S. Scapellato

Bio: S. Scapellato is an academic researcher from Sant'Anna School of Advanced Studies. The author has contributed to research in topics: Power walking & Preferred walking speed. The author has an hindex of 5, co-authored 5 publications receiving 890 citations.

Assessment of walking features from foot inertial sensing

Abstract: An ambulatory monitoring system is developed for the estimation of spatio-temporal gait parameters. The inertial measurement unit embedded in the system is composed of one biaxial accelerometer and one rate gyroscope, and it reconstructs the sagittal trajectory of a sensed point on the instep of the foot. A gait phase segmentation procedure is devised to determine temporal gait parameters, including stride time and relative stance; the procedure allows to define the time intervals needed for carrying an efficient implementation of the strapdown integration, which allows to estimate stride length, walking speed, and incline. The measurement accuracy of walking speed and inclines assessments is evaluated by experiments carried on adult healthy subjects walking on a motorized treadmill. Root-mean-square errors less than 0.18 km/h (speed) and 1.52% (incline) are obtained for tested speeds and inclines varying in the intervals [3, 6] km/h and [-5, +15]%, respectively. Based on the results of these experiments, it is concluded that foot inertial sensing is a promising tool for the reliable identification of subsequent gait cycles and the accurate assessment of walking speed and incline.

Design and Fabrication of a Motor Legged Capsule for the Active Exploration of the Gastrointestinal Tract

Abstract: This paper describes a novel solution for the active locomotion of a miniaturized endoscopic capsule in the gastrointestinal (GI) tract. In particular, the authors present the design, development, and testing of a legged locomotion system embedded in a capsule (with a volume of about 4-5 cm3) and actuated by a brushless minimotor. The actuation mechanism and transmission mechanism are described in detail in order to highlight the compactness of the overall design. This device is provided with four superelastic legs, allowing large stroke advancement in the GI tract, and a CMOS frontal camera, for diagnostic purposes. A dedicated electronic board for controlling the opening angle of the legs and adjusting their speed has been developed. In order to investigate the motion ability of the device, a set of experiments has been carried out. Four different types of superelastic legs have been designed and tested with the objective to identify the best leg configuration for capsule locomotion. Experimental results demonstrate that the device can travel in the digestive tract with a typical speed ranging between 10 and 40 mm/min.

In-use calibration of body-mounted gyroscopes for applications in gait analysis

Abstract: In this paper, we propose an in-use calibration procedure for gyroscopes. The case report is a simple inertial measurement unit (IMU), which is used in our current research on inertial motion-sensing for advanced footware. The IMU contains two biaxial accelerometers and one gyroscope; it is developed for being mounted on one subject's foot instep, with the aim to reconstruct the trajectory in the sagittal plane of the sensed anatomical point. Since the IMU sagittal displacements can be estimated by performing strapdown integration, they can also be compared with their true values. One movement, which corresponds to known (vertical) displacements, consists of foot placements from the ground level on to top of steps of known height (step climbing). Provided that the IMU accelerometers are calibrated separately by any standard calibration procedure, motion tracking during the stepping movement allows to estimate the gyroscope sensitivity. The experimental results we present in this paper demonstrate the proposed in-use calibration procedure.

Energy expenditure rate in level and uphill treadmill walking determined from empirical models and foot inertial sensing data

Abstract: An empirical model is used for predicting the energy expenditure rate of treadmill walking from walking speed and incline, which are measured by a foot-mounted inertial sensor. The difference between values of the energy expenditure rate obtained by entering measured and true values of these variables in the model equation is less than the errors that are reported to affect model based assessments of the metabolic response to locomotion in humans.

Quaternion-based extended Kalman filter for determining orientation by inertial and magnetic sensing

Abstract: In this paper, a quaternion based extended Kalman filter (EKF) is developed for determining the orientation of a rigid body from the outputs of a sensor which is configured as the integration of a tri-axis gyro and an aiding system mechanized using a tri-axis accelerometer and a tri-axis magnetometer. The suggested applications are for studies in the field of human movement. In the proposed EKF, the quaternion associated with the body rotation is included in the state vector together with the bias of the aiding system sensors. Moreover, in addition to the in-line procedure of sensor bias compensation, the measurement noise covariance matrix is adapted, to guard against the effects which body motion and temporary magnetic disturbance may have on the reliability of measurements of gravity and earth's magnetic field, respectively. By computer simulations and experimental validation with human hand orientation motion signals, improvements in the accuracy of orientation estimates are demonstrated for the proposed EKF, as compared with filter implementations where either the in-line calibration procedure, the adaptive mechanism for weighting the measurements of the aiding system sensors, or both are not implemented.

Machine Learning Methods for Classifying Human Physical Activity from On-Body Accelerometers

Abstract: The use of on-body wearable sensors is widespread in several academic and industrial domains. Of great interest are their applications in ambulatory monitoring and pervasive computing systems; here, some quantitative analysis of human motion and its automatic classification are the main computational tasks to be pursued. In this paper, we discuss how human physical activity can be classified using on-body accelerometers, with a major emphasis devoted to the computational algorithms employed for this purpose. In particular, we motivate our current interest for classifiers based on Hidden Markov Models (HMMs). An example is illustrated and discussed by analysing a dataset of accelerometer time series.

Biomedical Applications of Untethered Mobile Milli/Microrobots

Abstract: Untethered robots miniaturized to the length scale of millimeter and below attract growing attention for the prospect of transforming many aspects of health care and bioengineering. As the robot size goes down to the order of a single cell, previously inaccessible body sites would become available for high-resolution in situ and in vivo manipulations. This unprecedented direct access would enable an extensive range of minimally invasive medical operations. Here, we provide a comprehensive review of the current advances in biomedical untethered mobile milli/microrobots. We put a special emphasis on the potential impacts of biomedical microrobots in the near future. Finally, we discuss the existing challenges and emerging concepts associated with designing such a miniaturized robot for operation inside a biological environment for biomedical applications.

The relevance of clinical balance assessment tools to differentiate balance deficits

Abstract: Control of balance is complex and involves maintaining postures, facilitating movement, and recovering equilib- rium. Balance control consists of controlling the body center of mass over its limits of stability. Clinical balance assessment can help to assess fall risk and/or determine the underlying reasons for balance disorders. Most func- tional balance assessment scales assess fall risk and the need for balance rehabilitation but do not differentiate types of balance deficits. A system approach to clinical bal- ance assessment can differentiate different kinds of bal- ance disorders and a physiological approach can deter- mine underlying sensorimotor mechanisms contribut- ing to balance disorders. Objective measures of balance using computerized systems and wearable inertial sensors can bring more sensitive, specific and responsive bal- ance testing to clinical practice.