Research On Motor Dysfunction Assessment In Children With Cerebral Palsy

Cerebral palsy(CP)describes a heterogeneous group of disorders of movement and posture caused by abnormal development of,or damage to,the central nervous system(CNS).Motor function evaluation for CP children plays an important role in the rehabilitation treatment process.The motor function evaluation is not only able to quantify the degree of motor dysfunction but also able to assist the clinicians in clinical diagnosis and therapeutic decision making.Generally,the assessment scales serve as the clinical routine for evaluating motor functions.However,due to the lacking of quantitative index,these clinically used approaches are highly dependent on the experience of clinicians or their own visual sense.In recent years,with the development of motion capturing technology,wearable sensors have been widely used in the field of motion analysis and motor function evaluation.It provides the possibility for the objective diagnosis and quantitative evaluation of motor functions in CP children.Various levels of neurological injuries lead to abnormal muscle activities and motor dysfunction in CP children.As surface electromyography(sEMG)can sense muscular activities in a noninvasive manner and inertial sensors are able to capture motion attitude and trajectories,both kinds of sensors were employed.Firstly,our study focuses on exploring the upper limb and gait motor dysfunction in CP children from the aspect of neuromuscular control.A method for quantitative and effective motor dysfunction assessment was proposed based on muscle synergy analysis.Secondly,our study extended the motion capturing technique based on combined sEMG and inertial sensors to the lower limb gross motor function evaluation in CP children.A framework for lower limb gross motor function assessment was proposed accordingly.The main research work and achievement of this thesis can be summarized as follows:a.Upper limb motor dysfunction assessment in CP children.The aim is to explore a quantitative assessment of upper limb motor dysfunction from the aspect of neuromuscular control strategy differences among multiple tasks.This study included the following four steps.Firstly,three upper limb tasks which could comprehensively reflect the elbow and shoulder joints function were designed.Secondly,sEMG data acquisition was performed with healthy adults,healthy children and CP children.Thirdly,three synergy-related parameters were proposed and muscle synergy analysis in three tasks was to enable the number and structure of the extracted muscle synergies to reflect the degree of motor dysfunction.Finally,an assessment,which were defined as the combinations of synergy structure similarity coefficients of three tasks,were proposed to assess the upper limb motor function of CP children.The experimental results demonstrated that the assessment were able to assess upper limb motor function comprehensively and effectively.b.Motor dysfunction assessment in CP children during gait.This study aimed at exploring the neural control strategy of abnormal gait in CP children from the aspect of CNS control.A more comprehensive assessment of gait function in CP children was achieved based on the difference of muscle synergy activation patterns and structures between CP children and healthy children.Firstly,gait data acquisition experiment was carried out in healthy adults,healthy children and CP children.Secondly,from the aspect of neuromuscular control,we explored the relationship between muscle synergy and gait abnormality.Thirdly,a concept of mapping from motor function into muscle synergy structure was proposed,and it was implemented and demonstrated with gait functions.Fourthly,according to the integrity of the lower limb gait function,a comprehensive and quantitative assessments of gait function in CP children which were not only based on the abnormal descending neural control but also on the differences of muscle synergy structures were proposed.c.Quantitative assessment of lower limb gross motor function in CP children based on multi-sensor.Taking advantage of fusion of sEMG and inertial sensors in motion capturing and posture detection,a framework for lower limb gross motor function assessment was proposed and applied to the walking,running and jumping components of the gross motor function measure scale.This part of studies include:?.According to the requirements of lower limb gross motor function assessment,the placement of multi-channel sensors was designed and the evaluation platform was accordingly set up.?.Within the lower limb gross motor function assessment framework,a series of algorithms were employed to detect motion,including:a static motion detection algorithm based on the threshold of acceleration,a gait cycle detection and segmentation algorithm based on the vertical acceleration peak detection,an alternating and non-alternating gait detection algorithm based on dynamic time warping distance,a trunk rotation angles detection algorithm based on quaternion method,a dynamic motion pattern transition detection algorithm based on double-stream HMMs classifier.iii.To demonstrate the performance of the proposed framework,the lower limb gross motor data acquisition experiment was carried out in C.P children.Our study promoted the application of muscle synergy analysis in motor function assessment of patients with neurological injury.Furthermore,the motor function assessment based on the fusion of sEMG and inertial sensors,offers a novel tool for quantitative lower limb gross motor function evaluation in CP children.