1218 
MONITORING 
cally monitor an experiment by sampling, ana- 
lyzing, and storing data at pre-set intervals, or 
it may monitor on an interrupt basis. The inter- 
rupt can occur frequently, such as with each 
"R" wave of the ECG, or infrequently, only 
when a variable exceeds desired limits. Any of 
this automatically monitored information can 
be made available for review almost instantly 
by using the computer data file for storage. 
At the Utah Biomedical Test Laboratory 
(UBTL) in Salt Lake City, the problem of data 
acquisition and analysis is significant because 
of the large amounts of data that will be gener- 
ated. Early in the planning of the Laboratory, it 
was determined that a digital computer would 
serve as the center of the data system. The size, 
operation, and capability of the computer were 
studied thoroughly. It was soon evident that 
some capability would have to be sacrificed be- 
cause of the limited funds budgeted for the pur- 
chase of the computer. The main function of the 
computer is data acquisition and primary data 
reduction. A general purpose, sixteen-bit com- 
puter, XDS Sigma 3, with good interrupt capa- 
bility and excellent input/output (I/O) han- 
dling was selected. This machine has 32K of 
memory and standard peripherals, 400 wpm 
card reader, 200 1pm line printer, nine-track 
magnetic tape and 1.5M word Ready Access 
Disk (fixed head). The on-line data handling 
capability is presently provided by a 64-channel 
multiplexer and A-D converter, and extensive 
digital I/O interfaces. 
DATA SYSTEM 
The Test Laboratory building consists of three 
stories with the first floor containing the animal 
holding areas. The second floor is comprised of 
surgery, the catheterization laboratory, and an 
intensive care area with their supporting labo- 
ratories and supply rooms ; and the third floor 
contains offices and engineering laboratory 
space. Located in the center of the building is a 
monitor mezzanine. From this mezzanine, 
which is elevated above the second floor, there is 
visual contact with the four operating rooms 
and the large intensive care unit (ICU). From 
here, it is possible to observe surgery as well as 
the activities of the animals in the ICU. There 
is audio contact between the mezzanine and all 
animal areas. Figure 1 is a schematic floor plan 
showing all the animal sites, including the ani- 
mal holding rooms on the first floor. 
At each animal site in the Laboratory, an ani- 
mal monitor console can be located. Internal sig- 
nal wiring provides for one monitor console in 
each operating room and the catherization labor- 
atory. Forty consoles can be placed in the ICU, 
and there is wiring for one console in each hold- 
ing room, although three to four animals can be 
placed in each room. The monitor console is 
built in modular fashion and can amplify and 
condition up to sixteen analog variables at any 
one time. It also provides switching capability 
so that any eight variables can be sent to the 
computer for analysis, and any eight variables 
can be sent to the monitor mezzanine for ob- 
servation and recording. The console provides 
digital readout for a limited number of varia- 
bles and also some preprocessing of the signals 
so that a limited number of mean, systolic and 
diastolic pressures can be displayed at the ani- 
mal site. There are also alarm circuits con- 
nected to each analog amplifier-conditioner, and 
preset alarm levels will generate acute alarms 
at each site. These alarms are generated when 
life-threatening conditions exist, such as car- 
diac arrest or severe respiratory distress. 
Under development in the monitor mezzan- 
ine is a master monitor console (MMC), shown 
in Figure 2. This console is physically located 
for convenient observation of the animals in the 
ICU. It contains a patient selector system 
which gives indication whenever an acute alarm 
is generated at any animal site and permits the 
selection of eight signals from any animal for 
display. The MMC also contains a remote com- 
puter terminal which is used to control the au- 
tomatic monitoring of the animals at any loca- 
tion in the Laboratory. There will be an indica- 
tor panel associated with this terminal which has 
a set of three lighted indicators for each animal 
site. One will light when the animal data is 
being sampled; another, when routine medica- 
tion should be given ; and the third is both a vis- 
ual and audio indicator that is turned on when 
the computer detects that calculated physiologi- 
cal variables have exceeded preset limits. When- 
ever any alarm condition exists, either the acute 
