COP-DAC system utilizes oxygen and carbon dioxide analyzers, gas-flow meter, gas breathe-through system, analog computer, and data storage system to provide actual rather than average measurements of physiological and metabolic functions

Bush, J. C.

English

NASA Technical Reports Server

July 1972	 B72-10402 
NASA TECH BRIEF 
Marshall Space Flight Center 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
A Continuous Physiological Data Collector 
The problem: 
Metabolic rate and energy consumption of a human 
subject engaged in a specific task in a given environment 
are measured by an analysis of his exhaled gas. The 
present equipment used for such measurements is bulky 
and thus limited to laboratory areas. In addition, 
measurements are given as an average per work task 
obtained through lengthy computations of data. 
The solution: 
A continuous physiological data collector, COP-DAC, 
has been developed which is compact and gives actual 
measurements per work task and not the average. This 
system instantly monitors physiological and metabolic 
functions and can be used in most environments. 
How it's done: 
The COP-DAC contains an oxygen and carbon dioxide 
analyzers, a gas-flow meter, a gas breathe-through 
system, an analog computer, and a data storage system. 
During monitoring, a subject exhales through the gas-
flow meter by way of the gas breathe-through system. 
The oxygen and carbon dioxide analyzers are then 
exposed to the expired gases and convert any changes 
in 02 and CO 2 contents into electrical signals. The 
change in flow is also indicated by an electrical 
potential change. These signals are then introduced into 
the analog computer, mixed with pressure-temperature 
variables and oxygen-BTU constants, and evaluated 
over real time to give a continuous monitoring of the 
physiological and metabolic data. The data are displayed 
on digital voltmeters and incorporated into the data 
storage system. 
In this system, the oxygen analyzer contains an 
oxygen cell that responds electrochemically to the 
percentage change in 02 content of the expired gases. 
The carbon dioxide analyzer operates on the infrared 
absorption characteristics of CO 2 . As the CO 2 content
is changed, the infrared energy is changed which is 
translated into an electrical signal change. The gas flow 
meter which gives expired gas volume over real time, 
operates similarly to a bridge circuit. An electrical 
potential is applied to the expired gas tunnel, and as the 
volume of gas flows through the tunnel, it cools the 
surrounding areas, thereby changing the electrical po-
tential. 
The entire system can accommodate additional equip-
ment. A number of . computers, data storage systems, and 
display techniques can be incorporated. In addition, 
other physiological and metabolic functions such as 
heart rate, blood pressure, etc. can be included. The 
system can be connected directly to the computer or 
adapted to rf mode for remote operation. 
Notes: 
1. COP-DAC is applicable in industry and medicine. The 
industry can utilize COP-DAC for employee health 
surveys and to determine their energy requirements 
for certain tasks. The medical field can use COP-DAC 
for studies of respiratory diseases as well as for 
measurements of physiological and respiratory ef-
ficiencies. 
2. Requests for further information may be directed to: 
Technology Utilization Officer 
Marshall Space Flight Center 
Code A&TS-TU 
Huntsville, Alabama 35812 
Reference: B72-10402 
Patent status: 
No patent action is contemplated by NASA. 
Source: J. C. Bush
Marshall Space Flight Center
(MFS-20835) 
Category 05 
This document was prepared under the sponsorship of the National 	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19720000401 2020-03-17T03:39:06+00:00Z


A continuous physiological data collector

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server