Tuesday, April 01, 2014

1859: Lewin's Inhaler

Mathieu's Nephogene (from Lewin) (2)
There were many problems with the Nephogene (nebulizer) created by Mathieu.  The greatest concern was that the spray produced was so forceful most of the mist created pounded into the oral cavity and produced a cough, according to Jacob Cohen in his book "Inhalation: its therapeutics and practice."

This made it certain little of the spray made it to the lungs.  Of course Cohen makes sure to mention that this device was not first devised to deliver respiratory medicine, but to spray medicines on any part of the body.  

The person to fine tune the device to make it more appropriate for the inhalation of respiratory medications was Lewin of Berlin.  Cohen describes the device as such: (1, page 190)
Lewin, of Berlin, has constructed an apparatus with an ordinary suction pump (syringe) which forces the liquid into a reservoir, the air within which is thus compressed, and in its turn becomes a propelling force, driving the fluid, on the opening of a valve, out of a very fine aperture, whence it impinges on a convex button, and becomes thus broken into spray. This apparatus once set in action will continue to work for a considerable time without further pumping.

Lewin's glass nebulizer (1)
Yet another problem with inhalers prior to Lewin is that they were all mostly made of medal.  This meant that certain medicines couldn't be used if they interacted with metal.  Lewin aimed to correct this problem by using a "strong glass reservoir" instead of metal."  It's also graduated with markers so you know how much water to put into it.   (1, pages 194, 195)

It was covered by a "strong metal cap with three openings: one for the introduction of the liquid and the subsequent attachment of the condensing syringe; one affords exit to the capillary extremity of a slender tube which reaches to the bottom of the glass; and the third is covered by a spring safety-valve, through which the compressed air may escape after a certain pressure has been produced.  "  (see figure 19) (1, pages 194, 195)

To work it a "finger is placed upon the capillary extremity of the exit-tube until the air in the reservoir has been sufficiently compressed by a few strokes of the piston, when the finger is removed, and the fluid rushes out with great force and breaks upon a gilded metallic convex button secured in a glass drum, perforated to admit the stream, and attached by a support to the side of the instrument. The drum is not furnished with a waste-pipe, but is so inclined that the excess of fluid will flow over its edge into any convenient receptacle." (1, pages 194, 195)

So there were various advancements made by Lewin both to his nebulizer and to that of Mathieu's.   Yet his most significant contribution was the use of material that wouldn't react with medicine that might be used in it. Yet there were still flaws with it.

Either way, these nebulizers provided another option for physicians and patients, and were yet another step in the evolution of nebulizer therapy.  (1, pages 194, 195)

References:
  1. Cohen, Jacob Solis, "Inhalation in the treatment of disease: it's therapeutics and practice," 1876, Philadelphia, Lindsay and Blakiston, part II, "Inhalation of nebulized fluids, or sprays:  nebulized medicaments and the apparatus for their production," pages 184-212

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