Curve and surface representation by iterative B-spine fit to a data point set

Combination of flecainide and mexiletine for the treatment of ventricular tachyarrhythmias

A combination of oral flecainide and mexiletine was given to 11 patients in whom monotherapy with one of these drugs was ineffective for the suppression of inducible ventricular tachycardia or fibrillation. In eight of 11 studies, combination therapy prevented inducibility of a sustained ventricular tachycardia or resulted in induction of only nonsustained tachycardia (P = 0.0003, when compared to monotherapy). In one patient, a slow ventricular tachycardia was induced. During exercise testing ventricular tachycardia occurred in two of these nine patients, and ventricular fibrillation in another patient. Seven patients received combination on the long term, for a mean of 18 months. One patient had recurrences of ventricular tachycardia which was well tolerated. Another patient had a recurrent episode of ventricular fibrillation, but was successfully resuscitated. Severe congestive heart failure occurred in two patients. ACE inhibitors were given to them and to another four patients. No other important unwanted effects occurred. The combination of mexiletine and flecainide is very effective in suppressing inducible sustained ventricular tachycardia. The efficacy of this combination to prevent recurrences of ventricular tachyarrhythmias is acceptable. Exercise testing is of importance to unmask proarrhythmic effects before discharge from hospital.

Issues and themes in computer aided design for external prosthetics and orthotics

Computer aided design systems are finding use in prosthetics and orthotics in the production of customized components to match to and support body segments. Such systems consist essentially at present of shape measurement, computer manipulation of shape, and manufacture of the support surface or its mould. General themes of design philosophy, relationship of shape and pressure for body segments, representation and presentation of shape information by computer, surface adjustments, measurements and manufacturing geometry are considered. Aspects of existing systems are presented to highlight issues which may be the subject of future developments.