Non-contact Vital Signs Monitoring in Anesthesia

The standard vital signs routinely monitored in patients during anesthesia include heart rate, electrocardiogram, blood pressure, body temperature, respiratory rate, and peripheral blood oxygen saturation, and etc. Continuous measurement and interpretation of these vital signs can provide important information about the underlying physiological state.

Conventional techniques for tracking vital signs require physical contact, and most techniques are invasive. Body contact with sensors (for example, electrocardiograph electrodes) can irritate or damage the patient's skin, interfere with the patient's treatment or comfort, provide a vector for infection and cross-contamination, and only hinder mobility. In addition, when placing the sensor/wire on the body, the patient may feel uncomfortable (for example, anxiety, tension, and excitement). This negative experience may change the patient's breathing and heart rate and produce misleading results for medical service providers. Therefore, people need effective sensing methods that can wirelessly (non-contact/remote) monitor vital signs.

Since the 1970s, researchers have been looking for ways to conduct non-contact monitoring of vital signs. The following important medical situations have promoted continuous research in this field: (1) The patient's skin is fragile or vulnerable, such as low birth weight. , Premature infants, burn patients; (2) monitor wiring can endanger or interfere with patients, such as: Infant Death Syndrome and sleep apnea; (3) cross-contamination between patients (such as reusable wires) . The non-contact life monitoring technology does not involve electrodes or adhesives, does not touch the skin, does not have the risk of wires, entanglements or patient discomfort, does not consume any consumables, and there is no chance of cross-infection caused by inadequately disinfected equipment.

Today, advances in sensing technology have enabled smart systems to monitor vital signs, such as respiration and heart rate, in a non-contact manner. The two most advanced non-contact vital signs monitoring methods are the use of radio frequency (radar) and imaging (camera). In the past 15 years, the development of camera technology has increased its applicability and affordability, making people more and more interested in using these technologies in medical institutions. Monitoring methods using images can measure multiple vital signs at the same time and are relevant. The research has been applied to many ethnic groups, including sleeping healthy people, intensive care unit patients, kidney dialysis patients, and fibromyalgia patients.