The body and the medical devices that support it rely on continuous, uninterrupted fluid flow. Infusion pumps, dialysis, and applications for monitoring blood flow are vital technologies in addressing certain health issues. Sensors are integrated into various pump and flow applications to detect blockages and (air) bubbles in lines, as well as to measure fluid levels or continuous flow.
Infusion pump at the bedside
Infusion pumps
Infusion pumps are used in clinical settings to administer controlled doses of fluids, medications, or nutrients to patients. The pressure required for successful automatic fluid delivery depends significantly on whether the fluids are introduced intravenously, subcutaneously, or arterially. Contrast agents, in particular, can have very high viscosity, requiring up to 100 bar of pressure from the injection pump. However, such pressure could rupture any blood vessel in the human body, so pressure control is essential during injection.
To ensure proper dosing, AMSYS recommends using highly accurate and high-resolution sensors. Incorrect dosing can lead to severe complications or even death. This is one of the most critical applications for pressure in the medical industry.
- In these cases, relative or differential pressure needs to be measured in the range of 200 mbar to 2 bar. For this purpose, biocompatible relative sensors like the MS5547 or absolute sensors like the MS5849 can be used, as well as cost-effective, unamplified disposable sensors such as the 1620. In rare cases of highly viscous liquids requiring the measurement of relative pressures up to 100 bar, ceramic sensors like the ME772 or ME780 are employed. Additionally, external force sensors like the FS-19, mounted on the inlet hose, can be used to determine the internal hose pressure.
Bubble detectors
Injection sensor technology also includes bubble detectors that monitor the injection hose for unwanted air bubbles. Once a bubble is detected, the syringe pump or infusion solution supply is stopped via a valve, and an alarm is triggered.
The compact Air Bubble Detector AD-102 (ABD) is used for non-invasive, continuous monitoring of fluids to detect air bubbles. Reliable detection of fluid flow interruptions is crucial in applications such as infusion pumps, hemodialysis, and blood flow monitoring. Using ultrasound technology, the AD-102 sensor is capable of clearly identifying disruptive air bubbles. In addition to infusion pumps, these bubble detectors are also used in blood transfusions, general blood processing, biotechnology, and chemical analysis.
AD-102 – Air Bubble Detector for Flowing Liquids
- It detects air bubbles up to 25% of the tube’s inner diameter
- Input: 5 VDC
- Output: 5.0 V TTL logic
- Standard 6 mm outer tube diameter (the sensor can optionally be adjusted to tube outer diameters between 3 and 10 mm)
