Estimating qualitative parameters for assessment of body balance and arm function in a simulated ambulatory setting

Continuous daily-life monitoring of balance control and arm function of stroke survivors in an ambulatory setting, is essential for optimal guidance of rehabilitation. In a simulated ambulatory setting, balance and arm function of seven stroke subjects is evaluated using on-body measurement systems (Xsens MVN Biomech and the Xsens Instrumented Force Shoes). Ethical approval for this study was obtained. Qualitative parameters of body balance and arm function are estimated and compared with the results of a generally accepted clinical balance assessments (e.g. Berg Balance Scale and Fugl-Meyer)

Assessment and visualisation of daily-life arm movements after stroke

For an optimal guidance of the rehabilitation therapy of stroke patients in an in-home setting, objective, and patient specific assessment of upper extremity task performance is needed. Towards this goal, metrics of hand position relative to the pelvis were estimated and visualized. Metrics, including work area and maximum reaching distance, appeared to strongly correlate with the upper extremity part of the Fugl-Meyer Assessment scale (r>0.84, p<0.001). Proposed metrics and visualisation can be used to objectively assess the arm movement performance over a longer period of time in a daily-life setting, if combined with info about performed task derived from a activity monitor

Gait analysis using ultrasound and inertial sensors

Introduction and past research:\ud Inertial sensors are great for orientation estimation, but they cannot measure relative positions of human body segments directly. In previous work we used ultrasound to estimate distances between body segments [1]. In [2] we presented an easy to use system for gait analysis in clinical practice but also in-home situations. Ultrasound range estimates were fused with data from foot-mounted inertial sensors, using an extended Kalman filter, for 3D (relative) position and orientation estimation of the feet.\ud \ud Validation:\ud From estimated 3D positions we calculated step lengths and stride widths and compared this to an optical reference system for validation. Mean (±standard deviation) of absolute differences was 1.7 cm (±1.8 cm) for step lengths and 1.2 cm (±1.2 cm) for stride widths when comparing 54 walking trials of three healthy subjects.\ud \ud Clinical application:\ud Next, the system presented in [2] was used in the INTERACTION project, for measuring eight stroke subjects during a 10 m walk test [3]. Step lengths, stride widths and stance and swing times were compared with the Berg balance scale score. The first results showed a correlation between step lengths and Berg balance scale scores. To draw real conclusions, more patients and also different activities will be investigated next.\ud \ud Future work:\ud In future work we will extend the system with inertial sensors on the upperand lower legs and the pelvis, to be able to calculate a closed loop and improve the estimation of joint angles compared with systems containing only inertial sensors

Estimating center of pressure and center of mass patterns in stroke subjects during daily life activities using force sensing shoes

The aim of this study is to evaluate center of pressure and center of mass movement patterns in stroke patients, during activities of daily living while wearing instrumented shoes containing force sensors and inertial sensors. The use of instrumented shoes enables the measurement of balance parameters during ADL tasks without being restricted to a laboratory environment. Results indicate that in more demanding tasks, the mean CoP and CoM position shifts more towards the non-affected side compared to walking in a straight line

Estimating qualitative parameters for assessment of body balance in a simulated ambulatory setting

Continuous daily-life monitoring of balance control of stroke survivors in an ambulatory setting, is essential for optimal guidance of rehabilitation. The purpose of this study is to demonstrate the relation between qualitative parameters of body balance while measuring in stroke patients in a simulated ambulatory setting using on-body measurement systems (Xsens MVN Biomech and the Xsens Instrumented Force Shoes) and the results of a generally accepted clinical balance assessments (e.g. Berg Balance Scale). A total of twenty stroke subjects will be included in a clinical study which is approved by the local medical ethical committee

Assessing of motor performance in stroke using body worn sensing

As a part of the EU project INTERACTION, a modular and unobtrusive body worn sensing system has been developed for the objective assessment of capacity and performance of body balance and arm movements. Performance and capacity measures were proposed and clinically tested in stroke subjects and results were compared with results of frequently used clinical tests. First results show a discrepancy between subjects’ ability to use their affected side as evaluated with clinical tests and their actual performance during daily life tasks

Assessment of daily-life reaching performance after stroke

For an optimal guidance of the rehabilitation therapy of stroke patients in an in-home setting, objective, and patient-specific performance assessment of arm movements is needed. In this study, metrics of hand movement relative to the pelvis and the sternum were estimated in 13 stroke subjects using a full body ambulatory movement analysis system, including 17 inertial sensors integrated in a body-worn suit. Results were compared with the level of arm impairment evaluated with the upper extremity part of the Fugl-Meyer Assessment scale (uFMA). Metrics of arm movement performance of the affected side, including size of work area, maximum reaching distance and movement range in vertical direction, were evaluated during a simulated daily-life task. These metrics appeared to strongly correlate with uFMA scores. Using this body-worn sensor system, metrics of the performance of arm movements can easily be measured and evaluated while the subject is ambulating in a simulated daily-life setting. Suggested metrics can be used to objectively assess the performance of the arm movements over a longer period in a daily-life setting. Further development of the body-worn sensing system is needed before it can be unobtrusively used in a daily-life setting

Assessment of lower arm movements using one inertial sensor

Reduction of the number of sensors needed to evaluate arm movements, makes a system for the assessment of human body movements more suitable for clinical practice and daily life assessments. In this study, we propose an algorithm to reconstruct lower arm orientation, velocity and position, based on a sensing system which consists of only one inertial measurement unit (IMU) to the forearm. Lower arm movements were reconstructed using a single IMU and assuming that within a measurement there are moments without arm movements. The proposed algorithm, together with a single IMU attached to the forearm, may be used to evaluate lower arm movements during clinical assessments or functional tasks. In this pilot study, reconstructed quantities were compared with an optical reference system. The limits of agreement in the magnitude of the orientation vector and the norm of the velocity vectors are respectively 4.2 deg (normalized, 5.2 percent) and 7.1 cm/s (normalized, 5.8 percent). The limit of agreement of the difference between the reconstructed positions of both sensing systems were relatively greater 7.7 cm (normalized, 16.8 percent)