Compliant orthoses for repositioning of knee joint based on super-elasticity of shape memory alloys

Sadeghian, Farshid; Zakerzadeh, Mohammad Reza; Karimpour, Morad; Baghani, Mostafa

doi:10.1177/1045389x18783085

Cited by 9 publications

(14 citation statements)

References 25 publications

(48 reference statements)

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“…The linear actuator was able to control the vertical position of the slider, which determines the active length of the SMA hinge, resulting in the variation of the bending stiffness, which benefits the AFO. Sadeghian et al also designed a knee-ankle-foot orthosis with stance and swing for patients with quadriceps muscle weakness that operate SMAs, see Figure 7b [68]. The orthosis is needed to maintain the stability of the knee joint during the stance phase and assist in the extension of the leg using SMAs during the swing phase.…”

Section: Shape Memory Alloys (Smas)mentioning

confidence: 99%

“…They provided force in the range of 10 N -100 N. However, since they require changes in temperature to produce phase changes of the alloy they present a long response time (10s -30s) and significant nonlinearity, resulting in the challenge in the design of control systems. The state-of-the-art devices use PID controllers [62][63]68], adaptive control systems [31,33] and Bluetooth® tracing technology [70] in order to achieve desired motions. The control of SMAs needs to be further investigated to enhance the capabilities of the soft devices for better assistance.…”

Section: Shape Memory Alloys (Smas)mentioning

confidence: 99%

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Soft Actuators and Robotic Devices for Rehabilitation and Assistance

Pan

Yuan²,

Liang³

et al. 2021

Preprint

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Soft actuators and robotic devices have been increasingly applied to the field of rehabilitation and assistance, where safe human and machine interaction is of particular importance. Compared with their widely used rigid counterparts, soft actuators and robotic devices can provide a range of significant advantages; these include safe interaction, a range of complex motions, ease of fabrication and resilience to a variety of environments. In recent decades, significant effort has been invested in the development of soft rehabilitation and assistive devices for improving a range of medical treatments and quality of life. This review provides an overview of the current state-of-the-art in soft actuators and robotic devices for rehabilitation and assistance, in particular systems that achieve actuation by pneumatic and hydraulic fluid-power, electrical motors, chemical reactions and soft active materials such as dielectric elastomers, shape memory alloys, magnetoactive elastomers, liquid crystal elastomers and piezoelectric materials. Current research on soft rehabilitation and assistive devices is in its infancy, and new device designs and control strategies for improved performance and safe human-machine interaction are identified as particularly untapped areas of research. Finally, insights into future research directions are outlined. Corresponding author(s) Email: mp351@bath.ac.uk, liutao@zju.edu.cn

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Section: Shape Memory Alloys (Smas)mentioning

confidence: 99%

Section: Shape Memory Alloys (Smas)mentioning

confidence: 99%

Soft Actuators and Robotic Devices for Rehabilitation and Assistance

Pan

Yuan²,

Liang³

et al. 2021

Preprint

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show abstract

“…(1) Adaptive output reference for damping stiffness control As explained earlier, the mechanical properties of the AFO should match the needs of users, to maximize the benefits of the AFO [98,99]. The AFO with damping stiffness control already has advantages compared to the others (bending stiffness, assistive torque, and motion control) such as optimized weight, cost, and safety, because the actuator is a passive actuator.…”

Section: Future Researchmentioning

confidence: 99%

A Review on the Control of the Mechanical Properties of Ankle Foot Orthosis for Gait Assistance

et al. 2019

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In the past decade, advanced technologies in robotics have been explored to enhance the rehabilitation of post-stroke patients. Previous works have shown that gait assistance for post-stroke patients can be provided through the use of robotics technology in ancillary equipment, such as Ankle Foot Orthosis (AFO). An AFO is usually used to assist patients with spasticity or foot drop problems. There are several types of AFOs, depending on the flexibility of the joint, such as rigid, flexible rigid, and articulated AFOs. A rigid AFO has a fixed joint, and a flexible rigid AFO has a more flexible joint, while the articulated AFO has a freely rotating ankle joint, where the mechanical properties of the AFO are more controllable compared to the other two types of AFOs. This paper reviews the control of the mechanical properties of existing AFOs for gait assistance in post-stroke patients. Several aspects that affect the control of the mechanical properties of an AFO, such as the controller input, number of gait phases, controller output reference, and controller performance evaluation are discussed and compared. Thus, this paper will be of interest to AFO researchers or developers who would like to design their own AFOs with the most suitable mechanical properties based on their application. The controller input and the number of gait phases are discussed first. Then, the discussion moves forward to the methods of estimating the controller output reference, which is the main focus of this study. Based on the estimation method, the gait control strategies can be classified into subject-oriented estimations and phase-oriented estimations. Finally, suggestions for future studies are addressed, one of which is the application of the adaptive controller output reference to maximize the benefits of the AFO to users.

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“…The results obtained in their research demonstrated that the normal joint stiffness profile for each patient with a certain level of muscle weakness can be restored by designing a patient-specific orthosis. In another study conducted by Sadeghian et al (2018), a smart knee-ankle-foot orthosis design integrated with SMA element was proposed to assist patients suffering from QMW. QMW leads to flexion contracture as well as flexion instability during the gait cycle.…”

Section: Introductionmentioning

confidence: 99%

A novel smart assistive knee brace incorporated with shape memory alloy wire actuator

Moslemi

Gohari

Mozafari

et al. 2020

Journal of Intelligent Material Systems and Structures

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The knee plays a significant role in locomotion and stability of the entire body through supporting the body weight and assisting the lower body kinematics during walking. However, the knee is at constant risk of becoming weakened due to disease, age, and accidents. One approach to treating weakened knee is wearing an assistive knee brace. To design a clinical knee brace, many factors such as weight and compliant mechanism should be considered. In this study, a novel smart assistive knee brace mechanism incorporated with wire actuators made of shape memory alloys is proposed to ameliorate the issues associated with weight and flexibility of existing brace designs. Unlike earlier studies, the proposed orthosis includes pressure sensor, shape memory actuator, and smart linkage. Furthermore, two distinct shape memory alloy actuator design concepts with improved stiffness are developed, and the best option is chosen systematically and prototyped. The novel mechanism proposed in this research overcomes the weight of the lower limb during swing phase using the combined shape memory alloy actuation and feed-forward controller design. As such, it can be used as a potential replacement to its conventional counterparts when the higher weight reduction as well as a flexible and controllable mechanism are simultaneously sought.

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Compliant orthoses for repositioning of knee joint based on super-elasticity of shape memory alloys

Cited by 9 publications

References 25 publications

Soft Actuators and Robotic Devices for Rehabilitation and Assistance

Soft Actuators and Robotic Devices for Rehabilitation and Assistance

A Review on the Control of the Mechanical Properties of Ankle Foot Orthosis for Gait Assistance

A novel smart assistive knee brace incorporated with shape memory alloy wire actuator

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