Rosling Valve, 1922

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.

Beckman Metabolic Cart, 1994

Beckman_Metabolic_Cart_1994

A Beckman Metabolic cart in use in a study on exercise patients with spinal cord injuries. From: Muszkat R, Yazbek P, Arango CT, Moreira MC, Trombetta IC, Battistella LR. Assessment of functional capacity during gait using a reciprocal propulsion orthosis (ARGO) – a comparative study with a conventional  mechanical orthosis.  Sao Paolo Medical Journal, 1994, 112(1): page 496.

Spirometer, LSE Vanguard DS-601, circa 1980

Spirometer_LSE_Vanguard_DS601

Used a disposable pneumotach (plastic body with filter paper mesh).  Manufactured by the LSE corporation in the 1980’s.  There was an optional strip chart recorder for volume-time curves.  Numerical results were displayed one at a time on the digital front panel by pressing a button to step through them.  Taken from: http://www.ebay.com/itm/like/271258328169?lpid=82

Hewlett Packard 47804S PFT System – 1979

Hewlett-Packard 47804S PFT System 1979

State of the art for 1979. Built around a Fleisch pneumotachograph and included an HP desktop computer (with 24K of memory and a tape drive!).  It was capable of performing spirometry, DLCO and N2 washout tests.  It was only manufactured for a couple of years and was discontinued likely because very few units were sold. It was quite expensive for the time (totally equipped it was $53,175 in 1979 dollars). From “Automated pulmonary function measurements” by Maurice R. Blais and John L. Fanton, Hewlett-Packard Journal, September 1979, page 20.