Design and Analysis of The Energy Storage and Return (ESAR) Foot Prosthesis Using Finite Element Method

ABSTRACT. Disability issue has increased in recent years due to the high number of accidents and vascular disease. Loss of limb function for people with amputations often results in an abnormal gait. Energy Storage And Return (ESAR) foot prostheses provide an alternative to help improve gait and minimize metabolic energy expenditure during the walking phase of amputees. This study used 3 designs with models from the Catia V5 Software. The finite element method analysis used Ansys Workbench 18.1 software to evaluate the three designs with a loading of 1.2 times the user's body weight with a maximum weight of 70 kg in normal walking activities. The simulated material is carbon fiber prepreg which has tensile strength, Young's modulus, Poisson ratio, and density of 513.72 MPa, 77.71 GPa, 0.14, and 1.37 g/cm3. The decision-making matrix method is used to determine the best foot prosthesis design according to predetermined criteria. The highest value in the decision-making matrix is 76 in Design 3. The chosen design (Design 3) after gait cycle analysis has a maximum von Mises stress value of 76.956 MPa and the safety factor value for each gait cycle heel strike loading model is 1.0762; foot flat 3.2509; toe-off 6.6263.

A Review of Existing Transtibial Bionic Prosthesis: Mechanical Design, Actuators and Power Transmission

Transtibial and transfemoral amputations are the most common amputations in the world, loss of lower extremity result in impaired function extremities and also body balance. A prosthesis is a medical device designed to replace a specific body part to restore function to a body part lost due to an accident or disease. Most doctors strongly recommend the use of a prosthesis so that patients can return to normal activities after undergoing an amputation. Besides functioning to support beauty, the use of prostheses is also to restore the quality of life of prosthetic users, the issue of metabolic energy consumption when walking is also very important in designing transtibial bionic prosthesis because it involves the comfort of the user transtibial prosthesis. Most of the existing transtibial prosthesis products in Indonesia are conventional passive transtibial foot products, and passive prosthesis users show a limp or asymmetrical gait pattern so that conventional passive prosthesis users experience discomfort when walking in the form of pain in the amputated leg and normal foot, which can cause secondary musculoskeletal injuries such as joint disorders. Passive prostheses cannot generate propulsive force during push-off phase (terminal stance and preswing) of the human gait cycle. The use of passive prostheses can also consume 20-30% more metabolic energy while walking so that it can cause fatigue for the user. Transtibial bionic prosthesis research is growing, transtibial bionic prosthesis can overcome the weakness of passive prosthesis because it can produce push-off during gait cycle and several researchers have shown that bionic prostheses are capable of mimicking the human gait, as well as improve the performance in a more natural gait and normal walking. This study aims to study the existing transtibial bionic prosthesis by comparing between 6 existing designs of powered ankle or transtibial bionic prosthesis that have been published in several publications. The discussion focuses on the design and mechanical systems, actuators related to the selection of motors and drive mechanisms as well as power transmission from actuators to moving components.

MoFlus: An Open-Source Android Software for Fluorescence-Based Point of Care

High-sensitivity fluorescence-based tests are utilized to monitor various activities in life science research. These tests are specifically used as health monitoring tools to detect diseases. Fluorescence-based test facilities in rural areas and developing countries, however, remain limited. Point-of-care (POC) tests based on fluorescence detection have become a solution to the limitations of fluorescence-based tools in developing countries. POC software for smartphone cameras was generally developed for specific devices and tools, and it ability to select the desired region of interest (ROI) is limited. In this work, we developed Mobile Fluorescence Spectroscopy (MoFlus), an open-source Android software for camera-based POC. We mainly aimed to develop camera-based POC software that can be used for the dynamic selection of ROI; the number of samples; and the types of detection, color, data, and for communication with servers. MoFlus facilitated the use of touch screens and data given that it was developed on the basis of the SurfaceView library in Android and Javascript object notation applications. Moreover, the function and endurance of the app when used multiple times and with different numbers of images were tested.

The Effect of Plasma Nitridation on Surface Hardness of Titanium Alloy (Ti-6Al-4V) for Artificial Knee Joint Applications

Nitriding has been carried out using plasma nitriding techniques for surface treatment of Titanium as a biomaterial component. The purpose of this study was to determine the effect of plasma nitriding on surface hardness that occurs in titanium. The material used is Titanium Alloy (Ti-6Al-4V) Grade 5 which is processed by plasma nitriding by varying nitrogen (N2) and argon (Ar) gases of (100% N2/0% Ar), (95% N2/5% Ar), (90% N2/10% Ar), (85% N2/15% Ar), (80% N2/20% Ar), and (75% N2/25% Ar), and temperature 400ºC, time 5 hours and a pressure of 1.6 bar. The test results show that the optimum hardness is found in the gas composition with a ratio of 95% N2: 5% Ar. Obtained a hardness of 371 HV/VHN or an increase of 159% of the raw material with hardness value of 143 HV/VHN

A Preliminary Study on the Design of C-Section Props

A cesarean section (c-section) is a surgical procedure aimed to deliver a baby by opening the abdominal wall and uterus. Now, c-section is one of the choices that are often chosen by mothers when giving birth. The knowledge and skills of c-section are important in education that focuses on obstetrics and obstetrics, especially for prospective specialist doctors taking the title of Specialist in Obstetrics and Gynecology (SpOG). Residents are required to be able to understand the procedure of c-section both in theory and practice. To train and improve c-section skills, one of the methods used is to use c-section props. This study aims to design and manufacture c-section props that resemble actual conditions and can be used repeatedly. The cesarean section props consist of three main parts, namely the abdominal body, the uterus, and the synthetic skin layer of the abdomen. The product master uses 3D printer results with PLA filament material. The props are made of RTV-48 silicone rubber and Polyurethane Foam with a mold made of fiberglass composite using the Hand Lay-UP method. The c-section props produced can provide an overview of the general cesarean surgery procedure.

On the design of Remote Health Monitoring System

With improvement in technology and miniaturization of sensors, there have been attempts to utilize the new technology in various areas to improve the quality of human life. One main area of research that has seen adoption of the technology is the healthcare sector. The people in need of healthcare services find it very expensive, this is particularly true in developing countries. With improvement in technology previously expensive hospital equipment have been redesigned using current technology. The developments have seen a trend known as remote healthcare or previously known as Telemedicine. As a result, this paper is an attempt to solve a healthcare problem facing the society. The main objective of the paper is to design a remote healthcare system. It is comprised of three main parts. The first part being detection of a fall, second being detection of electrocardiogram commonly referred to as ECG or EKG( heartbeat detection) and the last part is providing the detected data for remote viewing. Remote viewing of the data enables a doctor or health specialist to monitor a patient’s health progress away from hospital premises.

Review of the temperature and holding time effects on hydroxyapatite fabrication from the natural sources

Biomaterial development is currently being carried out to help people who have daily needs. Hydroxyapatite has biocompatibility properties and suitables for the use as a biomaterial. Hydroxyapatite can be found in natural sources sometimes as waste. One of the hydroxyapatite fabrication methods is calcination process. Calcination and sintering are used to obtain the desired Ca/P ratio of the hydroxyapatite. This paper reviews several research which have been published by researchers to withdraw the connection during calcination process, with respect to the temperature and holding time effects on hydroxyapatite fabrication from the natural organism. The effect of temperature and holding time determines the yield of Ca/P ratio which affects the resulting mechanical properties. Choosing the right temperature and holding time will produce Ca/P which meets the standard

Effect of Using Coolant on the Formation of Microcracks, Burr and Delamination in Bone Drilling Process

Direct approach for bone fracture treatment usually involves restoring the fractured parts to their initial position and immobilizing them with plates, screws and wires. This approach needs a bone surgery drilling to produce hole for screw insertion. But this drilling process causes mechanical damages, i.e microcracks, burr formation and delamination, that can reduce the stability of the fixation. One of the ways to minimize it is by using coolant. Moreover, it is noted that bone has anisotropic microstucture. The object of this study is to understand the effect of coolant on mechanical damages that occur in bone drilling and to understand the effect of microstructure difference on microcracks that occur in the drilled walls holes. Adult bovine bones and adult goat bones were used in this study as the specimens to represent differences in cortical bone microstructure. Five consecutive holes from the distal to the proximal in each specimen were generated using manual hand-drill (spindle speed (n) = 1000 rpm; drill bit (d) = 4 mm diameter) with the use of coolant as variation. The drilling holes then stained and observed using a microscope. As the result, it was found that the use of coolant can significantly reduce the drilling temperature. Microcracks, burr formation and delamination were found to be quite large in the drilling holes without coolant. However, there is no microcrack found in the drilling holes with coolant, there is only a small number of burr formation was found. In addition, it was found that the differences in bone microstructure affect the number and length of microcracks that occur in the wall of the hole. It can be concluded from this study that the application of coolant is very effective to reduce the drilling temperature and enhancing the quality of the hole generated by bone drilling and the higher the density of osteon in cortical bone, the easier the microcrack to initiate and propagate.

Heart Rate Variability Analysis and The Influence of Exercise Intensity Over Time in Young-healthy Women

Our heart is a vital organ that pumps blood and through the vessels of the circulatory system. In medical applications, we can observe the heart rate using Electrocardiograph (ECG). Currently, people tend to have high working activity without a proper exercise intensity. This study was conducted to observe the heart rate variability (HRV) on the healthy young woman who was not doing any exercise. We evaluated the HRV characteristics while exercising with a regular period and different intensity (light to hard) and how the difference before and after of evaluation period. Seven young-healthy women (19 - 21 years old) women were observed during three observation stages: pre-exercise, main exercise-period, and post-exercise for 2 months. We analyzed MeanRR, SDRR, CVRR, rMSSD, VLF, LF, HF, and the Poincaré plot parameters (SD1 and SD2) as the HRV properties. We found that SDRR was decreased from the first week (0.08 s) to the last week of the evaluation period (0.03 s) followed by the HF component (0.15 – 0.2 Hz). The Poincaré plot properties also reduced from the first week to the last week of the exercise period (0.07 s to 0.03 s). We indicated the characteristics of a woman's HRV during regular exercise periods with different intensity have made the heart more effective in pumping blood. We concluded that the heart condition would be improved during regular exercise with the increment of intensity even in a short of a period. Finally, the heart rate performance may be decreased during absent from regular exercise for a month.

Multiparameter Biosignal Analysis in Elderly Ischemic Stroke Patients

Biosignal can provide information about body conditions, including physiological conditions of ischemic stroke. The regulation of blood in the brain is regulated through the mechanism of Cerebral Autoregulation (CA). Some parameters that can be used to determine this mechanism are Blood Flow Velocity (BFV) and Blood Pressure (BP). Stroke is also related to nervous system activity, which is represented through the Heart Rate Variability (HRV). This study aims to determine the relationship between those biosignals and their effects on the physiology of ischemic stroke sufferers. The subjects were divided into two groups (20 strokes and 20 controls). BFV data is obtained in the Middle Cerebral Artery (MCA), BP is obtained through the arteries of the upper arms, and 3 leads electrocardiogram is placed in the chest. The results showed that there was a relationship between BP and BFV in the control group (p-value < 0.05; r = -0.574). This correlation was not found in the stroke group. The relationship between BP and HRV was only found in the stroke group, which was associated with high sympathetic activity and lower parasympathetic activity (p-values < 0.05 and r > 0.4). It was based on SDRR, RMSSD, CVRR, LF, and SD1 parameters. In the control group, there was no relationship between HRV and BP. The relationship between BFV and HRV in the control group was not found statistically. Still, in the stroke group, this relationship was found in the LF and LF/HF Ratio parameters (p-value < 0.05; r > 0.4). Based on this research, parameters on HRV that can be used to determine the characteristics of stroke patients in all positions are MeanRR, VLF, and LF