The Preliminary Research Of Larynx Dynamicobserving And Analyzing System

The project of larynx dynamic observing and analyzing system were subsidized by China Association for Instrument Analysis. The ultimate goal of this project is to develop the larynx dynamic observing and analyzing instrument system and the computer software and hardware system with the function of the voice acoustic analysis and the glottal image analysis that based on the virtual instrument technique. The function of the software, result and significance of some basic experiments are discussed in detail.The laryngostroboscope, which is also known as larynx stroboscope, can help to observe the complicated vibration of vocal cords. It has been widely used in examination and documentation of laryngeal diseases. In recent years, with the development of electronic technology and widely spread use of computer, the objective and quantitative analytical technique, like the voice acoustic analysis and the glottal image analysis technique etc, were used to the diagnosis of the laryngeal diseases. All these technique and methods provide quantificational parameters to diagnose laryngeal diseases.The main hardware system of the larynx dynamic observing system is composed of a microcomputer, continuous and flash light sources, a CCD (charge-coupled device) type of camera, a video recorder, a microphone, a monitor or television screen, rigid telescope and/or a fiberscope.The software system is programmed with assembly language and LabWindows/CVI. The assembly language program was used to auto control the larynx dynamic observing system.The function of voice acoustic analysis and theglottal image analysis are realized by using the LabWindows/CVI virtual instrument programming language. The voice acoustic analyzing system may sample and store voice signals, pick up and analyze several parameters such as FPQ, APQ, HNR etc. The glottal image analyzing system may observe the image of a slowly continuous movement of vibrating vocal cords or the morphologic changes of glottal. When the vibrating vocal cords are illuminated in a strictly synchronous manner by the intermittent light source, the image will appear to be stationary because the same phase of the cycle will always be illuminated. Any phase in one cycle can be observed. It may pick up and analyze several parameters of image signals such as glottal length , glottal area etc. While observed directly, the glottal images can be displayed on screen and be stored by digital video camera in order to restore and analyze by computer.To research the correlation of measure distance and angle with the image of laryngostroboscope and the degree of their correlation, a series of basic experiments has been designed to measure the area and length of the image of a fixed size object from different distance and angle by the system of larynx dynamic observing which based on the Virtual Instruments. The result shown when the size of object was fixed, the area and length of the image of the laryngostroboscope are obviously related with measure distance, but not related with the metrical angle.Compared to congener products, this system possesses the multiple functions and is expected to be easy-to-use, low cost, capable of automatic quantitative analysis with perfect performance etc. It will be an ideal instrument for the modernization of laryngology and voice medical science.