In this study, a novel variable impedance control for a lower-limb rehabilitation robotic system using voltage control strategy is presented. The majority of existing control approaches are based on control torque strategy, which require the knowledge of robot dynamics as well as dynamic of patients. This requires the controller to overcome complex problems such as uncertainties and nonlinearit...

The object of this report is to establish the theoretical range of radio frequency impedance of the human body in the 1-30 MHz ringe. The report dtifines whole body rf impedance, sunmarized available specific tissue impedance data, and predicts likely values of total body impedance for various electrode sizes and locations from known specific tissue data and skin impedance. The report also disc...

The wave impedance and the environment impedance are important for the wave-variable based teleoperator. It is difficult to get good performance when the parameters are not proper. The paper addresses how to design the wave based teleoperator when working environment undergoes changed. It is concluded that wave impedance should match environment impedance by discussing how wave impedance and en...

In this paper, a novel approach based on the Thévenin tracing is presented to modified conventional impedance-based out-of-step (OOS) protection. In conventional approach, the OOS detection is done by measuring positive sequence impedance. However, the measured impedance may be change due to different factors such as capacitor bank switching and reactive power compensators that it can cause the...

background several methods for assessment of severity of pain have been proposed but all of them are subjective. objectives this study evaluated the association concerning changes in electrical resistance (er) between two acupuncture points and severity of postoperative pain in order to define an objective measurement of pain. patients and methods in a cross-sectional study, 50 patients undergo...

Also, the power-handling capacity of a transmission line is maximum when it is "flat", i.e., operating at low SWR. Lastly, it is important to be able to interconnect a number of different components into a system, and the only way that can be done reliably and predictably is by constraining the reflection coefficients of the various interfaces through impedance matching. Multiple reflections ca...

normal 0 false false false en-us x-none ar-sa microsoftinternetexplorer4 aim : this study was designed to investigate about findings of impedance ph-monitoring in patients with atypical symptoms of gerd. background : the routine treatment with proton pump inhibitors is not very effective in patients with atypical symptoms of gastro-esophageal reflux disease (gerd). it may be due to non-acid ref...

Impedance spectroscopy has long been recognized as one of the major techniques for the characterization of ac transport in materials. The primary limitation of this technique is the lack of spatial resolution that precludes the equivalent circuit elements from being unambiguously associated with individual microstructural features. Here we present a scanning probe microscopy technique for quant...

reservoir characterization plays an important role in different parts of an industrial project. the results from a reservoir characterization study give insight into rock and fluid properties which can optimize the choice of drilling locations and reduce risk and uncertainty. delineating hydrocarbon bearing zones within a reservoir is the main objective of any seismic reservoir characterization...

The electromechanical (E/M) impedance method is a powerful technique in active structural health monitoring (SHM). E/M impedance method utilizes as its main apparatus an impedance analyzer that reads the in-situ E/M impedance of piezoelectric wafer active sensors (PWAS) attached to the monitored structure. Present-day impedance analyzer equipments (e.g.HP4194) are bulky, heavy and expensive lab...