[General anesthesia and cervical anesthesia. What changes in carotid surgery]. / Anestesia generale ed anestesia plessica. Cosa cambia in chirurgia carotidea.

Carotid surgery must be preventive; therefore cerebral protection procedures have been the centre of interest for a decade. Nowadays local cervical block anaesthesia seems to have changed the terms of the problem allowing achieve the aim of "no risk surgery". Therefore we considered our 16 year experience (352 carotids operated on 290 patients). Since 1990 we employed cervical block anaesthesia. In order to ratify as much as possible the two groups of comparison, considering that we adopted some exclusion criteria, we compared the results of the first hundred carotids that underwent surgery with general anaesthesia and the first hundred operated using cervical block anaesthesia. Since we adopted cervical block anaesthesia there was no need of intra-operative monitoring systems because we considered exclusively the patients' clinical answer to preclamping. The use of shunt decreased from 9% to 3%. Surgery performed in cervical block anaesthesia gives a positive impression. This is due to the fact that there is not only a significant reduction of the morbidity rate, especially from a neurologic point of view, but also a reduction of the post-operation hospital stay. Furthermore there is also a better organization of the surgical phases. Direct monitoring of the cerebral function allows a precise analysis of the peri-operatory neurological events. In conclusion our study suggests that cervical block anaesthesia allows clinical benefits for the patient as far as safety is concerned being also more convenient under the economic point of view.

Assessment of inertial and gravitational inputs to the vestibular system.

A new device for the assessment of instantaneous angular and linear accelerations of the head is presented, which is based on four linear tri-axial accelerometers suitably attached to the head by an helmet. A procedure for reproducible helmet placement and calibration is given. A method is also illustrated to work out the different linear accelerations sensed by the vestibular organs in the left and right labyrinths and the components of the angular acceleration sensed by their semicircular canals. The computation is based on few individual parameters describing the helmet position with respect to external landmarks and on the average internal position and orientation of the vestibula. The purpose is to study the components of internal inertial forces, which represent the primary inputs to the vestibular system devoted to equilibrium and oculomotor control. The system is designed to be of easy application during rehabilitation exercises and in clinical environment during diagnostic and therapeutic manoeuvres. The prototype is tested with simple free movements such as "yes", "no", and gait.

A model of an electro-goniometer and its calibration for biomechanical applications.

The paper describes a detailed model of an electro-goniometer based on a elastic beam connecting two 'bases' whose relative orientation should be measured. This kind of device, which has been developed for the analysis of human motion, is also suitable for different applications even when one or more rotations around moving axes occur. After a theoretical analysis of the device working principles, experimental verifications of the model are presented. The paper analyses the characteristics of the device and shows how the goniometer outputs can be converted into more familiar angular conventions avoiding cross-talk and other artifacts.