The effects of an electronic head-mounted display in vision rehabilitation for patients with tunnel vision.

PURPOSE: To investigate the effect of a new head-mounted electronic visual aid-Acesight on improving visual function and daily activities in patients with tunnel vision. METHODS: 57 patients with tunnel vision participated in this study. The visual field (VF), visual acuity (VA), search ability, time of finding people from the side (TFPS), walking ability, and the subjective feelings of patients with and without Acesight were measured. RESULTS: 15 (36%) patients thought Acesight was "helpful", 16 (28%) thought it was "a little help", and 26 (46%) believed that it was "not helpful." The proportion of people aged < 60 years found Acesight helpful was higher. When wearing Acesight, the average horizontal VF diameter (°) (35.54[8.72]) and vertical VF diameter (°) (26.63[5.38]) were larger than those without visual aids (20.61[9.22], 18.19[6.67]) (P all < 0.001). The average TFPS before and while wearing the Acesight was 1.77s(0.32) and 1.19s(0.29), respectively (t = 14.28, P < 0.001). The average search times, number of collisions, walking speeds when wearing the Acesight were not statistically different from those without visual aids (P all > 0.05). CONCLUSION: More than half of patients with tunnel vision found the Acesight helpful, and a higher proportion of those aged < 60 years old found it helpful. Acesight can expand the horizontal and vertical VF of patients with tunnel vision and can enable patients to detect objects coming from the side earlier. TRIAL REGISTRATION: ChiCTR2000028859; Date of registration: 2020/1/5; URL: http://www.chictr.org.cn/showproj.aspx?proj=47129.

Advances in applications of head mounted devices (HMDs): Physical techniques for drug delivery and neuromodulation.

Head-mounted medical devices (HMDs) are disruptive inventions representing laboratories and clinical institutions worldwide are climbing the apexes of brain science. These complex devices are inextricably linked with a wide range knowledge containing the Physics, Imaging, Biomedical engineering, Biology and Pharmacology, particularly could be specifically designed for individuals, and finally exerting integrated bio-effect. The salient characteristics of them are non-invasive intervening in human brain's physiological structures, and alterating the biological process, such as thermal ablating the tumor, opening the BBB to deliver drugs and neuromodulating to enhance cognitive performance or manipulate prosthetic. The increasing demand and universally accepted of them have set off a dramatic upsurge in HMDs' studies, seminal applications of them span from clinical use to psychiatric disorders and neurological modulation. With subsequent pre-clinical studies and human trials emerging, the mechanisms of transcranial stimulation methods of them were widely studied, and could be basically came down to three notable approach: magnetic, electrical and ultrasonic stimulation. This review provides a comprehensive overviews of their stimulating mechanisms, and recent advances in clinic and military. We described the potential impact of HMDs on brain science, and current challenges to extensively adopt them as promising alternative treating tools.

Modular head-mounted cortical imaging device for chronic monitoring of intrinsic signals in mice.

SIGNIFICANCE: Intrinsic optical signals (IOS) generated in the cortical tissue as a result of various interacting metabolic processes are used extensively to elucidate the underlying mechanisms that govern neurovascular coupling. However, current IOS measurements still often rely on bulky, tabletop imaging systems, and there remains a dearth of studies in freely moving subjects. Lightweight, miniature head-mounted imaging devices provide unique opportunities for investigating cortical dynamics in small animals under a variety of naturalistic behavioral settings. AIM: The aim of this work was to monitor IOS in the somatosensory cortex of wild-type mice by developing a lightweight, biocompatible imaging device that readily lends itself to animal experiments in freely moving conditions. APPROACH: Herein we describe a method for realizing long-term IOS imaging in mice using a 0.54-g, compact, CMOS-based, head-mounted imager. The two-part module, consisting of a tethered sensor plate and a base plate, allows facile assembly prior to imaging sessions and disassembly when the sensor is not in use. LEDs integrated into the device were chosen to illuminate the cortical mantle at two different wavelengths in the visible regime (λcenter: 535 and 625 nm) for monitoring volume- and oxygenation state-dependent changes in the IOS, respectively. To test whether the system can detect robust cortical responses, we recorded sensory-evoked IOS from mechanical stimulation of the hindlimbs (HL) of anesthetized mice in both acute and long-term implantation conditions. RESULTS: Cortical IOS recordings in the primary somatosensory cortex hindlimb receptive field (S1HL) of anesthetized mice under green and red LED illumination revealed robust, multiphasic profiles that were time-locked to the mechanical stimulation of the contralateral plantar hindpaw. Similar intrinsic signal profiles observed in S1HL at 40 days postimplantation demonstrated the viability of the approach for long-term imaging. Immunohistochemical analysis showed that the brain tissue did not exhibit appreciable immune response due to the device implantation and operation. A proof-of-principle imaging session in a freely behaving mouse showed minimal locomotor impediment for the animal and also enabled estimation of blood flow speed. CONCLUSIONS: We demonstrate the utility of a miniature cortical imaging device for monitoring IOS and related hemodynamic processes in both anesthetized and freely moving mice, cueing potential for applications to some neuroscientific studies of sensation and naturalistic behavior.

Are gain values significantly altered by manual data selection when performing the video Head Impulse Test (v-HIT) on all six semicircular canals with two different v-HIT systems.

BACKGROUND: It has not yet been tested whether averaged gain values and the presence of pathological saccades are significantly altered by manual data selection or if data selection only done by the incorporated software detection algorithms provides a reliable data set following v-HIT testing. OBJECTIVE: The primary endpoint was to evaluate whether the averaged gain values of all six SCCs are significantly altered by manual data selection with two different v-HIT systems. METHOD: 120 subjects with previously neither vestibular nor neurological disorders underwent four separate tests of all six SCCs with either EyeSeeCam® or ICS Impulse®. All v-HIT test reports underwent manual data selection by an experienced ENT Specialist with deletion of any noise and/or artifacts. Generalized estimating equations were used to compare averaged gain values based on unsorted data with averaged gain values based on the sorted data. RESULTS: EyeSeeCam®: Horizontal SCCs: The estimate and the p-value (shown in parenthesis) for the right lateral SCC and the left lateral SCC were 0.00004 (0.95) and 0.00087 (0.70) respectively. Vertical SCCs: The estimate varied from -0.00858 to 0.00634 with p-values ranging from 0.31 to 0.78. ICS Impulse®: Horizontal SCCs: The estimate and the p-value for the right lateral SCC and the left lateral SCC were 0.00159 (0.18) and 0.00071 (0.38) respectively. Vertical SCCs: The estimate varied from 0.00217 to 0.01357 with p-values ranging from 0.00 to 0.17. Based upon the averaged gain value from the individual SCC being tested, 148 tests before and 127 after manual data selection were considered pathological. CONCLUSION: None of the two v-HIT systems revealed any clinically important effects of manual data selection. However, 21 fewer tests were considered pathological after manual data selection.

Innovative Head-Mounted System Based on Inertial Sensors and Magnetometer for Detecting Falling Movements.

This work presents a fall detection system that is worn on the head, where the acceleration and posture are stable such that everyday movement can be identified without disturbing the wearer. Falling movements are recognized by comparing the acceleration and orientation of a wearer's head using prespecified thresholds. The proposed system consists of a triaxial accelerometer, gyroscope, and magnetometer; as such, a Madgwick's filter is adopted to improve the accuracy of the estimation of orientation. Moreover, with its integrated Wi-Fi module, the proposed system can notify an emergency contact in a timely manner to provide help for the falling person. Based on experimental results concerning falling movements and activities of daily living, the proposed system achieved a sensitivity of 96.67% in fall detection, with a specificity of 98.27%, and, therefore, is suitable for detecting falling movements in daily life.

Long-term effects of vestibular rehabilitation and head-mounted gaming task procedure in unilateral vestibular hypofunction: a 12-month follow-up of a randomized controlled trial.

OBJECTIVE:: To investigate the long-term effects of adding virtual reality-based home exercises to vestibular rehabilitation in people with unilateral vestibular hypofunction. DESIGN:: Follow-up otoneurological examination in two randomized groups following a previous one-month trial. SETTING:: Tertiary rehabilitation center. SUBJECTS:: A total of 47 patients with unilateral vestibular hypofunction, one group ( n = 24) undergoing conventional vestibular rehabilitation and the other one ( n = 23) implementing, in addition, head-mounted gaming home exercises, 20 minutes per day for one month. INTERVENTIONS:: One year after completing rehabilitation, patients underwent testing with static posturography, video head impulse test, self-report questionnaires, and a performance measure. MAIN MEASURES:: Vestibulo-ocular reflex gain, posturographic parameters such as length, surface, and fast Fourier transform power spectra, self-report, and gait performance measure scores. RESULTS:: Vestibulo-ocular reflex gain was significantly better with respect to pretreatment in both groups. The mixed-method group showed significantly higher gain scores: mean (standard deviation (SD)) at 12 months was 0.71 (0.04), versus 0.64 (0.03) for the vestibular rehabilitation-only group ( P < 0.001). Accordingly, some classical posturography scores such as surface with eyes open and length with eyes closed and low-frequency power spectra were significantly different between groups, with the virtual reality group showing improvement ( P < 0.001). Self-report measures were significantly better in both groups compared to pretreatment, with significant improvement in the mixed-method group as compared to conventional rehabilitation alone: Dizziness Handicap Inventory mean total score was 24.34 (2.8) versus 35.73 (5.88) with a P-value <0.001. CONCLUSION:: Results suggest that head-mounted gaming home exercises are a viable, effective, additional measure to improve long-term vestibular rehabilitation outcomes.