[This post was researched and written by a Respiratory Care student who studied at the museum this semester.]
The Jones Motor Basal respirometer, manufactured in 1937, was created by the medical doctor, Horry M. Jones. The Jones Motor was a device used to look into a patient’s breathing patterns by using calculations for understanding breathing patterns, including respiratory rate, volume, rhythm and basal metabolism. Basal metabolic rate is the amount of energy used per day by a person at rest. It can be determined by measuring the amount of time it takes a person to consume a given quality of oxygen. The higher the metabolic rate, the faster the oxygen is consumed.
Respirometers commonly include: a seal-able metabolic chamber, oxygen sensor, a device for data recording, a thermometer to manage temperature, and valves to introduce gasses to patients. The Jones Basal Motor includes: a mouth piece, tubing that takes exhaled air into the motor, a small compact of alkali to help get rid of carbon dioxide and a rubber bag (known as the bellows) to allow for expiration and inspiration to contain oxygen supply. The Basal Motor also has a measuring apparatus for delivering oxygen into the rubber bag to measure an individual’s breathing rate and volume in his or her lungs. (See a YouTube video of the machine here.)
The basal motor respirometer contains one Liter of an oxygen tank and a pressure gauge with a dial to show how much oxygen has been exhaled. There are needle valves on the measuring canister which admits gas slowly from the oxygen tank until the bag distends sufficiently to just touch the side of the alkali tower.
Respirometers like The Jones Basal Motor were used to understand more about patients’ respiratory patterns, volumes within the lungs, and to monitor the health of an individual by using known information as a baseline such as height, weight, sex and age. Using a respirometer to gain baseline measurements allows medical researchers and practitioners to see how changes in environmental or genetic factors can impact respiration. (Such instances give information about the respiratory rate of the patient being studied.) It can also give data about how respiration takes place, which can conclude whether an individual has a defective respiration from anxiety or a leak in the system, or even from producing irregular breaths. Some patterns can quite possibly be concluded as asthma.
Respirometers today are different from those from the mid 1900’s. The significant changes are the graphical placements, measurements, and most importantly the model/make of the respirometers. Today Respiratory Therapists have a device called the “Wright Respirometer” which came out in 1994. It is used to measure how much oxygen an individual can hold in their lungs. The Wright Respirometer is placed in a breathing circuit of an anesthesia machine or ventilator. This device measures how much a person exhales throughout an entire minute. It will measure changes in gas volume related to the burning up of oxygen. This works by a person breathing into the unit. The breath will travel through slanted slots in a small cylinder that surrounds a small vane made to rotate and it can measure how much someone exhales in Liters.