Design, development, and evaluation of a pinch-grasp haptic interface

Interaction with virtual or teleoperated environments requires contact with objects on a multipoint level. We describe the design of a pinch--grasp hand interface device for use as a grasping mechanism to complement haptic interfaces. To preserve a suitable level of transparency for human--computer interaction, this novel interface is designed for high-resolution contact forces, while centered around a lightweight structure. This functionality renders the device scalable and adaptable to a wide range of haptic interface structures and force level requirements. We present an optimal configuration for a pinch--grasp interface, which produces bidirectional forces to an operator's fingers and a rotational force to the wrist through a cable drive system. The device is characterized for use on a commercial haptic interface through demonstration of sustained peak performance and also workspace utilization. The dynamic performance of the pinch--grasp interface is experimentally determined, and the frequency response is identified to illustrate its contact force resolution.

Modelling the maturation of grip selection planning and action representation: insights from typical and atypical motor development

We investigated the purported association between developmental changes in grip selection planning and improvements in an individual’s capacity to represent action at an internal level (i.e., motor imagery). Participants were groups of healthy children aged 6-7 years and 8-12 years respectively, while a group of adolescents (13-17 years) and adults (18-34 years) allowed for consideration of childhood development in the broader context of motor maturation. A group of children aged 8-12 years with probable DCD (pDCD) was included as a reference group for atypical motor development. Participants’ proficiency to generate and/or engage internal action representations was inferred from performance on the hand rotation task, a well-validated measure of motor imagery. A grip selection task designed to elicit the end-state comfort (ESC) effect provided a window into the integrity of grip selection planning. Consistent with earlier accounts, the efficiency of grip selection planning followed a non-linear developmental progression in neurotypical individuals. As expected, analysis confirmed that these developmental improvements were predicted by an increased capacity to generate and/or engage internal action representations. The profile of this association remained stable throughout the (typical) developmental spectrum. These findings are consistent with computational accounts of action planning that argue that internal action representations are associated with the expression and development of grip selection planning across typical development. However, no such association was found for our sample of children with pDCD, suggesting that individuals with atypical motor skill may adopt an alternative, sub-optimal strategy to plan their grip selection compared to their same-age control peers.

Young women with type 1 diabetes' management of turning points and transitions

The authors used grounded theory to explore and develop a substantive theory to explain how 20 young women with type 1 diabetes managed their lives when facing turning points and undergoing transitions. The women experienced a basic social problem: being in the grip of blood glucose levels (BGLs), which consisted of three categories: (a) the impact of being susceptible to fluctuating BGLs, (b) the responses of other people to the individual woman’s diabetes, and (c) the impact of the individual women’s diabetes on other people’s lives. The women used a basic social process to overcome the basic social problem by creating stability, which involved using three interconnected subprocesses: forming meaningful
relationships, enhancing attentiveness to blood glucose levels, and putting things in perspective. Insights into the processes and strategies used by the women have important implications for provision of care and service delivery.

Anthropometric and biochemical markers for nutritional risk among residents within an Australian residential care facility

The risk of malnutrition is high among elderly population, yet few studies have measured indicators of nutritional status among Australian aged-care residents. To determine the relationship between nutritional status and bone density, hand grip strength, and the timed-up and go test, in a group of Australian aged-care residents. Anthropometric and biochemical analysis measured in subjects recruited to be part of a six month multivitamin supplementation study. One hundred and fifteen subjects participated (68% female). The mean (SD) age and body weight was 80.2(10.6) years, and 66.5(15.0) kg, respectively. Eleven percent were underweight (body mass index, BMI, <or =20.0 kg/m(2)), and 20% were obese BMI >or =30 kg/m(2)). Low serum 25-hydroxy-vitamin D (25(OH)D, <or =50 nmol/L) concentrations were found among 79% of subjects. After adjustment for body weight, there was an association between serum 25(OH)D and bone density (heel ultrasound) (r=.204, p=.027). Low serum zinc <or =10.7 micromol/L) concentrations were found among 46% of subjects; this group had a slower timed up and go time compared with those with higher zinc concentrations (n=19, 44.6 +/- 5.6 seconds vs. n=27, 30.0 +/- 3.3 seconds, p=.020). There were no associations between nutritional markers and hand grip strength. In this group, more than (3/4) of subjects had low serum 25(OH)D, and 46% had low zinc concentrations. Serum 25(OH)D was associated a lower bone density and zinc with a slower walking time. This indicates that the elderly in long term residential care facilities are at high risk for poor nutritional status, potentially increasing morbidity and mortality.

A medium-temperature solar thermal power system and its efficiency optimisation

This paper firstly expounds that the reheat-regenerative Rankine power cycle is a suitable cycle for the parabolic trough collector, a popular kind of collector in the power industry. In a thermal power cycle, the higher the temperature at which heat is supplied, the higher the efficiency of the cycle. On the other hand, for a given kind of collector at the same exiting temperature, the higher the temperature of the fluid entering the collector, the lower the efficiency of the collector. With the same exiting temperature of the solar field and the same temperature differences at the hottest end of the superheater/reheater and at the pinch points in the heat exchangers (e.g., the boiler) in the cycle, the efficiencies of the system are subject to the temperature of the fluid entering the collector or the saturation temperature at the boiler. This paper also investigates the optimal thermal and exergetic efficiencies for the combined system of the power cycle and collector. To make most advantage of the collector, the exiting fluid is supposed to be at the maximum temperature the collector can harvest. Hence, the thermal and exergetic efficiencies of the system are related to the saturation temperature at the boiler here.

Construct validity of the Chinese version of the disability of the arm, shoulder and hand questionnaire (DASH-HKPWH)

The study evaluated the construct validity of the Chinese Hong Kong version of the disabilities of the arm, shoulder and hand questionnaire (DASH-HKPWH). Three hundred and thirty four patients with a broad range of upper extremity disorders were recruited into the study. Each completed DASH-HKPWH and SF-36 forms and their pain intensity (numeric pain rating scale) and grip strength were also measured. The mean DASH-HKPWH score was 40 (SD = 20). Principal component factor analysis identified a single factor, which accounted for 47% of the total variance. Pearson correlation was applied to assess convergent and divergent validity of the DASH-HKPWH by comparison with the above-mentioned subjective and objective measurements. Our findings were comparable to the DASH of other languages

An investigation into the usability of graphical authentication using AuthentiGraph

There is increasing coverage in the literature relating to the different facets surrounding the security service of authentication, but there is a need for further research into the usability of graphical authentication. Specifically, the usability and viability of graphical authentication techniques for providing increased security needs to be further explored. There is a significant amount of evidence relating to traditional authentication techniques which highlight the fact that as technological advances grip modern societies, the requirement for more advanced authentication and security approaches increases. The exponential growth in the number of people using the Internet carries with it the high potential for increased security threats, suggesting that there are needs for further techniques to increase security in online environments. This paper presents the findings of how various interface design approaches affect the usability of a previously developed alternative graphical authentication technique called AuthentiGraph. The security design provided by Authentigraph has been established and justified in previous research by the authors. The primary focus of this paper is the usability of this technique. Using an experimental laboratory based approach, combined with an online survey, 20 university students evaluated a combination of five varying graphical interfaces in three different screen sizes. The outcome provides the interface design criteria best suited for the implementation and use of the AuthentiGraph technique.

The effects of a simplified tai-chi exercise program (STEP) on the physical health of older adults living in long-term care facilities : a single group design with multiple time points

Background
Studies support the positive effects that Tai Chi has on the physical health of older adults. However, many older adults residing in long-term care facilities feel too weak to practice traditional Tai Chi, and a more simplified style is preferred.
Objective
To test the effects of a newly-developed, Simplified Tai-Chi Exercise Program (STEP) on the physical health of older adults who resided in long-term care facilities.
Design
A single group design with multiple time points: three pre-tests, one month apart; four post-tests at one month, two months, three months, and six months after intervention started.
Settings
Two 300–400 bed veteran homes in Taiwan.
Participants
The 51 male older adults were recruited through convenience sampling, and 41 of them completed six-month study. Inclusion criteria included: (1) aged 65 and over; (2) no previous training in Tai Chi; (3) cognitively alert and had a score of at least eight on the Short Portable Mental Status Questionnaire; (4) able to walk without assistance; and (5) had a Barthel Index score of 61 or higher. Participants who had dementia, were wheel-chair bound, or had severe or acute cardiovascular, musculoskeletal, or pulmonary illnesses were excluded.
Methods
The STEP was implemented three times a week, 50 min per session for six months. The outcome measures included cardio-respiratory function, blood pressure, balance, hand-grip strength, lower body flexibility, and physical health actualization.
Results
A drop in systolic blood pressure (p=.017) and diastolic blood pressure (p<.001) was detected six months after intervention started. Increase in hand-grip strength from pre to post intervention was found (left hand: p<.001; right hand: p=.035). Participants also had better lower body flexibility after practicing STEP (p=.038).
Conclusions
Findings suggest that the STEP be incorporated as a floor activity in long-term care facilities to promote physical health of older adults.

Multivitamin supplementation improves nutritional status and bone quality in aged care residents

Objectives: To assess the effectiveness of a multivitamin (MV) tablet on nutritional status, quantitative heel ultrasound (QUS), mobility, muscle strength and falls. The design comprised two groups matched on mobility levels, randomized to receive a daily MV or placebo (P) tablet for 6 months. The setting was an Australian residential care facility.

Subjects: A total of 92 aged care residents. Serum micronutrients, body weight, QUS, rate of falls, hand grip strength, and the timed up and go test were assessed at baseline and 6 months.

Results: A total of 49 participants consumed a MV and 43, a matched P for 6 months. There was a greater increase in the MV vs P group for serum 25(OH)D (mean differencestandard error, 33.42.6 nmol l-1), folate (13.42.8 nmol l-1), and vitamin B12 (178.040.3 pmol l-1) (all P<0.001). Adequate 25(OH)D concentrations (50 nmol l-1) were found among 77% of participants in the MV group vs 10% taking P (P<0.001). Adjusting for baseline levels, the increase in QUS was greater in the MV vs P group (3.02.0 dB MHz-1 vs -2.92.1 dB MHz-1, respectively, P=0.041). There was a trend towards a 63% lower mean number of falls in the MV vs P group (0.30.1 falls vs 0.80.3 falls, P=0.078).

Conclusions: MV supplementation raised serum vitamin B12 and folate concentrations and increased serum 25(OH)D, which was accompanied by an apparent positive effect on bone density. We also found a trend towards a reduction in falls and this could contribute to a reduction in fractures.

Effects of long-term tennis playing on the muscle-bone relationship in the dominant and non-dominant forearms

The relationship between muscle strength and bone mineral density illustrates the positive effect of mechanical loading on bone. But local and systemic factors may affect both muscle and bone tissues. This study investigated the effects of long-term tennis playing on the relationship between lean tissue mass and bone mineral content in the forearms, taking the body dimensions into account. Fifty-two tennis players (age 24.2 +/- 5.8 yrs, 16.2 +/- 6.1 yrs of practice) were recruited. Lean tissue mass (LTM), bone area, bone mineral content (BMC), and bone mineral density were measured at the forearms from a DXA whole-body scan. Grip strength was assessed with a dynamometer. A marked side-to-side difference (p < 0.0001) was found in favor of the dominant forearm in all parameters. Bone area and BMC correlated with grip strength on both sides (r = 0.81 - 0.84, p < 0.0001). The correlations were still significant after adjusting for whole-body BMC body height, or forearm length. This result reinforced the putative role of the muscles in the mechanical loading on bones. In addition, forearm BMC adjusted to LTM or grip strength was higher on the dominant side, suggesting that tennis playing exerts a direct effect on bone.