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Intervention: Nanotechnology in Reconstructive Intervention and Surgery
Published in Harry F. Tibbals, Medical Nanotechnology and Nanomedicine, 2017
We will discuss the nanomedical aspects of protein interactions at the cellular level in Chapter 7 on nanotechnology in regenerative medicine. We will look at artificial muscle applications in Chapter 8, dealing with functional nanomaterials for tissue engineering and prosthetics.
A numerical study to determine the effect of strengthening and weakening of the transversus abdominis muscle on lumbar spine loads
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Katarzyna Nowakowska-Lipiec, Robert Michnik, Paweł Linek, Andrzej Myśliwiec, Katarzyna Jochymczyk-Woźniak, Marek Gzik
The model also takes into consideration the IAP model, which is mainly composed of one rigid buckle that provides attachments to the abdominal muscles and five rigid artificial disks forming structure for the transversus muscles which are responsible for generating the IAP (Figure 1(c)). The activated TrA attached to the artificial disks will control the anterior-posterior movement of the artificial segments - this movement contributes to the change in the volume of the abdominal cavity. The abdominal volume is modelled (in an idealised manner) as a cylinder, the value of which depends on the following dimension: R – an approximated cross-section of the abdomen in a given body posture and H – height of the abdomen (the length between pelvis and thorax). When this volume is ‘squeezed’ by postural changes or contraction of the TrA muscle that acts upon it, the IAP is generated by an artificial muscle associated with this volume. The maximum value of the IAP in the model is limited to the value of 26.6 kPa (Arshad et al. 2016; Liu et al. 2019). The IAP artificial muscle enters the problem of muscle recruitment and, when activated, applies forces in the transverse plane on the intervertebral joints. It contributes to the antero-posterior shear forces in intra-vertebral joints, but not compression.
Review of ankle rehabilitation devices for treatment of equinus contracture
Published in Expert Review of Medical Devices, 2022
Kamila Dostalova, Radek Tomasek, Martina Kalova, Miroslav Janura, Jiri Rosicky, Marek Schnitzer, Jiri Demel
Current development trends in actuators seem to lie in the field of pneumatic artificial muscles with properties similar to human muscles and in self-powered devices which provide energy restoration. These can offer a reduction in the dimensions and weight of devices, especially for wearable orthoses, which determine their performance. The great potential of mechanical design lies in the use of novel materials, such as composites, to replace steel or metallic components, although their price is still an issue.
An insight into Transfemoral Prostheses: Materials, modelling, simulation, fabrication, testing, clinical evaluation and performance perspectives
Published in Expert Review of Medical Devices, 2022
K. Amudhan, A. Vasanthanathan, J. Anish Jafrin Thilak
Composites are durable and light in weight and are fabricated by joining layers of reinforcement fibers like fiberglass, nylon or carbon. The fibers are tough, malleable, and brittle. Fiber and resin mixture is vacuum-molded onto residual limb models. Wet laminations are made by mixing resins and hardeners and pouring them over the fibers. High heat hardens thermosets. These acrylic, epoxy and polyester composites can be manufactured in various thicknesses for use in sockets. Unlike thermoplastics, thermoset polymers are difficult to reshape after manufacture. The kind, quantity, and combination of fibers and resins can be tailored to a patient’s weight and activity level. Polymer matrix composites are simpler, less expensive alternatives to steel, high-grade Aluminum, Titanium, and Magnesium, especially for applications that require less weight without compromising strength [59,60]. Ionomeric polymer metal composites (IPMC) [61] are cationic capacitive actuators and sensors. They are operated actively due to ionic redistribution in response to imposed electric field or physical deformation. In a prosthetic limb, IPMC material works as an artificial muscle, with actuation controlled by electric impulses. Large electrically induced bending, mechanical flexibility, low excitation voltage, low density and ease of production make IPMC appealing electro-active polymer actuation materials. The most crucial advancement in patient comfort is in socket material technology. Silicone and urethane are used to cushion sockets and prevent skin irritation. Gel liners preserve and cushion the residual limb’s bony prominence [32,34]. Silicone gel, Silicone elastomers, and urethane are the most common materials utilized for liners [33]. Extra-long silicone and PVC gloves are supplied for a smooth transition over the proximal socket brim. Table 1 shows the common reinforcement and matrix materials in polymer matrix composites to fabricate lower limb prosthetic components. All of these papers use respective American Society for Testing and Materials standards (ASTM) to study mechanical parameters including tensile strength, Young’s modulus, and fatigue strength. The number of layers, thickness, layer placement, and volume fraction determines the characteristics of fiber reinforced composites. In fact, most research focuses on producing the socket component using composites and most prosthetic foot components rely on Carbon fiber reinforced polymers (CFRP) composites for their excellent mechanical qualities. Carbon fibers were created in the twentieth century while seeking for a lighter load bearing material. It is known for its high specific strength, specific modulus, high stiffness, and tensile strength. It was determined that it could support a hefty amputee. The specific modulus of Carbon fiber reinforced composites is roughly three times higher than common materials used for prosthetics [62,63]. CFRP also offer high specific tensile and compressive strengths, as well as excellent elastic deformation responsiveness.