Evaluation of Feedforward and Feedback Contributions to Hand Stiffness and Variability in Multi-Joint Arm Control.

Evaluation of Feedforward and Feedback Contributions to Hand Stiffness and Variability in Multi-Joint Arm Control.

Filed under: Rehab Centers

IEEE Trans Neural Syst Rehabil Eng. 2012 Dec 20;
He X, Du YF, Lan N

The purpose of this study is to validate a neuromechanical model of the virtual arm (VA) by comparing emerging behaviors of the model to those of experimental observations. Hand stiffness of the VA model was obtained by either theoretical computation, or simulated perturbations. Variability in hand position of the VA was generated by adding signal dependent noise (SDN) to the motoneuron pools of muscles. Reflex circuits of Ia, Ib and Renshaw cells were included to regulate the motoneuron pool outputs. Evaluation of hand stiffness and variability was conducted in simulations with and without afferent feedback under different patterns of muscle activations during postural maintenance. The simulated hand stiffness and variability ellipses captured the experimentally observed features in shape, magnitude and orientation. Steady state afferent feedback contributed significantly to the increase in hand stiffness by in area, and in major and minor axes; and to the reduction of hand variability by in area, and in major and minor axes. The VA model reproduced the neuromechanical behaviors that were consistent with experimental data, and it could be a useful tool for study of neural control of posture and movement, as well as for application to rehabilitation.
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[Surgical operations for the improvement of hearing in the children: the current state of the problem. Part II. Ossiculoplasty, stapedoplasty, shunting of the tympanic cavity, cochlear implantation.]

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Vestn Otorinolaringol. 2012; 109-113
Bogomil’ski? MR, Ivanichkin SA

The second part of this review paper devoted to the modern views of the problem of cophosurgery in Russia is concerned with the methods of ossiculoplasty, stapedoplasty, and shunting of the tympanic cavity. The results of the Russian-language and foreign publications are compared. Especially much attention is given to the problem of cochlear implantation in this country with reference to the achievements of Russian specialists in this field. The stages of preparation for this surgical intervention are described in much detail along with the criteria for the choice of the patients. The importance of their postoperative rehabilitation is emphasized.
HubMed – rehab

 

[Immune reactions of palatine tonsils in the patients with chronic tonsillitis and the possibilities for their immunological rehabilitation with the use of imudon.]

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Vestn Otorinolaringol. 2012; 67-70
Aznabaeva LF, Aref’eva NA, Gumerova MI

The objective of the present study was to develop a rationale for the application of imudon (a bacterial lysate preparation)in the treatment of the patients presenting with chronic tonsillitis based on the elucidation of characteristics of local immunity in the oropharynx (determined from the results of cytograms, immunoenzyme assays for the quantitation of IgG, sIgA, IgA, and IgM antibodies, and calculation of the relative secretion coefficients). A total of 74 patients with chronic tonsillar pathology (24 children and 50 adults) were available for the observation along with 42 subjects having no tonsillar pathology with concomitant chronic bacterial rhinosinusitis. The control group was constituted by 25 practically healthy subjects. It was shown that the local application of imudon in the patients with the preserved function of palatine tonsils (in the absence of symptoms of chronic inflammation) produces the adequate response of the humoral and cellular immunity systems. In the patients with the simple form of chronic tonsillitis imudon therapy ensured statistically significant activation of congenital immunity including the phagocyte function and a tendency toward normalization of antibody formation. It is concluded that alteration of the function of palatine tonsils in the patients presenting with the toxico-allergic form (???-2) of chronic tonsillitis implies the necessity of surgical treatment (tonsillectomy).
HubMed – rehab

 

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