User-centered development process of an operating interface to couple a robotic glove with a virtual environment to optimize hand rehabilitation following a stroke

Introduction

Task-specific neurorehabilitation is crucial to optimize hand recovery shortly after a stroke, but intensive neurorehabilitation remains limited in resource-constrained healthcare systems. This has led to a growing interest in the use of robotic gloves as an adjunct intervention to intensify hand-specific neurorehabilitation. This study aims to develop and assess the usability of an operating interface supporting such a technology coupled with a virtual environment through a user-centered design approach.

Methods

Fourteen participants with hand hemiparesis following a stroke were invited to don the robotic glove before browsing through the operating interface and its functionalities, and perform two mobility exercises in a virtual environment. Feedback was collected for improving technology usability. Participants completed the System Usability Scale and ABILHAND questionnaires and their recommendations were gathered and prioritized in a Pugh Matrix.

Results

The System Usability Scale (SUS) score for the operating interface was excellent (M = 87.0 SD = 11.6). A total of 74 recommendations to improve the user interface, calibration process, and exercise usability were identified.

Conclusion

The application of a full cycle of user-centred design approach confirms the high level of usability of the system which is perceived by end users as acceptable and useful for intensifying neurorehabilitation.

Visualization of cutaneous hemoglobin oxygenation and skin hydration using near-infrared spectroscopic imaging

BACKGROUND/AIMS

The visualization of skin hemodynamics and tissue water content has important implications in a number of areas of dermatology, plastic surgery, and clinical skin evaluation. The aim of this study was to develop instrumentation and techniques for infrared spectroscopic imaging, and to evaluate whether they can be used to make objective assessments of skin health, perhaps even before clinical signs are evident.

METHODS

A liquid-crystal tunable filter was mounted on the front of the objective lens of an infrared-sensitive charge-coupled device digital camera. Sets of narrow-band images of skin were acquired in vivo at wavelength intervals of 10 nm from 650 to 1050 nm, under computer control. The data processing techniques used to extract interpretable clinical information from the raw image sets included normalization, ratios, and multivariate analysis.

RESULTS

To highlight the capabilities of these techniques, results are presented of two studies that generated spectroscopic images. One examined a volunteer's forearm subjected to short interruptions of blood flow, and the other followed changes in a skin flap elevated on a rat model. The data sets were processed in different ways to determine several skin and blood parameters, in particular hemoglobin oxygen saturation, blood volume, and skin hydration. Variations in these parameters were followed non-invasively as a function of time and location to study the skin's response to blood flow changes, and to predict the viability of the skin.

CONCLUSION

Near-infrared reflectance spectroscopic imaging is demonstrated to be a powerful augmentation to the standard clinical assessment of skin.

Infrared microscopic functional group mapping and spectral clustering analysis of hypercholesterolemic rabbit liver

Fourier transform infrared microscopy has been applied to the characterization of hypercholesterolemic rabbit liver. A combination of the traditional "group frequency" approach to spectral interpretation and the technique of functional group mapping was applied to aid understanding of the spectral changes observed between normal and hypercholesterolemic liver. Using this approach, spectral differences could be attributed to the accumulation of cholesterol esters (most likely in the form of lipoprotein complexes) in the hypercholesterolemic liver. A novel approach, spectral clustering, was used to identify regions of hypercholesterolemic liver tissue which possessed similar spectral (and by inference similar biochemical/histological) properties. Using this approach, a complex data set consisting of 400 discrete spectra acquired from an area of tissue approximately 1 x 1 mm could be reduced to five types of spectra, and the distribution of each type of spectrum within the tissue analyzed.