Towards free-breathing spirometery-on-chip: Design, implementation and preliminary experimental results

This paper presents a new approach towards the development of a free-breathing micro-spirometer system on a single chip for point-of-care (POC) diagnosis of lung diseases. In this paper, we take the first step by designing and implementing a cantilever array chip using a standard micro-electromechanical system (MEMS) process. Each cantilever beam is incorporated with capacitive electrodes for sensing the cantilever deflection. Herein we also put forward a custom-made readout interface circuit for the measurement of minute capacitive changes and for data acquisition purposes. Furthermore, we demonstrate and discuss the fabrication and characterization and spirometry results. Based on these results, the device is used for measuring the breathing airflow with a resolution better than 12 bits. These preliminary results reveal the functionality and applicability of the propose d system for POC diagnostics applications related to lung disease.