Use of Accelerometers in the Control of Practical Prosthetic Arms

Abstract

Accelerometers can be used to augment the control of powered prosthetic arms. They can detect the orientation of the joint and limb, and the controller can correct for the amount of torque required to move the limb. They can also be used to create a platform, with a fixed orientation relative to gravity for the object held in the hand. This paper describes three applications for this technology, in a powered wrist and powered arm. By adding sensors to the arm making these data available to the controller, the input from the user can be made simpler. The operator will not need to correct for changes in orientation of their body as they move. Two examples of the correction for orientation against gravity are described and an example of the system designed for use by a patient. The controller for all examples is a distributed set of microcontrollers, one node for each joint, linked with the control area network bus. The clinical arm uses a version of the Southampton adaptive manipulation scheme to control the arm and hand. In this control form, the user gives simpler input commands and leaves the detailed control of the arm to the controller.

Homecare Robotic Systems for Healthcare 4.0: Visions and Enabling Technologies

“…While machines mentioned above mainly aim to assist patients with complete limbs, related studies are targeting amputees who lose motility due to injury or disease. Prosthetics are such devices designed to restore physiological functions of the disabled, researches of which mainly focus on upper limb prosthetics [95], and lower limb prosthetics [96]. Furthermore, with the convergence of the fields of robotics, automation, embedded system, and AI, traditional manual powered equipment, a wheelchair for instance, has also been replaced and created to support the disabled community [97].…”

Development and design specifications for an accelerometer-based biomechanical, prosthetic sensorimotor platform

“…Additionally, these system elements must have appropriate interfaces and the ability to sustain constant activity for practical prosthesis. Kyberd and Poulton suggest the use of a tri-axial system whereby sensors and controllers are employed to detect and correct for 1) segment orientation, 2) motion compensation, and 3) inertial platform [4]. This basic model represents an intermediate stage prior to full integration with limbs, where certain actuators and sensors are independently controlled to create a functional system (Figure 1).…”

“…Many current prosthetics, including myoelectric prosthetic upper and lower limbs, employ EMG-based methods for sensing, detection, and feedback processing of motor control signals. Over the recent years, there has been a growing body of evidence establishing the utilization of tri-axial MEMs (Micro Electro-Mechanical System) sensor accelerometers as an alternative or composite sensorimotor feedback platform for use in rehabilitation [4–7]. Here, we suggest a novel design for accelerometers for the implementation of this model, which could allow multiple degrees of freedom (DOF) sensors built into prosthetic and orthotic wearable.…”