Monday, January 16, 2017

1870-1900: The Pneumatometer (Part II)

By 1903 there were various pressure devices used to provide positive pressure breaths for therapeutic reasons and for artificial respiration.  The devices were mainly operated by some form of physical labor, such as through pumps and bellows.  
Stoerk's Apparatus (Figure 30)
(1, page 211)

Please note that all of these apparatus's are described in a book called, "Pneumotherapy: Including Aerotherapy and inhalation methods," by Paul Lewis Alexandre Tissier, and edited by Solomon Solis Cohen.

Stoerk's Apparatus:  It allows for inspiration by positive pressure and exhalation through rarified (less oxygen that what's in the air) air.  Rarified air caused a sort of suction or negative pressure that caused a negative intrathoracic pressure that induced expiration.  (1, pages 211-212)

Unlike the other pressure devices, this one didn't require direct or physical depression of bellows or pumps, instead "compression is obtained by a change of level in the water in a system of communicating vessels, brought about by setting up an oscillatory movement which changes their relative positions (Fig. 30). (pages 211-212)

An oscillating motion was created by swinging it back and forth with your hand. So the oscillations cause positive pressure (condensation) to cause inspiration, and negative pressure (rarified air or suction) that caused expiration.  (pages 211-212)

Dorell's Residual Air Pump (1, page 213)
Dobell's Residual Air Pump:  The device was small and compact, and could be carried in your pocket.  (See figure 31) (1, page 213)

It's described as "kind of mask which isfitted to the front of the mouth and held in place with a ribbon which passes around behind the ears; the apparatus is provided with valves to embarrass inspiration while expiration remains free. As a result the intrathoracic air is rarefied, and at the end of three to six respirations the residual air is reduced to a minimum and the diaphragm attains its maximum elevation. The patient then inspires in ordinary air, and this inspiration being freer than he is accustomed to, he experiences a sense of increased comfort. The same manoeuver is repeated several times at each sitting. The apparatus is certainly ingenious, but there is no means of determining with accuracy the degree of success attained."

Water Engine Bellows (Figure 32)
(1, page 214)
Water Engine Bellows:  It's also referred to as The Water-blower or Double Ventilator of Geigel and Mayer. The container is made of sheet iron and is filled to two thirds of it's capacity with water.  The container is completely enclosed except for four openings at the top.  To of these openings communicate with room air.  One holds a meter to measure volumes.  The fourth opening is where the pressure escapes.  A tube is connected to this opening, and a rubber mask is connected to the opposite end.  (1, pages 213-215)

Bellows inside are operated by a crank. The principle is similar to the way water engine or gasometer is operated. The patient holds the mask over his face, and turns the crank  As the crank is turned pressure escapes through the fourth opening, and this caused inspiration.  (see figure 32)  (1, pages 213-215)
Dupont's Apparatus (Figure 35)
(1, page 216)

Dupont's Apparatus:  It's based on the principle of the Bunson water pump or aspirator, is inexpensive, allows for inspiration as deep as you desire, and can be used wherever there is a flow of water.  The pressure is regulated by a mercury pressure manometer. (1, pages 216-217)

Tissier said it was the best apparatus for the reasons indicated in the previous paragraph.  Rarification and compression of air is done simply by pumping a pump alongside the apparatus.  Pressure is determined by flow of water or by working a stopcock on the patient tubing.  (1, pages 216-217)

S. Solis Cohen's Double Apparatus:  This is combination gasometer (a container that stores gas)  and water pump and was created by the author of one of our other 19th century respiratory therapy books and the editor of of Tissier's book.  There were various advantages to this device: (1, pages 217-221)
  1. It corrects the flaws of the other pressure devices
  2. It is continuous in action and relatively compact
  3. The price is moderate
  4. It can be used by the patient at his or her home
Cohen's Apparatus (1))
The device was described as follows:   (1, pages 217-221)

"It is true that the degree of compression of the air is regulated by means of weights placed on the upper portion of the condensed-air cylinder, and that the degree of rarefaction is regulated by means of weights attached to a system of cords and pulleys by which the cylinder containing the rarefied air is raised; but the apparatus is operated and the pressure modification obtained by means of a double-acting bellows—so that air is drawn out from the cylinder which is to contain rarefied air and discharged into the outer atmosphere, while fresh air is forced into the cylinder intended for condensed air. Although one stroke of the footlever accomplishes both condensation and rarefaction, the two systems are independent, and there is no communication between the cylinders except through the air-passages of the patient. This is an extremely ingenious idea, which, in addition to the other good qualities of the apparatus, should insure its success."  (1, pages 217-221)

The Cohen's Apparatus was invented in 1883, and introduced to the medical community via the New York Medical Journal in the October 18 issue

I think these were all "ingenious" inventions meant to help people with breathing difficulty.  It would be another century before such devices were mastered and redesigned for patient comfort and convenience.

  1. Tissier,Paul Lewis Alexandre, edited by Solomon Solis Cohen, "Pneumotherapy: Including Aerotherapy and inhalation methods," volume X, 1903, Philadelphia, P. Blakiston's Sons and Co., pages 296-224.  If the profession of respiratory therapy existed in their era, we would be reading their books.  However, as it was, their books were written for the medical profession.
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