Electrocardiographs, plethysmographs, tonometers, Holter ECG are conventional tools in practical medicine.
Most of them are stationary and widely used in hospital as well as in clinics, for instance traditional
electrocardiograph (see appendix I, Fig 15.29). Holter ECG (see appendix I, Fig 15.30) is capable to record
electrocardiogram as the standard electrocardiograph and designed for the ambulatory use. However, still
stationary electrocardiographs are irreplaceable in hospitals and clinics. Functionality of stationary
electrocardiographs can be available in real time use, for instance during surgery, which is the lack in
traditional Holter ECG. Normally 24h record transferred from Holter ECG to a computer application, which is
later analyzed by the health care provider.
Hardware related issues
Practical medicine is already full of available tools and methods, which are day to day improved by new
technologies. However, technologies and techniques in hospitals are far from daily time use. Most
challenging part is bio-signal recordings, which should preserve daily life activities with minimal intervention
of sensors. This chapter reviews found state of the art hardware solutions and existing blood pressure
measuring techniques related to the practical use in daily life activities.
Dry foam electrodes
Micro-needle  and nano-spikes  electrodes
capacitive coupling electrodes
Concentric circular ring (Fig 5.4) electrode
Blood pressure measuring techniques
Pulse transit time technique
Pulse wave velocity technique
Pulse wave feature technique