Hult P, Wranne B, Ask P
Department of Biomedical Engineering and Medicine and Care, Clinical Physiology, Linköping University, S-581 85, Linköping, Sweden.
Med Eng Phys. 2000 Jul;22(6):425-33. doi: 10.1016/s1350-4533(00)00050-3.
It is well known that the flow of air through the trachea during respiration causes vibrations in the tissue near the trachea, which propagate to the surface of the body and can be picked up by a microphone placed on the throat over the trachea. Since the vibrations are a direct result of the airflow, accurate timing of inspiration and expiration is possible. This paper presents a signal analysis solution for automated monitoring of breathing and calculation of the breathing frequency. The signal analysis approach uses tracheal sound variables in the time and frequency domains, as well as the characteristics of the disturbances that can be used to discriminate tracheal sound from noise. One problem associated with the bioacoustic method is its sensitivity for acoustic disturbances, because the microphone tends to pick up all vibrations, independent of their origin. A signal processing method was developed that makes the bioacoustic method clinically useful in a broad variety of situations, for example in intensive care and during certain heart examinations, where information about both the precise timing and the phases of breathing is crucial.
众所周知，呼吸过程中通过气管的气流会导致气管附近组织产生振动，这些振动传播到身体表面，并且可以被放置在气管上方喉咙处的麦克风检测到。由于这些振动是气流的直接结果，因此可以准确地确定吸气和呼气的时间。本文提出了一种用于自动监测呼吸和计算呼吸频率的信号分析解决方案。该信号分析方法利用了时域和频域中的气管声音变量，以及可用于区分气管声音和噪声的干扰特征。与生物声学方法相关的一个问题是其对声学干扰的敏感性，因为麦克风倾向于拾取所有振动，而不管其来源如何。开发了一种信号处理方法，使生物声学方法在广泛的情况下在临床上有用，例如在重症监护和某些心脏检查期间，其中关于呼吸的精确时间和阶段的信息至关重要。
