Sick and frail individuals are less active. However, it is precisely this group that requires systematic, light exercise to train their muscles and maintain mobility. Healthy individuals also increasingly use sensor technology to track their sports activities and motivate themselves through comparisons with others or with their own past performance.
Differential pressure sensor SM9333 for ± 125 Pa
Barometric Height and Depth Measurement
With high-resolution absolute pressure sensors such as the MS5637 or MS5607, which are attached to the patient, height differences of just a few centimeters can be measured using the barometric height formula. This allows easy recording of altitude profiles during hikes, but also in buildings where GPS tracking fails. For example, the calories burned while climbing stairs can be calculated.
In sports aviation, sensors like the AMS 5915 not only monitor altitude but also the rate of climb and descent, as described in this interesting article about a variometer for hobby pilots: Link to article on linkedIn
With absolute pressure sensors such as the MS5611 and AMS 5915, Akaflieg Saarbrücken e.V. has also developed an automated takeoff detection system for aircraft.
Waterproof absolute pressure sensors like the MS5837 or MS5849, which are protected from water ingress by silicone gel, are used in sports watches to measure current depth during dives, issue warnings, and support controlled ascent.
Position control
Patients who stay in the hospital for long periods often spend a lot of time lying in bed. Pressure sensors can be incorporated into hospital beds to ensure that patients move sufficiently to prevent pressure ulcers. Pneumatic bed inserts are often used for this purpose, which influence the patient’s lying position. Air cushions, monitored by relative pressure sensors, control the position of patients, e.g., in beds and wheelchairs.
- In these applications, relative pressure must be measured up to 2 bar using sensors such as the digital AMS 6915 or analog AMS 6916.
For intensive care patients, the position (lying down) often needs to be strictly maintained due to connected devices or previous treatments. Sensitive pressure sensors attached to the patient’s body can detect whether the patient is rising or maintaining their position.
- In these applications, absolute pressure must be measured up to 2 bar using sensors such as the MS5637.
Movement control
A movement control can be necessary for therapeutic reasons. By using absolute or barometric pressure sensors that can detect the body position of patients, it is possible to monitor whether the patient is lying down, sitting, standing upright, or walking. The same monitoring method is also applicable for elderly, frail individuals for whom a fall cannot be ruled out.
- In all these cases, absolute or barometric pressure sensors with high resolution up to 2 bar are used. The AMS 5935, in addition to offering a 24-bit resolution, features an extremely low power consumption thanks to its built-in sleep mode, making it ideal for mobile applications when combined with its 3.3V supply voltage.
Blood Pressure Measurement
Pressure sensors are of course also widely used in medical technology for measuring blood pressure. Ex-vivo measuring pressure sensors for determining the relative pressure of air cuffs such as the AMS 6915 are mostly used here. An application note on building a blood pressure monitor based on an AMS 5915 using an Arduino microcontroller and a suitable Arduino Nano Shield can be found here: Application note: Construction of a blood pressure measurement device
With biocompatible relative pressure sensors such as the 1620, blood pressure can also be measured directly in contact with body fluids. The advantage of this sensor is its interchangeability: after use, this inexpensive disposable sensor does not need to be sterilized, but is simply replaced with an identical model. The stable series production allows a deviation of less than 1% between the sensors used.