Diaphyseal Screw Prominence in Distal Radius Volar Plating

Background Volar plating for distal radius fractures has become common. Screw prominence on the dorsal side from long screws can lead to tendon injury. Methods for detecting screws that penetrate the far cortex involve X-ray or ultrasound. These have focused on the distal row of screws. No studies have addressed screw penetration in the diaphysis. We describe two cases where diaphyseal screws caused symptoms. We then insert screws in the diaphysis of synbones 2 mm longer than measured and determine what angle of pronation or supination was best to detect this on X-ray. Methods Three synbones were plated using Synthes volar plate. The three diaphyseal screws were drilled perpendicular to the plate, and the depth measured. Cortical 2.4-mm screws were inserted, 2 mm longer than measured. The three synbones were then placed in a custom clamp to measure rotation. Lateral X-rays were taken at 0 degree rotation, and 5, 10, and 15 degrees of supination and pronation. The prominence of each screw was measured using the synapse digital ruler. Results For the screws that were placed at a neutral angle (perpendicular to the plate) the maximum visualization of the prominent tips occurred around 0 degree rotation. With screws angled 15 degrees ulna, maximum visualization was between 5 and 10 degrees of pronation. With screws angled 15 degrees radial, maximum visualization was between 5 and 10 degrees of supination. Every 5 degrees of rotation changes the profile of the screw by 0.4 mm. Discussion The diaphysis of the radius becomes approximately trapezoidal distally. Prominent screws that are placed below the “peak” of the trapezoid may appear to be the correct length. Rotating the wrist into pronation or supination to bring the relevant cortex as parallel to the X-ray beam as possible will help to identify if screws are of the correct length. Screws that are prominent in the second compartment may be particularly symptomatic as the tendons here are closely opposed to the bone. We recommend screening for 2 mm diaphyseal screw prominence in neutral, with 10 degrees of pronation and supination.

Carpal Tunnel Syndrome Soft Relief Device for Typing Applications

Carpal Tunnel Syndrome (CTS) affects roughly 3%–6% of the working population ages 18–64 [1]. This affliction is caused by applying stress on the median nerve that is routed through the carpal tunnel while it is at a positive or negative angle, greater than 15 degrees in either direction, to the human wrist [2]. The median nerve can become inflamed and swollen due to pressure from the palmar carpal ligament causing numbness, stiffness and in some cases severe pain. Tasks like typing can become nearly impossible when the median nerve is inflamed. A number of products on the market and research prototypes have been suggested that try to alleviate CTS strains, however, these designs are generally passive e.g. braces, splints, etc. Instead of actively trying to adjust the wrist angle, the general trend is to prop the wrist up with some sort of rigid ramp, similar to the bottom of a keyboard [3]. The goal of this work is to design a wearable, soft-actuated, robotic sleeve that will dynamically adjust the position of the wrist in real-time to a neutral angle to prevent or release CTS strains.

Human Gait Prediction with a High DOF Upper Body: A Multi-Objective Optimization of Discomfort and Energy Cost

To predict the 3D walking pattern of a human, a detailed upper body model that includes the spine, shoulders, and neck must be made, which is challenging because of the coupling relations of degrees of freedom (DOF) in these body sections. The objective of this study was to develop a discomfort function for including a high DOF upper body model during walking. A multi-objective optimization (MOO) method was formulated by minimizing dynamic effort (DE) and the discomfort function simultaneously. The discomfort function is defined as the sum of the squares of deviation of joint angles from their neutral angle positions. The neutral angle position is defined as a relaxed human posture without actively applied external forces. The DE is the sum of the joint torque squared. To illustrate the capability of including a high DOF upper body, backward walking is used as an example. By minimizing both DE and the discomfort function, a 3D whole-body model with a high DOF upper body for walking was simulated successfully. The proposed MOO is a promising human performance measure to predict human motion using a high DOF upper body with full range of motion. This has been demonstrated by simulating backward walking, lifting, and ingress motions.

Multi-Objective Optimization of Human Gait With a Discomfort Function

The objective of this study was to develop a discomfort function for including a high DOF upper body model during walking. A multi-objective optimization (MOO) method was formulated by minimizing dynamic effort and the discomfort function simultaneously. The discomfort function is defined as the sum of the squares of deviation of joint angles from their neutral angle positions. The dynamic effort is the sum of the joint torque squared. To investigate the efficacy of the proposed MOO method, backward walking simulation was conducted. By minimizing both dynamic effort and the discomfort function, a 3D whole body model with a high DOF upper body for walking was demonstrated successfully.

Robust optimal design of a neutral valve for hydrostatic transmissions using Grey relational analysis

Problems of pressure impact and improper neutral angle of a neutral valve for hydrostatic transmissions were solved using Taguchi method for robust optimal design with aids of Grey relational analysis and computer simulation. An ITI-Simulation X-based model of a hydrostatic transmission with the neutral valve was developed and used to simulate the pressure impact and extended neutral angle during the pressure modulation when the swash plate angled from neutral to forth or back. The simulation results were converted to the Grey relational coefficients for 108 combinations of 27 design and four operational conditions. The Grey relational grades were also calculated for seven design parameters and each of the design conditions as the performance index. Through three times repeated robust optimal design process, the design parameters reached to the optimal which satisfied the performance goals of the neutral valve set to smaller the better for the pressure impact and nominal the best for the extended neutral valve.

Effect of Strip Size on Neutral Angle during a Novel Semisolid Shearing-Rolling Process

Based on the SCR process, semisolid shearing-rolling process was proposed. Effect of strip size on neutral angle during the process was analyzed. Neutral angle decreases gradually with the increment of the strip width. When the strip width is less than 40 mm, the neutral angle decreases more obviously with the increment of the strip width. When the strip width is greater than 40 mm, the neutral angle decreases slowly with the increment of the strip width. The neutral angle decreases gradually with the decrease of the strip thickness. Neutral angle is mainly affected by the strip thickness.

Analysis for Compression Strength of Elbow Rubber Hose Reinforced by Fibers

The stress of curved rubber hose with inner pressure is analyzed. On the base of the spiraled geometrical configuration of fiber around the curved rubber hose, the formulation of its neutral angle and compression strength is derived. The theoretical analysis and experimental results indicate that the axial stress of curved rubber hose with inner pressure is the same as that of straight rubber hose, and the hoop stress of curved rubber hose with inner pressure reaches the maximum value on the inside of its camber line and the minimum value on its outside respectively. The compression strength of curved rubber hose is not only dependent on the strength, layer and spiraled density of reinforced materials, but also on its geometrical configuration.