Вслед за контрактом с Францией на закупку вертолётоносцев «Мистраль» может быть подписан ещё один контракт — на приобретение опытной партии комплектов индивидуальной экипировки пехотинца, отличающийся модульной конструкцией и открытой архитектурой, так называемый «комплект солдата будущего».

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Категория: Амуниция | Нет комментариев »

In this paper, we propose an original and biologically-inspired leg prosthesis control system. We demonstrate that human walk periodic patterns can be modeled by a Programmable Central Pattern Generator (PCPG) algorithm. Assuming that high-level commands reflecting the user’s intention (such as accelerate, decelerate or stop) — and optionally, with their associated confidence level — are available, we show that the PCPG can generate an output signal directly exploitable to control the prosthesis actuators at different desired walking speeds in a smooth way. Thanks to an adequate tuning of the PCPG parameters relying on realistic human walk kinematics, such a prosthesis would undoubtedly increase the comfort of the patient. In this study, we modeled the kinematics of foot angle of elevation of seven subjects walking on a treadmill at 10 different speeds. The method we used to modify at best the PCPG parameters is presented. We found that a low-level order polynomial interpolation of the PCPG parameters as a function of speed provides good similarity indices between real walk and generated patterns at different speeds. This proves the relevancy of our approach and paves the way for numerous applications of human walk rehabilitation. Additionally, results suggest that walk would be advantageously modeled by two PCPGs.

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Категория: Научные статьи | Нет комментариев »

Experiments for the online closed-loop control of neural prosthetics require feedback within 100ms. In a typical neurophysiology laboratory with local computing machines, a majority of this time is spent on acquiring and analyzing the neural signals and a minority (i.e. less than a millisecond) is actual data transfer among machines on local- or campus-area networks. However, the local computing machines may not offer the computational resources necessary for running complex algorithms or scenarios that have been recently proposed. While scientists can take advantage of remote computing resource providers, wide-area networks present much larger latencies that can affect an online experiment. This work presents a split modeling approach that allows the execution of a controller on the neurophysiology resource and the execution of computationally intensive modeling and adaptation algorithms on a remote datacenter, even with the inevitable network latency. Simulation results are presented to quantify how the accuracy of the controller is affected by the split modeling approach in the presence of delays, and to demonstrate that scientists can take advantage of remotely available massive resources.

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Purpose.  To investigate the effects of dynamic ankle-foot orthoses (DAFOs) on functional ambulation activities, weight bearing and spatio-temporal characteristics of hemiparetic gait and to inquire whether wearing a DAFO for 3 months has a carryover effect.

Method. Fourteen chronic hemiparetic patients who could walk independently with or without a cane were the subjects of the study. Patients were assessed initially with tennis shoes and were given custom fabricated DAFOs which they wore for three months and were retested under two conditions: with tennis shoes only and with DAFOs worn in these shoes. All patients were assessed for weight bearing percentage of the affected side, cadence, step length of the involved and uninvolved sides, step width, functional reach, timed up and go, timed down stairs, timed up stairs, physiologic cost index and velocity.

Results. Comparison of initial and third month assessments with shoes only condition showed that there was no significant improvement for the measured parameters. When comparison was made at the third month while patients were wearing tennis shoes only and when they were wearing DAFO’s in their shoes there was a significant difference in favour of the condition where patients were wearing DAFOs.

Conclusion. The benefits of using DAFOs in chronic hemiparetic patients are lost when the patients are not wearing their orthoses.

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Patients with neurological disorders, such as stroke survivors, can be treated with physical rehabilitation to regain motor control and function. Conventional therapy techniques are labor intensive and non-standardized. This is especially true in gait rehabilitation. A natural and tunable rehabilitation gait system (NaTUre_gaits) has been developed to assist gait rehabilitation with body-weight support locomotion training (BWSLT), gait control (GC), balance control (BC) and pelvic control (PC). All of those components are attached to a mobile platform (MP) with a total weight of more than 200kg. In order to coordinate the system with the motion of GC/BC/PC and to provide BWS for the subject throughout the walking test, the mobile system needs to move adaptively and steadily against those dynamic disturbance and heavy load. Motivated by reducing the tuning time, an identification and control method are proposed. Based on the relay response during operation, the system model is obtained and then PD controller with feed forward feedback is designed. Trials with/without subject are performed to demonstrate the effectiveness and merit of the proposed modeling and tuning method.

Категория: Ищем научные статьи | 1 Комментарий »