Development of a real-time breathing-rate monitor using difference operation method and adaptive windowing on dry-electrode ECG signal.

Estimation of breathing rate (BR) along with electrocardiogram signal plays an important role in patient health monitoring. Continuous monitoring of BR is often required during diagnosis of many diseases. Traditional methods like nasal air flow equipments employ cumbersome methods of BR monitoring which is not suitable for continuous monitoring. Therefore, a non-invasive method of estimation is required. This paper proposes a non-invasive way of BR estimation using dry-electrode ECG from the palm of a person. The paper uses Respiratory Peak Arrhythmia and Respiratory Sinus Arrhythmia based ECG derived respiratory rate estimation technique. We have developed an algorithm for real-time BR estimation which can be run on embedded platform having limited computation capability. The whole algorithm was first tested on MIT-BIH polysomnographic database and then later extended to obtained signal from developed analog circuitry and the embedded platform. Nasal airflow sensor is used for calculating reference BR. The developed setup was tested on volunteers and the obtained results show accuracy to be in between 2 breaths per minutes.

Analysis of a GMR-based plethysmograph transducer and its utility for real-time Blood Pressure measurement.

The paper presents study and analysis of a Giant Magneto Resistance (GMR)-based magneto plethysmograph and illustrates its efficacy as a tool for real-time cuff-less measurement of Blood Pressure (BP). The proposed scheme employs two GMR sensors and associated biasing and signal conditioning in its architecture. The delay between output of the GMR sensors is used to estimate the BP. The methodology, circuits and signal processing stages used are described in the paper. A prototype of the GMR-sensing solution is developed and tested. Initially, tests are carried out to determine the quality and characteristics of the plethysmographs produced by developed sensor unit, in different conditions such as various body positions, bias current etc. Good quality bio-signals were obtained during the above tests. Then, the experiments were conducted on 29 volunteers to find the feasibility of developed scheme as a BP monitor. The results obtained show that the performance of developed BP monitor is within acceptable limits.