Engineering Dynamics and Life Sciences

From Preface: This is the fourteenth time when the conference “Dynamical Systems: Theory and Applications” gathers a numerous group of outstanding scientists and engineers, who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without a great effort of the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and Ministry of Science and Higher Education of Poland. It is a great pleasure that our invitation has been accepted by recording in the history of our conference number of people, including good colleagues and friends as well as a large group of researchers and scientists, who decided to participate in the conference for the first time. With proud and satisfaction we welcomed over 180 persons from 31 countries all over the world. They decided to share the results of their research and many years experiences in a discipline of dynamical systems by submitting many very interesting papers. This year, the DSTA Conference Proceedings were split into three volumes entitled “Dynamical Systems” with respective subtitles: Vibration, Control and Stability of Dynamical Systems; Mathematical and Numerical Aspects of Dynamical System Analysis and Engineering Dynamics and Life Sciences. Additionally, there will be also published two volumes of Springer Proceedings in Mathematics and Statistics entitled “Dynamical Systems in Theoretical Perspective” and “Dynamical Systems in Applications”

Validation and uncertainty of inverse dynamics analysis applied to high acceleration movements.

This thesis is motivated by the lack of knowledge of the uncertainty in the estimation of joint forces and moments derived through inverse dynamics analysis. Previous studies have shown uncertainty bounds can be substantial during slow, simple movements such as gait or lifting however little is known about the uncertainty in inverse dynamics solutions applied to high acceleration, open chain, complex tasks. A three dimensional full body model was used to provide a mechanical basis for evaluating joint forces and moments during the golf swing. Eight male skilled golfers were used; kinematic data was recorded using the Polhemus LIBERTY, an electromagnetic tracker system, using 12 sensors attached to the body with a specially designed jacket. Force plates were used to measure ground reaction forces.Validation of the derived joint forces and moments is problematic since no 'gold standard' is available for comparison. A comparison of the measured with the estimated ground reaction forces, as well as a comparison of the moments at the T8/T9 intervertebral joint that results from bottom up and top down mechanical analysis provided an initial measure of validity. The high acceleration, complex nature of the golf swing resulted in a reduced validity compared to previous studies concerned with lifting, fast trunk rotations and slow speed golf swings. The residuals between the measured and predicted GRF were greatest during the downswing. Similarly, the residuals between the joint reaction forces and moments at the upper trunk joint measured using a top down and bottom up mechanical analysis were greatest during the downswing, exemplified by an increase in joint moment RMS differences of 30.9 Nm, 24.4 Nm and 25.2 Nm for lateral bending, axial rotation and flexion-extension respectively. It was shown that for open chain movements, through periods of high acceleration, inverse dynamics solutions can be subject to errors which have the capacity to significantly affect the interpretation of resultant joint moments depending on whether a top down or bottom up mechanical analysis is used. Top down-bottom up comparisons do not account for two sources of error; the joint centre location and the anatomical coordinate system of the joint where the two models meet. A further drawback associated with these validation methods is that nothing can be learnt about the individual sources of error and how they contribute to the total residual error.A consideration of how errors in measured variables propagate through inverse dynamics equations to produce uncertainties associated with the result was necessary. To analyse this, the Taylor Series Method for error propagation was used. Inaccuracies in body segment parameters, kinematics and external force measurement were determined experimentally. Soft tissue artefact and joint centre location errors were extracted from the literature. Inaccuracies in variables were assumed to be random and uncorrelated and results were representative of the upper bound uncertainty. Uncertainty in joint moment estimations was greatest for downswing where segments were moving with the greatest acceleration. The magnitude of the uncertainty was substantial and ranged from 6-339% of the peak joint moment magnitude.Inaccuracies in proximal moment arms and centre of mass accelerations had the most influence on the joint moment uncertainty and this uncertainty had the capability to alter the timing of peak joint moments by as much as 560ms. The results were critical to the interpretation of inverse dynamics derived joint forces and moments for high acceleration, open chain motions

Applications of EMG in Clinical and Sports Medicine

This second of two volumes on EMG (Electromyography) covers a wide range of clinical applications, as a complement to the methods discussed in volume 1. Topics range from gait and vibration analysis, through posture and falls prevention, to biofeedback in the treatment of neurologic swallowing impairment. The volume includes sections on back care, sports and performance medicine, gynecology/urology and orofacial function. Authors describe the procedures for their experimental studies with detailed and clear illustrations and references to the literature. The limitations of SEMG measures and methods for careful analysis are discussed. This broad compilation of articles discussing the use of EMG in both clinical and research applications demonstrates the utility of the method as a tool in a wide variety of disciplines and clinical fields

Smart Sensors for Healthcare and Medical Applications

This book focuses on new sensing technologies, measurement techniques, and their applications in medicine and healthcare. Specifically, the book briefly describes the potential of smart sensors in the aforementioned applications, collecting 24 articles selected and published in the Special Issue “Smart Sensors for Healthcare and Medical Applications”. We proposed this topic, being aware of the pivotal role that smart sensors can play in the improvement of healthcare services in both acute and chronic conditions as well as in prevention for a healthy life and active aging. The articles selected in this book cover a variety of topics related to the design, validation, and application of smart sensors to healthcare

Proceedings SIAMOC 2019

Il congresso annuale della Società Italiana di Analisi del Movimento in Clinica, giunto quest'anno alla sua ventesima edizione, ritorna a Bologna, che già ospitò il terzo congresso nazionale nel 2002. Il legame tra Bologna e l'analisi del movimento è forte e radicato, e trova ampia linfa sia nel contesto accademico che nel ricco panorama di centri clinici d'eccellenza. Il congresso SIAMOC, come ogni anno, è l’occasione per tutti i professionisti dell’ambito clinico, metodologico ed industriale di incontrarsi, presentare le proprie ricerche e rimanere aggiornati sulle più recenti innovazioni nell’ambito dell’applicazione clinica dei metodi di analisi del movimento. Questo ha contribuito, in questi venti anni, a fare avanzare sensibilmente la ricerca italiana nel settore, conferendole un respiro ed un impatto internazionale, e a diffonderne l'applicazione clinica per migliorare la valutazione dei disordini motori, aumentare l'efficacia dei trattamenti attraverso l'analisi quantitativa dei dati e una più focalizzata pianificazione dei trattamenti, ed inoltre per quantificare i risultati delle terapie correnti

CT Scanning

Since its introduction in 1972, X-ray computed tomography (CT) has evolved into an essential diagnostic imaging tool for a continually increasing variety of clinical applications. The goal of this book was not simply to summarize currently available CT imaging techniques but also to provide clinical perspectives, advances in hybrid technologies, new applications other than medicine and an outlook on future developments. Major experts in this growing field contributed to this book, which is geared to radiologists, orthopedic surgeons, engineers, and clinical and basic researchers. We believe that CT scanning is an effective and essential tools in treatment planning, basic understanding of physiology, and and tackling the ever-increasing challenge of diagnosis in our society

Automated Pose Estimation for the Assessment of Dynamic Knee Valgus and Risk of Knee Injury during the Single Leg Squat

Many clinical assessment protocols rely on the evaluation of functional movement tests such as the Single Leg Squat (SLS), which are often assessed visually. Visual assessment is subjective and depends on the experience of the clinician. Developing a reliable automatic human motion tracking and assessment system can improve the accuracy of SLS clinical assessments and provide objective results that can be tracked and monitored over time to guide rehabilitation and determine an individual's response to an intervention. In this study, an Inertial Measurement Unit (IMU) based method for automated assessment of squat quality is proposed to provide clinicians with a quantitative measure of SLS performance. First, an automated pose estimation method is applied to SLS motion data. A set of three IMUs is used to estimate the joint angles, velocities and accelerations of the squatting leg. To tackle noisy sensor measurements and gyro drift, a 7 degree of freedom (DOF) kinematic model of the lower leg was applied together with a constant acceleration assumption to approximate the angular velocity and linear acceleration at each sensor location. The kinematic model predictions of the angular velocity and linear acceleration and sensor measurements were fused via an Extended Kalman Filter (EKF). The position, velocity, and acceleration of each DOF were defined as the states to be estimated by the EKF. The pose estimation results showed successful extraction of joint angles with an average RMS error of 3.2 degrees, 5.5 degrees, 7 degrees compared to joint angles estimated from motion capture for the ankle, knee, and hip joints, respectively. For this estimation, the required parameters for the kinematic model, including information about the sensor placement and orientation as well as the kinematic link lengths, were extracted from the marker data. However, in clinical applications of the proposed method, when marker data is not available, these parameters need to be measured. Measuring these parameters is time consuming in the clinical setting, which limits application of IMUs for clinical purposes. With the motivation to make this procedure easier and faster, a method for approximating the parameters using placement assumptions and body measures was described. A sensitivity analysis was performed to detect those parameters which most affect pose estimation accuracy. The sensitivity analysis results revealed that sensor orientation is the most critical factor for accurate pose estimation. In this thesis, a simple and easy to use method is proposed for sensor orientation calibration, based on a systematic placement of sensors and using gyroscope information for orientation estimation. This protocol was evaluated experimentally and pose estimation error with approximated parameters before and after applying the calibration protocol were compared. The comparison results showed that the estimate of the sensor orientation increases the pose estimation accuracy by 6.5 degrees for the knee joint angle and with an average of 1.8 degrees for other joints without the need for time consuming calibration. In the second part of the thesis, an algorithm for automated assessment of the SLS in terms of dynamic knee valgus and risk of knee injury is developed. After applying the pose estimation algorithm to IMU data of SLS motions, the estimated time series data of joint angles, velocities and accelerations for consecutive squats were segmented into individual squat repetitions. Statistical time domain features were generated from each repetition. The most informative features were selected using a combination of 18 feature selection techniques. Six common classifiers in including SVM, Linear Multinomial Logistic Regression, Decision Tree, Naive Bayes, K Nearest Neighborhood, and Random Forests were applied to the full dimensional data, the subset of selected features, and extracted features by supervised principal component analysis. The proposed approach was evaluated in two trials. First, a pilot study was conducted on a small dataset, followed by analysis on a larger clinical data set, collected by our clinical collaborator. For the clinical study, a dataset of SLS performed by healthy participants was collected and labelled by three expert clinical raters using two different labeling criteria: "observed amount of knee valgus" and "overall risk of injury". Labels included "good", "moderate", and "poor" squat quality or "high risk", "mild to moderate risk", and "no risk" of injury. Feature selection results showed that both flexion at the hip and knee, as well as hip and ankle internal rotation are discriminative features, and that participants with "poor" squats bend the hip and knee less than those with better squat performance. Furthermore, improved classifi cation performance was achieved by training separate classifi ers strati ed by gender. Classifi cation results showed excellent accuracy, 93.1% for classifying squat quality as "poor" or "good" and 95.3% for differentiating between high and no risk of injury

Proceedings SIAMOC 2019

Il congresso annuale della Società Italiana di Analisi del Movimento in Clinica, giunto quest'anno alla sua ventesima edizione, ritorna a Bologna, che già ospitò il terzo congresso nazionale nel 2002. Il legame tra Bologna e l'analisi del movimento è forte e radicato, e trova ampia linfa sia nel contesto accademico che nel ricco panorama di centri clinici d'eccellenza. Il congresso SIAMOC, come ogni anno, è l’occasione per tutti i professionisti dell’ambito clinico, metodologico ed industriale di incontrarsi, presentare le proprie ricerche e rimanere aggiornati sulle più recenti innovazioni nell’ambito dell’applicazione clinica dei metodi di analisi del movimento. Questo ha contribuito, in questi venti anni, a fare avanzare sensibilmente la ricerca italiana nel settore, conferendole un respiro ed un impatto internazionale, e a diffonderne l'applicazione clinica per migliorare la valutazione dei disordini motori, aumentare l'efficacia dei trattamenti attraverso l'analisi quantitativa dei dati e una più focalizzata pianificazione dei trattamenti, ed inoltre per quantificare i risultati delle terapie correnti

Biomechatronics: Harmonizing Mechatronic Systems with Human Beings

This eBook provides a comprehensive treatise on modern biomechatronic systems centred around human applications. A particular emphasis is given to exoskeleton designs for assistance and training with advanced interfaces in human-machine interaction. Some of these designs are validated with experimental results which the reader will find very informative as building-blocks for designing such systems. This eBook will be ideally suited to those researching in biomechatronic area with bio-feedback applications or those who are involved in high-end research on manmachine interfaces. This may also serve as a textbook for biomechatronic design at post-graduate level