| Summary: | 碩士 === 南臺科技大學 === 電機工程系 === 103 === According to World Health Organization reports cardiovascular disease
is one of the major cause of death around the world. Continuous monitoring
of the cardiovascular system for disease prevention is a very important
issue. Pulse wave velocity (PWV) is an important index in the detection
of cardiovascular disease, and it can be used to estimate atherosclerosis.
PWV is defined as the rate of change of displacement with respect to time.
PWV measurements have invasive methods and non-invasive methods. Blood
pressure cuff methods is one of non-invasive measurement methods, it is
utilizes blood pressure cuff to measure the pulse of the upper arm and the
ankle. However, using this method it is difficult to estimate the vascular
length. Hence, the bio-impedance method is a measurement method in recent
years, which is cheap, portable and non-invasive. At present, there are
several studies using bio-impedance method to measure the lung activity,
cardiac output, heart rate and PWV. Prospectively, bio-impedance method
is a possibility for the detection of cardiovascular disease. In this
paper, we used a simple bio-impedance measurement system to measure the
PWV of the radial artery to the finger in fixed-length, and we also
combined the bio-impedance measurement system with the ECG to calculate
the PWV of the R wave and T wave to finger. Results showed the pulse
wave of finger can be measured to calculate PWV. We also analyzed the
differences between the signal of bio-impedance pulse wave and PPG,
the reflection waveform of PPG couldn’t be detected on some subjects,
but bio-impedance measurement systems could. It showed using
bio-impedance method to measure the pulse wave is more stable than PPG.
In the future, the bio-impedance method may replace the PPG. In this
experiment, we used the blood pressure cuff to block blood flow
temporarily. The statistics showed that blocking the blood flow
temporarily is no significant impact for the PWV of normal persons.
Multiple regression analysis indicated that abdomen circle and height
are independent predictors of wfPWV（r＝0.893）, SBP and DBP are
independent predictors of tfPWV（r＝0.898）. Correlation analysis
showed the wfPWV is associated significantly with tfPWV（r＝0.770,
p＜0.01）, wfPWV is also associated with abdomen circle, SBP,
and body fat（r＝-0.699, r＝0.673 and r＝-0.648, p＜0.05）. The tfPWV
is associated with arm length（r＝0.778, p＜0.01）, SBP, and heart
rate（r＝0.728 and r＝-0.763, p＜0.05）. In the future, we hope to
measure the PWV of patients of peripheral vascular disease, and
improve the number of samples to observe the difference with patients
and normal persons.
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