Reviewer: Ronald J Cotton, MD, PhD (Shirley Ryan AbilityLab)
Description: In part, this is a survey of biomechatronics (an interdisciplinary meld of electronics, mechanics, and biology), but really it's more of a survey of research conducted at the Medical and Rehabilitation Research Centre in the University of Auckland in this field. It reviews work in three areas: 1) EEG-based control, largely focused on their work on detection of steady state evoked potentials; 2) EMG-based control of an upper limb exoskeleton; and 3) muscle and movement modeling, augmented with EMG.
Purpose: The authors aims are to review their work in biomechatronics with regard to rehabilitation, to provide a book of interest to students and research in biomechatronics, and finally to introduce these methods to clinicians. These are worthy goals, because these technologies have such potential to help those with disabilities. In terms of reviewing their work, the book does a fair job of delving into several research projects. The chapters do somewhat feel like papers collected together, somewhat lacking in editing that would make a cohesive narrative. For example, the same signal preprocessing technique is described in almost identical detail at the beginning of several consecutive chapters. At the same time, the results sometimes feel superficial with many questions left open (for example, how does their approach compare to the state of the art?). Almost all studies in this book are performed on people without disabilities and thus their relevance to clinical rehabilitation remains open. This book would help a clinician engaging in a relevant research project, but does not present information that would influence standards of care.
Audience: The authors target this book at students and researchers in biomechatronics as well as clinicians in research. It will be of interest to the former, although in a limited way; that is, to researchers working on similar projects as the authors. It would not be sufficient as a survey of the field, although chapter 2 fulfills this role to an extent. It is of less interest to clinicians, given that almost all the work described is applied to healthy subjects. For those engaging in research studies, the book does provide a fairly in-depth review of the topics it focuses on. The first author has published extensively in this field, especially with a focus on rehabilitation robotics and exoskeletons.
Features: The book starts with an overview of the field of biomechatronics and then moves into a summary of the state of the art. It specifically focuses on three areas within this field: EEG, EMG for exoskeletal control, and biomechanics modeling. It covers this from the perspective of research from the authors' lab, so it quickly becomes focused on a handful of specific use cases. Because it is based on their research, it tells this story with good attention to the pertinent details. On the flip side, for the same reason, it is somewhat limited for putting their work in the context of the wider field or comparing their results to alternative approaches. For EEG, it focuses on their work improving SNR and artifact resilience of using steady-state visually evoked potentials to select among numerous options. This culminates in their work allowing people to play the game "Street Fighter" via EEG. For EMG, the focus is on their work modeling the movement of the elbow through an the activity of measurements which culminates in controlling an exoskeleton to augment the elbow flexion/extension and supination/pronation. Finally, they move on to modeling the joint forces and dynamics at play during walking for individual subjects and then augmenting these models with EMG activity. Here they show how these models apply to patients with cerebral palsy, leading to the hope that the model could be used to control a rehabilitation robot in the future. Because the topics in the book are tailored to the authors' research project, there are many topics in biomechatronics as it relates to rehabilitation that are not addressed, including in the introduction. For example, there is no mention of any of the robotic systems (including exoskeletons) that have become more widely used in clinical rehabilitation. Similarly, there is no reference to functional electrical stimulation.
Assessment: This book provides a fairly good summary of the work from the authors' laboratory, at a level of detail that could be understood by motivated readers. As a general survey of the field of biomechatronics, it is heavily biased toward the laboratory's experience. While rehabilitation plays prominently in the title, it would be more accurate to say this book covers research that may apply to rehabilitation in the future. The vast majority of experiments were performed on healthy control subjects and it is unknown how well these methods would translate to people with disabilities, either as assistive technologies or to augment recovery. The authors are aware of these limitations, however, and highlight areas for future work.