Eddy Currents Distribution in Upper Extremities During Magnetotherapy

Author(s):  
Przemyslaw Syrek ◽  
Cristian Barz ◽  
Mikolaj Skowron ◽  
Antoni Ciesla
2009 ◽  
Vol 14 (4) ◽  
pp. 1-6
Author(s):  
Christopher R. Brigham

Abstract The AMAGuides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, does not provide a separate mechanism for rating spinal nerve injuries as extremity impairment; radiculopathy was reflected in the spinal rating process in Chapter 17, The Spine and Pelvis. Certain jurisdictions, such as the Federal Employee Compensation Act (FECA), rate nerve root injury as impairment involving the extremities rather than as part of the spine. This article presents an approach to rate spinal nerve impairments consistent with the AMA Guides, Sixth Edition, methodology. This approach should be used only when a jurisdiction requires ratings for extremities and precludes rating for the spine. A table in this article compares sensory and motor deficits according to the AMA Guides, Sixth and Fifth Editions; evaluators should be aware of changes between editions in methodology used to assign the final impairment. The authors present two tables regarding spinal nerve impairment: one for the upper extremities and one for the lower extremities. Both tables were developed using the methodology defined in the sixth edition. Using these tables and the process defined in the AMA Guides, Sixth Edition, evaluators can rate spinal nerve impairments for jurisdictions that do not permit rating for the spine and require rating for radiculopathy as an extremity impairment.


2017 ◽  
Vol 22 (2) ◽  
pp. 3-5
Author(s):  
James B. Talmage ◽  
Jay Blaisdell

Abstract Physicians use a variety of methodologies within the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, to rate nerve injuries depending on the type of injury and location of the nerve. Traumatic injuries that cause impairment to the peripheral or brachial plexus nerves are rated using Section 15.4e, Peripheral Nerve and Brachial Plexus Impairment, for upper extremities and Section 16.4c, Peripheral Nerve Rating Process, for lower extremities. Verifiable nerve lesions that incite the symptoms of complex regional pain syndrome, type II (similar to the former concept of causalgia), also are rated in these sections. Nerve entrapments, which are not isolated traumatic events, are rated using the methodology in Section 15.4f, Entrapment Neuropathy. Type I complex regional pain syndrome is rated using Section 15.5, Complex Regional Pain Syndrome for upper extremities or Section 16.5, Complex Regional Pain Syndrome for lower extremities. The method for grading the sensory and motor deficits is analogous to the method described in previous editions of AMA Guides. Rating the permanent impairment of the peripheral nerves or brachial plexus is similar to the methodology used in the diagnosis-based impairment scheme with the exceptions that the physical examination grade modifier is never used to adjust the default rating and the names of individual nerves or plexus trunks, as opposed to the names of diagnoses, appear in the far left column of the rating grids.


1986 ◽  
Vol 13 (1) ◽  
pp. 107-118 ◽  
Author(s):  
Norman S. Levine ◽  
Robert T. Buchanan
Keyword(s):  

2020 ◽  
pp. 54-58
Author(s):  
S. M. Plotnikov

The division of the total core losses in the electrical steel of the magnetic circuit into two components – losses dueto hysteresis and eddy currents – is a serious technical problem, the solution of which will effectively design and construct electrical machines with magnetic circuits having low magnetic losses. In this regard, an important parameter is the exponent α, with which the frequency of magnetization reversal is included in the total losses in steel. Theoretically, this indicator can take values from 1 to 2. Most authors take α equal to 1.3, which corresponds to the special case when the eddy current losses are three times higher than the hysteresis losses. In fact, for modern electrical steels, the opposite is true. To refine the index α, an attempt was made to separate the total core losses on the basis that the hysteresis component is proportional to the first degree of the magnetization reversal frequency, and the eddy current component is proportional to the second degree. In the article, the calculation formulas of these components are obtained, containing the values of the total losses measured in idling experiments at two different frequencies, and the ratio of these frequencies. It is shown that the rational frequency ratio is within 1.2. Presented the graphs and expressions to determine the exponent α depending on the measured no-load losses and the frequency of magnetization reversal.


Author(s):  
Nadezhda I. Kuprina ◽  
Ekaterina V. Ulanovskaya ◽  
Olga A. Kochetova

Introduction. Vibration disease (VD) is an example of the most common pathology due to the systematic exposure of the worker to intense vibration with sufficient work experience, the main manifestation of which is peripheral angiodystonic syndrome. The aim of study was to learn the features of peripheral blood flow in the arteries of the forearm in vibration disease using the ultrasound method. Materials and methods. The radial and ulnar arteries in patients with vibration disease were examined by ultrasound in B- and PW-mode. These materials present the results of an ultrasound assessment of the speed indicators of the main arteries of the forearm in vibration disease stages 1 and 2. The selection criteria for patients in the study ware the presence of pronounced clinical manifestations of angiodystonic syndrome in vibration disease, confirmed by instrumental research methods and data on the sanitary and hygienic characteristics of working conditions, the absence of cardiovascular chronic diseases (ischemic heart disease, heart defects, rhythm and conduction disturbances), rheumatic, oncological, infectious diseases, osteo-traumatic changes in the upper extremities. Results. The groups of patients with the established diagnosis of vibration disease of 1 and 2 degrees were studied. With vibration disease stage 1 a decrease in the pulse velocity of blood flow was observed in isolation on the ulnar artery and an increase in peripheral resistance (pulsation index and resistance index) in the radial and ulnar arteries symmetrically on both upper extremities. The second stage of vibration disease differed from the first by a more significant decrease in speed indicators both on the ulnar and radial arteries on both sides, symmetrically in combination with a more pronounced increase in peripheral resistance indicators on both main arteries of the forearm (pulsation index and resistance index). The revealed changes were determined with the same frequency in men and women. Conclusions. A significant decrease in speed indicators on the ulnar artery and an increase in peripheral resistance indicators are detected already at the initial stages of vibration disease. Thus, the method of ultrasound examination of the main arteries of the middle caliber of the upper extremities is currently the only available and objective method for examining the vascular system in vibration disease.


Author(s):  
Ji Eun Son ◽  
Tae Woon Jang ◽  
Yoon Kou Kim ◽  
Young Seoub Hong ◽  
Kap Yeol Jung ◽  
...  

2007 ◽  
Author(s):  
Ray T. Ko ◽  
Shamachary Sathish ◽  
Jeremy S. Knopp ◽  
Mark P. Blodgett

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