An overview of existing head supports for people with reduced or altered head mobility: current solutions and future developments

The first objective of this research was to create an overview of existing assistive devices for supporting the head of people with decreased or altered head mobility. The second objective was to identify future research opportunities, also by investigating what functionalities are still missing in the current head support solutions. A systematic literature review was performed, combined with searches in technology manufacturer databases and websites, to get an overview of existing head support solutions. Expert opinions were gathered, as well as feedback from a number of head support users by means of semi-structured interviews. A database was constructed from the assistive devices that were found. Devices were categorized with respect to type of interface with the user, functionality and amount of adjustability in the system. Existing solutions that stabilize the head are mainly static, meaning that the head can only be stabilized in one position. Some systems offer freedom of movement but do not really support the head. Additionally, some systems can be configured such that there is a certain level of adaptability to the user. However, if head support systems are adjustable, most often it are systems which enable the caregiver and/or end user to manually change the head support to another position. Based on feedback from experts and users it can be concluded that there is a need for assistive devices that provide independent adjustability in such a way that changes in position of the trunk and head are combined with continuous stabilization. Combining this need with current developments in robotic assistive devices, recommendations are given for future research on head supports

An overview of head support solutions for people with reduced or altered head mobility

Objective: To create an overview of existing assistive devices for supporting the head of people with decreased or altered head mobility. Additionally, to investigate if there are any functionalities missing in the current head support solutions. Search strategy: A systematic literature review was performed, combined with searches in technology manufacturer databases and websites, to get an overview of existing head support solutions. Expert opinions were gathered, as well as feedback from a number of head support users by means of semi-structured interviews. Selection of articles: A database was constructed from the assistive devices that were found. Evaluation of articles and results: Devices were categorized with respect to type of interface with the user, functionality and amount of adjustability in the system. Conclusion: Existing solutions that stabilize the head are mainly static, meaning that the head can only be stabilized in one position. Some systems offer freedom of movement but do not really support the head. Additionally, some systems can be configured such that there is a certain level of adaptability to the user. However, if head support systems are adjustable, most often it are systems which enable the caregiver and/or end user to manually change the head support to another position. Based on feedback from experts and users there can be concluded that there is a need for assistive devices that provide independent adjustability in such a way that changes in position of the trunk and head are combined with continuous stabilization

Investigating Use of a Parent Report Tool to Measure Vocabulary Development in Deaf Greek-speaking Children with Cochlear Implants

Objective: There are very few measures of language development in spoken Greek that can be used with young deaf children. This study investigated the use of Cyprus Lexical List (CYLEX), a receptive and expressive vocabulary assessment based on parent report that has recently been adapted to Standard Greek, to measure the vocabulary development of deaf Greek-speaking children with cochlear implants. Design: A Standard Greek version of CYLEX was used to collect data on receptive and expressive vocabulary development from parents of thirteen deaf children with cochlear implants aged between 21 and 71 months. These data were compared with data collected previously from typically developing hearing Greek-speaking children. Results: Use of the test by parents of deaf children was found to be reliable. No correlation was found between children's vocabulary scores and chronological age. A positive correlation was however found between children's post-implant age and expressive vocabulary. The vocabulary skills of implanted children with a mean post-implant age of 20 months were not significantly different from those of typically developing hearing children of similar chronological age. Conclusion: CYLEX is a reliable and useful tool for exploring vocabulary development with this clinical group. Findings confirm the results of other studies in indicating that the vocabulary size of implanted pre-school-aged deaf children is related to the amount of time that children have used their implant, rather than chronological age

Dynamic ordering and frustration of confined vortex rows studied by mode-locking experiments

The flow properties of confined vortex matter driven through disordered mesoscopic channels are investigated by mode locking (ML) experiments. The observed ML effects allow to trace the evolution of both the structure and the number of confined rows and their match to the channel width as function of magnetic field. From a detailed analysis of the ML behavior for the case of 3-rows we obtain ({\it i}) the pinning frequency $f_p$, ({\it ii}) the onset frequency $f_c$ for ML ($\propto$ ordering velocity) and ({\it iii}) the fraction $L_{ML}/L$ of coherently moving 3-row regions in the channel. The field dependence of these quantities shows that, at matching, where $L_{ML}$ is maximum, the pinning strength is small and the ordering velocity is low, while at mismatch, where $L_{ML}$ is small, both the pinning force and the ordering velocity are enhanced. Further, we find that $f_c \propto f_p^2$, consistent with the dynamic ordering theory of Koshelev and Vinokur. The microscopic nature of the flow and the ordering phenomena will also be discussed.Comment: 10 pages, 7 figure, submitted to PRB. Discussion has been improved and a figure has been adde

Design of a dynamic and adaptive head support

For people with severe muscle weakness or paresis in the trunk and neck muscles, adequate head support is required. Although several assistive devices exist that can support a person’s head position, there is an absence of devices that are capable to support head movements in a natural and safe way. The large individual variation between users requires an individual match between user and assistive device. Existing solutions to stabilize the head are mainly static, meaning that the head can only be stabilized in one position. Some systems offer freedom of movement but do not provide support to the head. Additionally, some systems can be configured to allow a certain level of adaptability to the user. However, if head support systems are adjustable, mostly they are systems which enable the caregiver to manually change the head support to another position. There is no opportunity for adjustment by the user. It can be concluded that there is a need for assistive devices that provide dynamic adjustability by combining changes in position of the trunk and head with continuous stabilization. The main objectives of this project are to characterize this need for support, and to develop a first proof‐of‐concept of a dynamic and adaptive head support. This report explores the use of new control methods, implementing position control on an actuated head support system. The presented system can steer the head support position in 3D (including orientation) in a more efficient and natural way. Additionally, the system can autonomously adapt the head support position according to the back seat angle of the electric wheelchair. Thus, it is a first step in the development of a new generation of dynamic and adaptive head supports that are intelligent enough to autonomously personalize their behavior to the user. This PDEng project is done in collaboration with the company Focal Meditech B.V. and is part of the TTW research project Symbionics

Investigating head-neck stabilization using combined mechanical and galvanic vestibular stimuli

The goal of this study was to assess if the superposition principle is valid in head-neck stabilization during combined torso perturbations and continuous galvanic vestibular stimulation. Nine seated subjects were perturbed in lateral direction on a motion platform while GVS was simultaneously applied. Both the mechanical and galvanic input signals consisted of multisine signals and were designed to be mathematically uncorrelated. For the motion perturbations, two direction and two amplitude variations were included. The GVS signal was applied in a bilateral bipolar configuration at 4 mA. During trials subjects had their eyes closed and were asked to perform a natural stabilization task. Displacements of the head, torso and platform were recorded using a motion capture system. System identification techniques were used to identify the relationship between respectively inputs GVS and torso motion and output head motion. Results show that it is feasible to apply low-level torso perturbations together with continuous galvanic stimulation in studying the head-neck system as high coherencies and consistent behavior are found for the transfer functions from mechanical and galvanic inputs to head motion over all subjects. It is concluded that superposition principle does not hold as gain, phase and coherence modulations were found with the addition of GVS.BMEBioMechanical EngineeringMechanical, Maritime and Materials Engineerin