In most medical applications, an increased pressure relative to the atmosphere (positive pressure) is used, such as in ventilation. The human body also generally operates under positive pressure, for example, in blood vessels. However, there are also several use cases where negative pressure (vacuum) needs to be measured.
Here, too, the sensor can be installed in a way that it remains unaffected by contact with (condensing) moisture. See also our application note on media resistance through backside exposure: Mediacompatibility of silicon pressure sensors

Pressure sensors for negative pressure wound therapy
Wound Therapy
When patients suffer from large wounds or particularly severe burns, negative pressure wound therapy (NPWT) can be used to accelerate the healing process and reduce the risk of infection. A slight negative pressure in the wound area can drain wound moisture and significantly improve healing conditions.
To perform accurate vacuum level measurements, AMSYS offers bidirectional differential pressure sensors or relative pressure sensors for the pressure range of 50 to 150 mbar. For hygienic and cost reasons, biocompatible disposable sensors such as the 1620 are often used, which can measure relative pressure in the medically relevant range up to 300 mmHg.
Saliva Suction
In the dental field, pressure sensors are used not only in air-blowers powered by compressed air but also in saliva suction systems. Since the sensors come into contact with saliva, they need to be resistant to moisture and a small amount of hydrogen peroxide.
Ceramic sensors excel in their superior chemical resistance. Already calibrated and encapsulated in stainless steel housings, sensors like the ME900 are therefore ideal for these applications. Alternatively, unencapsulated sensors like the ME780 with additional low-pressure ranges are also suitable.
Breast Pumps
The negative pressures occurring in breast pumps, typically around a few hundred mbar, can be accurately measured and regulated to avoid discomfort, using relative pressure sensors such as the new MS5547. Its silicon sensing cell is protected by a biocompatible gel, preventing contamination of the valuable breast milk.
Vacuum Devices / Sterilization
In the packaging industry as well as in sterilizers, items are vacuum-sealed. Industrial transmitters, such as the compact AMS 4710, are typically used for this purpose. With its 0..10V output (alternatively 4-20mA (AMS 4712) or 0..5V (AMS 4711)), it is ideal for direct connection to a PLC. Additionally, pressure switches like Pico and P.Touch, which can be programmed on-site or via IO-Link, are used to directly control most relays and many valves with their switch outputs.