A smart thin-film flow sensor for biomedical applications

Presents the prototype of a thin-film flow sensor for biomedical applications. A quick response, a high sensitivity, recognition of flow direction and a wide dynamic range characterize the miniaturized thermal flow sensor, based on thin film amorphous germanium thermistors. Further enhancement of the sensitivity and a fast response to flow changes has been achieved by an integration of the thermistors on a micro-machined thin membrane. Within an exploratory work this sensor principle had been adapted to measure the respiratory flow. The wide dynamic range in combination with an adaptive control unit maximizes the measurable flow resolution, especially for low flow applications. Along with the minimization of the sensor size the added airway resistance was also reduced. Based on the first results it is envisioned that it will be possible to increase the performance of respiratory monitoring systems and reduce the costs at the same time.