1,721,026 research outputs found
Tuning of myoelectric prostheses using fuzzy logic
No full textThis contribution concerns the use of a supervisory expert system based on fuzzy logic for the parameter adjusting of myoelectric prostheses. The prosthesis system is an artificial arm produced by INAIL in Vigorso (Bologna, Italy), which is equipped with an on-board actuation system. The expert system guides patients through an interactive session whose aim is to test the prosthesis functionality and, when necessary, to self-adjust the parameters
Design of Upper Limb Prostheses: a New Subject-oriented Approach
No full textThe challenge to develop innovative electrically actuated prostheses for upper limb amputees is the basis of this study. The whole project is intended to provide highlevel bilateral amputees with devices which can give them back a sufficient quality of life, since current prostheses are rather limited. High mobility, advanced control and good “wearability” are the main features required of artificial arms. The method presented here provides the specifications needed to guide the mechanical design of the prosthetic system, defining its architecture (i.e., geometry and topology of its model) as a trade-off solution between contrasting requirements like, for instance, functionality and simplicity. The approach is subject-oriented, that is, the process is based upon the specific needs of patients undergoing prosthetic rehabilitation; the expected result of the proper application of the procedure is the systematic determination of a limited number of prosthesis architectures suitable for a few corresponding classes of amputee profiles. Thus, the mechanical design of the prosthetic system is based on these indications
Goniometric Sensor For An Upper Limb Prosthesis Arm Dc Motor
No full textThis paper shows the stages of project and realization of a sensor for an elbow motor in an upper limb prosthesic arm. The sensor acts as a magnetic field detector. The magnetic field is generated by magnetic elements placed in an outer circle around the final element of the gearbox.
To measure this field two Hall sensors have been used, with continuous linear voltage output, in the range 0-5 V
In vivo validation of a new technique that compensates for soft tissue artefact in the upper-arm: preliminary results
No full textBackground. Soft tissue artefact is the dominant error source for upper extremity motion analyses that use skin-mounted markers, especially in humeral axial rotation.
Methods. A new in vivo technique is presented that is based on the definition of a humerus bone-embedded frame almost “artefact free” but influenced by the elbow orientation in the measurement of the humeral axial rotation, and on an algorithm designed to solve this kinematic coupling. The technique was validated in vivo in a study of six healthy subjects who performed five arm-movement tasks. For each task the similarity between a gold standard pattern and the axial rotation pattern before and after the application of the compensation algorithm was evaluated in terms of explained variance, gain, phase and offset. In addition the root mean square error between the patterns was used as a global similarity estimator.
Findings. After the application, for four out of five tasks, patterns were highly correlated, in phase, with almost equal gain and limited offset; the root mean square error decreased from the original 9° to 3°.
Interpretation. The proposed technique appears to help compensate for the soft tissue artefact affecting axial rotation. A further development is also proposed to make the technique effective also for the pure prono-supination task
Prototype manufacturing of upper limb prosthesis with five active joints for shoulder disarticulated amputees
No full textConceptual Design of a Powered Humeral Rotator for Upper Limb Prostheses
No full textA new electromechanic device that actuates the humeral intra/extra rotation of upper limb myoelectric prostheses is presented. The main element of the kinematic chain is a special planetary geartrain that allows respecting the required performance and limiting the mechanism global size and mass
Fuzzy logic expert system for automatic tuning of myoelectric prostheses
No full textThe paper presents a software package for automatic tuning of control parameters of myoelectric prosthesis. The prosthesis system is the INAIL artificial arm controlled by a microprocessor using myoelectric signals acquired from skin-surface electrodes placed on the patient muscle stump. Usually, qualified staff is necessary for control parameters set-up and subsequent recurrent adjustments, and therefore patients are forced to come back frequently at prosthesis factory laboratories. The proposed software interacts with unskilled patients and automatically set up the control parameters of the prosthesis using qualified staff knowledge stored in a Fuzzy Logic Expert System (FLES). In this paper the software package is presented and some preliminary results from its application are discussed
OUTDOOR GAIT ANALYSIS USING INERTIAL AND MAGNETIC SENSORS: PART 1 - PROTOCOL DESCRIPTION
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