ABSTRACT
A multichannel biotelemetry system using pulse-width modulation-frequency modulation (PWM-FM) is described in detail for laboratory construction. Its application in a kinematic gait-analysis system is demonstrated, employing minimally encumbering electrogoniometry and foot-contact switches. The triaxial electrogoniometers sense rotational joint motion, and four foot-switches under the sole of each foot provide information on placement and temporal contact. Signals from the multiple sensors are amplified, encoded by pulse-width modulation, and transmitted at an FM radio frequency of 107 MHz. Received data are decoded and then sampled by a minicomputer for analysis. Results from a comparative study of kinematic gait in five normal subjects and five children with cerebral palsy demonstrate system effectiveness in providing quantitative data and various intrasubject and intersubject gait differences. Factors reviewed in the analysis include swing and stance times; cadence; hip-joint motion in sagittal, coronal, and transverse planes; and sequence of foot placement.
Subject(s)
Electrodiagnosis/instrumentation , Gait , Telemetry/instrumentation , Analog-Digital Conversion , Biomechanical Phenomena , Cerebral Palsy/diagnosis , Child , Equipment Design , Female , Humans , Male , Movement , Radio/instrumentation , TransducersABSTRACT
The activity of 82Rb produced from a 82Sr/82Rb generator is dependent on elution conditions (volume and eluent flow rate) and sampling conditions (time and position of collection). Assays for 82Rb in generator eluates are described using a commercial dose calibrator in a static procedure and a plastic scintillator in a dynamic procedure. Dynamic assays more accurately reflect the 82Rb administered when the eluate is injected directly. Radionuclidic contaminants which may be present with 82Sr are identified and procedures for their measurement are described.
