Search results for "Constant speed"

Spring constants of capsular tension rings.

2004

Purpose To determine the spring constants of several types of capsular tension rings (CTRs). Setting Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. Methods Fourteen models of CTRs provided by 9 companies were tested; all were 11.0 mm in diameter. The CTRs were positioned in a special retainer of a material-testing machine and compressed at a constant speed of 10.0 mm per minute. The distance and force values were recorded, and each CTR model was tested 3 times using a new specimen each time. The resulting measurements were used to calculate a mean spring constant for each CTR model. Results All tested CTRs showed linear proportionality between force and compress…