Mass flow meter sensing serves multiple medical device types

November 17, 2015 // By Graham Prophet
Swiss sensor manufacturer Sensirion has expanded its SFM3xxx platform for flow measurement in medical applications, to include autoclavable mass flow meters. The five products in the platform can offer the right solution for all gas flow measurement applications in medical technology.

The five mass flow meters in the range share characteristics such as high precision and robustness. The fully calibrated and temperature-compensated sensors measure the flow rates of air and other non-aggressive gases bidirectionally and highly accurately, and with low pressure drop and fast response time.

The SFM3000 digital mass flow meter is suitable in particular for high-volume applications where cost is paramount. Joining it is the SFM3100, an analogue product that can be integrated into existing devices. A temperature sensor in the gas channel of the sensor enables highly precise temperature compensation and eliminates the need for an additional temperature sensor. The SFM3200 mass flow meter offers a broad dynamic measurement range and high precision at low flow rates. Thanks to the very low pressure drop in the flow body, this sensor is particularly suitable for medical ventilation and other respiratory applications. With the SFM3200-AW and SFM3300-AW, Sensirion adds two autoclavable mass flow meters. Withstanding being treated in an autoclave, they are reusable. The SFM3200-AW offers exceptional performance at low flow rates, while the SFM3300-AW is notable for its stability in varying inlet conditions. Sensirion is also working on the development of a disposable product.

The sensors can be used in a wide range of medical applications, such as ventilation or anesthesia, inhalers, drug delivery and metabolic measurements. The SFM3000, SFM3100 and SFM3200 mass flow meters are particularly suitable for inspiratory flow measurements, while the autoclavable sensors are the first choice for expiratory respectively proximal flow measurements.

The SFM3xxx is based on the company's CMOSens Technology. This enables integration of sensor and evaluation circuit on a single CMOS silicon chip. The result is an ultra-precision system that offers long-term stability for sophisticated and cost-sensitive applications. The technology is also highly resistant to environmental effects, which is why CMOSens-based flow sensors are perfect for use as sterilisable sensors.

Sensirion; www.sensirion.com/gasflow and www.sensirion.com/aw-sensors