Ilham Yustar Afif

The paper available of total hip arthroplasty is still concerned with the external factors of implant user, but the internal factor that is the user’s body weight has not deeply understood. Our research presents deformation analysis of total hip arthroplasty with different loading conditions based on the patient’s body mass index category. 2D model is selected to conducting numerical analysis of CoCrMo-on-CoCrMo that giving vertical load from different category of body mass index, namely underweight, normal, overweight, and obese class I, obese class II, and obese class III using finite element procedures. Peak loading under normal walking conditions from actual condition of human hip joint is adopted. Our result explains that displacement in direction - y is larger in line with greater user’s body mass index.

This investigation aims to wear analyze of acetabular cup on metal-on-metal total hip arthroplasty with and without dimple addition. Our contribution that present in this paper is to explore the effect of surface texturing application to reduce wear that important for implant's survival. Finite element method is using with 3D human's hip joint loading under normal walking conditions. Updating geometry also consider for more realistic simulation result. Wear prediction performed for one year from using implant that equal to 1x10 6 gait cycle. Textured surface in total hip arthroplasty found have to reduce cumulative linear wear and cumulative volumetric wear by around 24% compared untextured surface.

Traveling with children with autism can be very challenging for parents due to their reactions to sensory stimuli resulting in behavioral problems, which lead to self-injury and danger for themselves and others. Deep pressure was reported to have a calming effect on people with autism. This study was designed to investigate the physiological effect of deep pressure, which is an autism hug machine portable seat (AHMPS) in children with autism spectrum disorders (ASD) in public transportation settings. The study was conducted with 20 children with ASD (16 boys and 4 girls) at the Semarang Public Special School with an age ranging from 4 to 13 years (mean 10.9 ± 2.26 years), who were randomly assigned into two groups. The experiment consisted of group I who used the AHMPS inflatable wraps model and group II who used the AHMPS manual pull model. Heart rate (HR) and skin conductance (SC) were analyzed to measure the physiological calming effect using pulse oximeter oximetry and a galvani...

Ultra-High Molecular Weight Polyethylene (UHMWPE) is one of the most widely used biomaterials for applications in the field of medical devices, especially implants. The use of these materials together with metal is widely used for the combination of materials in total hip arthroplasty as hard-on-soft. Although the use of this combination of materials has been widely adopted, the long-term adverse effects of UHMWPE are a concern for implant users. The selection of the right metal material as a UHMWPE counterpart is crucial to minimize the risk to the patient. Three types of metal materials, namely Cobalt Chromium Molybdenum (CoCrMo), Stainless Steel 316L (SS 316L), and Titanium Alloy (Ti6Al4V) were evaluated using Tresca stress. The computational simulation was chosen with a two-dimensional model using the highest load in normal walking activities as the loading condition. The results show that the combination of materials on CoCrMo-on-UHMWPE bearings gives a Tresca stress value of 7.595 MPa, which is the lowest when compared to the other two combinations of metal and UHMWPE materials.

Children with autism spectrum disorder (ASD) have challenging behaviors, which are associated with difficulties in parenting. Deep pressure is a therapeutic modality in occupational therapy, and it was reported to produce a calming effect. This study aimed to determine whether the short-term use of an autism hug machine portable seat (AHMPS) improves behavioral and neurobiological stress in children with ASD, and to determine whether AHMPS with an inflatable wrap or manual pull is more effective. This study enrolled children with ASD who were administered with the inflatable wrap (group I) and manual pull (group II) for 20 min twice a week for 3 weeks. Conners’ Parent Rating Scale-48 (CPRS-48) was used to rate behavioral improvements, and galvanic skin response (GSR) was used to measure sympathetic stress response. A total of 20 children with ASD (14 boys and 6 girls; aged 7–13 years) were included. CPRS-48 presented conduct problems: behavior was significantly decreased in the infl...

The selection of biomaterials for bearing in total hip arthroplasty is very important to avoid various risks of primary postoperative failure for patients. The current investigation attempts to analyze the Tresca stress of metal-on-metal bearings with three different materials, namely, cobalt chromium molybdenum (CoCrMo), stainless steel 316L (SS 316L), and titanium alloy (Ti6Al4V). We used computational simulations using a 2D axisymmetric finite element model to predict Tresca stresses under physiological conditions of the human hip joint during normal walking. The simulation results show that Ti6Al4V-on-Ti6Al4V has the best performance to reduce Tresca stress by 45.76% and 39.15%, respectively, compared to CoCrMo-on-CoCrMo and SS 316L-on-SS 316L.

This preliminary study proposes to investigate (i) the mean comfortable deep pressure of Autism Hug Machine Portable Seat (AHMPS) manual pull and inflatable wrap models; and (ii) the effect of using AHMPS in reducing anxiety in children with autism spectrum disorder (ASD). The first phase was done to determine the comfort test. Fifteen healthy adolescents (13 men and 2 women; aged 19-25 years) individuals volunteered to participate in the comfort test in determining the pressure of AHMPS, both manual pull, and inflatable wrap. The second phase was completed in children with ASD, in which the comforting pressure from the first phase was then applied to five children with ASD (4 boys and 1 girl; aged 8-15 years) from the Putra Mandiri Public Special School Semarang. All children were administered both the AHMPS inflatable wrap and manual pull as a deep pressure apparatus while traveling by bus. A pulse oximeter was used to measure heart rate variability (physiological arousal). The me...