| 摘要 |
A hearing aid shell is moulded using a rapid prototyping system such as stereolithography. Three-dimensional data of the contours of the ear canal of a user are determined using an ultrasonic probe, and this data is then processed in a computer to produce a digital image file. This file is then used by the rapid prototyping system to produce a hearing aid shell that is a precise fit for the ear canal. During the measurement of the ear canal by the ultrasonic probe, the ear canal is filled with a liquid, eg saline. Details of various embodiments of the probe are shown in figures 2 to 7. The ultrasonic measuring system can also be used to monitor the shape of the ear canal for medical diagnostic purposes, as well as the measurement of the shape of any enclosed surface, such as a void or cavity, of a natural or man-made structure. |
