Pressure sensors: a key player in medical devices

The birth of medicine emerged with the application of sensing devices. A type of therapy in traditional Chinese medicine, namely "looking, smelling, asking, and feeling", embodies the method of human beings using their sensory abilities, including touch, hearing, and vision, for diagnosis and treatment. In Western medicine, various types of sensors are also widely used in various scientific instruments, expanding the doctor's perception capabilities. From traditional stethoscopes and hammers to modern CT and B-ultrasounds, to clinical operations and the recently popular oxygen concentrators and ventilators, sensors have become a key component and play an important role. It can be said that the development history of medical equipment is also the history of continuous advancement of sensor technology.

Breakthroughs in MEMS sensor technology have brought unprecedented convenience and experience to medical applications. As the population ages, health care is more important than ever. In areas such as in vitro diagnostics, pharmaceutical research, patient monitoring, drug delivery, and implantable medical devices, increasing demands require the continued development of innovative technologies to improve product performance, reduce costs, and reduce product size. The application of MEMS sensor technology is expected to achieve more accurate, convenient and economical solutions in the field of healthcare to meet the growing medical needs. This technology trend will help improve patients' medical experience and promote the advancement of medical equipment and technology.

BioMEMS technology has brought miniature devices to these fields, improving sensing and execution functions, including acceleration sensors, pressure sensors, flow sensors, and micropumps.

MEMS sensors are also used in non-invasive fetal heart rate monitoring. Detecting fetal heart rate is a highly technical task because the fetal heart rate is very fast, between 120 and 160 beats per minute. Traditional stethoscopes or even ultrasonic Dopplers face challenges with measurement accuracy. Ultrasound Doppler fetal heart rate monitors with digital display functions are expensive and are only used by a few large hospitals and cannot be popularized in small and medium-sized hospitals and rural areas. In addition, ultrasonic vibration waves are harmful to the fetus, so they are not suitable for frequent and repeated examinations and home use. The application of MEMS sensors provides a more convenient, more economical and safer option for non-invasive fetal heart rate monitoring, and is expected to achieve important breakthroughs in the field of medical care.

Fetal heart rate detectors designed based on MEMS acceleration sensors can be further improved and become part of a remote fetal heart monitoring system. At the hospital end, the central signal acquisition and analysis monitoring host will automatically analyze the data and provide it for doctors to make diagnoses. If there are any problems, the doctor can promptly notify the pregnant woman to come to the hospital. This technology helps pregnant women monitor the status of their fetuses at any time, thereby benefiting the health of both pregnant women and fetuses. This innovative remote monitoring system not only provides convenient and timely fetal monitoring, but also reduces the burden on hospital resources, allowing doctors to focus more on cases that require attention, while improving the safety and quality of medical care for pregnant women and fetuses. The application prospects of this technology are very broad and it is expected to provide more innovative and convenient solutions for maternal health care in the future.

In addition, MEMS pressure sensors are also widely used in the medical field. These sensors sense pressure signals and convert them into output electrical signals. In medical equipment, MEMS pressure sensors play a key role in respiratory equipment, infusion pumps, pressure pumps, diagnostic equipment and various monitoring instruments, promoting the process of medical digitalization.

High blood pressure is a common health problem that is becoming increasingly important due to an aging population and increasing obesity. Hypertension refers to the impact of long-term high-pressure blood flow on artery walls, which may lead to health problems such as heart disease. The pressure in the arterial wall depends on the amount of blood supplied by the heart and the resistance of the arterial wall to blood flow. The more blood the heart provides, the greater the resistance to blood flow in the arterial walls, and the higher the blood pressure.

Home automatic blood pressure monitors are increasingly used for the diagnosis and management of hypertension. These blood pressure monitors include arm and wrist units. The basic function of a sphygmomanometer is to measure the pressure in the arterial walls. One way to obtain measurement data is to use a pressure sensor that measures the current pressure. Changes in blood pressure cause changes in the speed of the motor that controls the air pump. The air bag compresses the arm, causing systolic blood pressure. Once systolic pressure is reached, a valve in the arm gradually releases air while a pressure sensor takes a measurement.

MEMS sensors are widely used in patient diagnostic equipment. These devices are used to monitor a patient's heart function. Typically, medical staff use an electrocardiogram to assess a patient's heart function. During an electrocardiogram, medical staff attach a set of electrodes to the patient's body, in contact with the skin. This method can measure a complex vector electrocardiogram (VCG), recording the amplitude and timing of the heart's P-QRS-T waves, or simply the timing of the peak of the R wave. This EKG is similar to the images displayed on heart rate monitors or exercise computers.

Although an ECG can provide a wealth of information about heart dysfunction, heart disease, and a patient's physical and psychological stress, it does not do a good job of detecting the heart's mechanical pumping function or its overall performance. In addition, these electrodes may interfere with patients' daily activities, especially recreational activities and nighttime ECG monitoring. Fortunately, in the medical field, we have other methods to check heart function, such as cardiac ultrasound monitoring and ballistocardiology (BCG). Mechanical cardiograms record electrical signals from the heart, but there is a 30 to 40 microsecond delay in the signals.

As healthcare technology continues to evolve, these market trends are revolutionizing the healthcare landscape. Clinical devices once found only in hospitals or doctors' offices are now found in homes. Portable medical devices such as blood pressure monitors, blood glucose meters, and weight scales are already connected to data hubs or securely send personal monitoring data to the medical cloud. All types of medical equipment are moving from hospitals to homes.

In addition to bringing medical devices into the home, widespread use of mobile connectivity for healthcare can significantly reduce healthcare costs, increase the coverage and accessibility of healthcare services, and reduce the impact of disease on people's lives. As the cost of embedded mobile health solutions decreases, remote patient monitoring capabilities are expected to explode, creating opportunities for the development of innovative services. The goal of remote patient monitoring is to reduce the healthcare cost burden caused by unhealthy lifestyles and an aging population.

These trends indicate that the application of sensor technology in the healthcare field will continue to play a key role in providing patients with more convenient and efficient medical services, while promoting the innovation and digitalization of medical equipment. This development will have a profound impact on human health and healthcare.