Electrical stimulation, electrode

Other biomedical applications of polymers include sustained and controlled drug delivery formulations for implantation, transdermal and trans-cornealuses, intrauterine devices, etc. (6, 7). Major developments have been reported recently on the use of biomaterials for skin replacement (8), reconstruction of vocal cords (9), ophthalmic applications such as therapeutic contact lenses, artificial corneas, intraocular lenses, and vitreous implants (10), craniofacial, maxillofacial, and related replacements in reconstructive surgery (I), and neurostimulating and other electrical-stimulating electrodes (I). Orthopedic applications include artificial tendons (II), prostheses, long bone repair, and articular cartilage replacement (I). Finally, dental materials and implants (12,13) are also often considered as biomaterials. 

Axelgaard, J., Grussing, T., 1988. Electrical Stimulation Electrode, US Patent 4722354. 

Postictal inhibition has been demonstrated after bilateral ECS through ear-clip electrodes as well as after direct electrical stimulation of specific brain areas [for review, see Krauss and Fisher 1993]. TMS might exert anticonvulsive effects by stimulation of brain areas that are responsible for seizure inhibition. Alternatively, TMS might inhibit by direct inhibition of neural excitability in brain regions that are responsible for seizure initiation and spreading. Indeed, the TMS-induced decrease in postsynaptic action potentials hints that TMS might generate direct inhibitory mechanisms on neural excitability. 

Electrical Stimulation Devices. Bioelectrodes that transmit electrical signals into the body are generally known as electrical stimulation devices, examples of which include cardiac pacemakers, transcutaneous electronic nerve stimulators (TENs) for pain suppression, and neural prostheses such as auditory stimulation systems for the deaf and phrenic nerve stimulators for artificial respiratory control. In these, and other similar devices, electrodes transmit current to appropriate areas of the body for direct control of, or indirect influence over, target cells. 

Two areas of signal processing research in cochlear implants are coding strategies for multi-electrode excitation and the development of noise-suppression systems. One of the problems in cochlear implants is that there is a large spread of the electrical stimulation within the cochlea. Because of this, simultaneous electrical pulses at... 

The electrodes are manufactured from single or multistrand stainless steel wires (Fig. 4). The interconnection cables are coated with silicone. Besides a simple manufacturing technology, the electrodes demonstrate good electrical and mechanical properties [35]. In long term implantations the nerve damage due to continuous electrical stimulation was below 4.8%. Explantation of the electrodes is easy to perform [36]. 

A heart muscle cell (rabbit cardiomyocyte) was aligned in a narrow PDMS-glass microchannel. The muscle cell was electrically stimulated via a pair of Au electrodes ( 60 pm apart) in contact with the cell. Intracellular Ca measurement showed that the cell remained contracted for 60 min within the restricted space. An electric field strength of 20 V/cm translates to 0.12 V, which is lower than the electrolysis threshold of 0.8 V [834]. 

While in the mentioned work on PABA on a charged silver electrode also the adsorption degree of the molecules was controlled by surface charge, Lahann et al. showed a concept in which molecules immobilized as a low-density self-assembled monolayer on a gold surface were electrically stimulated to undergo conformational transitions between a hydrophilic and a hydrophobic state (Lahann et al., 2003). Such a surface wetting switch may then be used to immobilize, for example, enzymes, as was discussed in the previous section. This is an example of switching both the orientation and the activity of adsorbed molecules. 

The effects of DBS on the cortex-basal-ganglia-thalamus-cortex motor loop appear to be more complex than initially believed. The paradox of DBS is that electrical stimulation of brain tissue (which presumably induces brain activation), has a similar effect as that of a surgical lesion of that same structure (which effectively destroys brain tissue). These two realities are hard to reconcile. As indicated by [64] the ultimate elucidation of this paradox depends on the nature of the complex and interactive neural connections in the brain that communicate through electrical and chemical processes. There is an emerging view that DBS has both excitatory and inhibitory effects on how brain circuits communicate with one another depending on the distance from the electrode, the cell structures activated and the direction of the activation (ortho- versus anti-dromic). The effect appears to modulate the activity of a network as well as neural firing patterns. Long term effects on neurotransmitters and receptor systems cannot be excluded [64]. 

Acetylcholineesterase and choline oxidase A glassy C electrode surface was modified with osmium poly (vinyl-pyridine) redox polymer containing horseradish peroxidase (Os-gel-HRP) and then coated with a co-immobilized layer of AChE and ChO. A 22 pL pre-reactor, in which ChO and catalase were immobilized on beads in series, was used to remove choline. The variation in extracellular concentration of ACh released from rat hippocampal tissue culture by electrical stimulation was observed continuously with the online biosensor combined with a microcapillary sampling probe. Measurement of ACh and Ch was carried out by using a split disc C film dual electrode. 

The preparation of the isolated, innervated urinary bladder of the rat was reported by Hukovic et al. (1965). Electrical stimulation was performed by a bipolar electrode from the nerves running close to the ureter. 

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