This paper presents a new human-machine interface for controlling a wheelchair by head movements. The position of the head is determined by use of infrared sensors, with no parts attached to the head of the user. The placement of the infrared sensors are behind the head of the user, so that the field of view is not limited. Tests on a wheelchair have shown that the system is functioning in real...

This work investigates the control of horizontal head movements in the context of unconstrained visually guided head and arm/finger aiming tasks. In a first experiment, the head was free to move while gaze was directed at randomly presented eccentric targets distributed horizontally (0 degrees-120 degrees) at eye level. In a second experiment, the horizontal head orientation was constrained to ...

Dinocephalian therapsids are renowned for their massive, pachyostotic and ornamented skulls adapted for head-to-head fighting during intraspecific combat. Synchrotron scanning of the tapinocephalid Moschops capensis reveals, for the first time, numerous anatomical adaptations of the central nervous system related to this combative behaviour. Many neural structures (such as the brain, inner ear ...

background: obtaining a good sensory and motor block is the goal of performing spinal anesthesia for surgeries. the aim of this study is to compare the effect of trendelenburg position on sensory block level after spinal anesthesia with intrathecal hyperbaric bupivacine. methods: we enrolled 80 men, classified as asa i, scheduled for elective hernia repair under spinal anesthesia. participants ...

OBJECTIVE To determine the reliability of obtaining two-dimensional cephalometric measurements using two virtual head orientations from cone-beam computed tomography (CBCT) models. MATERIALS AND METHODS CBCT scans of 12 patients (6 class II and 6 class III) were randomly selected from a pool of 159 patients. An orthodontist, a dental radiologist, and a third-year dental student independently ...

The ability to simultaneously move in the world and maintain stable visual perception depends critically on the contribution of vestibulo-ocular reflexes (VORs) to gaze stabilization. It is traditionally believed that semicircular canal signals drive compensatory responses to rotational head disturbances (rotational VOR), whereas otolith signals compensate for translational movements [translati...

a fundamental assumption in prosthetic dentistry is that the axis-orbital plane will usually be parallel to the horizontal reference plane. most articulator systems have incorporated this concept into their designs and use orbitale as the anterior reference point for transferring the vertical position of the maxilla to the articulator. clinical observations of cantonese patients suggest that in...

BACKGROUND In order to avoid microaspiration and tracheal injury, the target for endotracheal tube cuff pressure is 20 to 30 cm H2O. OBJECTIVE To assess the effect of changes in body position on cuff pressure in adult patients. METHODS Twelve orally intubated and sedated patients received neuromuscular blockers and were positioned in a neutral starting position (backrest, head-of-bed elevat...

[Purpose] This study examined differences in neck muscle activity in two different head positions during tackles with the aim of contributing to the prevention of sports injuries. [Subjects] The subjects were 28 male high-school rugby players. [Methods] Two tackle positions were considered: a head-up position and a head-down position. Muscle activities of the sternocleidomastoid muscles and the...