Category Archives: Plethysmograph

Plethysmograph, Dubois Water-Filled, circa 1955

Found on the South Australia Medical Heritage website.  Attributed to an article in the Journal of Clinical Investigations, vol 49, Issue 6 (June 1, 1970), pg 1238.  Described as:

“The picture above shows a schematic design of one of DuBois’ early plethysmograph designs from the early 1950’s. The person sat inside a large box filled with warm water, which would allow for easy monitoring of volume changes. It is reported that as the person entered or left the box, it flooded the Dean’s office below. For some strange reason, this design did not last long.

Plethysmograph, Mead-Type, circa 1970

A variable-volume, constant pressure plethysmograph.  Undated photo from the South Australia Medical Heritage Society website  and probably constructed around 1970. Manufacturer or builder was unnamed.  The following description was included:

“The picture above is a more recent example of a variable volume plethysmograph. This type of box was designed in 1960 by Dr Jere Mead, and is similar to the box used by Haldane and Priestley.
The subject breathed air from outside of the box. The resulting change in box volume was recorded by a spirometer or calculated from a pneumotachograph. The pressure at the mouth could be measured directly, and the amount of air breathed was recorded by a pneumotachograph.”