The Human Body Model versus conventional gait models for kinematic gait analysis in children with cerebral palsy.

With the rise of biofeedback in gait training in cerebral palsy there is a need for real-time measurements of gait kinematics. The Human Body Model (HBM) is a recently developed model, optimized for the real-time computing of kinematics. This study evaluated differences between HBM and two commonly used models for clinical gait analysis: the Newington Model, also known as Plug-in-Gait (PiG), and the calibrated anatomical system technique (CAST). Twenty-five children with cerebral palsy participated. 3D instrumented gait analyses were performed in three laboratories across Europe, using a comprehensive retroreflective marker set comprising three models: HBM, PiG and CAST. Gait kinematics from the three models were compared using statistical parametric mapping, and RMSE values were used to quantify differences. The minimal clinically significant difference was set at 5°. Sagittal plane differences were mostly less than 5°. For frontal and transverse planes, differences between all three models for almost all segment and joint angles exceeded the value of minimal clinical significance. Which model holds the most accurate information remains undecided since none of the three models represents a ground truth. Meanwhile, it can be concluded that all three models are equivalent in representing sagittal plane gait kinematics in clinical gait analysis.

Upper body balance control strategy during continuous 3D postural perturbation in young adults.

We explored how changes in vision and perturbation frequency impacted upright postural control in healthy adults exposed to continuous multiaxial support-surface perturbation. Ten subjects were asked to maintain equilibrium in standing stance with eyes open (EO) and eyes closed (EC) during sinusoidal 3D rotations at 0.25 (L) and 0.50 Hz (H). We measured upper-body kinematics--head, trunk, and pelvis--and analyzed differences in horizontal displacements and roll, pitch, and yaw sways. The presence of vision significantly decreased upper-body displacements in the horizontal plane, especially at the head level, while in EC the head was the most unstable segment. H trials produced a greater segment stabilization compared to L ones in EO and EC. Analysis of sways showed that in EO participants stabilized their posture by reducing the variability of trunk angles; in H trials a sway decrease for the examined segments was observed in the yaw plane and, for the pelvis only, in the pitch plane. Our results suggest that, during continuous multiaxial perturbations, visual information induced: (i) in L condition, a continuous reconfiguration of multi-body-segments orientation to follow the perturbation; (ii) in H condition, a compensation for the ongoing perturbation. These findings were not confirmed in EC where the same strategy--that is, the use of the pelvis as a reference frame for the body balance was adopted both in L and H.

Experimental evaluation of indoor magnetic distortion effects on gait analysis performed with wearable inertial sensors.

Magnetic inertial measurement unit systems (MIMU) offer the potential to perform joint kinematics evaluation as an alternative to optoelectronic systems (OS). Several studies have reported the effect of indoor magnetic field disturbances on the MIMU's heading output, even though the overall effect on the evaluation of lower limb joint kinematics is not yet fully explored. The aim of the study is to assess the influence of indoor magnetic field distortion on gait analysis trials conducted with a commercial MIMU system. A healthy adult performed gait analysis sessions both indoors and outdoors. Data collected indoors were post-processed with and without a heading correction methodology performed with OS at the start of the gait trial. The performance of the MIMU system is characterized in terms of indices, based on the mean value of lower limb joint angles and the associated ROM, quantifying the system repeatability. We find that the effects of magnetic field distortion, such as the one we experienced in our lab, were limited to the transverse plane of each joint and to the frontal plane of the ankle. Sagittal plane values, instead, showed sufficient repeatability moving from outdoors to indoors. Our findings provide indications to clinicians on MIMU performance in the measurement of lower limb kinematics.

Compensation to whole body active rotation perturbation.

The aim of the present study is the exploration of the compensation mechanisms in healthy adults elicited by superimposing a horizontal perturbation, through a rotation of the support base, during a whole body active rotation around the participant's own vertical body axis. Eight healthy participants stood on a rotating platform while executing 90° whole body rotations under three conditions: no concurrent platform rotation (NP), support surface rotation of ± 45° in the same (45-S) and opposite (45-O) directions. Participants' kinematics and CoP displacements were analyzed with an optoelectronic system and a force platform. In both 45-S and 45-O conditions, there was a tendency for the head to be affected by the external perturbation and to be the last and least perturbed segment while the pelvis was the most perturbed. The observed reduced head perturbation in 45-S and 45-O trials is consistent with a goal-oriented strategy mediated by vision and vestibular information, whereas the tuning of lumbar rotation is consistent with control mechanisms mediated by somato-sensory information.

Patient-centered rehabilitation, three years of gait recovery in a child affected by hemiplegia:. case report.

The aim of this report was to illustrate and to discuss a method capable of improving the person-oriented decision-making process during three years of gait rehabilitation based on the integration of: 1) the fundamental principles of motor learning and 2) the outcomes made available by both clinical standardized assessment tools (SAT) and measures made available by a gait analysis system (GA). The subject studied was a six-year-old child affected by hemiplegia after arterial ischemic stroke (AIS) who had limited upper and lower right-limb function but unaffected sensory and cognitive skills. Four different rehabilitative treatments were chosen when the child was inpatient or outpatient. Measurements of gait performance before and after selected treatments were evaluated using PEDI and GMFM (i.e., SAT) and kinematic and kinetic parameters (i.e., GA). Gait pattern and inter- and intralimb-joint coordination changed over time during the three examined years. However, after the first eight months of recovery, gait pattern modifications were detected by GA measures but not by SAT. The integration of SAT and GA findings, during the examined recovery evolution, resulted effective in the decision-making process for a person-oriented rehabilitative treatment.

Abnormal adaptation in children affected by cerebral palsy to robot generated dynamic environment.

This paper aims to investigate how robotic devices can be used to understand the mechanism of sensorimotor adaptation in pediatric subjects affected by hemiparetic cerebral palsy. Previous studies showed how healthy adults, after training in presence of a systematic structured disturbing force field, show an "after effect" and therefore they highly adapt and compensate the external disturbance. An open issue is whether this adaptive capability is preserved or disrupted in pediatric impaired subjects when they experience a robot generated dynamic environment. Fourteen pediatric Cerebral Palsy subjects (CP group), and age-matched control group were exposed to a robot generated speed-dependant force field; during familiarization (no forces generated by the robot) the movement of the CP subjects were more curved, displaying greater and variable directional error; in the force field phase both the groups showed an after-effect, but the CP group had a non significant adaptation rate. This outcome suggests the CP subjects have reduced ability to learn external force and they make greater aiming error because of an inefficient anticipatory strategy during visuomotor task.

The impact of robotic rehabilitation in children with acquired or congenital movement disorders.

AIM: The aim of this study was to evaluate if the robot-mediated therapy (RMT) can yield positive outcomes in children with acquired or congenital upper extremity movement disorders. METHODS: This was an uncontrolled pilot study with pre-post treatment outcome comparison carried out by the Pediatric Rehabilitation Department of a Children's Hospital. The study enrolled 12 children, aged 5 to 15 years, suffering from acquired (at least 12 months post-onset) or congenital upper limb motor impairment. ETIOLOGY: 4 stroke, 6 traumatic brain injuries, and 2 hemiplegic cerebral palsy. RMT was provided 3 times a week for an hour during 6 weeks for a total of 18 robot therapy sessions. The Melbourne Scale (MS) and the upper-extremity subsection of the Fugl-Meyer Assessment (FMA) were used for measurement of impairment. Secondary outcome measurements were made through the Modified Ashworth Scale (MAS); the Reaching Performance Scale (RPS); Parent's Questionnaire, and robot-based evaluation measurements. Specifically, authors compared the smoothness, as measured by the jerk metric, and average speed of unconstrained reaching movements. RESULTS: Pre-post clinical evaluation revealed statistically significant gains for all primary and secondary metrics. In addition, significant improvement of robot-based metrics was observed. The primary outcome measurement mean (SEM) gains were 6.71 (1.29) for MS and 3.33 (0.80) for the FMA. RMT led to spasticity decreases in chronic cases, as shown by the reduction of MAS. It led to improved trunk-upper extremity postural attitude as demonstrated by improved RPS, and it was well accepted by parents and children as observed in the Parent's Questionnaire. CONCLUSIONS: This study suggests that RMT may hold rehabilitative benefits in children suffering from acquired and congenital hemiparesis.

Design and Characterization of Hand Module for Whole-Arm Rehabilitation Following Stroke.

In 1991, a novel robot named MIT-MANUS was introduced as a test bed to study the potential of using robots to assist in and quantify the neurorehabilitation of motor function. It introduced a new modality of therapy, offering a highly backdrivable experience with a soft and stable feel for the user. MIT-MANUS proved an excellent fit for shoulder and elbow rehabilitation in stroke patients, showing a reduction of impairment in clinical trials with well over 300 stroke patients. The greatest impairment reduction was observed in the group of muscles exercised. This suggests a need for additional robots to rehabilitate other target areas of the body. Previous work has expanded the planar MIT-MANUS to include an antigravity robot for shoulder and elbow, and a wrist robot. In this paper we present the "missing link": a hand robot. It consists of a single-degree-of-freedom (DOF) mechanism in a novel statorless configuration, which enables rehabilitation of grasping. The system uses the kinematic configuration of a double crank and slider where the members are linked to stator and rotor; a free base motor, i.e., a motor having two rotors that are free to rotate instead of a fixed stator and a single rotatable rotor (dual-rotor statorless motor). A cylindrical structure, made of six panels and driven by the relative rotation of the rotors, is able to increase its radius linearly, moving or guiding the hand of the patients during grasping. This module completes our development of robots for the upper extremity, yielding for the first time a whole-arm rehabilitation experience. In this paper, we will discuss in detail the design and characterization of the device.

Experimental evaluation of errors in the measurement of respiratory parameters of the newborn performed by a continuous flow neonatal ventilator.

Pulmonary ventilators for intensive care provide information on, among many other patient respiratory parameters, patient resistance, compliance and 'work of breathing' values calculated from pressure and flow data patterns according to a widely utilized algorithm. The effects induced by the breathing circuit and analogue filtering of the ventilator measuring system are experimentally investigated during controlled ventilation. Three main phenomena are observed: (a) errors in calculation of resistance and compliance due to filtering of pressure and flow waveforms; (b) the presence of pressure oscillations at the beginning of inspiration and expiration phases; and (c) the phase shift between pressure and flow waveforms. The experimental evaluation of the measuring system of a neonatal ventilator is then conducted and: (a) a delay in pressure and flow measurement synchronization equal to 22 +/- 2 ms is evaluated; moreover, (b) a difference between the values provided by the ventilator and those measured by the reference experimental setup on respiratory parameters such as the compliance, resistance and work of breathing that lies in the range of 7-16% of reading is observed.

A novel device to evaluate the stiffness of ankle-foot orthosis devices.

The evaluation of mechanical behavior of plastic Ankle-Foot Orthosis (AFO) is important since AFO can provide an efficient support to patients with disabilities in locomotion. This paper reports on a novel testing apparatus that allows: (a) the evaluation of AFO stiffness in sagittal and frontal planes; (b) the conduction of semi-automatic trials; and, finally, (c) a global accuracy associated to the AFO stiffness values always less than 4%. The stiffness values are determined by the measurements of the imposed relative displacements between the foot and the shank of the orthosis and the induced reaction forces. The data collected together in an exact 2-D approach, together with those provided by gait analysis systems, allows to better understand gait alteration induced by ankle orthosis, and to improve clinical management of patients.

Outfitting your hospital for the new wave of robots.

Automated materials handling systems have provided dramatic labor savings and efficiency benefits to healthcare facilities. A growing trend is the use of a new breed of service robots that provide automated materials handling without major modifications to the existing building. The robots navigate through hallways, go through doors and ride elevators using a computerized controller that contains a layout of each floor of the hospital; the robots do not rely on any type of physical track to guide them on their way. The robots are programmed to pick up or deliver supplies to nursing stations or other departments, and determine the best route. Purchase and rental options exist at a substantial savings over human labor.

Development of a computerized equipment management program at Children's Hospital "Bambino Gesù" of Rome, Italy.

The main activities of the Clinical Engineering Service at the Children's Hospital "Bambino Gesù" of Rome, Italy and the computerized system developed in-house for electromedical equipment management are described here. The approach recently adopted and implemented for an objective cost/benefit evaluation of the equipment installed at the hospital is also described. The program outputs appear to be effective tools, both in evaluating maintenance costs and workload increases from new equipment installations and, more relevantly, in comparing similar equipment from different manufacturers during prepurchase evaluation.

HLA class I- like antigen expression on human leukemic cells.

The expression of HLA class I- like molecules was analyzed on human acute and chronic leukemic cells. The presence on leukemic cells of class I- like molecules, absent on the patient's normal lymphocytes, was examined by complement- dependent lymphocytotoxicity using platelet absorbed alloantisera that recognize HLA-linked, 45-12 kd, beta-2-microglobulin associated molecules, selectively expressed on PHA-activated cells. A positive reactivity of the anti- class I- like alloantisera was found in 50% of the acute leukemias (cALL, T-ALL and AML), independently of the lineage of differentiation, while chronic lymphocytic leukemias (B-CLL) were constantly negative. It is suggested that beta-2-microglobulin associated HLA molecules may represent markers of leukemic blast activation and/or maturation state.

Influence of gangliosides on primary and metastatic neoplastic growth in human and murine cells.

The influence of gangliosides on tumor growth and frequency of metastasis in vivo as well as on growth and motility of neoplastic cells in vitro was tested utilizing human and rodent cell populations. In mice receiving injections of a ganglioside mixture twice daily the tumor volume, the number of spontaneous metastases per animal, and the number of mice with metastasis was approximately double that of controls. Preincubation of neoplastic cells with the ganglioside mixture doubled the number of metastatic foci in the lungs of mice receiving the cells by i.v. injection. Addition of a ganglioside mixture to the culture medium enhanced motility of neoplastic cells about 3-fold. This finding was similar to that observed for capillary endothelium. The presence of gangliosides in the culture media for a 48-h incubation period about doubled the number of neoplastic cells as compared to controls; the same was observed for capillary endothelium. The data are interpreted to indicate that gangliosides improve growth and mobilization of capillary endothelium and neoplastic cells. Both events may concur in enhancing tumor growth in vivo, the first by improving angiogenesis, the second by direct action on the neoplastic cell population.