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The concept of a fiber-optic Strain rosette is introduced. A mathematical framework describing how surface adhered optical fibers can be configured to measure t h e state d Strain is presented. Details d the design, fabrication, and testing d fiber-optic strain rosmtes based MI Fabry-Perm interferometers are given. The performance of these devices indicates that they are viable anernatives to resistive-foil rosettes in situations where the benefits of using optical fiber for Strain measurement are significant.

A fiber optic analogue of the electrical strain rosette is proposed and shown to be necessary if two -dimensional strain fields are to be mapped using fiber optic sensors. The first fiber optic strain rosette has been constructed and preliminary testing demonstrates its ability to determine principal strain magnitudes and axis orientation.Polarimetric transduction was used for this device; the strain sensing region along each arm was localized using 45°f usion splices. This ensured that the strain rosette was lead -in and lead -out insensitive. Possible non -polarimetric designs for optical strain rosettes are also suggested.

Ten patients with retained biliary calculi demonstrated by postoperative T-tube cholangiography were managed by a simple nonoperative washout technique. The bile was cultured routinely before each group of washouts, since fever was a common sequel in the presence of infected bile. After a parenteral dose of propantheline bromide, the biliary tree was flushed through the T-tube with 1 litre of normal saline containing 40 ml of lignocaine. Progress was followed by T-tube cholangiography, and the criterion of success was a cholangiogram showing adequate filling of the biliary tree, absence of filling defects, and free flow of contrast medium into the doudenum. The technique was successful in six of the ten patients. There was no mortality and no significant morbidity.