Content area
Full Text
Introduction
The endoscope is an effective and indispensable tool in otolaryngological clinics.1,2 Working in tandem with a charge-coupled device camera, the endoscope can be used for observation, presentation and documentation.3 In addition, the video-endoscope offers superior image quality compared with conventional fibrescopy with a charge-coupled device camera.4 However, dedicated charge-coupled device camera systems for endoscopy and video-endoscopy are expensive. Here, we report a new and economical method for recording extremely high quality laryngeal images, using a full digital, high definition video camera.
Methods
We used video cameras which had newly become available (i.e. the HDR-HC1 and HDR-HC3 models, Sony, Tokyo, Japan). An endoscopic adaptor (AT-N adaptor, Nagashima Medical Instrument Ltd, Tokyo, Japan) for a popular digital video camera (filter bore: 37.5 and 30.5 mm) was attached to the camera.5,6 By screwing this adaptor to the lens top, either a flexible or rigid endoscope could then be attached to the camera. We mainly used a rigid endoscope (Karl Storz, Tuttlingen, Germany) because of its superior image quality (Figure 1).7 These video cameras could record a 1080i digital high definition video format. This system had 1080 effective scanning lines, and the image quality was much better than that obtained from ordinary digital video format (or from a different type of high definition video format, 720p).
Fig. 1
A full digital, high definition video camera (HDR-HC3 model) and 80 cm high definition video monitor being used in the laryngeal examination of a 75-year-old man with laryngeal cancer. The patient can simultaneously watch a small camera monitor which is turned towards him.
Such cameras provided a high definition video output signal. Using a high definition multimedia interface cable or component video cable, the endoscopic images obtained via full digital, high definition video could be shown simultaneously on the monitor (Figure 1). Both focus and exposure were automatic. However, since glottic movement causes focal plane changes, we preferred to use a fixed focus and to bring the video into focus on the vocal folds. Date and time of recording, as well as the patient's voice, were automatically recorded.
The endoscopic image was recorded on a mini-digital videocassette, the same media as the previous models of digital video camera. The images were...