一种医用声觉报警信号输出算法及应用

An Algorithm of Generating the Signals for Medical Audio Alarm

为了提高对音频报警发生源的空间定位,帮助操作者迅速准确的确定报警发生位置,医疗电子设备通常要求其声觉报警具有更加丰富的泛音。但目前主要采用音频录制或脉冲信号为驱动信号的方式,容易引入噪声,从而影响报警质量。为此,将复数领域的Goertzel算法简化为实数领域,以便于编写用于嵌入式单片机的应用程序。提出了一种多泛音声觉报警信号输出的算法,并以实现500 Hz基音及其2~5次泛音的音频信号发生器为例,开发设计了基于嵌入式单片机LM3S9B92的应用程序和硬件音频驱动电路,得到了低噪声、多泛音的声觉报警信号。

An acoustical audible alarm is generally requested in the medical electronics devices to posit where an alarm happen.At present,the medical audio alarm signals are mainly generated by voice recording or pulse-based signals.With those methods,many shrill voices and sharp noises are easily produced to affect the quality of an alarm.Therefore,aim at a qualified medical audible alarm,the traditional Goertzel algorithm was simplified into the real number field from the complex number field.Based on this simplified Goertzel algorithm,a recursive algorithm was proposed to generate a serial of sinusoidal fundamental and its harmonic signals.The algorithm was programmed and tested with an audio processing circuit.The audio circuit was designed based on microcomputer LM3S9B92.According to the tested signal waveforms and the frequency spectrum,a group of lownoise and multi-overtone audible alarm signals were produced.