Pressure Pad Research Articles

Experimental Research on Dynamic Characteristics of a Multi-Disc Rotor System Supported by Aerostatic Bearings

Gas bearings have the advantages of small friction loss, wide applicable speed range, no pollution, etc., and have important application prospects in micro and small high-speed rotating machinery. However, due to its compressibility and low viscosity, its dynamic stability in high-speed rotating machinery is the key to constraining its development. The experimental study of shaft system dynamics is the main means to explore the mechanism of rotor behavior. On the test platform of dynamic characteristics of multi-disc rotor system supported by aerostatic bearings, experimental research on the nonlinear dynamic characteristics of a rotor system was carried out, and nonlinear vibration test and analysis methods, such as axial orbits, bifurcation diagrams, and spectral characteristics, were adopted, and vibration phenomena, including the critical rotational speed accumulating energy and low-frequency accumulating energy, were presented and the vibration characteristics of bearing fracture faults were presented. The bearing supply pressure and rubber damping pad were introduced as a method to suppress the low-frequency vibration of the aerostatic bearing rotor system, and its vibration-reduction effect was verified by experiments. The above results can provide technical support for vibration control and fault diagnosis of rotor systems supported by aerostatic bearings.

CORSET PRESSURE PADS EVALUATION USING A CAD/CAM METHOD

Pressure pads are small hand-made corset components used for scoliotic curve correction by applying pressure to the body segment. The design and accuracy of these pads can be increased by using modern approaches like CAD modeling and additive manufacturing. The aim of this research was to apply these methods in the pressure pad development process and evaluate the suitability of the designed prototypes. A CAD software SOLIDWORKS was used for the pad design and 2 manufacturing technologies have been selected, specifically FDM and MJF, for the pad production. As for the material of which the pads could be manufactured, PLA, PETG and PA12 have been selected. Abaqus software, using the finite element method, has been chose for the 9 pad prototypes strength calculation, from which 6 have passed the test. It would be appropriate to expand the given research with CAD pressure pads of various optimized designs with different types and densities of infills.

Explosion behaviors of hydrogen-nitrous oxide mixtures with propane addition

In the present work, the explosion of hydrogen-propane-nitrous oxide mixtures with various equivalence ratios (ϕ=0.2-2.4), propane fractions (ωC=0-1.0) and initial pressures (P0=50-100 kPa) at ambient temperature (288 K, room temperature) was experimentally performed in a standard 3.375-L cubic vessel. The maximum explosion pressure (Pmax), maximum pressure rise rate ((dp/dt)max) and explosion time (te) were obtained in light of pressure–time curves, and the normalized maximum explosion pressure (Pmax/P0) and normalized explosion time (td/te) were analyzed as well. Moreover, the adiabatic pressure (Pad) and laminar burning velocity (SL) were also calculated for argumentation. The results indicate that with the increase of ωC, Pmax and (dp/dt)max both present three characteristic variation trends for different ϕ, while the inflections of Pmax-ϕ and (dp/dt)max-ϕ transient gradually from lean to rich mixtures. Besides, te and td/te are monotonously rising with ωC, illustrating that propane addition can remarkably decelerate the explosion process. In addition, with the increase of P0, Pmax/P0 raises monotonously and is asymptotic to Pad/P0 at ωC⩽0.2, demonstrating that heat loss decreases under higher P0. Linear dependence is also found between (dp/dt)max and P0 for any composition. Furthermore, te monotonically decreases with P0, due to the flame acceleration occurring in the combustion period. In general, the presence of nitrous oxide (N2O) with a large content makes the explosion extremely unstable, and a spot of propane can dramatically alter the explosion characteristics of H2-N2O mixtures. These results will be meaningful for the development of explosion-mitigation devices and technology in case of underlying explosion and fire hazards.

A method for calculating left ventricular ejection fraction noninvasively from left ventricular arterial coupling (Ees/Ea)

BackgroundEjection fraction (EF), which is assessed using ultrasonography, is a standard parameter for evaluating cardiac function in clinical cardiology and for cardiovascular management during general anesthesia. However, it is impossible to continuously and non-invasively assess EF using ultrasonography. The aim of our study was to develop a method for estimating EF non-invasively using the left ventricular arterial coupling ratio (Ees/Ea).MethodsEes/Ea was estimated non-invasively using the parameters pre-ejection period (PEP), ejection time (ET), end-systolic pressure (Pes) and diastolic pressure (Pad), which were calculated from a vascular screening system, VeSera 1000/1500 (Fukuda Denshi Co., Ltd., Tokyo, Japan). Then, left ventricular efficiency (Eff) as a pump, defined as the ratio of external work (EW) to myocardial oxygen consumption, which strongly correlates with the pressure-volume area (PVA), was calculated by a new formula using Ees/Ea, and was used to approximate EF (EFeff). Simultaneously, we measured EF using transthoracic echocardiography (EFecho), and compared it with EFeff.ResultsThe study included 44 healthy adults (36 males, 8 females), in whom mean EFecho was 66 ± 5% and EFeff was 57 ± 9%. We found a positive correlation between EFecho and EFeff (R2 = 0.219, p < 0.05) on Bland-Altman analysis, with limits of agreement of – 7.5 to 24.4%, and percentage error of 24%.ConclusionThe results suggest that EF can be measured non-invasively using left ventricular arterial coupling.

Comparison of Forces Exerted by a Chiropractor on Children and Adults During High-Speed, Low-Amplitude Spinal Manipulations: A Feasibility Study

ObjectiveThe aim of this study was to demonstrate that quantification of the forces exerted by a single chiropractor on children and adults during high-velocity, low-amplitude spinal manipulations and the correlation of forces to age was feasible. MethodsThe force-time profiles of high-velocity, low-amplitude spinal manipulations were measured in 48 children (109 manipulations) ranging from 14 weeks to 17 years of age, and 20 adults (49 manipulations) in a clinical setting. The measurements were taken using a thin, flexible pressure pad. Outcome variables (peak forces, preload forces, thrust forces, thrust durations, rates of force application, and thrust impulses) were quantified and compared across age groups using Kruskal-Wallis testing with Dunn post hoc analysis. Outcome variables were fitted with best-fitting linear regressions with age as the dependent variable. The level of significance for all statistical tests was set a priori at α = 0.05. ResultsMost outcome variables increased with the age of the patient. Specifically, peak forces, thrust forces, and the rate of force application were positively correlated with age, while thrust durations remained constant across all ages and preload forces decreased slightly with patient age for cervical spine manipulations. ConclusionFor this single chiropractor in private practice, the forces he used increased with the age of the patient, and he thus used lower forces in children than adults. This study shows that measuring the forces used by a chiropractor in clinical practice on patients with a range of ages was feasible.

Kinematics of the head and associated vertebral artery length changes during high-velocity, low-amplitude cervical spine manipulation

BackgroundCervical spine manipulation (CSM) is a frequently used treatment for neck pain. Despite its demonstrated efficacy, concerns regarding the potential of stretch damage to vertebral arteries (VA) during CSM remain. The purpose of this study was to quantify the angular displacements of the head relative to the sternum and the associated VA length changes during the thrust phase of CSM.MethodsRotation and lateral flexion CSM procedures were delivered bilaterally from C1 to C7 to three male cadaveric donors (Jan 2016–Dec 2019). For each CSM the force–time profile was recorded using a thin, flexible pressure pad (100–200 Hz), to determine the timing of the thrust. Three dimensional displacements of the head relative to the sternum were recorded using an eight-camera motion analysis system (120–240 Hz) and angular displacements of the head relative to the sternum were computed in Matlab. Positive kinematic values indicate flexion, left lateral flexion, and left rotation. Ipsilateral refers to the same side as the clinician's contact and contralateral, the opposite. Length changes of the VA were recorded using eight piezoelectric ultrasound crystals (260–557 Hz), inserted along the entire vessel. VA length changes were calculated as D = (L1 − L0)/L0, where L0 = length of the whole VA (sum of segmental lengths) or the V3 segment at CSM thrust onset; L1 = whole VA or V3 length at peak force during the CSM thrust.ResultsIrrespective of the type of CSM, the side or level of CSM application, angular displacements of the head and associated VA length changes during the thrust phase of CSM were small. VA length changes during the thrust phase were largest with ipsilateral rotation CSM (producing contralateral head rotation): [mean ± SD (range)] whole artery [1.3 ± 1.0 (− 0.4 to 3.3%)]; and V3 segment [2.6 ± 3.6 (− 0.4 to 11.6%)].ConclusionsMean head angular displacements and VA length changes were small during CSM thrusts. Of the four different CSM measured, mean VA length changes were largest during rotation procedures. This suggests that if clinicians wish to limit VA length changes during the thrust phase of CSM, consideration should be given to the type of CSM used.

Immediate Outcomes and Benefits of 3D Printed Braces for the Treatment of Adolescent Idiopathic Scoliosis.

Spinal bracing is a proven effective treatment for children with adolescent idiopathic scoliosis (AIS). Four factors have been reported to affect brace treatment outcome including (1) growth or curve-based risk, (2) the in-brace correction, (3) the brace wear quantity, and (4) the brace wear quality. The in-brace correction is impacted by spinal flexibility. The quality of brace design also affects the in-brace correction and comfort which indirectly affects the brace wear quantity and quality. A traditional polypropylene spinal brace is bulky and uncomfortable, and its manufacturing process is labor intensive. As 3D printing technology becomes more common and advanced, there is a potential to manufacture spinal braces using 3D printing technology. The objectives of this paper were to report the immediate effectiveness and benefits in using 3D printed brace to treat children with AIS. Six children with AIS (5F, 1M; 12.9 ± 1.4 years old; Cobb angle: 26° ± 7°), who were new to brace treatment, were recruited. Spinal flexibility and pressure pad locations were acquired using ultrasound assisted method to ensure braces were designed properly. To manufacture the braces, all participants were scanned by a handheld 3D scanner to obtain their body shapes. The 3D braces were then printed with Nylon 12 material. The average in-brace Cobb angle correction was 10 ± 4° (41 ± 18% correction). The 3D brace was 33% thinner, 26% lighter, 37% lower cost and required 3.7 h less labor time to manufacture when compared with the standard polypropylene brace. As a conclusion, the 3D printed brace had good immediate treatment effectiveness, but the long-time effect is still required time to explore.

Classification of Foot Pressure Images Using Machine Learning Algorithm

Arthritis is an acute systemic disease of a joint accompanied by pain. In developed countries, it mainly causes disability among people over 50 years of age. Rheumatoid Arthritis is a type of arthritis that occurs commonly among elders. The incidence of arthritis is higher in females than in males. There is no permanent diagnosis method for arthritis, but if it was identified in the early stages based on the foot pressure, it can be diagnosed before attaining the critical stage of Rheumatoid Arthritis. The analysis and study of arthritis patients were done using design thinking methodology. Design thinking is a problem-solving methodology that is used to find a solution for the identification of the early stage of arthritis. This process consists of five stages follows Empathy, Define, Ideate, Prototype, and Testing. To define the problem statement, the Empathy was done with the arthritis patients to know the difficulties faced by them. This paper proposes a measurement technique of early measurement of arthritis using a non-invasive technique. It helps us to detect arthritis using a foot pressure pad that was designed with piezoresistive material and the feature classification was done using Weka.

Improved Smart Pillow for Remote Health Care System

The outbreak of novel coronavirus (COVID-19) resulted in the clinical decision that reduced direct contact is optimal, especially for senior citizens residing in nursing homes. A smart pillow adapted for the Remote Healthcare System is presented in this paper, whose core is a Bluetooth (BT) host equipped with temperature and pressure sensors. The measurement of Core Body Temperature (CBT) from the perspective of heat transfer is first analyzed, with two proven effective methods introduced—classical Zero-Heat-Flux (ZHF) and Dual-Heat-Flux (DHF)—then finally the similarities between the Smart Pillow and ZHF are demonstrated. A pressure pad is inserted inside the pillow to detect occupancy and the specific position of the head on the pillow that meets clinical diagnostic needs. Furthermore, a real-time proactive monitoring mode is enabled for urgent warnings, which forces the pillow to keep detecting and reporting data in a defined time duration but results in rapid battery drain of the pillow. In this way, the system can detect the CBT and in-bed situation of the inhabitant without being physically present to determine critical measurements. Utility of this system can be extended to elderly people living alone in regional or remote areas, such that medical help can be dispatched as soon as possible in case of medical emergency.

Determination of water loss for an adiabatic cooling of a fin fan water cooler

Evaporative coolers are suitable where summer is hot and dry. The evaporative pad made from cellulose material reduces the condensation temperature and improve the specific cooling power of an air cooled condenser. Water is needed in the adiabatic cooler to cool the fresh hot outside air and to reduce the condensing temperature. The cooler manufacturing companies as well as the customers should be aware about the water loss throughout the year for a particular cooler. In this paper, the main intention is to determine the water loss for the specific fin fan cooler. When the pads are wetted, temperature of air decreases which results into cooling and humidified air. The water losses are estimated with the weather data for different pad materials. Due to the scale formation in evaporative condenser, pressure drop increases and pad saturation efficiency decreases. It is estimated that 5.2 L per hour water consumption is needed for the fin fan cooler studied at dry bulb temperature of air at 38 °C in summer condition.

Differences in force-time parameters and electromyographic characteristics of two high-velocity, low-amplitude spinal manipulations following one another in quick succession

BackgroundSpinal manipulative therapy is an effective treatment for neck pain. However, the mechanisms underlying its clinical efficacy are not fully understood. Previous studies have not systematically compared force-time parameters and electromyographic responses associated with spinal manipulation. In this study, force-time parameters and electromyographic characteristics associated with multiple manual high-velocity, low-amplitude cervical and upper thoracic spinal manipulations were investigated. The purpose of this analysis was to compare the force-time parameters and electromyographic characteristics between two spinal manipulations delivered following one another in quick succession if the first thrust was not associated with an audible cavitation.MethodsNine asymptomatic and eighteen symptomatic participants received six Diversified-style spinal manipulations to the cervical and upper thoracic spines during data collected February 2018 to September 2019. Peak force, rate of force application and thrust duration were measured using a pressure pad. Bipolar surface electrodes were used to measure the electromyographic responses and reflex delay times in sixteen neck, back and limb outlet muscles bilaterally. Differences in force-time parameters and electromyographic data were analyzed between the first and second thrust.ResultsFifty-two spinal manipulations were included in this analysis. Peak force was greater (p < 0.001) and rate of force application faster (p < 0.001) in the second thrust. Furthermore, peak electromyographic responses were higher following the second thrust in asymptomatic (p < 0.001) and symptomatic (p < 0.001) subjects. Also, electromyographic delays were shorter in the symptomatic compared to the asymptomatic participants for the second thrust (p = 0.039). There were no adverse patient events.ConclusionWhen a second manipulation was delivered because there was not audible cavitation during the first thrust, the second thrust was associated with greater treatment forces and faster thrust rates. Peak electromyographic responses were greater following the second thrust.

Foot pressure monitoring using single layer carbon loaded piezoresistive material

Arthritis is an intense or unremitting irritation ailment that influences the joints, connective tissues, muscle, ligaments, and stringy tissue. It is the leading cause of inability among individuals more than 50 years old in a developed country. Also, it tends to strike amid the most beneficial long periods of adulthood, regularly causing torment and deformation. It offers to ascend to tremendous healthcare expenditures and loss of work. With the existing system, there is a different size of FSR sensors used for foot pressure analysis. A sole with significant pressure points (2–9) was designed to analyze the foot pressure, but unfortunately, the foot size differs from one person to another person. So the single sole design setup cannot be used for all the persons. In the proposed method, a sensor array designed with single-layer carbon loaded polyethylene film was designed, and each sensor with sides 21 mm × 21 mm to form the 7 × 3 array pattern of the foot pressure pad. By using the array foot pressure pad, we can analyze the pressure points throughout the pad. Each of the sensors in the array is having a gap of 5 mm. The output analog signal acquired, and these electrical signals may result in preemptive of the knee problem.

Application of urethral pressure profilometry in artificial urinary sphincter implantation

Objective: To investigate the changes of maximum urethral pressure (MUP) and maximum urethral closure pressure (MUCP) after artificial urethral sphincter (AUS) implantation and their prognostic value. Methods: The clinical data of patients who had undergone AUS implantation in multiple medical centers between March and July 2019 were retrospectively analyzed. Data of urethral pressure profilometry, pad usage, related scores and complications related to surgery were collected and compared. The primary endpoint was social continence (defined as 0-1 pad/d) 1 month after activation of the pump. Results: A total of five male patients were included in this study. Two underwent transurethral resection of the prostate for benign prostatic hyperplasia, two underwent radical prostatectomy for prostate cancer, and one underwent urethral reunion, urethral stricture dilatation and cystostomy due to trauma from traffic accident. All patients had different degrees of urinary incontinence. The results of preoperative urethral profilometry test showed that the MUP of five patients were 52, 53, 88, 32, and 66 cmH(2)O(1 cmH(2)O=0.098 kPa), respectively, and the MUCP were 17, 52, 62, 27, and 40 cmH(2)O, respectively. AUS implantation was performed. The intraoperative urethral pressure profilometry showed that the MUP were 53, 113, 50, 77, and 89 cmH(2)O in the inactivated state, and the MUCP were 50, 97, 31, 71, and 51 cmH(2)O, respectively. In the activated state, the MUP were 112, 174, 193, 121, and 120 cmH(2)O, and the MUCP were 109, 160, 175, 114, and 92 cmH(2)O, respectively. All patients met the social continence (0-1 pad/d) criterion. No complications were reported during the follow-up. Conclusions: The relationship between the range of intraoperative urethral pressure and the effect of urinary control can be gained by measuring the specific values of MUP and MUCP during AUS implantation and the post-operative effects, which provides as a data basis for standardizing AUS implantation.

RehabFork: An Interactive Game-assisted Upper Limb Stroke Rehabilitation System.

In this paper, we present the design and development of a game-assisted stroke rehabilitation system RehabFork that allows a user to train their upper-limb to perform certain functions related to the task of eating. The task of eating is divided into several components: (i) grasping the eating utensils such as a fork and knife; (ii) lifting the eating utensils; (iii) using the eating utensils to cut a piece of food; (iv) transferring the food to the mouth; and (v) chewing the food. The RehabFork supports the user through sub-tasks (i)-(iii). The hardware components of RehabFork consist of an instrumented fork and knife, and a 3D printed pressure pad, that measure and communicate information on user performance to a gaming environment to render an integrated rehabilitation system. The gaming environment consists of an interactive game that utilizes sensory data as well as user information about the severity of their disability and current level of progress to adjust the difficulty levels of the game to maintain user motivation. Information pertaining to the user, including performance data, is stored and can be shared with care providers for ongoing oversight.

Correlations between Performance in a Virtual Reality Game and the Movement Assessment Battery Diagnostics in Children with Developmental Coordination Disorder

We aimed to compare the performance in a Virtual Reality (VR) game between Typically Developed (TD) children and children with Developmental Coordination Disorder (DCD). We then compared the performance in a VR game with the sub-grades of the Movement Assessment Battery for Children (MABC). Twenty TD children (10 boys; mean and SD age 5.1 ± 0.6) and 10 children with DCD (4 boys; mean and SD age 5.6 ± 0.6) participated in the study. The parents filled out the DCD questionnaire. The MABC was administered. Each subject stood on a pressure pad and played a non-immersive VR game. The game score, hand path length, and movement of center of pressure were recorded. The game score achieved by the control group was ~22% higher compared to the game score achieved by the research group (p = 0.042). The path length of the right hand strongly correlated with the visual-motor coordination MABC subcategory score (r = 0.902, p &lt; 0.001), with the balance MABC subcategory score (r = 0.769, p = 0.009), and with the total MABC score (r = 0.667, p = 0.035). This VR game might provide a preliminary distinction between TD children and children with DCD. Furthermore, investigation of hand path length may reflect the visual-motor coordination impairment of the child.

Smart library: Need of 21st Century

Today technology had made an impact on all sectors. Not any sector of the world can be run without technology, as it reduced human efforts and work smoothly. We can find and access information from wherever we are and whenever we want. “The term “Smart Library” has recently been used more frequently, for labelling a vision of libraries of the future, in particular as part of the so called “Smart City” concept. This concept addresses the integration of digital processes and informational feedback loops in the public infrastructure and claims this integration to be a desirable state, in which cities become “smarter”, i.e. more efficiently organized, resource-friendly, flexible, sustainable, green, and socially inclusive”1. “The concept “smart library” appears in various contexts, as a synonym for the concept “intellectual library”. Such phrases as “digital library” and “virtual library” can also be found. The term “smart” means “flexible, adaptive, extendible, acknowledging and human”. Smart library is a hardware and software complex with a wide range of opportunities for searching and providing necessary information to virtual users according to their inquiries and requirements. Smart libraries make the user available of access to library information from mobile devices. The services of smart libraries are delivered to the user via smart phones, internet and other handheld gadgets. Smart libraries have to focus on innovation of library services to reach all library users through mobile devices. Smart libraries provide advanced services such as computer-aided design, hypertext services, knowledge mining services, and personalized services, cross-media services which make the library more active, professional and intelligent. In this descriptive approach of the paper authors highlights the smart concept of smart library architecture, IoT based library services which included Cloud computing, RFID, Magic Mirrors, and Pressure pad sensors services and ICT based library services in presents scenario in-consist with Digital Library, Institutional Repository services, Library 2.0 and Reprographic, Micrographic & Digital Scanning Service.

Performance analysis of the flip turn in swimming: The relationship between pressures and performance times

This study examined the effects of pressure and other kinetic variables on freestyle flip turn performance. It was hypothesized that an increase in average and peak pressure, and a decrease in the magnitude difference between left and right foot pressure, would result in an improved performance of a swimmer as they performed a flip turn. Ten University level (varsity) swimmers performed five freestyle flip turns using their competition technique. Data were collected from a pressure pad mounted to the vertical wall of the pool and from an underwater camera in the sagittal plane. A negative correlation of .58 and .67 was seen for average and peak pressures respectively when compared to five-meter performance times. Average contact area throughout the push-off phase compared to average and maximum load was .94 and .88. An increase in average contact area from 40 cm 2 to 50 cm 2 resulted in a 26% increase in maximum load. No difference in performance was seen for varying maximum knee flexion angles. Differences between pressure magnitudes between left and right foot did not impact the five-meter performance time. Therefore, increased average contact area throughout the push-off phase caused higher average and maximum loads, and to a lesser extent average and peak pressures. Increases in pressure and load resulted in an improved five-meter performance time. It is concluded that flip turn performance increases through higher contact area with the feet when pushing off the wall.

Development and Application of Image-base Plantar Measurement System

The foot pain affects daily life function about 14-4b2% of adults over the age of 45 years old, since feet bear all the weight of the body. The most foot problems come from a great impact on the human body. It affects not only bone structures, but also the organs. Plantar information can be checked through the plantar pressure and arch index. The plantar pressure distribution is related to the walking balance, while the arch index can understand the foot bone structure. The paper aims to develop a system of plantar self-detection which is economical and easy to carry and operate. The system has built up two parts: one is the image capture equipment; another is the data analysis software. The portable scanning platforms can obtain high-resolution image, scanning work area is 216x356mm which the resolution is 1200dpi image. It only needs 10 seconds, using the wireless transmission to the plantar image through the pad for data analysis, calculated the plantar pressure distribution and arch index. The whole system price is less than one-tenth of the market selling pressure pad, providing a general system which is designed for plantar self-detection.

Short- and Mid-Term Improvement of Postural Balance after a Neurorehabilitation Program via Hippotherapy in Patients with Sensorimotor Impairment after Cerebral Palsy: A Preliminary Kinetic Approach

There is still a lack of studies focused on trunk neurorehabilitation. Accordingly, it is unclear which therapeutic modalities are the most effective in improving static/dynamic balance after brain damage. We designed a pilot study on hippotherapy to assess its short- and mid-term effect on dynamic postural balance in patients with moderate-to-severe sensorimotor impairment secondary to cerebral palsy. Five patients aged 15.4 ± 6.1 years old were recruited. All of them had moderate-to-severe alterations of the muscle tone with associated postural balance impairment. Standing and walking were also impaired. Ten minutes horse riding simulator followed by twenty minutes hippotherapy session were conducted during five session days separated by one week each. We analyzed the displacement of the Center of Pressure (COP) on the sitting surface of the simulator’s saddle by means of a customized pressure pad. We measured the general behavior of the COP displacement as well as the postural adjustments when pace changed from walk to trot to walk during the sessions and among sessions. Statistical analysis revealed an improved postural control both by the end of the session and from session 1 to session 5. These results suggest that hippotherapy might support regularization of postural control in a long-term neurorehabilitation context.

Meta-analysis of efficacy of pressure therapy in treating patients with hypertrophic scars

Objective: To systematically evaluate the efficacy of pressure therapy in treating patients with hypertrophic scars by meta-analysis. Methods: Databases including PubMed, Embase, Web of Science, and Cochrane Library were retrieved with the search terms"hypertrophic scar, hyperplastic scar, HTS, pressure therapy, pressure treatment, and the Chinese Journals Full-text Database was retrieved with the search terms in Chinese version",,,,"to obtain the publicly published randomized controlled trials about pressure therapy in the treatment of patients with hypertrophic scar from the establishment of each database to July 2017. The measurement indexes included the effective ratio, Vancouver Scar Scale (VSS) score, scar vascularity, scar hardness, scar pigment, scar thickness, and value of scar color (brightness, red, and yellow). RevMan 5.3 and Stata 12.0 statistical software were used to conduct a meta-analysis of eligible studies. Results: A total of 667 hypertrophic scar patients were enrolled in 11 articles, including 362 patients in pressure therapy group who received pressure treatment and 305 patients in untreated group who received no treatment. The bias risks of the 11 studies included were uncertain. Compared with those of untreated group, the effective ratio of patients in pressure therapy group was significantly increased, with the relative risk of 5.98 (95% confidence interval=1.83-19.46, P<0.01); the VSS score and scar vascularity of patients in pressure therapy group were obviously decreased, with weighted mean differences of -2.24 and -0.66 respectively (95% confidence interval=-4.16--0.33, -1.21--0.12, P<0.05); the scar hardness, scar pigment, scar thickness, and value of scar color (brightness, red, and yellow) of patients in pressure therapy group were not changed obviously (P≥0.05). Significant heterogeneity existed in the included studies of the effective ratio, VSS score, scar vascularity, scar hardness, scar pigment, and scar thickness, P<0.01, I(2)=90%, 87%, 80%, 93%, 86%, 94%. Pressure range might be the heterogeneity source of effective ratio, and pressure clothing combined with pressure pad therapy might be a heterogeneous source of VSS score. Sensitivity analysis showed that the combined effect size results were stable in the effective ratio and scar pigment, but not stable in the VSS score, scar thickness, scar hardness, and scar vascularity. There was no publication bias in the effective ratio, VSS score, scar hardness, scar pigment, and scar vascularity (P>0.1), while there was publication bias in the scar thickness (95% confidence interval=-19.77--3.30, P<0.1). Conclusions: Compared with patients without treatment, in the treatment of hypertrophic scars, pressure therapy can obviously increase the effective ratio, reduce the VSS score and scar vascularity, but can not obviously improve the scar hardness, scar pigment, scar thickness, and value of scar color (brightness, red, and yellow).