BCG sensing technology allows you to hear your "heart"

During traffic jams, it is inevitable that the heart rate will increase, and the blood pressure will rise. During rest, the breathing will be stable and the heart rate will be stable. The vital signs are fickle and sensitive. We are paying more and more attention to the monitoring of vital signs. What will the monitors of the future look like?

Encountered in traffic jams on the way to work, the car seems to be stuck in place between stops and starts. I couldn't help looking forward, but what I saw was a long line of cars that couldn't see the end, as if I was in a parking lot. Faced with such a scene, it is inevitable that you will be anxious, your heart rate will increase, and your blood pressure will rise...

Human's vital signs are fickle and sensitive. In daily life, even insignificant emotional fluctuations still lead to a series of changes in physiological activities. As we all know, vital sign data is also an important basis for judging personal health status. A large number of physiological indicators can accurately and directly reflect people's health status.

In recent years, the concept of vital sign monitoring has gradually penetrated into the non-medical field, and a variety of vital signs monitoring products have emerged. The use method that requires wearing a bundle and sticking to the skin often gives people a strong sense of restraint, especially when performing sleep monitoring, the use of wearing a bundle can even change the user's sleeping habits, aggravate anxiety and anxiety, and be counterproductive. Because of this, the non-contact vital sign sensing technology represented by BCG is gradually entering the stage of history.

The concept of Ballistocardiography (BCG) was first proposed in 1877. Its essence is the weak change of external pressure on the surface of the human body caused by the heart beat and arterial blood flow, and it is the mechanical characteristic of the heart. Its medical value was once comparable to electrocardiography (ECG). However, due to the instability and difficulty of measurement, it was gradually forgotten in the laboratory. However, since the beginning of this century, BCG technology has become a research hotspot of major research institutions at home and abroad. In addition to its own potential medical value and sensor technology advancements, the natural fit between BCG and IoT technology has also made people more interested in Its comprehensive value has new expectations.

Everything is a health monitor

The BCG signal acquisition device consists of sensors and a number of signal conditioning circuits. If the high-precision sensors are "hidden" in suitable weight scales, pillows, mattresses, tables and chairs, vital signs can be monitored without contact and without disturbing the user's normal work and rest. And these ordinary household daily necessities can also be transformed into high-precision "life health monitors" with the blessing of BCG technology.

Science has long proved that the heart can cause a series of corresponding periodic motions and vibrations in the human body during the beating process. After these signals are coupled through the sensor circuit, they are then passed through differential preamplifier circuits, multi-stage amplifier circuits, DC blocking circuits, and wave traps. circuit, band-pass filtering circuit, and finally obtain a valuable and analyzable BCG signal. The BCG signal itself is very weak, and is easily disturbed by breathing, body movement, and power frequency noise. As a result, the BCG signal obtained by direct measurement is often submerged in noise, and the physiological characteristic information such as heart rate and respiration contained in it cannot be obtained.

In order to effectively identify the BCG signal, it is also necessary to perform noise reduction processing on the signal to effectively restore the characteristics of the BCG signal. The commonly used noise reduction method is the wavelet transform method. In the process of piezoelectric sensor and signal conditioning circuit processing, conversion and noise reduction, the BCG signal is converted into a millivolt-level identifiable voltage signal, and finally the processed signal is converted by the chip to complete the analog-to-digital conversion. With the help of the BCG signal, the value of the BCG signal is displayed on the display side, which is convenient for subsequent calculation processing and analysis and evaluation.

The BCG sensing device based on "piezoelectric passive sensing technology" can accurately sense the vibration force of the heart and breathing chest and abdomen of the human body in resting or sleeping scenarios, and measure important vital signs such as heartbeat interval and respiration. With the help of heartbeat interval and respiratory fluctuation feature extraction and modeling technology, the detection of obstructive and central sleep apnea events in non-contact scenarios can also be realized, so as to truly plan ahead and monitor the health status in real time before the disease occurs.

The final piece of the puzzle for the medical IoT

In medical-grade monitoring products, various types of monitors abound, but large-scale medical equipment has too many application scenarios that cannot be reached, and this provides sufficient development space for home-based vital sign sensing equipment. With the support of 5G, artificial intelligence and other related technologies, household non-contact vital sign sensing equipment is expected to become the "nerve terminal" of the medical Internet of Things, supplementing and improving the clinical scenarios that monitoring products reach. This will enable thousands of users to establish a personalized health model even if they are outside the hospital, and realize the health management of the whole life cycle. Non-sensing, light-management professional medical terminals like BCG equipment are bound to occupy a place in the future wave of smart sensing, smart life, and smart medical care.