Handbook of Electronic Assistive Technology

Ladan Najafi, Donna Cowan

• Publisher: Academic Press
• Year: 2018
• ISBN:
  9780128124888
• Topic: Technik & Maschinenbau
• Subtopic: Biomedizinwissenschaft

Electronic Assistive Technology (EAT) is a subset of a wider range of products and services known as Assistive Technology (AT). AT is designed to support and enable people with disabilities, either acquired or congenital, to participate in activities with greater independence and safety. With a global aging population, it has an important role to play in enabling and supporting those with disability and their carers.

Handbook of Electronic Assistive Technology discusses a range of commonly available or emerging electronic assistive technologies. It provides historical background, advice when assessing for these devices and references different models of provision. It includes both medical and engineering aspects of provision. It is anticipated that the book will support students, trainees, and newly qualified Assistive Technology Practitioners to develop their understanding of the field, by considering the variables that could potentially influence the decision-making process when assessing for and providing this equipment. It also provides a reference point for those already practicing in this field and offers coverage of a broader range of technologies than clinicians may be exposed to, in their daily work

This is the first reference book to focus on a comprehensive set of electronic assistive technologies and discuss their clinical application.

• Provides comprehensive coverage of electronic assistive devices
• Gives an overview of physical and cognitive pathologies and approaches for utilizing electronic assistive devices for individuals affected by these pathologies
• Covers essentials for assistive technology practitioners, human factors and technologies

1

Basic Neurosciences With Relevance to Electronic Assistive Technology

Charlie Fairhurst Paediatric Neurosciences, Evelina London Children’s Hospital, Guys and Saint Thomas’ NHS Foundation Trust, London, United Kingdom

Abstract

This chapter takes the reader through the development of the nervous system and the human body as relevant to those involved in the delivery of assistive technology. It describes the areas of the brain and the functions each controls alongside the impact of damage to these structures. This forms the basis for the description of some of the conditions commonly seen in rehabilitation and assistive technology services.

Keywords

Assistive technology; Human development; Neurophysiology; Neurosciences; Pathologies; Rehabilitation

Chapter Outline

1. Introduction
2. Concepts of Impairment Function and Participation
3. Basic Neurosciences
4. How the Central Nervous System Is Made – Neuroembryology
5. Blood Supply
6. Basic Structural Anatomy and Physiology
   1. Basic Neurophysiology
   2. Central Nervous System
   3. Motor System
7. When Things Don’t Work
   1. Specific Conditions
8. References
9. Further Reading

Introduction

The brain is as complicated and yet as simple as you want to make it, honestly! Talk to a neurologist and they can confuse you within seconds and ramble on for months. Back in the old days, when medical school focused entirely on the minutiae, the complexity of the anatomy and physiology taught was mind numbing. We parrot learnt and forgot it all instantaneously as no relevance was given – I’ve always thought it didn’t need to be like that.

We are fundamentally a limited chemical soup, structured in a series of interlinked computerised pathways with a variety of interrelated inputs, mediators and outputs; working on areas of feeling, moving and reasoning. As we develop we start simply and become more and more differentiated. What we can functionally do is initially challenged by child growth; muddled then by our emotional and structural fragilities through adulthood and finally limited by our capacity to maintain senses and biomechanical abilities into old age.

Concepts of Impairment Function and Participation

Old concepts of how health impairments lead to physical disability and then handicap were revised by the World Health Organisation (2002), when they developed a ‘common language for functioning, disability and health’, the International Classification of Functioning, Disability and Health (ICF) (Fig. 1-1).

This structures the states of:

• 1. Health in terms of function, activity and participation; and
• 2. Disability in terms of impairment, limitation of activity and restriction in participation; from both an individual and societal perspective.

This utilises aspects of both a medical and social model of disability to balance the problems of internal health and developmental challenges and the external responses to them, to help us all in developing pathways of appropriate, holistic management.

These factors are key when thinking about how we support children and adults with health disorders. Minimise the impact on the individual by maximising health, potential individual function and participation: health and habilitation. Medical therapy teams, engineers, innovators and social support all working together to potentiate ability and minimise disability.

Figure 1-1 International classification of functioning disability and health (WHO, 2012).

Basic Neurosciences

Before we concentrate on different health disorders often seen in individuals accessing electronic assistive technology, it is important to focus on the basics of how we work. Functionally, the two critical areas for a level of independent life are communication and mobility.

How the Central Nervous System Is Made – Neuroembryology

We are all made the same way; how that happens is obviously up to personal practice, but fundamentally a sperm and egg get it together, share their nuclear information and start to double up and double up until a ball of cells is formed – an early embryological blastocyst (Fig. 1-2).

At this early point we differentiate into three fundamental layers of cell type:

1. • Endoderm (inner) develops into most of our internal organs.
2. • Mesoderm (middle) develops into muscle and bone.
3. • Ectoderm (outer) develops into skin and the nervous system.

By the fourth week of foetal development, this ball squashes down to a plate, with the ectoderm on one side differentiating into a plate of primitive nervous tissue – the neuroectoderm. This plate develops a groove and the pizza oval folds up into a calzone, thereby creating a tube with internal neuroectoderm (central nervous system (CNS)) and external ectoderm (skin). This closes from the middle so that complete internalisation occurs at both ends by around day 24, with an obvious top rostral neuropore and bottom caudal neuropore.

Figure 1-2 Basic embryology of the nervous system.
Courtesy of Fig. 2-1 The development of the nervous system. Barnes, L., Fairhurst, C., 2011. Hemiplegia Handbook for Parent and Professionals. Mackeith Press.

The head end then bends, flexes and wraps up on itself into what is by 11 weeks a fairly recognisable fore-, mid- and hindbrain with a clear caudal spinal projection.

From there, there is lot of neuronal (nerve cell) and pathway specialisation that occurs within the brain while the rest of our body development catches up. The brain cortex folds in on itself to form a large surface area of grey matter within a relatively small volume; core pockets of cells differentiate into a series of integrated central circuits – the basal ganglia; central white matter pathways are constantly created and regress together with a vast differentiation of supporting cell types forming and supporting the nascent system.

We used to think that the development of embryological pathways from the CNS out to their specific peripheral effector organs was a carefully structured process. It seems there is a lot more of a blunderbuss approach. The whole cortex sends early projections down circuits to the terminal fields of projection, both on the same side (ipsilateral) and opposite side (contralateral), not just to the areas that they end up innervating but pretty well everywhere. The specific remodelling and restriction of circuits and tract development from certain key areas of the brain is extremely dynamic. Pathways specialise much later in humans than in other mammals, in comparison to the overall timing of foetal development that allows us to increase the complexity of our circuits.

By 24/40 weeks of gestation the wiring (axons) from the cells has developed to the lower end of the cord. Rhythmical patterns of movement at an early stage of foetal growth modify innervation, tracts nip and regress, facilitating specialisation of the pathways. By full term, 40/40, there is relatively complete innervation to the peripheries with much more in the way of crossing of messages from one side of the brain to the opposite side of the body.

With all the cellular organisation and specification, by the...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of Contributors
• Foreword
• Preface
• Acknowledgement
• Glossary
• 1. Basic Neurosciences With Relevance to Electronic Assistive Technology
• 2. Cognitive Impairment and EAT
• 3. Functional Posture
• 4. Assessment and Outcomes
• 5. Alternative Access Technologies
• 6. Environmental Control
• 7. Alternative and Augmentative Communication
• 8. Assisted Living
• 9. Powered Mobility
• 10. Assistive Technology Integration and Accessibility
• 11. Robotics
• Index