Research On Portable Laryngoscope Based On Embedded System

Orotracheal intubation is an effect way to maintain airway under emergent situation. However, because of visual blind spots orotracheal intubation makes the patients suffer severe complication. A solution to this problem is the video laryngoscope, which displays the image of trachea on the LCD. At present, the domestic products cannot process the image such as saving the images and the video, which can be used to diagnose later. So it is very necessary to develop the video laryngoscope with image processing functions.This paper mainly studies the video laryngoscope with an embedded processor, the software is developed based on wince real time operating system, The paper includes the following two aspects:(1)The design of the hardware circuit lay the foundation of the whole system, The processor capture the image by the camera interface, which is stored in the SDRAM, then after demosaicking the processor displays the image on the LCD by the RGB888serial interface. The decoding circuit is designed to decode LVDS signal, which can extends the working distance to5meters with good image quality, The processor stores the image in the SD card through the SDMMCO interface and controls the sound chip by the â…¡S interface, The video or the image can be saved by the key.(2) The software of the wince operating system is divided into two parts: the application and the drivers, The camera driver, LCD driver, button driver has been realized to control the hardware, the software has been elaborated to show the image on the LCD and store the video or the picture. The performance of the image display has been greatly improved by using the double-thread methods. The MFC methods is taken to encode the image and the compression ratio is140:1,an algorithm is designed to change the image from the RGB color space to YUV color space fast, According the circumstance auto exposure function is realized based on the peak value or the average value of image. Only1second is needed to adjust brightness of the image into proper range, for the application of the emergency situation the boot time of the wince system is reduce to5seconds by the multi-bin and tailing the kernel.The system supports the functions of TV and HDMI, The system display image on the LCD with the resolution of320*240, the frame rate can reach to25fps even when the video of640*480resolution is encoding, white balance, automatic exposure has been realized to make the video laryngoscope more convenient.The performance of the video laryngoscope has met the requirements of the clinical practice and it has practical values.