The transition from water-seal volume displacement spirometers to electronic flow measurement systems began in the 1970’s. The first instruments were completely analog but as microprocessors became more powerful spirometers eventually became fully digital. Because this kind of spirometer is relatively inexpensive to develop and manufacture, this era (which continues to today) saw many small companies rise and either fall or get acquired by larger corporations.
Godart Pneumotachograph, 1962. From the time before electronics became miniaturized. An amplifier and integrator for a Fleisch pneumotach. From “Pneumotachography” by W.M. Pols,
Mercury Electronics Computing Spirometer CS1, circa 1970. From a Mercury Electronics product brochure, found on the Legacy Tobacco Documents website. Undated, but likely from around 1970.
National Cylinder Gas Pulmonary Function Indicator, probably manufactured in the 1970′s. Used a hot-wire transducer to measure flow. A completely analog spirometer. Taken from an Ebay listing.
National Cylinder Gas (division of Chemtron) Pulmonary Function Indicator, 1974. Used a hot-wire transducer to measure gas flow, now partly digital.
From: Burton RM, Kozel WM, Penley RP, Ward GH, Chapman RS. Application and evaluation of portable field instruments for measuring Forced Expiratory Volume of children and adults in environmental health surveys. Environmental Health Perspectives, 1974; 8: 123-131. Page 125.
Donti Pulmonary Performance Analyzer. Manufactured by Cavitron. Advertisement in Chest, vol 65, no 3, March 1974, page 356D. Although it had a digital display it was primarily analog circuitry.
Marion Labs Spirostat, 1970s: The Marion Labs Spirostat was an odd blend of optical, analog and digital components. It used a disposable turbine sensor. An optical pickup counted the revolutions and converted them to volume. A volume-time curve was printed using a packed array of optical fibers onto Polaroid film and the plastic overlay was used to measure FVC and FEV1. The turbine was small (less than 1/2″ in diameter) and resistance through the sensor was high. Manufactured and sold in the late 1970’s. Picture found on a Ebay listing.
Monaghan M403, 1974: Used a hot-wire sensor. The readout was digital, the rest of its electronic circuitry was likely analog. From: The British Journal of Anesthesia, 1974, Vol 46, No.2, Page 1.
Tracor DS-601 R, 1976. From Medical Instrumentation for Healthcare, by Cromwell L, Arditti M, Weibell FJ, Pfeiffer EA, Steele B, Labok J. Published by Prentice-Hall, 1976. Page 261. This spirometer was later sold as the LSE Vanguard and was probably the first to use disposable pneumotachs. Numerical results were displayed one at a time on the digital front panel by pressing a button to step through them. The optional strip chart recorder is shown on the right.
deVilbiss Surveyor I, late 1970’s. Photograph courtesy of Richard H. Lord of µPward Concepts. Developed by Biotrine Inc. for deVilbiss. It had an embedded 6800 (8-bit) processor and used a ceramic pneumotachograph. It had a 40 character single-line display. A small text printer and an HP pen plotter were options.
Vitalograph Spirometer, Model S, 1980. Probably the first computer-based system from Vitalograph. From InfoWorld Sep 15, 1980, page 22.
CDX Autospiro from the late 1970′s or early 1980’s. Used a vortex-shedding mass flow sensor. Probably completely digital but limited by the digital displays available at that time. Cheap LCD displays were still a decade or two away. Found on a Dotmed listing.
Gould 5000 IV, 1983: The Gould 5000 IV was capable of performing spirometry, single-breath DLCO, closing volumes and either helium dilution or nitrogen washout lung volumes. It came with a “large 9″ CRT for real-time graphics” and used a dry, rolling-seal spirometer. Photo from a sales brochure courtesy of James Sullivan, BA, RPFT, Supervisor, Pulmonary Laboratories, Memorial Sloan Kettering Cancer Center
Pneumedics Dataloop Spirometer, 1984: Pneumotach-based. Photo from a sales brochure courtesy of James Sullivan, BA, RPFT, Supervisor, Pulmonary Laboratories, Memorial Sloan Kettering Cancer Center
Spirometrics 2500, 1980’s. Spirometers kept getting smaller and lighter. Pneumotach based. From a Dotmed Listing.
Micro Medical turbine spirometer, 1987. One of the very first hand-held spirometers. From: Gunawardena KA, Houston K, Smith AP. Evaluation of the turbine pocket spirometer. Thorax 1987; 42: 689-693. Page 690.
CDX SpiroComp, 1987. Used an un-heated Fleish pneumotach. From Office Spirometry. A practical guide to the selection and use of spirometers. By PL Enright and RE Hyatt. Published by Lea and Febiger, 1987. Page 109.
Medical Equipment Designs MultiSpiro PC, 1987. Originally manufactured by Biotrine and re-sold by Medical Equipment Designs. Used a ceramic pneumotach with an integral temperature sensor. From Office Spirometry. A practical guide to the selection and use of spirometers. By PL Enright and RE Hyatt. Published by Lea and Febiger, 1987. Page 135.
Originally manufactured by Chest Corporation of Japan and re-sold by SpectraMed, a division or subsidiary of Gould/SRL. From Office Spirometry. A practical guide to the selection and use of spirometers. By PL Enright and RE Hyatt. Published by Lea and Febiger, 1987. Page 113.
CDX101, 1987. Manufactured by CDX for Mayo Pulmonary Services as the 3M/Mayo2001. Included a telephone modem to transmit results. From Office Spirometry. A practical guide to the selection and use of spirometers. By PL Enright and RE Hyatt. Published by Lea and Febiger, 1987. Page 109.
Spirometerics 4000, 1990’s. One of the first spirometers with a graphics LCD display. Pneumotach based. From a Dotmed listing.
Creative Biomedics DX Plus spirometer, late 1990’s. From a Creative Biomedics sales brochure. Many PC-based spirometry systems have a birthday cake with candles displayed on the screen as an incentive during spirometry. This spirometer came with its own birthday cake!
Puritan Bennett PS600, circa 1990’s. A volume displacement spirometer that included a microprocessor. Found on an Ebay listing.
Spirometrics CMD/PC-Flow+, 1997. Page 1 of a brochure kindly provided by Angela Cole, RN.
A Koko Legend Spirometer. Typical of the electronic spirometers of today, it has a color LCD touch display and is battery powered.
PFT History by Richard Johnston is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.