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R. B. Pachori and V. Gupta
flow can be obtained during inspiratory phase of snoring. The amplitude of flow is
also increased during the phase of both inspiration and expiration of snoring. These
oscillations and increased amplitude of flow are due to intermittent closures of the
airways and the aforementioned intensified respiratory efforts [34].
In addition to these methods, the thermal biomedical signal is known as
thermorespirogram signal in which variations of the air temperature are observed in
front of the nostrils during breathing. The temperature increases during expiration
and decreases during inspiration phases of breathing. The registration of the respiratory activity is also possible with an electric signal known as electroplethysmogram
signal. In this method, the inflated and deflated lung changes the thoracic electrical
impedance which can be observed by electroplethysmogram signal. The optical
biomedical signal known as optoplethysmogram signal can also be used to register
the respiration activities. This signal reflects the peripheral blood volume changes
over the respiratory cycle [34].
During respiration, the breath-holding condition deserves some extended
description. This condition is generally known as a Greek word apnea
(breathlessness) in which a complete or partial cessation of effective respiration
occurs. This breath-holding condition can also be possible during sleep at
night and it is known as sleep apnea. The sleep apnea is usually detected by
polysomnography [34].
12.5.1.3 Blood Circulation
The blood circulation mainly depends on systemic and pulmonary circulation in
which the first one comprises the rhythmic transport of the oxygenated blood to
the body and the deoxygenated blood back to the heart, whereas the second one is
used for the transportation of the deoxygenated blood to the lungs and oxygenated
blood back to the heart. In addition to assessment of cardiac cycle with heart rate, a
simultaneous registration of blood circulation is also required for the highly relevant
diagnosis purpose with the help of circulatory parameters, namely, blood pressure,
blood flow, and arterial radius. The brief description for the registration of these
circulatory parameters is as follows [34].
Blood Pressure
The unobtrusive and long-term monitoring is difficult in blood pressure registration.
The characteristics such as systolic value, diastolic value, and the pressure pulse
waveform are used to assess the blood pressure. There are basically some invasive
and direct methods as well as noninvasive and indirect methods to register the
artifacts of free blood pressure values [34].
In invasive and direct methods, the blood pressure is directly recorded in the
vessel by inserting a catheter with a mounted internal pressure sensor or a fluidfilled and rigid catheter for transmitting the blood pressure characteristics to the
R. B. Pachori and V. Gupta
flow can be obtained during inspiratory phase of snoring. The amplitude of flow is
also increased during the phase of both inspiration and expiration of snoring. These
oscillations and increased amplitude of flow are due to intermittent closures of the
airways and the aforementioned intensified respiratory efforts [34].
In addition to these methods, the thermal biomedical signal is known as
thermorespirogram signal in which variations of the air temperature are observed in
front of the nostrils during breathing. The temperature increases during expiration
and decreases during inspiration phases of breathing. The registration of the respiratory activity is also possible with an electric signal known as electroplethysmogram
signal. In this method, the inflated and deflated lung changes the thoracic electrical
impedance which can be observed by electroplethysmogram signal. The optical
biomedical signal known as optoplethysmogram signal can also be used to register
the respiration activities. This signal reflects the peripheral blood volume changes
over the respiratory cycle [34].
During respiration, the breath-holding condition deserves some extended
description. This condition is generally known as a Greek word apnea
(breathlessness) in which a complete or partial cessation of effective respiration
occurs. This breath-holding condition can also be possible during sleep at
night and it is known as sleep apnea. The sleep apnea is usually detected by
polysomnography [34].
12.5.1.3 Blood Circulation
The blood circulation mainly depends on systemic and pulmonary circulation in
which the first one comprises the rhythmic transport of the oxygenated blood to
the body and the deoxygenated blood back to the heart, whereas the second one is
used for the transportation of the deoxygenated blood to the lungs and oxygenated
blood back to the heart. In addition to assessment of cardiac cycle with heart rate, a
simultaneous registration of blood circulation is also required for the highly relevant
diagnosis purpose with the help of circulatory parameters, namely, blood pressure,
blood flow, and arterial radius. The brief description for the registration of these
circulatory parameters is as follows [34].
Blood Pressure
The unobtrusive and long-term monitoring is difficult in blood pressure registration.
The characteristics such as systolic value, diastolic value, and the pressure pulse
waveform are used to assess the blood pressure. There are basically some invasive
and direct methods as well as noninvasive and indirect methods to register the
artifacts of free blood pressure values [34].
In invasive and direct methods, the blood pressure is directly recorded in the
vessel by inserting a catheter with a mounted internal pressure sensor or a fluidfilled and rigid catheter for transmitting the blood pressure characteristics to the