SIGNAL CONDITIONING, DATA ACQUISITION, AND SPECTRAL ANALYSIS - Design and Development of Medical Electronic Instrumentation - page 205

SIGNAL CONDITIONING, DATA ACQUISITION,
AND SPECTRAL ANALYSIS

So far we have seen how to design electrodes, ampli filters to detect electrophys-

iological signals that result from electrochemical events occurring in the living body.
However, biopotentials are only a small fraction of the signals generated by physiological
processes. Think about it for a second—physicians most often assess your health condi-
tion by looking at changes in weight, heart and lung sounds, arterial blood pressure, and
temperature—none of these involve recording biopotential signals.
Mimicking what your doctor does today, the next mirror in your bathroom, your next
bathroom scale, and your future shower and toilet will probably be loaded with sensors
that can automatically and unobtrusively measure your temperature, look at skin marks,
analyze your body composition, and examine your secretions for the telltale signs of infec-
tions or chemical imbalance. A behind-the-scenes computer will scan the sensor data set
and suggest that you visit your doctor if it

fi ers, and fi

finds suspicious changes.
It will take a while before we develop instruments sophisticated enough to make
“Bones” McCoy feel cozy, but the trend of embedding sensors and intelligence into
even the simplest medical instruments and home health appliances will continue to
grow in the years to come. In fact, a recent study by a major technology-development
company demonstrated that the largest emerging markets for the decade of the 2000s
will be based on a

fi

c, very reliable sensors. This trend has
already resulted in the development of many self-contained sensors that incorporate all
the necessary front-end electronics. Typically, these only need a power input to produce
a high-level output signal proportional to the measured variable. As shown in Table 5.1,
many sensors with onboard electronics are already available to measure temperature,
pressure, acceleration, gas concentrations,

ff ordable, highly speci fi

fields, and so on. Although
the robo-doc may not be here yet, these sensors are being designed for incorporation
into consumer appliances, and as such they are becoming more available and more
a

fl flow, magnetic fi

ff ordable by the day.