Paulette Guitard

Force Estimation with a Non-Uniform Pressure Sensor Array

Embedding pressure sensors into household fixtures enables unobtrusive occupant health and safety monitoring at home. To monitor bathroom grab bar use, the force applied to a grab bar is desired from the output of three embedded pressure sensors. We examine the measurement of applied force in a non-uniform pressure sensor array, where forces are distributed with spatial nonlinearity to the pressure sensors. Two methods that ignore the spatial nonlinearities are compared to two methods that incorporate them. These include a polynomial response curve, a theoretical model, a lookup table, and an artificial neural network. When many calibration points can be taken and location estimates are accurate, the location-based lookup table presented the lowest error. However, when calibration time is limited, the theoretical model performs best, while an artificial neural network is preferred when location inputs are inaccurate.

Contact Location Estimation from a Nonlinear Array of Pressure Sensors

In physical medicine and rehabilitation, it is important to be able to collect information regarding a patients behavior and range of mobility throughout their daily activities. Grab bars are used widely in the homes of individuals with mobility impairments so their usage while performing physical tasks can provide valuable information as to the individuals physical status. This paper explores the extraction of location information for forces applied to a grab bar embedded with a nonlinear pressure sensor array of low spatial resolution. It first describes the instrumentation of the grab bar and the calibration procedure. It then investigates three methods of estimating the contact location; a simple centroid, a percentage-based lookup table and an artificial neural network. Results of the three methods are reported based on data collected from different forces and contact locations applied along the bar. The artificial neural network proves to be the most successful method of estimating the points of contact, by most accurately modeling the nonlinearities in the system.

Use of Different Bath Grab Bar Configurations Following a Balance Perturbation

ABSTRACT Although commonly prescribed, little research exists on bath grab bars. This study examined the use of bath grab bars following an experimentally induced balance perturbation, the influence of the task on grab bar use, and the influence of balance loss on acceptance of grab bars. A mixed design documented the use of four different grab bar configurations: (a) no bars, (b) vertical/horizontal combination, (c) L-shaped bar, and (d) vertical/angled combination following balance loss. Eighty adults were randomly assigned to three groups. Each group tried the “no bar” configuration and one of the other grab bar configurations. In 25% of the trials for each configuration, balance perturbation was induced. Older adults used grab bars 59.4% of time to regain balance, compared to 13.6% for younger adults. The vertical bar on the side wall was favored by both groups of participants during both bathtub entry and exit. To promote safety in the home, existing building codes must be revised to recommend minimally a vertical grab bar on the side wall. Additional bars may be needed to ensure safety during stand-to-sit and sit-to-stand phases of bath transfers. Initiatives must be taken to decrease the prejudice associated with grab bars.

Analysis of commode grab bar usage for the monitoring of older adults in the smart home environment

The occurrence of falls inside the home is a common yet potentially hazardous issue for adults as they age. Even with the installation of physical aids such as grab bars, weight transfers on and off a toilet or bathtub can become increasingly difficult as a person’s level of physical mobility and sense of balance deteriorate. Detecting this deterioration becomes an important goal in fall prevention within a smart home. This paper develops an unobtrusive method of analyzing the usage of toilet grab bars using pressure sensors embedded into the arm rests of a commode. Clinical parameters are successfully extracted automatically from a series of stand-to-sit (StSi) and sit-to-stand (SiSt) transfers performed by a trial group of young and older adults. A preliminary comparison of the parameters indicates differences between the two groups, and aligns well with published characteristics obtained using accelerometers worn on the body. The unobtrusive nature of this method provides a useful tool to be incorporated into a system of continuous monitoring of older adults within the smart home environment.

Toilet Grab-Bar Preference and Center of Pressure Deviation During Toilet Transfers in Healthy Seniors, Seniors With Hip Replacements, and Seniors Having Suffered a Stroke

Multiple toilet grab-bar configurations are required by people with a diverse spectrum of disability. The study purpose was to determine toilet grab-bar preference of healthy seniors, seniors with a hip replacement, and seniors post-stroke, and to determine the effect of each configuration on centre of pressure (COP) displacement during toilet transfers. METHODS: 14 healthy seniors, 7 ambulatory seniors with a hip replacement, and 8 ambulatory seniors post-stroke participated in the study. Toilet transfers were performed with no bars (NB), commode (C), two vertical bars (2VB), one vertical bar (1VB), a horizontal bar (H), two swing-away bars (S) and a diagonal bar (D). COP was measured using pressure sensitive floor mats. Participants rated the safety, ease of use, helpfulness, comfort and preference for instalment. RESULTS: 2VB was most preferred and had the smallest COP deviation. Least preferred was H and NB. C caused largest COP displacement but had favourable ratings. DISCUSSION: The preference and safety of the 2VB should be considered in the design of accessible toilets and in accessibility construction guidelines. However these results need to be verified in non-ambulatory populations. C is frequently prescribed, but generates large COP deviation, suggesting it may present an increased risk of falls.

The Ottawa Panel guidelines on programmes involving therapeutic exercise for the management of hand osteoarthritis

Objective: To identify programmes involving therapeutic exercise that are effective for the management of hand osteoarthritis and to provide stakeholders with updated, moderate to high-quality recommendations supporting exercises for hand osteoarthritis. Methods: A systematic search and adapted selection criteria included comparable trials with exercise programmes for managing hand osteoarthritis. Based on the evaluated evidence, a panel of experts reached consensus through a Delphi approach endorsing the recommendations. A hierarchical alphabetical grading system (A, B, C+, C, C-, D-, D, D+, E, F) was based on clinical importance (≥15%) and statistical significance (P < 0.05). Results: Ten moderate- to high-quality studies were included. Eight studies with programmes involving therapeutic exercise (e.g. range of motion (ROM) + isotonic + isometric + functional exercise) seemed to be effective. Forty-six positive grade recommendations (i.e. A, B, C+) were obtained during short-term (<12 weeks) trials for pain, stiffness, physical function, grip strength, pinch strength, range of motion, global assessment, pressure pain threshold, fatigue and abductor pollicis longus moment and during long-term (>12 weeks) trials for physical function and pinch strength. Conclusion: Despite that many programmes involving exercise with positive recommendations for clinical outcomes are available to healthcare professionals and hand osteoarthritis patients that aid in the management of hand osteoarthritis, there is a need for further research to isolate the specific effect of exercise components.