Pressure Pad Research Articles

Virtual Reality Rehabilitation for Vestibular Dysfunction

Objective: People with chronic vestibular dysfunction can be treated with balance rehabilitation. Virtual reality (VR) technology may serve as a useful therapeutic tool to facilitate rehabilitation. The aim of this pilot study was to investigate the clinical applicability of VR technology in treating patients with vestibular dysfunction. Method: Five patients with chronic vestibular dysfunction were recruited for this uncontrolled clinical study. The rehabilitation protocol (modified Cawthorne-Cooksey exercises, MCCE) was adapted into a VR-based training system. Patients followed the instructions of MCCE to complete 20 sessions of vestibular rehabilitation within a 4-week period. Results: A VR-based rehabilitation system was developed with various latest technologies, including Kinect Xbox for full-body interaction, 3D-ready projector with shutter-glasses for stereo imaging, Wii Fit pressure pad for tracing the center of gravity, and Unity game engine for leveled-difficulty design. Five VR tasks were built, and more than 100 training trials were designed. Subjectively, all patients experienced the improvement of balance function performing daily activities and were overall positive to the training protocol. After intervention the fast component of postural sway ( P < .05) was reduced. The follow-up interview showed decreased disability and increased general health. Conclusion: VR has many advantages over traditional rehabilitation techniques in improving the testing or training environment of human performance. This study demonstrates that VR technology offers great promise in the field of vestibular rehabilitation.

The innovative application of chalazion forceps in surgery of eyelid full-thickness laceration

Objective To evaluate the innovative application of the chalazion forceps in surgery of eyelid full-thickness laceration,especially in surgery with palpebral full-thickness laceration or with parts of the eyelid tissue loss. Methods In the surgery of full-thickness eyelid laceration, clampping the chalazion forceps on the wound. The clinical data were retrospectively analyzed. Results Of 40 cases of patients with eyelid lacerations,wounds were fixed appropriately,there are stable pressure pad, good hemostasis, and good protection in surgery, and surgical time was significantly shorter with excellent results. After surgery,39 of 40cases (40 eyes) became one stage repair of laceration without infection, ischemia, necrosis or ptosis, but there was 1 case( skin defect)with eyelid deformity. Conclusion The chalazion forceps used in the surgery of eyelid laceration,the result is good, the operation is efficiency and the difficulty of surgical operation is reduced. Key words: chalazion clamp; full-thickness eyelid laceration ; innovative applications

Bandless Hearing Protector And Method

A hearing protection device and method of use intended for a human ear. A plug member caps or enters ear canal, and may be shaped to conform to the external auditory meatus. The plug member may be part of a replacement assembly. The device is biased at least in part by a pressure pad to provide some force against the plug member. An optional handle may be provided to assist with temporarily pulling the plug member away from the ear canal or providing adjustment. An optional bow member clips about the pinna. The device may be adapted for use as an ear phone.

An objective measurement of brace usage for the treatment of adolescent idiopathic scoliosis

Effectiveness of orthotic treatment for scoliosis depends on how much time and how well the orthosis is worn. Questionnaires and clinical judgment are subjective methods to wear compliance. Even though using a temperature sensor can objectively record how long the orthosis has been used, it may not be able to answer the orthosis effectiveness without knowing the wear tightness. Custom made thoracolumbosacral orthoses (TLSO) were instrumented with low power wireless data acquisition systems to measure the time and loads imposed by the pressure pad during daily activities. Force measurements were recorded at 1 sample/min and the system was able to record data up to 4 months without patient-involvement. Ten subjects (9F, 1M), age between 9 and 13.5 years, average 11.6 ± 1.3 years, who prescribed a new TLSO and full-time brace wear were took part in this study over 4.4 ± 1.0 months. Long-term logging of loads within a spinal orthosis is a reliable method to measure compliance objectively. The monthly quantity of brace wear ranged from 33% to 82%, average 60.0 ± 4.3%. The monthly average loads imposed by the pressure pads varied from 39% to 78% relative to the reference level, average 64.3 ± 4.6%. There was a statistically significant decrease in force, but increase in wear time over the period after the brace fitting session. This information may help to better understand the effectiveness of bracing and to predict the brace treatment outcomes.

Experimental study on the contact patch pressure and sinkage of a lightweight vehicle on sand

This study focuses on improving the understanding of the mobility of lightweight wheeled vehicles on sand by testing the significance of payload, ground speed, sand gradation/grain size, and sand moisture content on contact patch pressure and tire sinkage. Extensive testing of a lightweight wheeled all-terrain vehicle (ATV) was structured in two experiments. Tire sinkage was measured at the width-wise center of the imprint of both the tread and the carcass. Pressure distribution in the contact patch was recorded using an embedded pressure pad, from which the average and peak (and difference) pressures were found. In the first experiment, measurements were taken each time the ATV was driven over combinations of four plots of groomed sand, two moisture contents, three payloads, and three speeds. Average pressure was highly affected (95+% confidence) by sand grade, vehicle speed, and payload and the interactions of sand grade–speed, and sand grade–moisture content–vehicle speed, and borderline affected (90–94.9% confidence) by the moisture content–speed interaction. In the second experiment, the ATV was driven over each plot of dry sand one hundred consecutive times at one speed–payload combination without grooming between runs, showing the cumulative effect of multiple passes over each sand pit on each measure of mobility.

Transient and thermal contact analysis for the elastic behavior of functionally graded brake disks due to mechanical and thermal loads

In this paper, the transient and contact analysis of functionally graded (FG) brake disk is presented. The analysis was carried out using ANSYS parametric design language (APDL). The FG brake disk is made of metal–ceramic material. The material properties vary in radial direction with the values from full-metal at the inner radius to that of full-ceramic at the outer radius. In the analysis, FG brake disk is in contact with one pure pad disk and coulomb contact friction is considered as heat source. The non-dimensional results are obtained for specific value of grading index ( n = 1) by considering different material property divisions of 25, 50, 100 and 200. The results presented are for the pressure distribution, total stress, pad penetration, friction stress, heat flux and temperature during contact, for different values of contact stiffness factor, F kn , which depends on the property gradation of FG brake disk with 200 material property divisions. The results show that the contact pressure and contact total stress increase with increasing values of F kn , and hence it can be concluded that gradation of the metal–ceramic has significant effect in the thermomechanical response of FG brake disks.

A comparison of forces acting on the horse’s back and the stability of the rider’s seat in different positions at the trot

The aim of the study was to compare the stability of the rider as well as the forces acting on a horse's back with different seating positions at the trot (sitting trot, rising trot and two-point seat). The same experienced rider was mounted on 10 sound horses trotting on a treadmill. The kinetic data were recorded with an electronic pressure mat, placed under a well-fitting dressage saddle with no saddle pad. The rider used three different seating positions, each for 20 s. Right forelimb motion was used to synchronise the pressure data with the stride cycles. To determine the rider's stability, the movement of the centre of pressure (COP) along the transverse (X) and longitudinal (Y) axes was calculated. The force was taken as the sum of all segments of the pressure pad multiplied by the area of the pressure pad. The maximum force and the X- and Y-deviations were evaluated using ANOVA for repeated measures with a Bonferroni Post hoc test. The stability of the rider in the Y-direction was significantly highest in the two-point seat, followed by the rising trot and the sitting trot, respectively. In the X-direction, there was no significant difference between the three positions. The significantly highest load on the horse's back was at the sitting trot (2112 N), followed by the rising trot (2056 N) and the two-point seat (1688 N). The rider was most stable in the two-point seat while transferring the lowest load on the horse's back. The rising trot was found to be more stable and less stressful for the horse's back compared to the sitting trot.

Maternal Low Protein Diet and Fetal Glucocorticoid Exposure Program Adult Murine Cardiovascular and Endocrine Status

Fetal programming of human hypertension (HTN) and the metabolic syndrome is associated with low birth weight. We have modeled this process in mice using iso‐caloric low protein (LP) or normal protein (NP) diets provided to dams from E0 to19. Dams on NP received either saline injections or the 11‐βHSD inhibitor carbenoxolone (CX, 12.5mg/g E10 to 19). Offspring were fed either NP or a high fat (HF) diet. Blood pressure (BP) was recorded by radiotelemetry at baseline, on a high salt diet (9% NaCl), or on high salt plus a nitric oxide synthase (NOS) inhibitor (L‐NAME). Dam caloric intake was not altered by LP or CX, but pup birth weight was reduced (LP 1.7 ± 0.1g, CX 1.9 ± 0.1g, NP 2.2 ± 0.2g). Adult female LP and CX offspring had decreased fat pad weight and blood pressure on either NP or high salt (p<0.05). The decrease in BP was blocked by L‐NAME. In contrast, male LP and CX mice had increased fat pad weight and HTN that was exacerbated by both salt and L‐NAME. HF diet increased blood pressure and fat pad weight in NP mice which became similar to LP and CX. Conclusions: LP or CX impair fetal growth and program HTN in male mice. The HTN is partially compensated by NOS activation and is associated with obesity. Female mice are protected from programmed HTN and display decreased adiposity and enhanced NOS activation.

Measurement of ski snow-pressure profiles

Bulge-disc type pressure sensors of diameter 6 mm were fitted as near as possible to the running edge of a modern carved ski. The pressure signals were sampled at 30 Hz during long turns on snow, synchronously with signals from a geomagnetic compass and a pressure pad in the ski boot. The pressure from the snow was found to be highly variable with a mean value of about 50 kPa and dynamic pressure spikes up to 300 kPa. With the outside leg, the snow contact width in the rear part of the ski was found to be slightly wider, on average, than for the front part, as expected for a carving turn. Correlation within the pressure sensor data showed that the rapid pressure fluctuations were probably not due to bumps or features on the snow; instead they were probably caused by many small-scale collapses of the snow structure as the ski passed.

Air Bearing Slider-Disk Interface for Single-Sided High Speed Recording on a Metal Foil Disk

There are disk-drive data storage applications best served by single-sided recording configurations. These include situations where (i) storage requirements can be achieved on a single side of a disk and (ii) dimensional constraints on the disk drive prohibit the presence of a recording head and its associated mounting device on each side of the disk. Even if dimensional requirements are not a concern, the most cost-effective and operationally efficient slider-disk air-bearing interface for single-sided recording is one that does not include an air-bearing slider, pressure pad, or other air-bearing structure on the nondata side of the disk. A metal foil disk offers some of the best characteristics of both the hard disk and floppy disk for digital data storage. It offers hard disk recording densities, increased shock resistance, reduced manufacturing cost, and requires less operational energy than a hard disk. However, use of a conventional recording head slider assembly without opposing air-bearing support for single-sided recording on a high-speed metal foil disk presents a fundamental problem because the air-bearing surface of the slider produces a net transverse force to the disk. This force causes the disk to deflect and can result in flying height and stability problems at the slider-disk interface. The current work describes an air-bearing interface for low flying height single-sided recording on a high-speed metal foil disk that minimizes disk deflection and instability without the presence of air-bearing components on opposing sides of the disk. The new interface utilizes a vacuum cavity-type air-bearing with little or no preload. Examples will be presented and discussed for the new interface that illustrate the flying characteristics of a picosized slider on a 1.8in. stainless steel disk with thickness of 25.4μm.

Pressure-sensing pad test and computer simulation for the pressure distribution on the contact patch of a tyre

The characteristics of tyre contact with the road surface have considerable influence on various properties of the tyre. In this research, the contact pressure on the tyre was measured with a pressure-measuring device, and finite element (FE) analysis for the contact pressure was also carried out. A physical experiment device using a quarter-car uniaxial simulator and pressure pad system was set up, and the commercial FE code LS-DYNA was used for numerical calculations. FE models containing reinforcement cords and various tyre plies were generated, and the numerical results were compared with those of the physical experiment. These analyses and investigations showed reasonable results, and the reliability of the proposed FE tyre model and analysis methodology was verified.

New Approach for Estimation of Static and Seismic Active Earth Pressure

To estimate static and seismic active earth pressure (Pad) on a rigid retaining wall, numerical analyses using different step sizes have been carried out in this paper, based on the modified Culmann line method by considering Coulomb’s planar rupture surface. Equivalent pseudo-static seismic forces are considered in the analysis. A new concept of modified unit weight by considering ground surcharge is introduced under static and seismic conditions. By numerical analysis, area of soil (A) has been estimated to obtain the ratio of A/A0 where A0 is θh2, θ is the angle between retaining structure and ground surface and h is the vertical height of the wall. This ratio remains constant for a particular type of soil and has been used to estimate the maximum active earth pressure using force diagram. Results are provided in tabular form for easy calculation of the coefficient of static and seismic active earth pressure. Present results by considering the new technique, compares well with the results obtained by earlier researchers.

Assessing Palmar and Pinch Forces in a Manufacturing Plant Using a Dynamic Pressure System

For work tasks requiring hand force and repetitive motions, risk increases directly proportional to an increase in force and repetition. Data on hand force exertion is generally collected by estimation of these forces by using subjective measurements, EMG recordings, or strain gauges. The objective of this study was to evaluate the use of a pressure pad system to quantify the ergonomic risk of a repetitive forceful manufacturing task. Effects of palmar and pinch forces and pressures associated with the current and proposed new work tasks were investigated by using a Novel Pliance dynamic pressure analysis system. Use of this system allowed the researchers to validate the reduction in forces associated with the tasks. This methodology has profound implications in that no compromise between internal and external validity is necessary, and allows quantification of ergonomic issues around forces, including tasks which requiring repetition and force exertions.

Slider Air Bearing Design Enhancements for High Speed Flexible Disk Recording

The current effort was motivated largely by the fact that computing and communication platforms are becoming more portable and mobile with increased demands for both speed and disk storage. This work makes use of an asymmetric opposed slider arrangement to provide both static and dynamic improvements to the recording head air bearing interface for high speed flexible disk applications. The combination of a longitudinally slotted rail opposed by an uninterrupted rail that functions as a noncontact hydrodynamic pressure pad causes the disk to deflect at the submicron level over critical areas of the slider interface. This allows the required static minimum flying height to be focused over the recording transducer while higher clearances are positioned elsewhere, resulting in minimized exposure to contact between slider and disk. The high stiffness and low flying height of the air film at the recording element together with the low stiffness and high flying height of the opposing air film provides a noncontact air bearing interface that is especially immune to mechanical shock. A computer code called FLEXTRAN was developed that provides both static and dynamic numerical solutions of the air bearing interface composed of two opposed gimbal mounted sliders loaded against a high speed flexible disk. Simulations of the asymmetric opposed slider configuration are presented and compared with those of other slider air bearing designs.

Tracks and trackways of Myotragus balearicus Bate (Artiodactyla, Caprinae) in Pleistocene aeolianites from Mallorca (Balearic Islands, Western Mediterranean)

Tracks and trackways of the ruminant goat, Myotragus balearicus Bate, 1909 are abundant in the Late Pleistocene aeolianites of the south coast of Mallorca, Spain. The carbonate aeolianites form impressive dunes and related sand ramps that were initiated as echo dunes in front of a 20–40 m high paleocliff of Miocene reefal limestone. Where the dunes built up to the cliff top, they covered it as an aeolian ramp. The dunes and sand ramps were active during the dry summer months but were passive during the wet winter period. The small, goat-like animals were abundant on the island, and for unknown reasons crossed the aeolian accumulations in large numbers. This study deals with the tracks formed in the dune deposits. All preserved trackways indicate impression into moist sand. Special features of the tracks include the structure produced by the withdrawal of the foot, here called the ‘axis’, and a disturbance zone of plastic deformation around this. On dune crests, the disturbance zone surrounds the axis more or less symmetrically. However, in addition, a ‘pressure pad’ of dislocated, slightly rotated sediment bound by curved microfaults is commonly produced posterior to the axis by propulsive pressure of the foot. On steep stoss and lee slopes, the pressure pad becomes oriented in a down-slope position as a result of gravitational slip of the walking animal. Combination of disturbance of the sediment in this way by manus followed by overprinting of similar disturbance by pes produces highly complicated track structure. This structure may be characteristic of artiodactylous mammals in soft sand, particularly aeolian deposits. The structure is designated as Bifidipes aeolis isp. nov.

The effective forces transmitted by high-speed, low-amplitude thoracic manipulation.

Twenty asymptomatic volunteers each received three spinal manipulative treatments to the thoracic spine. The treatments consisted of a straight posterior-to-anterior high-speed, low-amplitude thrust to the transverse process of T3-T10 using a reinforced hypothenar contact. All treatments were given by a full-time practicing clinician with 3 years of experience. The primary objective of this study was to quantify local measures of loading applied by the clinician on the volunteers during spinal manipulative treatments and to compare these local measures of loading with previously described global measures. The sparse information on the mechanics of spinal manipulative treatments deals exclusively with global force or pressure measurements. On the basis of these global data, incorrect conclusions may be drawn about the beneficial effects of spinal manipulative therapy, the loading of internal structures, and the risks associated with these treatments. Twenty asymptomatic subjects each received three posterior-to-anterior, high-speed, low-amplitude spinal manipulative treatments to the transverse process of the thoracic spine. Total force, local force, contact area, peak pressure, and average pressure at the contact interface between clinician and subject were measured continuously by use of a thin, flexible pressure pad. Local and global measures of loading were compared and analyzed by use of nonparametric statistics (alpha = 0.01). The average peak total force was 238.2 N. The average peak local force over a target area of 25 mm2 was 5 N, indicating that global measures of loading vastly overestimate the local effective forces at the target site. The peak pressure point moved, on average, 9.8 mm during the course of the manipulation. To the authors' best knowledge, this is the first study to quantify local, effective measures of loading and compare them with the global measures typically used. The conclusions are limited because the study used a single clinician. The effective loading of specific target sites is much smaller than the global measures might suggest. This result occurs because as the forces during spinal manipulative treatment increase, so does the contact area; therefore, much of the total treatment force is taken up by non-target-specific tissues. Because of the vast discrepancy between the global and local measures of loading, it is suggested that risk-benefit assessments of high-speed, low-amplitude spinal manipulative treatments should be made, including local measures of loading. Finally, because theoretical approaches and the inverse dynamics approach can provide only global measures of loading, the results of such studies should be interpreted with caution.

IGF-I treatment reduces hyperphagia, obesity, and hypertension in metabolic disorders induced by fetal programming.

The discovery of a link between in utero experience and later metabolic and cardiovascular disease is one of the most important advances in epidemiology research of recent years. There is increasing evidence that alterations in the fetal environment may have long-term consequences on cardiovascular, metabolic, and endocrine pathophysiology in adult life. This process has been termed programming, and we have shown that undernutrition of the mother during gestation leads to programming of hyperphagia, obesity, hypertension, hyperinsulinemia, and hyperleptinemia in the offspring. Using this model of maternal undernutrition throughout pregnancy combined with postnatal hypercaloric nutrition of the offspring, we examined the effects of IGF-I therapy. Virgin Wistar rats (age 75 +/- 5 d, n = 20 per group) were time mated and randomly assigned to receive food either ad libitum or 30% of ad libitum intake (UN) throughout pregnancy. At weaning, female offspring were assigned to one of two diets (control or hypercaloric [30% fat]). Systolic blood pressure was measured at day 175 and following infusion with 3 microg/g per day recombinant human IGF-1 (rh-IGF-I) by minipump for 14 d. Before treatment, UN offspring were hyperinsulinemic, hyperleptinemic, hyperphagic, obese, and hypertensive on both diets, compared with ad libitum offspring and this was exacerbated by hypercaloric nutrition. IGF-I treatment increased body weight in all treated animals. However, systolic blood pressure, food intake, retroperitoneal and gonadal fat pad weights, and plasma leptin and insulin concentrations were markedly reduced with IGF-I treatment. IGF-I treatment resulted in a 3- to 5-fold increase in 38--44 kDa and 28--30 kDa IGF binding proteins, although in UN animals, there was an impaired and differential up-regulation of these insulin-like growth factor binding proteins following IGF-I treatment. The 24-kDa IGF binding protein representing IGF binding protein-4 was down-regulated in all IGF-I-treated animals, but the decrease was more marked in UN animals. Our data suggest that IGF-I treatment alleviates hyperphagia, obesity, hyperinsulinemia, hyperleptinemia, and hypertension in rats programmed to develop the metabolic syndrome X.

Dressed to heal: new options for graft site dressing.

To ensure the close apposition and immobilization required for survival of full thickness skin grafts, the traditional method is to use pexing sutures or tie-over pressure dressings. In certain areas, such as around the eye, other methods are required because either a concave or convex surface prevents adequate pressure, or the use of sutures as ties produces distortion of anatomical free margins. Alternative dressing methods include; telfa chips kept in place by a pressure pad; calcium alginate (which has the advantages of assisting haemostasis and absorbing serous discharge) under a pressure pad; and extra thin hydrocolloid dressings which decrease slough and are less conspicuous than other dressings.

A wheelchair cushion designed to redistribute sites of sitting pressure

Objectives: Despite the diversity of wheelchair cushions currently in clinical use, pressure on bony prominences continues to be a major problem for wheelchair-bound patients, and the incidence of pressure ulcers remains high. No static surface has been reported to reduce resting pressure under the ischial tuberosities to below that of capillary pressure, which may well be the threshold for inducing tissue damage. An entirely new form of seating was designed to decrease absolute pressure using a prosthetic fitting technique analogous to a below-the-knee prosthesis Design: A repeated measures randomized design was used to test differences between the experimental (TCS) and three other standard cushions. Setting: A Veterans Medical Center outpatient service. Patients: Wheelchair-bound volunteer subjects, n = 47, were selected who weighed more than 60kg. Main Outcome Measures: Pressures were measured by a standard air pressure pad and also by a computer-linked array of pressure transducers. The grid was standardized and used to generate topographic maps for each site over time. These data were used to measure the seating interface pressures. Results: There was a significant main effect of cushio over site, F = 131 for left ischial tuberosity. Pressures were lowest while patients sat on the experimental seat and differences were significant at all time points. Using 1psi as presumed capillary pressure, frequency of success at achieving this pressure threshold was greatest for the experimental seat, p < .001. This difference persisted throughout the 30 minutes of testing. Conclusions: A computerized pressure grid was developed that allowed evaluation of anatomically localized pressures. The prosthetically designed TCS displays lower seating pressures than any other cushion tested. Consistent and sustained pressures were below the postulated threshold for tissue damage.

Experimental investigations on the forming of regularly spaced deep recesses on aluminium sheet metal panels

A tooling for forming deep recesses at regular intervals on aluminium sheet-metal panels was recently designed, fabricated and tested successfully. This tooling was further refined, the refinements including a larger area for the application of blank-holding force in the first station, an extra spring-operated pressure pad for the sheet being fed in, the ejectors to push the product from off the die after forming. With these refinements the forces on the die-set are properly balanced, and fracturing and wrinkling of the sheet metal are eliminated. Experiments were conducted with: (i) different lubricants; and (ii) different values of the blank-holding force in station 1 for the bulk of the metal, except at the two ends. Thickness strains were determined at several points around the recess for five points along the length of the recess for a fully-formed recess and also at the intermediate stages of forming.