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A model of the upper extremity is developed in which the forearm is constrained to lie in a horizontal plane and electrical stimulation is applied to the triceps muscle. Identification procedures are described to estimate the unknown parameters using tests that can be performed in a short period of time. Examples of identified parameters obtained experimentally are presented for both stroke patients and unimpaired subjects. A discussion concerning the identification's repeatability, together with results confirming the accuracy of the overall representation, is given. The model has been used during clinical trials in which electrical stimulation is applied to the triceps muscle of a number of stroke patients for the purpose of improving both their performance at reaching tasks and their level of voluntary control over their impaired arm. Its purpose in this context is threefold: Firstly, changes occurring in the levels of stiffness and spasticity in each subject's arm can be monitored by comparing frictional components of models identified at different times during treatment. Secondly, the model is used to calculate the moments applied during tracking tasks that are due to a patient's voluntary effort, and it therefore constitutes a useful tool with which to analyze their performance. Thirdly, the model is used to derive the advanced controllers that govern the level of stimulation applied to subjects over the course of the treatment. Details are provided to show how the model is applied in each case, and sample results are shown. [DOI: 10.1115/1.3005332]

A kinematic model is presented based on surface marker placement generating wrist, metacarpal arch, fingers and thumb movements. Standard calculations are used throughout the model and then applied to the specified marker placement. A static trial involving eight unimpaired participants was carried out to assess inter-rater reliability. The standard deviations across the data were comparable to manual goniometers. In addition, a test-retest trial of ten unimpaired participants is also reported to illustrate the variability of movement at the wrist joint, metacarpal arch, and index finger as an example of model output when repeating the same task many times. Light and heavyweight versions of the tasks are assessed and characteristics of individual movement strategies presented. The participant trial showed moderate correlation in radial/ulnar deviation of the wrist (r = 0.65), and strong correlation in both metacarpal arch joints (r = 0.75 and r = 0.85), the MCP (r = 0.79), and PIP (r = 0.87) joints of the index finger. The results indicate that individuals use repeated strategies of movement when lifting light and heavyweight versions of the same object, but showed no obvious repeated pattern of movement across the population. Index Terms--Biomedical measurements, hands, kinematics, motion analysis.

This research investigates the potential of contactless finger motion measurement, focusing particularly on ease of use to improve the success of home-based hand rehabilitation exercises. Previously, a mathematical model was developed based on a finite-element method simulation. This article validates this model on multifinger noncontact measuring under laboratory conditions. Twenty-three healthy subjects with normal hand and finger functions participated. An independent near-field distance measurement was developed and compared with the output from an optical sensor. It was observed from the experiment that the prediction model worked well with the measuring system reported here. The average uncertainties of measurement using the prediction model are 0.68 and 0.55 mm, which are 3.5% and 2.7% of the full-scale range for the index finger and middle finger, respectively. The results from the experiment show that the reported system is capable of measuring the small movements of fingers. With the combination of the noncontact measuring feature and the lack of complicated setup, this system is easy-to-use as the basis of a home-based independent rehabilitation system. [ABSTRACT FROM AUTHOR]

There is a growing and significant interest in home-based therapy or telerehabilitation for physiological disabilities, for example, as a result of stroke. These technologies allow more flexibility in implementing rehabilitation sessions and offer the potential to reduce the economic burden of outpatient appointments and reduce the reliance on healthcare systems. However, extra effort needs to be made to make such systems effective. This paper investigates the feasibility of a home-based device, which is capable of detecting minute movements of patients’ fingers in regular training and testing sessions, addressing ease of use, motivation of practice, as well as feedback and guidance on performance. Toward this aim, the measuring techniques that are compatible with these targets were investigated. Based on a customizable three-layer electrodes design for use with an MGC3030 motion sensor IC, a finite-element method simulation in COMSOL Multiphysics and a nonlinear regression analysis using MATLAB were carried out. Four nonlinear equations were introduced to describe the motion of the index and middle fingers in the electrical field (E-field) generated. The form of the prediction models agrees with the hypothesis based on the quasi-static E-field sensing theory. In addition, these prediction models fit well with the relationship between finger distance and the voltage signals detected. With the prediction model, the targeted system is capable of detecting combined movements of two fingers at a resolution of 0.94 mm in a portable smart device for robust hand rehabilitation. [ABSTRACT FROM AUTHOR]

The aim of this paper is to propose an exploratory study on simple, accurate and computationally efficient movement classification technique for prosthetic hand application. The surface myoelectric signals were acquired from 2 muscles—Flexor Carpi Ulnaris and Extensor Carpi Radialis of 4 normal-limb subjects. These signals were segmented and the features extracted using a new combined time-domain method of feature extraction. The fuzzy C-mean clustering method and scatter plots were used to evaluate the performance of the proposed multi-feature versus other accurate multi-features. Finally, the movements were classified using the adaptive neuro-fuzzy inference system (ANFIS) and the artificial neural network. Comparison results indicate that ANFIS not only displays higher classification accuracy (88.90%) than the artificial neural network, but it also improves computation time significantly. [ABSTRACT FROM AUTHOR]

The results from experiments with a screen-printed piezoelectric sensor, mounted on an artificial finger-tip and including a cosmetic covering, are shown to detect surface information from regular texture patterns. For the automatic control of an artificial hand and to feedback information to the amputee, an algorithm has been developed based on the standard deviation (SD) of signal data from the sensor. The SD analysis for texture detection is novel as it uses a combination of arithmetic processes. It windows the data sequentially and calculates the SD of the data in the windows and then averages the SDs. The output from the algorithm is the frequency spectrum of a signal. Plots, from the output of the algorithm, show events that correspond to the cyclic waveforms produced from the regularity of object surface patterns. The results from the algorithm are confirmed with an analysis of the signals using fast Fourier transforms. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the potential of employing a classification tool to objectively classify participants with clinically assessed movement faults (MFs) of the scapula. Six participants with a history of shoulder pain with MFs of the scapula and 12 healthy participants with no movement faults (NMFs) performed a flexion movement control test of the scapula, while scapular kinematic data were collected. Principal component scores and discrete kinematic variables were used as input into a classifier. Five out of the six participants with a history of pain were successfully classified as having scapular MFs with an accuracy of 72%. Variables related to the upward rotation of the scapula had the most influence on the classification. The results of the study demonstrate the potential of adopting a multivariate approach in objective classification of participants with altered scapular kinematics in pathological groups. [ABSTRACT FROM AUTHOR]

Purpose. User perceptions are critical, yet often ignored factors in the design and development of rehabilitation technologies. In this article, measures for collection of patient perceptions are developed and applied to a novel upper limb workstation that combines robotic therapy and electrical stimulation (ES). Method. Five participants with chronic upper limb hemiplegia post-stroke used a robotic workstation to undertake supported tracking tasks augmented by precisely controlled ES to their triceps muscle. Following a 6 week trial, a purpose designed set of questions was developed and individual interviews were conducted by an independent health psychologist. Results. The simple, quick to administer question set showed that participants had a positive response to the system, and contributed valuable feedback with regard to its usability and effectiveness. Participants want a home-based system targeting their whole arm. Conclusion. This article demonstrates the value in assessing user perceptions of a rehabilitation system via a simple question set. While the results of this study have implications for a wider audience, our recommendations are for a qualitative study to develop a generic evaluation tool which could be used across the growing number of devices to provide feedback to enhance future development of any new technology for rehabilitation. [ABSTRACT FROM AUTHOR]

The Southampton Hand Assessment Procedure (SHAP) was devised to assess quantitatively the functional range of injured and healthy adult hands. It was designed to be a practical tool for use in a busy clinical setting; thus, it was made simple to use and easy to interpret. This paper describes four examples of its use: before and after a surgical procedure, to observe the impact of an injury, use with prostheses, and during recovery following a fracture. The cases show that the SHAP is capable of monitoring progress and recovery, identifying functional abilities in prosthetic hands and comparing the capabilities of different groups of injuries. [ABSTRACT FROM AUTHOR]

Focuses on the prosthesis control of the Southampton Hand, an artificial arm developed in Southampton, England. External power source; Degree of freedom for opening and closing; Comparison of the Southampton version to other devices.

A force sensor, for use with an artificial hand, needs to be small, robust, low power, cheap and easily interfaced to a controller using digital techniques. The prototype featured in this paper uses capacitance effects to measure the strain on an elastic polymer foam. Low power consumption results in a device that can be supplied from a miniature battery thereby requiring only signal wires to the controller. A non-linear model accurately describes the characteristic of the sensor, requiring the estimation of only three parameters. The device has been tested up to 20 N but is capable of measuring greater forces. [ABSTRACT FROM AUTHOR]

This paper highlights the potential of using prosthetic devices to sense surface textures; an important characteristic of a lower arm that is often neglected. An artificial finger equipped with a piezoelectric sensor, mounted on a fingertip, has been designed to detect surface textures of different dimensions. Signal frequencies generated during the exploratory movement of the artificial finger reliably correlate to all the widths of grooves and ridges of the surface textures under investigation. This capability provides a positive outlook in recreating a touch sensation that has been previously lost from natural fingers and palms.

The measurement of dynamic scapular kinematics is complex due to the sliding nature of the scapula beneath the skin surface. The aim of the study was to clearly describe the acromion marker cluster (AMC) method of determining scapular kinematics when using a passive marker motion capture system, with consideration for the sources of error which could affect the validity and reliability of measurements. The AMC method involves placing a cluster of markers over the posterior acromion, and through calibration of anatomical landmarks with respect to the marker cluster it is possible to obtain valid measurements of scapular kinematics. The reliability of the method was examined between two days in a group of 15 healthy individuals (aged 19-38 years, eight males) as they performed arm elevation, to 120°, and lowering in the frontal, scapular and sagittal planes. Results showed that between-day reliability was good for upward scapular rotation (Coefficient of Multiple Correlation; CMC = 0.92) and posterior tilt (CMC = 0.70) but fair for internal rotation (CMC = 0.53) during the arm elevation phase. The waveform error was lower for upward rotation (2.7° to 4.4°) and posterior tilt (1.3° to 2.8°), compared to internal rotation (5.4° to 7.3°). The reliability during the lowering phase was comparable to results observed during the elevation phase. If the protocol outlined in this study is adhered to, the AMC provides a reliable measurement of upward rotation and posterior tilt during the elevation and lowering phases of arm movement.

A survey of the literature is presented regarding the simulation of port wine stain (PWS) skin color. Knowledge of PWS features, such as the depths and diameters of affected vessels, is essential for informing laser treatment. These may be determined through the inverse application of a skin model. The techniques which have been applied to achieve this are analyzed in detail. Radiative transfer (RT) is found to be the preferred method of simulation. By far the most common approximations to RT are the diffusion approximations, which have been applied successfully in the past and Monte Carlo techniques, which are now the methods of choice. As the requirements for improvement of laser treatment on an individual basis continues, the needs for further work towards accurate estimations of individual optical coefficients and robust, flexible simulation techniques are identified.

A survey of the literature is presented that provides an analysis of the optical properties of human skin, with particular regard to their applications in medicine. Included is a description of the primary interactions of light with skin and how these are commonly estimated using radiative transfer theory (RTT). This is followed by analysis of measured RTT coefficients available in the literature. Orders of magnitude differences are found within published absorption and reduced-scattering coefficients. Causes for these discrepancies are discussed in detail, including contrasts between data acquired in vitro and in vivo. An analysis of the phase functions applied in skin optics, along with the remaining optical coefficients (anisotropy factors and refractive indices) is also included. The survey concludes that further work in the field is necessary to establish a definitive range of realistic coefficients for clinically normal skin.

Objective: To develop a new assessment procedure, the Southampton Hand Assessment Procedure (SHAP), that allows contextual results of hand function to be obtained readily in a clinical environment., Design: Reliability (test-retest, interrater) and validity (criterion, content) of new assessment procedure against standard medical outcome measure techniques., Setting: Normative data collected in a university laboratory., Participants: Twenty-four volunteers selected on the basis of optimum hand function using these criteria: age (range, 18-25 y), and no adverse hand trauma, neurologic condition, or disabling effects of the upper limb., Interventions: Not applicable., Main Outcome Measures: The normative control group was assessed for variability, and the procedure measured in terms of interrater and test-retest reliability. The absence of a direct comparison prevents a criterion standard from being established; however, content validity was shown by expert peer review., Results: The control group data were shown to be multivariate gaussian; test-retest and interrater reliability were demonstrated at the 95% confidence level. The content validity was demonstrated by peer panel approval., Conclusions: Results of the control group established the statistical integrity of SHAP. Clinical trials are underway, although more extensive use of the procedure is advocated in primary care and rehabilitation centers where physiotherapy and occupational therapy are actively used in hand rehabilitation., (Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation)