Continuous Wear Research Articles

Non-invasive, multi-modal sensing of skin stretch and bioimpedance for detecting infiltration during intravenous therapy.

Intravenous infiltration is a condition wherein an infused solution leaks inadvertently into soft tissue surrounding a hypodermic needle site. This occurrence affects approximately 6.5% of patients in hospitals worldwide, and can lead to severe tissue damage if not treated immediately. The methods currently used by medical staff to detect an infiltration are subjective and can potentially be prone to error. Infiltration is an even larger concern in pediatric patients, who have smaller veins than adults and have more difficulty in communicating pain or other discomfort associated with the infiltration with medical staff. For these reasons, automatic IV infiltration detection could potentially reduce the risk associated with this damaging condition. This paper proposes a novel proof-of-concept system that uses non-invasive sensing in conjunction with a low-power embedded computing platform to deliver continuous infiltration monitoring around the IV catheter site. This kind of system could be able to detect an infiltration by non-invasively monitoring for known symptoms: swelling of soft tissue and increased skin firmness; these symptoms can be sensed by measuring skin stretch and local bioimpedance. Moreover, the low-power design and wireless capabilities can potentially enable continuous wear. The proposed automatic IV infiltration detection system could significantly improve the number of infiltrations identified and treated on time.

Tribofilms Forming in Oil-Lubricated Contacts

The subject of the present paper is the characterization of third bodies of run-in systems. By means of continuous friction and wear measurement, lubricated steel-steel and steel-aluminum contacts were evaluated. Microstructure, chemical composition and response of the materials to shear were analyzed by XPS/AES and focused ion beam technique. After a proper running-in, both systems developed a third body. The third body differs significantly from the base materials. In addition to adapted microstructure and near-surface chemistry, the third body exhibited a substructure characterized by a near-surface zone that accommodates shear and a second, deeper region that ensures strengthening.

The influence of constant slight myopic defocus prescribed in the binocular and alternating monocular spectacle formats on the onset and progression of myopia in the children

Objective. To elucidate the long-term influence of constant slight myopic defocus prescribed in the binocular and the alternating monocular spectacle formats on the dynamics of refraction and its components in the children. Material and methods. The study involved 129 children (258 eyes) at the age varying from 5 to 12 years. The patients were divided into four groups. Group 1 was comprised of 48 children at the age of 5-8 years presenting with emmetropia and risk factors of the development of myopia. Group 2 consisted of 46 children at the age from 7 to 11 years with slight myopia between -0.75 and -2.25 D to whom the alternating continuous wearing of two pairs of spectacles was prescribed. The first control group was composed of 15 children (30 eyes) at the age from 6 to 9 (mean 7.5 ± 1.4) years presenting with pseudomyopia without correction. The second control group was comprised of 20 children (40 eyes) at the age from 7 to 12 (mean 9.7 ± 1.2) years having slight myopia and wearing conventional spectacle correction. Results. The children of group 1subjected to constant slight myopic defocus during one month experienced a shift of refraction toward hypermetropia attributable to the thinning of the lens and deepening of the anterior chamber. None of the children in this group developed myopia during the follow-up period of up to 9 years. In the patients of group 2, refraction remained unaltered during either 4 years (81.8% of the cases) or 7 years (66.6% of the cases). An insignificant increase in the length of the antero-posterior axis was documented in these children along with the significant increase of the horizontal diameter (HD) of the eyeball. The dynamic observation of the children of both control groups during 3 years has demonstrated the strengthening of cycloplegic refraction associated with the significant increase of the length of the antero-posterior axis and the insignificant increase of the transverse diameter of the eyeball. Conclusion. The permanent slight myopic defocusing of the image in the binocular spectacle format slows down the growth of the eyes and the shift of refraction toward myopia in the children with mild hypermetropia, emmetropia, and slight myopia. The proposed method for alternating monolateral constant slight myopic defocus inhibits progression of myopia in 81.8% of the children presenting with mild myopia during 4 years and in 66.6% of them during 7 years.

Predicting railway wheel wear under uncertainty of wear coefficient, using universal kriging

Railway wheel wear prediction is essential for reliability and optimal maintenance strategies of railway systems. Indeed, an accurate wear prediction can have both economic and safety implications. In this paper we propose a novel methodology, based on Archard's equation and a local contact model, to forecast the volume of material worn and the corresponding wheel remaining useful life (RUL). A universal kriging estimate of the wear coefficient is embedded in our method. Exploiting the dependence of wear coefficient measurements with similar contact pressure and sliding speed, we construct a continuous wear coefficient map that proves to be more informative than the ones currently available in the literature. Moreover, this approach leads to an uncertainty analysis on the wear coefficient. As a consequence, we are able to construct wear prediction intervals that provide reasonable guidelines in practice.

Three-Year Longitudinal Survey Comparing Visual Satisfaction with LASIK and Contact Lenses

To assess patient satisfaction and perceived outcomes with different methods of refractive error correction through annual surveys administered over a 3-year period. Prospective, longitudinal, parallel-group, multicenter survey. A total of 1800 subjects, aged 18 to 60 years, who had LASIK or continued using contact lenses. Twenty sites across the United States enrolled subjects who completed a study-specific baseline survey during a contact lens examination or while being evaluated as a candidate for LASIK. Links to follow-up surveys were emailed annually for 3 years. Between-group differences were assessed by analysis of variance, and associations were assessed by logistic multivariate regression. Visual satisfaction. Of 1800 subjects, 694 (39%) comprised the control group who continued contact lens wear, 819 (45%) wore contacts at baseline and had LASIK, and 287 (16%) wore glasses at baseline and had LASIK. Most contact lens users had worn them successfully ≥5 years. The proportion expressing strong satisfaction with their current vision correction method decreased from 63% at baseline to 54% at year 3 in the contact lens control group, whereas 88% of former contact lens wearers and 77% of former glasses wearers were strongly satisfied with LASIK at year 3. Patients 40 years of age or younger when they had LASIK were somewhat more likely to be strongly satisfied than older patients. LASIK significantly reduced difficulties with night driving and nighttime visual disturbances among former contact lens users and former glasses users. The proportion with dry eye symptoms at 1, 2, or 3 years after LASIK was not significantly increased relative to baseline contact lens wear but was significantly increased relative to baseline glasses use, consistent with many glasses users having tried and abandoned contact lenses because of latent dry eye problems. Compared with continued contact lens wear, LASIK significantly reduced the self-reported rates of eye infections, ulcers, and abrasions each year. Compared with contact lens wear, current LASIK technology improved ease of night driving, did not significantly increase dry eye symptoms, and resulted in higher levels of satisfaction at 1, 2, and 3 years follow-up.

Associations of Monitor-Assessed Activity with Performance-Based Physical Function.

The purpose of this study was to investigate the cross-sectional associations of monitor-derived measures of sedentary time and physical activity with performance-based physical function in healthy Australian adults. Data from 602 participants (mean age 58.1±10.0 years; 58% female) from the 2011/12 wave of the Australian Diabetes, Obesity and Lifestyle (AusDiab3) study were analyzed. The thigh-worn activPAL3™ monitor (7-days continuous wear) was used to derive time during waking hours spent: sitting/reclining; standing; and, stepping (overall, and separately as light [<3 METs] and moderate-to-vigorous physical activity [MVPA; ≥3 METs]), and number of sit-stand transitions. Associations of these (in hours/day, or 15 transitions/day) with physical function measures (8ft Timed Up and Go [TUG-8; log-transformed seconds] and Knee Extensor Strength [KES; kg]) were tested via linear regression, adjusting for confounders. Interactions by sex and age-category (<45; 45–54; 55–64; ≥65 years) were tested. In all participants, KES was significantly (p<0.05) associated with stepping and MVPA stepping only; none of the activity measures were associated with TUG-8. However, subgroup analysis revealed that in older adults (≥65 years), TUG-8 was associated with stepping and MVPA stepping (both p<0.05). All associations with sitting time, standing, sit-stand transition and sex interactions were not statistically significant. In summary, sitting time was not significantly associated with impaired muscle strength or gait/mobility in Australian adults aged 36–80 years, but light- to moderate activity (stepping) was positively associated with muscle strength, and gait/mobility in older adults aged ≥65 years. The direction of causation is not known and remains important to investigate considering the high prevalence of both poor function and limited activity in older age.

The improvement of XD-MSM friction tester based on Labview

Purpose With the widespread use and development of automobile, much attention has been paid to its security issues. So to ensure the driving safety, the automobile must be equipped with good braking performance. In the process of braking, the friction from friction pair causes continuous wear and tear of the surface of brake lining and increases the gap between break pairs, until the lining is not being used (Belhocinea et al., 2014); thus, it is very important to detect the lining wear rate. Design/methodology/approach This paper designed the automobile brake friction test wear rate detection system based on Labview. Findings Through the detect data, we find that the automobile brake lining wear rate detection system has higher detect accuracy, in the process of detection, the brake lining without the defects such as cracks and bulges, which shall effect the normal use, the lining has no remarkable scratch to disk friction surface, can completed meet the requirements of users. Originality/value The automobile brake friction test wear rate detecting system adopts the components of USB-9211 DAQ, optoNCDT1700 non-contract high accuracy displacement sensor, in addition the Labview software to complete the functions such as lining wear rate real time detection, data multichannel real time acquisition, display, and storage record, etc., and uses LabSQL to import the detecting data to Microsoft Access database, which can satisfy the demands of various customers. Moreover, the wear rate real time detection can reflect the lining’s wear regulation of different manufacturers and different material and provide a reliable basis for selecting the appropriate lining material and predicting the lining’s lifetime.

Efficient Steady-State Computation for Wear of Multimaterial Composites

Traditionally, iterative schemes have been used to predict evolving material profiles under abrasive wear. In this work, more efficient continuous formulations are presented for predicting the wear of tribological systems. Following previous work, the formulation is based on a two parameter elastic Pasternak foundation model. It is considered as a simplified framework to analyze the wear of multimaterial surfaces. It is shown that the evolving wear profile is also the solution of a parabolic partial differential equation (PDE). The wearing profile is proven to converge to a steady-state that propagates with constant wear rate. A relationship between this velocity and the inverse rule of mixtures or harmonic mean for composites is derived. For cases where only the final steady-state profile is of interest, it is shown that the steady-state profile can be accurately and directly determined by solving a simple elliptic differential system—thus avoiding iterative schemes altogether. Stability analysis is performed to identify conditions under which an iterative scheme can provide accurate predictions and several comparisons between iterative and the proposed formulation are made. Prospects of the new continuous wear formulation and steady-state characterization are discussed for advanced optimization, design, manufacturing, and control applications.

How a New Color Aftereffect Happened To Turn Up at Oberlin, 50 Years Ago

At Oberlin in the ‘60s, Introductory Psychology was a full-year course introducing general experimental psychology as a biosocial science. Single cell recordings from cat and monkey visual cortex had recently enabled visual science to move beyond the retina to the early cortical stages of visual processing. Ivo Kohler had reported studies of behavior during continuous wearing of prism spectacles that displace the retinal image laterally. They showed that one can regain fairly normal visuomotor coordination in a few weeks. His reports made adaptation to prism glasses a hot topic for investigation.

Prosthetic replacement of the ocular surface ecosystem: impact at 5 years

Background/aimsTo determine the impact of prosthetic replacement of the ocular surface ecosystem (PROSE) treatment at 5 years.MethodsRetrospective review of clinical, manufacturing and quality databases at the Boston Foundation for Sight.Results121...

Brush Seals Used in Steam Environments—Chronological Wear Development and the Impact of Different Seal Designs

During the last decades, turbo machine efficiency was considerably increased by using more efficient seals. Brush seals, as a compliant contacting filament seal, have become an attractive alternative to conventional labyrinth seals in the field of aircraft engines as well as in stationary gas and steam turbines. The aim of today's research related to brush seals is to understand the characteristics and their connections, in order to be able to make performance predictions, and to ensure the reliability over a defined operating period. The wear behavior is essentially influenced by frictional contacts at the seal-to-rotor interface during operation. For realistic investigations with representative circumferential velocities, the TU Braunschweig, Germany, operates a specially developed steam test rig which enables endurance investigations under varying operating steam conditions up to 50 bar and 450 °C. Wear measurements and the determination of seal performance characteristics, such as blow down and bristle stiffness, are enabled by an additional test facility, using pressurized cold air up to 8 bar as a working fluid. This work presents the chronological wear development on both rotor and seal sides in a steam test lasting 25 days or 11 days, respectively. Interruptions after stationary and transient intervals were made in order to investigate the degree of wear. Two different seal arrangements, a single tandem seal, and a two-stage single seal arrangement, using different seal elements were considered. Besides a continuous wear development, the results clearly show that the abrasive wear of the brush seal and rotor is mainly caused by transient test operations, particularly by enforced contacts during shaft excursions. Despite the increasing wear to the brushes, all seals have shown a functioning radial-adaptive behavior over the whole test duration with a sustained seal performance. Thereby, it could be shown that the two-stage arrangement displays a load shift during transients, leading to a balanced loading and unloading status for the two single brush seals. From load sharing, and in comparison with the wear data of the tandem seal arrangement, it can be derived that the two-stage seal is less prone to wear. However, the tandem seal arrangement, bearing the higher pressure difference within one configuration, shows a superior sealing performance under constant load, i.e., under stationary conditions.

Film compression bandage

SummaryPurpose: Textile compression stockings or bandages are limited in comfort; they do not allow uninterrupted wearing. A novel elastic film bandage was evaluated regarding practicability, patient comfort and effect on vein regression. Main endpoint was the frequency of symptomatic inflammatory reactions.Methods: In a comparative pilot study, a compression film bandage (CFB, investigational) comprising an elastic, self-adhesive breathable polymer film of d &lt;20 µm was continuously worn for 14 d after foam sclero-therapy. Inclusion: 62 patients (26–68 y.) frequently doing sports and taking daily showers, 90 legs with superficial varicosities, 5–12 mm ø (MW: 7.3 mm), randomized to A) CFB + medical compression stocking (MCS), B) MCS alone, C) CFB alone. Follow-up examinations including ultrasound and photography were performed after 2, 4 and 8 weeks.Results: Continuous wearing time of 14 days was completed in 57/60 cases with CFB (95.0 %, A+C), while 3/60 (5.0 %) finished wearing after 8–10 d. There were no adverse skin reactions except minor irritations at the upper edge (n = 2). Vein diameters were reduced within 14 days by 29–54 % (mean: 43.5 %) in group A, 16–44% (mean: 39.1 %) in group B, and 24–50 % (mean: 37.3 %) in group C. Symptomatic inflammation, indu-ration or discolouration was observed within 28 days in 5/60 cases (8.3 %) when using CFB (A, C) versus 19/30 (63.3%) related to stocking compression (B). Comfort was rated by the patients 6.6 (A), 4.3 (B) and 9.2 (C) on a 10 degree scale. This difference was statistically highly significant (p &lt;0.01).Conclusions: The film bandage is an effective and safe compression modality. For superficial varicosities the adhesive bond to the skin seems to be relevant additional to the elastic properties. The device significantly improves vein regression of foam-treated superficial varicosities when combined with compression stockings or even as stand-alone modality. Continuous wearing for two weeks is well tolerated. The bandage may also offer an alternative for patients not tolerating textile compression media, or during summer.

Sitting time and physical activity after stroke: physical ability is only part of the story

Background: Understanding factors that influence the amount of time people with stroke spend sitting and being active is important to inform the development of targeted interventions.Objective: To explore the physical, cognitive, and psychosocial factors associated with daily sitting time and physical activity in people with stroke.Method: Secondary analysis of an observational study (n = 50, mean age 67.2 ± 11.6 years, 33 men) of adults at least 6 months post-stroke. Activity monitor data were collected via a 7-day, continuous wear (24 hours/day) protocol. Sitting time [total, and prolonged (time in bouts of ≥ 30 minutes)] was measured with an activPAL3 activity monitor. A hip-worn Actigraph GT3X+ accelerometer was used to measure moderate-to-vigorous-intensity physical activity (MVPA) time. Univariate analyses examined relationships of stroke severity (National Institutes of Health Stroke Scale), physical [walking speed, Stroke Impact Scale (SIS) physical domain score], cognitive (Montreal Cognitive Assessment), and psychosocial factors (living arrangement, SIS emotional domain score) with sitting time, prolonged sitting time, and MVPA.Results: Self-reported physical function and walking speed were negatively associated with total sitting time (r = − 0.354, P = 0.022 and r = − 0.361, P = 0.011, respectively) and prolonged sitting time (r = − 0.5, P = 0.001 and − 0.45, P = 0.001, respectively), and positively associated with MVPA (r = 0.469, P = 0.002 and 0.431, P = 0.003, respectively).Conclusions: Physical factors, such as walking ability, may influence sitting and activity time in people with stroke, yet much of the variance in daily sitting time remains unexplained. Large prospective studies are required to understand the drivers of activity and sitting time.

Using an electronic activity monitor system as an intervention modality: A systematic review.

BackgroundObesity is a growing global health concern that may lead to cardiovascular disease, type II diabetes, and cancer. Several systematic reviews have shown that technology is successful in combating obesity through increased physical activity, but there is no known review on interventions that use an electronic activity monitor system (EAMS). EAMSs are defined as a wearable device that objectively measures lifestyle physical activity and can provide feedback, beyond the display of basic activity count information, via the monitor display or through a partnering application to elicit continual self-monitoring of activity behavior. These devices improve upon standard pedometers because they have the ability to provide visual feedback on activity progression, verbal encouragement, and social comparison. This systematic review aimed to synthesize the efficacy and feasibility results of EAMSs within published physical activity interventions.MethodsElectronic databases and journal references were searched for relevant articles. Data sources included CINAHL, Cochrane CENTRAL, Medline Ovid, PsycINFO, and clinicaltrials.gov. Out of the 1,574 retrieved, 11 articles met the inclusion criteria. These articles were reviewed for quality and content based on a risk of bias tool and intervention components.ResultsMost articles were determined to be of medium quality while two were of low quality, and one of high quality. Significant pre-post improvements in the EAMS group were found in five of nine studies for physical activity and in four of five studies for weight. One found a significant increase in physical activity and two studies found significant weight loss in the intervention group compared with the comparator group. The EAMS interventions appear to be feasible with most studies reporting continual wear of the device during waking hours and a higher retention rate of participants in the EAMS groups.ConclusionThese studies provide preliminary evidence suggesting that EAMS can increase physical activity and decrease weight significantly, but their efficacy compared to other interventions has not yet been demonstrated. More high-quality randomized controlled trials are needed to evaluate the overall effect of EAMS, examine which EAMS features are most effective, and determine which populations are most receptive to an EAMS.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-1947-3) contains supplementary material, which is available to authorized users.

Dual drug delivery from vitamin E loaded contact lenses for glaucoma therapy

Glaucoma patients frequently instill eye drops multiple times each day, which is a cause for reduced compliance. Additionally, eye drops suffer from other limitations including low bioavailability, which can lead to side effects. We propose to develop drug-eluting contact lenses for managing glaucoma with increased bioavailability and improved compliance.Contact lenses are developed for extended simultaneous release of timolol and dorzolamide, both of which are commonly prescribed hydrophilic drugs. The extended release is achieved by loading lenses with vitamin E barriers. In vitro release studies are performed with control and vitamin E loaded lenses for both drugs loaded separately and then together in the same lens. The safety and efficacy of combination therapy by contacts are demonstrated in a Beagle model of glaucoma.Simultaneous loading of timolol and dorzolamide increases the release duration of both drugs. Also vitamin E incorporation is highly effective in increasing the release durations of both drugs to about 2-days. The lenses loaded with both drugs exhibited superior IOP reduction compared to eye drops with about 6-fold lower drug loading. More importantly, combination therapy by continuous wear of vitamin E loaded contact for 2-days, followed by a new set of contacts for another two days, reduced IOP during the 4days of wear time and for another 8days after removal of the contacts.Vitamin E loading is very effective for providing combination therapy by contact lenses due to the increase in release durations of several drugs. The contact lens based therapy reduces IOP with lower drug dose compared to eye drops and may significantly improve the compliance as the effect of the therapy lasts significantly longer than the wear-duration.

Ocular discomfort responses after short periods of contact lens wear.

To investigate if contact lens-related discomfort is a function of the time of day at which lenses are worn. This was a randomized, crossover, open-label clinical trial where subjective responses, with and without contact lenses, were assessed every 2 hours during five stages (A to E). Each stage began at the time when subjects would normally have inserted their contact lenses (T0). During stage A, no lenses were worn, whereas in stage B, lenses were worn continuously for 12 hours. In stages C to E, lenses were worn for only 4 hours. Contact lenses were inserted at T0 for stage C, but for stages D and E, lenses were not inserted until T0 + 4 and T0 + 8 hours, respectively. Mixed linear models were used for statistical analysis. In the absence of contact lenses, ocular comfort and dryness remained reasonably constant throughout the observation period. Ocular comfort and dryness decreased during 12 hours of continuous lens wear and became significantly worse from the 8-hour time onward compared with insertion (p < 0.023). There were no significant differences in terms of ocular comfort and dryness between any of the 4-hour lens wear stages (p < 0.82). During each 4-hour stage, both comfort and dryness behaved in a similar fashion (p > 0.05) to the first 4 hours of continuous contact lens wear. Comparing the scores of each of these stages with the no-lens response at the corresponding time showed no significant differences for comfort (p > 0.23) or dryness (p > 0.37). Short periods of wear can be experienced at any time of day without significant change in ocular discomfort and dryness. This suggests that subjective responses at the end of the day are determined by the length of time lenses are in contact with the eye, rather than the time of day at which lenses are worn.

Comparative Accuracy Evaluation Of A Disposable, Self-adhesive Multi-sensor Activity Monitor

Wearable activity monitors can play a valuable informational and motivational role in promoting healthy exercise habits, but intermittent compliance or user reactivity can complicate their everyday use. A new disposable, multi-sensor activity monitor designed for continuous multi-day wear has recently been introduced into the consumer market. The device records the user’s calorie expenditure and step count, among other lifestyle assessment parameters, while it is worn on the arm, attached by skin-friendly adhesives. PURPOSE: A comparative study was undertaken to assess the new device’s relative accuracy in estimating calorie expenditure and step count during treadmill walking, versus two other consumer-oriented monitoring devices. METHODS: A group of twenty-five subjects with a distribution of body mass indices that is representative of American adults wore the device for five days. On the first and fifth day of wear, the subjects also donned a reusable multi-sensor armband device and a digital pedometer while completing a physical activity sequence that consisted of walking on a treadmill at defined speed/incline combinations (80.5 m/min and 0, 5, or 10% incline), and also while resting. The resulting data was used to make quantitative comparisons of reported energy expenditure and step count. RESULTS: With respect to energy expenditure, the disposable sensor agreed with the armband within a mean error of 2.1 ± 29.9% (mean ± 95% CI) on the first day of wear and 1.7 ± 19.3% on the fifth, and correlation coefficients of r = 0.928 and 0.921 on days one and five, respectively. The number of steps recorded by the disposable sensor agreed with the digital pedometer within mean errors of -1.9 ± 3.8% on the first day and -1.8 ± 4.1% on the fifth, with correlation coefficients of r = 0.959 on day one and 0.961 day five. CONCLUSIONS: The results suggest that the new disposable, multi-sensor activity monitor is as accurate a tool for measuring energy expenditure and step count during treadmill walking as other, best-in-class consumer-oriented activity monitors.

Wear of a high cBN content PCBN cutting tool during hard milling of powder metallurgy cold work tool steels

The wear characteristics of a high cBN content PCBN cutting tool during hard milling of two different hardened cold work tool steels have been evaluated. Post-cutting examination of the worn cutting inserts was performed using high resolution field emission gun scanning electron microscopy, energy dispersive X-ray spectroscopy, Auger electron spectroscopy and optical surface profilometry. Also, the machined work material surfaces and collected chips were characterized in order to evaluate the prevailing wear mechanisms.The results show that both flank and crater wear are controlled by continuous wear due to tribochemical reactions, adhesive wear and mild abrasive wear. Besides, the cutting inserts show a tendency to micro-chipping along the cutting edge especially at higher cutting speed. The latter mechanism was also found to be dependent on type of work material. High lateral resolution Auger electron spectroscopy of the crater region shows that the worn surface is covered by a thin SixOy rich tribofilm with a thickness of 50–500nm, the tribofilm being thicker on the binder phase regions. Also, the Co-rich regions of the binder phase seem to be more tribochemically affected by the prevailing contact conditions as compared with the W-rich regions of the binder phase and the cBN phase.

45 * ARE ACCELEROMETERS A USEFUL WAY TO MEASURE ACTIVITY IN CARE HOME RESIDENTS?

Introduction: Accurate measurement of activity in care home residents is important for monitoring and evaluating interventions for activity promotion. Accelerometers provide a potential method. However, their usefulness in this population has not been well documented. We aimed to explore the feasibility of these in care home residents. Method: Mobile residents who had fallen in the past year, were asked to wear a tri-axial accelerometer (ActivPAL3TM) on the lower thigh for 7 days. Care staff were trained in device application. Users’ skin and problems with use were checked daily. Activity data sought were: step count, time sedentary, time standing and Metabolic Equivalent of Task. Care records were checked for falls. Results: 10/16 residents agreed to wear accelerometers. 7 wore them for 7 days and the remainder for 4, 5 and 6 days respectively. No falls were recorded. Data indicated 1 resident continuously standing which was verified not to be the case by observation. Problems were: data disturbance through removal/fidgeting, hydrofilm dressing flaccidity, premature detachment, care staff non-compliance to waterproof continuous wear, resident skin check non-compliance, prior leg ache attributed to accelerometers (with no worsening), pink skin and activity restriction by care staff. The accelerometers and attachment materials cost £2062.59. Conclusion: In this small feasibility study of care home residents tri-axial accelerometers were so problematic to be of negligible use and we will not be using them in our definitive trial. Activity levels, where recorded were in keeping with published literature showing care residents to be highly sedentary,

Effect of Rotational Sliding Velocity on Micro Tribological Behaviors of Cu50Zr50 Amorphous Alloy Foils

In this study, the micro tribological behavior of Cu50Zr50 amorphous alloy foils was investigated experimentally at room temperature by pin-on-disc tribological tests. It is found that the friction coefficients are mainly located between 0.15 and 0.45, and increase with the rotational sliding velocity. With the increase of rotational sliding velocity, the wear weight loss also increases. At lower rotational sliding velocity, the wear mechanism tends to a combination action of continuous wear and surface flow. At higher rotational sliding velocity, the wear mechanism tends to a continuous wear. The reported results provide a basis understanding of the tribological behavior of Cu50Zr50 amorphous alloys in micro scale.