air containing carbon dioxide, enters at A through a short piece of very thin rubber tubing made of a surgeon’s finger cot, passes through the portion designated by the arrows to the end of the beam and downward through two rubber connections like that just mentioned, and a glass tube D (Fig. 1) to the chamber for the absorption of carbon dioxide, upon the air of the balance. (C Fig 1.) From the absorption apparatus the air passes upward through similar connections to the balance-tube C, back on the opposite side of the balance-beam to the center, where it leaves the balance through another piece of rubber tubing, and then passes into guard tubes G’ and G”, which will be described later.

“Since there was a question of removing the carbon dioxide from air flowing at the rate of 30 liters per minute during work, the absorption apparatus is necessarily large. It consists of a beaker 20 centimeters deep, with cover of thin copper, provided with opening two centimeters in diameter, into which are fitted the inlet and outlet tubes. The air passes downward into the beaker through a thin glass tube 2 centimeters in diameter, to within about 2 centimeter of the bottom of the beaker, ending in a open space 3 centimeters deep and of a diameter equal to that of the beaker. (This open space was left because it was thought that the carbonic acid gas would thereby be more uniformly distributed throughout the whole cross-section of absorbent placed above.) The air now rises through the 5 kilograms of coarse, carefully screened soda-lime, and then through glass-wool covered with phosphorus pentoxide to hold back dust and the last trace of water formed in the reaction. This beaker when charged weighs about 5-1/2 kilograms. It is counterpoised by another beaker of the same exterior volume filled with spent soda-lime.”

1920s, Carbon Dioxide, Diagram, Douglas Bag

Douglas Bag, Rebreathing system for CO2 response, 1925

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Douglas_Bag_Rebreathing_CO2_1925

From: The respiratory response to carbon dioxide. By HW Davies, GR Brow, CAL Binger. Journal of Experimental Medicine, 1925, page 38.

“The effect of gradually increasing percentages of carbon dioxide was studied by means of rebreathing in a closed circuit consisting of a modified Douglas Bag with inflow and outflow tubes, a dry meter, and a rubber mouthpiece fitted with inspiratory and expiratory valves. The general arrangement of the apparatus is shown semidiagrammatically in text-fig. 1. The direction of airflow is indicated by means of arrows. A is the modified Douglas Bag of 100 liters capacity.  B, B’ are wide bored three-way taps. C is the mouthpiece. D is a twenty-light capacity “B-type” dry meter manufactured by D. MacDonald and company of Albany. The resistance of this meter is almost negligible even at the maximal rates of pulmonary ventilation produced by high percentages of carbon dioxide in the inspired air. E is a small bore side tube connected with an oxygen tank fitted with reducing valve and a flow meter calibrated with approximate accuracy rates of flow of less than 1 liter per minute. A similar side tube, F, is used to obtain samples of inspired air, either into exhausted sampling tubes or directly into the burette of the Haldane gas analysis apparatus. By way of the three-way stop cocks B,B’ the subject may be made to inhale from and exhale into the room air through the meter, and his normal respiratory rate and minute volume may be determined. When the stop-cocks are turned the apparatus becomes a closed circuit, inspiration and expiration being from and to the Douglas Bag, A.”