Goniometer Crosstalk Compensation for Knee Joint Applications

Autor(es)

Sato, Tatiana de Oliveira ^[1] ; Hansson, Gert-Ake ^[2] ; Cote Gil Coury, Helenice Jane ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Phys Therapy, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Lund Hosp, Div Occupat & Environm Med, SE-22185 Lund - Sweden

• Tipo de documento: Artigo Científico
• Fonte: SENSORS; v. 10, n. 11, p. 9994-10005, NOV 2010.
• Citações Web of Science: 8

Resumo

Electrogoniometers are prone to crosstalk errors related to endblocks rotation (general crosstalk) and to the characteristics of each sensor (individual crosstalk). The aim of this study was to assess the crosstalk errors due to endblock misalignments and to propose a procedure to compensate for these errors in knee applications. A precision jig was used to simulate pure +/- 100 degrees flexion/extension movements. A goniometer was mounted with various degrees of valgus/varus (+/- 20 degrees) and rotation (+/- 30 degrees) misalignments. For valgus/varus misalignments, although offset compensation eliminated the error in the valgus/varus recordings for 0 degrees of flexion/extension and reduced it to a few degrees for small (+/- 30 degrees) flexion/extension angles (root mean square error = 1.1 degrees), the individual crosstalk caused pronounced errors for large (+/- 100 degrees) angles (18.8 degrees). Subsequent compensation for this crosstalk reduced these errors to 0.8 degrees and 4.5 degrees, respectively. For rotational misalignment, compensation for the general crosstalk by means of coordinate system rotation, in combination with compensation for the individual crosstalk, reduced the errors for small (+/- 30 degrees) and large (+/- 100 degrees) flexion/extension angles from 3.6 degrees to 0.5 degrees and from 15.5 degrees to 2.4 degrees, respectively. Crosstalk errors were efficiently compensated by the procedures applied, which might be useful in preprocessing of knee functional data, thereby substantially improving goniometer accuracy. (AU)

• Processo FAPESP: 08/10372-4 - Avaliação de movimentos da região cervical e ombros em eletricistas durante atividade ocupacional
• Beneficiário: Helenice Jane Cote Gil Coury
• Modalidade de apoio: Auxílio à Pesquisa - Regular