Search

The positioning problem considered in this paper is an attempt to find system’s of a few points position using accelerations. Today’s industry provides with various types of accelerometers suitable for acceleration measure. That data may be used to trace object movement. Final results showed that such movement trace is possible and may be applicable. The results also showed origins for errors which according to the results, are quite high globally. The final conclusion follows: the model created must be analized further in a deeper level, and error origins must be eliminated or at least minimized by either chosing different solving or modeling methods, either by revising used ones.

Background and Aims: A present prospective study was conducted to evaluate ocular changes occurring in patients undergoing spine surgery in the prone position. Material and Methods: A total of 44 patients of either sex, belonging to American society of Anaesthesiology I and II (aged 18-60 years) scheduled for elective spine surgery in prone position were enrolled in the study. Baseline IOP and MAP measurement were taken prior to induction. After induction of anaesthesia patients were intubated using flexo-metallic tube of appropriate size. IOP and MAP were recorded after induction of anaesthesia, following completion of surgery and immediately after turning the patient supine and 30 min following extubation. Blood loss and duration of surgery was also noted. The OPP was derived using the formula (OPP = MAP-IOP). Ophthalmic examination was also performed using direct and indirect ophthalmoscopy on the day prior to surgery and on first post-operative day to rule out anterior ischemic optic neuropathy (AION), posterior ischemic optic neuropathy (PION), and retinal ischemia. Results: Mean IOP significantly increased (18.91 ± 3.56 mm Hg) (P < 0.001) at the end of surgery as compared to baseline value 12.85 ± 3.07 mm Hg. As a result mean OPP significantly reduced (75.12 ± 16.45) (P = 0.0018) at the end of the procedure. Conclusion: In patient's undergoing spine surgery in the prone position, careful patient positioning with no extrinsic pressure on the eyes, minimal surgical time and blood loss, and prevention of intraoperative hypotension, should be ensured to prevent the IOP rise and a reduction in OPP which can further prevent post-operative visual disturbance.