Unipolar systems

Sensitivity may be defined according to any transfer function our interest is on impedance sensitivity. The spatial variation of S is the sensitivity field. At the neutral electrode in a unipolar system, J is low, so the contribution of the tissue there wiU be negligible. In a tube with cross-sectional area A and J = I/A constant, Eq. (6.41) reverts to the well-known R = pL/A. For the unipolar hemisphere on the tissue surface, Eq. (6.3) shows that J is proportional to r. From Eq. (6.41), Z is proportional to J p, and the contribution of a... 

Sensing of intracardiac electrograms. With its broad inter-electrode distance, the unipolar system sees more of the heart in which to detect a spontaneous intracardiac electrical event and thus it was assumed that unipolar was superior to bipolar sensing. In reality, the modem unipolar and bipolar pacing systems show comparable and usually excellent atrial and ventricular electrogram amplitudes and slew rates which usually exceed the standard limits of the sensing circuit by a comfortable margin. 

Use a bipolar pacing system whenever possible, as they are much less likely than unipolar systems to be affected by EMI. 

In a unipolar system, electrical current moves from the pulse generator through the leadwire to the negative pole. From there, it stimulates tiie heart and returns to the pulse generator s metal surface (the positive pole) to complete the circuit. 

An air-gap is required for all unipolar flux drive applieations sueh as this. One method of aehieving this is shown in Equation 3.28a (CGS system (U.S.)). 

Figure 1.14 (a) Basic structure of a neurone. A motor neurone is shown, but the basic structure of all the neurones is the same. Dendrites transfer information from other nerves to the neurone, while the axon transfers information from the neurone to other neurones or tissues. The axon is particularly long in motor neurones (Chapter 14). (b) Structures of unipolar, bipolar and multipolar neurones. Unipolar neurones transfer information from tissues or organs to the brain. Multipolar neurones are the most abundant in the nervous system. 

Unipolar and bipolar depressive disorders in children and adolescents are serious conditions. The pathophysiology of these disorders is poorly understood. The new tools available through neuroimaging techniques will help to unravel the neuroanatomical systems involved in the onset and recurrence of these disorders. There is a need for more developmentally informed predinical research and more studies of the normal development of the neural systems implicated in emotional regulation. 

Choudhary and Horvath constructed a homemade CEC system, which can be operated at up to 90 kV [26]. The system is presented in Fig. 2.4. The 90 kV voltage power supply was composed of a bipolar 30 kV and a unipolar 60 kV power supply. The system allows the application of 90 kV with a cathodic EOF and a voltage drop... 

Lundstrom and Egelrud10 found a unipolar spontaneous cell dissociation in pieces of hypertrophic human plantar stratum corneum incubated in a simple buffer. The cell dissociation occurred only at the surface that had faced outward in vivo. The rate of cell dissociation was increased in the presence of EDTA. It was inhibited by inhibitors of serine proteases, but not by inhibitors of other groups of proteases. Since the tissue had not been heated with exogenous proteases before the experiments, it was concluded that the observed cell dissociation was mediated by an endogenous serine protease. This experimental system has been used as an in vitro model of desquamation. In addition to information about the enzyme(s) involved in the cell dissociation, it has provided information about the nature of the cohesive structures in the stratum corneum. 

Most theories about the origin of mood disorders refer to the subcellular or molecular level, mainly emphasizing an imbalance between different transmitter systems [17] as a possible cause for unipolar depression as well as bipolar disorders. No concrete concepts exist to explain how and in which way such molecular disturbances modify the neural dynamics and lead to an increased mental vulnerability with progressive occurrence of disease episodes. 

Unconfined sedimentation, 65 Unipolar ions, 186-189 Units, 1, 347-350 electrical, 211-212 photometric, 265 for viable aerosols, 320-323 Unpolarized incident light, 282 Upper respiratory system, 7... 

The first water electrolyzers used the tank design and an alkaline electrolyte.20 These electrolyzers can be configured as unipolar (tank) or bipolar (filter press) designs. In the unipolar design (see Figure 1), electrodes, anodes, and cathodes are alternatively suspended in a tank. In this design, each cell is connected in parallel and the entire system operated at 1.9-2.5 Vac. 

Multipolar neurons have many processes and serve principally as motor neurons. Motor neurons, efferent because they conduct impulses away from the central nervous system (the brain and spinal cord) regulate the function of muscles and glands. Afferent neural pathways that send signals to the (CNS) are generally composed of unipolar neurons. Unipolar neurons also serve as sensory neurons— their filamentous dendritic processes exposed and elaborated into or connected to sensory receptor cells. Intemeurons are neurons that connect neurons along a neural pathway. 

Rehman, W.R. Lader, H.J. Messerly, J.W. Unipolarity Powder Coating Systems Including Improved Tribocharging and Corona Guns. US Patent 6,645,300, November 11, 2003. 

The processes responsible for the selection of the appropriate output for a particular mossy fiber-parallel fiber input may function at the level of the synapses of the mossy fibers with granule cells, unipolar brush cells, or Golgi cells and at the level of the parallel fiber-Purkinje cell synapse. Several systems may be involved in this selection process. Nitric oxide, that is synthetized by subsets of granule cells (Schilling et ah, 1994 Hawkes and Turner, 1994) and in stellate and basket cells (Bredt et ah, 1990) (Section... 

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