A 15 Channel Multiplexed Analog Data Transmission System.
Medical research progress rept. no. 2,
NAVAL MEDICAL RESEARCH INST BETHESDA MD
Pagination or Media Count:
As Navy divers explore greater and greater depths in the sea, the need to monitor their physiological condition becomes increasingly important. A vital part of this monitoring is the data transmission link between the diver and the surface. An inexpensive, highly reliable multichannel data transmission systems has been designed and built specifically for this purpose. The system utilizes a pulse-amplitude modulation multiplexing scheme and transmits 15 channels of analog data over 2 conductors. Input voltages may range from 5.0 to -3.5 volts and the frequency response of each channel is 25 Hz with a 4 KHz system clock. This is more than adequate to reproduce electrocardiograms and most other signals of interest. Automatic synchronization is provided. The diver-mounted transmitter occupies approximately 1.5 cubic inches and operates on plus or minus 15 volts D.C. Power consumption of the transmitter is approximately 500 milliwatts. This may be provided by batteries on the diver or by adding an additional 2 conductors to the umbilical from the surface. The addition of one more wire would allow the monitoring of 15 channels of data from each of two divers operating on the same general area. Integrated circuits have been used extensively throughout the system and result in reduced cost and ease of construction and maintenance. The cost of parts for a dual diver system, including power supplies and hardware, is approximately 1,500. Author
- Stress Physiology
- Non-Radio Communications