Abstract
Purpose
Esophageal stethoscope is a device to measure heart sound or respiratory sound by inserting a catheter into the patients’ esophagus during operation. It is easy to use, noninvasive, and not influenced by ambient noise, but does not provide the quantitative information about cardiovascular system. Thus, in this study, we tried to develop a digital esophageal stethoscope system (DESS) that can be used to monitor the heart sounds of anesthetized patients during operation.
Methods
It consists of the wireless sensor module and the base station. The wireless sensor module acquires and amplifies heart sound data with microphone connected to esophageal catheter and transmits the data to the base station through Bluetooth. The base station is composed of a receiver and a PC. The receiver processes and forwards the heart sound data to a PC, where MatLab based software (Cardiac Sound Analyzer) records and displays the heart sound as phonocardiogram and spectrogram in time and frequency domain in real time. Besides, it can quantify and objectify heart sound information by calculating its intervals, heart rates, and intensity values in dB.
Results
We performed a pilot experiment with patients under general anesthetic surgery and evaluated the performance of the developed system.
Conclusions
This system is so simple and useful for anesthesiologist to evaluate the included information on cardiac condition without being disturbed by ambient noise and is helpful for comparing a patient’s states before and after surgery.
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Shin, J.Y., Kim, Y.C., Lim, S.W. et al. A digital esophageal stethoscope system for monitoring anesthetized patients’ cardiovascular system. Biomed. Eng. Lett. 2, 265–270 (2012). https://doi.org/10.1007/s13534-012-0080-9
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DOI: https://doi.org/10.1007/s13534-012-0080-9