Category Archives: 1970s

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.”

Spirometer, Mijnhardt Vicatest-2, 1979

Found in Occupational Medicine, 1979, 29(1), page 40.

“This spirometer, recently introduced to this country, is a direct measurement dry spirometer of 6 litres capacity which functions on a metal sliding cylinder/rubber rolling seal principle.

“The instrument uses an A-4 size recording paper with space provided on the paper for entering essential test and test subject information.

“The Vicatest-2 has an integral microcomputer which provides instantaneous digital display of essential respiratory parameters – FVC, FEV1, FEV1%, MVV, PEF, FEF, FMF and FMFT, thereby eliminating manual calculations. It can be supplied with an integral printer module and a print-out unit, as optional accessories, which at the tough of a button give a print-out of all parameter which can be attached to the recorded expiratory curve, thus giving a complete and permanent record of the test.”