Transducers

This chapter introduces transducers that are commonly used in biomedical devices. We describe the main operations of these transducers and show how to model them using equivalent circuit models. Models developed in this chapter will be used in later chapters as components of biomedical devices. We start with transducers that measure displacement and introduce resistive, piezoelectric, and capacitive transducers. When discussing optical transducers, we present LEDs and photodetectors. Finally, electrodes used for electrocardiogram and bioimpedance monitoring are discussed. Equivalent circuit models and features of wet, dry, and non-contact electrodes are presented in detail.