Parsaei H, Vakily A, Shafiei A M
Department of Medical Physics and Engineering, Shiraz University of Medical Sciences, Shiraz, Iran.
Health Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
J Biomed Phys Eng. 2017 Mar 1;7(1):69-78. eCollection 2017 Mar.
The basic requirements for monitoring anesthetized patients during surgery are assessing cardiac and respiratory function. Esophageal stethoscopes have been developed for this purpose, but these devices may not provide clear heart and lung sound due to existence of various noises in operating rooms. In addition, the stethoscope is not applicable for continues monitoring, and it is unsuitable for observing inaccessible patients in some conditions such as during CT scan.
A wireless electronic esophageal stethoscope is designed for continues auscultation of heart and lung sounds in anesthetized patients. The system consists of a transmitter and a receiver. The former acquires, amplifies and transmits the acquired sound signals to the latter via a frequency modulation transmitter. The receiver demodulates, amplifies, and delivers the received signal to a headphone to be heard by anesthesiologist.
The usability and effectiveness of the designed system was qualitatively evaluated by 5 anesthesiologists in Namazi Hospital and Shahid Chamran Hospital, Shiraz, Iran on 30 patients in several operating rooms in different conditions; e.g., when electro surgery instruments are working. Fortunately, the experts on average ranked good quality for the heard heart and lung sounds and very good on the user friendly being of the instrument.
Evaluation results demonstrate that the developed system is capable of capturing and transmitting heart and lung sounds successfully. Therefore, it can be used to continuously monitor anesthetized patients' cardiac and respiratory function. Since via the instrument wireless auscultation is possible, it could be suitable for observing inaccessible patients in several conditions such as during CT scan.
手术期间监测麻醉患者的基本要求是评估心脏和呼吸功能。为此已开发出食管听诊器，但由于手术室存在各种噪音，这些设备可能无法提供清晰的心肺声音。此外，听诊器不适用于连续监测，在某些情况下，如CT扫描期间，也不适合观察难以接近的患者。
设计一种无线电子食管听诊器，用于连续听诊麻醉患者的心肺声音。该系统由一个发射器和一个接收器组成。前者采集、放大并通过调频发射器将采集到的声音信号传输到后者。接收器对接收到的信号进行解调、放大，并将其传送到耳机供麻醉师收听。
伊朗设拉子纳马齐医院和沙希德·查姆兰医院的5名麻醉师在不同条件下的几个手术室中，对30名患者进行了定性评估，以评价所设计系统的可用性和有效性；例如，当电外科器械工作时。幸运的是，专家们对听到的心肺声音平均质量评价良好，对仪器的用户友好性评价非常好。
评估结果表明，所开发的系统能够成功地捕捉和传输心肺声音。因此，它可用于连续监测麻醉患者的心脏和呼吸功能。由于通过该仪器可以进行无线听诊，它可能适用于在多种情况下观察难以接近的患者，如CT扫描期间。
