Preference elicitation: Obtaining gestural guidelines for PACS in neurosurgery.

OBJECTIVE: Accessing medical records is an integral part of neurosurgical procedures in the Operating Room (OR). Gestural interfaces can help reduce the risks for infections by allowing the surgical staff to browse Picture Archiving and Communication Systems (PACS) without touch. The main objectives of this work are to: a) Elicit gestures from neurosurgeons to analyze their preferences, b) Develop heuristics for gestural interfaces, and c) Produce a lexicon that maximizes surgeons' preferences. MATERIALS AND METHODS: A gesture elicitation study was conducted with nine neurosurgeons. Initially, subjects were asked to outline the gestures on a drawing board for each of the PACS commands. Next, the subjects performed one of three imaging tasks using gestures instead of the keyboard and mouse. Each gesture was annotated with respect to the presence/absence of gesture descriptors. Next, K-nearest neighbor approach was used to obtain the final lexicon that complies with the preferred/popular descriptors. RESULTS: The elicitation study resulted in nine gesture lexicons, each comprised of 28 gestures. A paired t-test between the popularity of the overall gesture and the top three descriptors showed that the latter is significantly higher than the former (89.5%-59.7% vs 19.4%, p < 0.001), meaning more than half of the subjects agreed on these descriptors. Next, the gesture heuristics were generated for each command using the popular descriptors. Lastly, we developed a lexicon that complies with surgeons' preferences. CONCLUSIONS: Neurosurgeons do agree on fundamental characteristics of gestures to perform image manipulation tasks. The proposed heuristics could potentially guide the development of future gesture-based interaction of PACS for the OR.

Development and Characterization Pulsatile Microspheres of Nifedipine for Hypertension.

BACKGROUND: To develop pulsatile microspheres of Nifedipine blend of polymers Carbopol 971P and Eudragit RS100 for antihypertensive to release the drug at a particular lag time. METHODS: Pulsatile nifedipine microspheres were prepared using the blend of Carbopol 971P and Eudragit RS100 at different ratios in a mixture of solvents. Formulations were prepared and optimized on the basis of particle size, percentage yield and drug entrapment efficiency. Optimized formulations were further analyzed at different resolutions per minute (rpm) by optical microscopy, scanning electron microscopy (SEM), in-vitro dissolution studies and kinetics model. The most promising formulation was compared with the marketed products. The recent patents on microsphere used for hypertension for drug used Liensinine (CN104757561). Dopamine antagonist (US20030069232A1), Human Serum Albumin (EP19990304616) and Omeprazole (IN2107/DEL/2014) helped in selecting the drug and polymers. RESULTS: The formulated microspheres had mean particle size ranging from 177.31 to 277.48 &micro;m. Formulation F83 showed slow release of drug initially for 4 h and drastically release of drug enhanced at a particular lag time (Showed pulsatile release) after 6 h. However, conventional marketed products showed maximum release initially at 1 h and decreased gradually while controlled released marketed product showed sustained pattern. CONCLUSION: On the basis of data formulation F83 showed slow release and at a particular lag time followed by pulsatile release pattern and followed first order kinetics model. It was concluded that the formulated nifedipine pulsatile dosage form could be useful in the treatment of hypertension.