By Topic

Implantable transducer for two-degree of freedom joint angle sensing

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

7 Author(s)
M. W. Johnson ; Dept. of Pediatric Neurol., Univ. Hospitals of Cleveland, OH, USA ; P. H. Peckham ; N. Bhadra ; K. L. Kilgore
more authors

An implantable joint angle transducer (IJAT) was developed to provide command-control and feedback-control information for chronic use with functional neuromuscular stimulation (FNS) neuroprostheses. The IJAT uses Hall effect sensors to transduce joint angle. A titanium encapsulated array of Hall effect sensors and support circuitry is surgically implanted in one bone, and a similarly encapsulated permanent magnet in an opposing bone, across a joint. The IJAT provides consistent, reliable, high quality signals that reflect joint movement from midsized two-degree-of-freedom joints. IJATs were implanted using a chronic in vivo dog model to demonstrate the feasibility of implantation and periodic measurement techniques, and to validate modeling techniques used for prediction of function and calibration. The flexion resolution ranged from 0.4 to 3.0° over a range of 115°. The maximum deviation from a linear response was 9°. The resolution and linearity depend on several transducer and joint geometry parameters, and can be predicted prior to implantation and calibrated after implantation. The results of this study (1) defined the most appropriate hermetic capsule designs for the IJAT sensor and magnet, (2) defined the best orientation of the magnetic field to optimize device function, (3) provided a computer model of the IJAT to aid in placement, calibration, and evaluation of the device, (4) verified the surgical techniques used to implant the device, and (5) verified the long-term functionality and the biocompatibility of the device

Published in:

IEEE Transactions on Rehabilitation Engineering  (Volume:7 ,  Issue: 3 )