|
Electrography (other)
Electrography often refers to electrophotography, that is, Kirlian photography. Electrography may also refer to: * Measurement and recording of electrophysiology, electrophysiologic activity for diagnostic purposes ** Electrocardiography (ECG or EKG), electrography of heart electrical activity and rhythm ** Electromyography (EMG), electrography of other muscle action potentials throughout the body ** Electroencephalography (EEG), electrography of brain waves (from outside the skull) *** Electrocorticography or intracranial EEG (iEEG or ECoG), EEG with direct contact to the cerebral cortex ** Electrooculography (EOG), electrography of intraocular potential differences ** Electro-olfactography, Electroolfactography (EOG), electrography of olfaction (smell) ** Electroretinography (ERG), electrography of retinal cell action potentials ** Electronystagmography (ENG), electrography of eye muscle movements ** Electrocochleography (ECOG), electrography of cochlear auditory activity ** E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirlian Photography
Kirlian photography is a collection of photographic techniques used to capture the phenomenon of electrical coronal discharges. It is named after Semyon Kirlian, who, in 1939, accidentally discovered that if an object on a photographic plate is connected to a high-voltage source, an image is produced on the photographic plate.Julie McCarron-Benson in ''Skeptical - a Handbook of Pseudoscience and the Paranormal'', ed Donald Laycock, David Vernon, Colin Groves, Simon Brown, Imagecraft, Canberra, 1989, , p11 The technique has been variously known as "electrography", "electrophotography", "corona discharge photography" (CDP), "bioelectrography", "gas discharge visualization (GDV)", "electrophotonic imaging (EPI)", and, in Russian literature, "Kirlianography". Kirlian photography has been the subject of scientific research, parapsychology research, and art. Paranormal claims have been made about Kirlian photography, but these claims are rejected by the scientific community.Singer, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophysiology
Electrophysiology (from Greek , ''Ä“lektron'', "amber" etymology of "electron"">Electron#Etymology">etymology of "electron" , ''physis'', "nature, origin"; and , '' -logia'') is the branch of physiology that studies the electrical properties of biological cells and tissues. It involves measurements of voltage changes or electric current or manipulations on a wide variety of scales from single ion channel proteins to whole organs like the heart. In neuroscience, it includes measurements of the electrical activity of neurons, and, in particular, action potential activity. Recordings of large-scale electric signals from the nervous system, such as electroencephalography, may also be referred to as electrophysiological recordings. They are useful for electrodiagnosis and monitoring. Definition and scope Classical electrophysiological techniques Principle and mechanisms Electrophysiology is the branch of physiology that pertains broadly to the flow of ions (ion current) in biologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrocardiography
Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the heart using electrodes placed on the skin. These electrodes detect the small electrical changes that are a consequence of cardiac muscle depolarization followed by repolarization during each cardiac cycle (heartbeat). Changes in the normal ECG pattern occur in numerous cardiac abnormalities, including cardiac rhythm disturbances (such as atrial fibrillation and ventricular tachycardia), inadequate coronary artery blood flow (such as myocardial ischemia and myocardial infarction), and electrolyte disturbances (such as hypokalemia and hyperkalemia). Traditionally, "ECG" usually means a 12-lead ECG taken while lying down as discussed below. However, other devices can record the electrical activity of the heart such as a Holter monitor but also s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromyography
Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG is performed using an instrument called an electromyograph to produce a record called an electromyogram. An electromyograph detects the electric potential generated by muscle cells when these cells are electrically or neurologically activated. The signals can be analyzed to detect abnormalities, activation level, or recruitment order, or to analyze the biomechanics of human or animal movement. Needle EMG is an electrodiagnostic medicine technique commonly used by neurologists. Surface EMG is a non-medical procedure used to assess muscle activation by several professionals, including physiotherapists, kinesiologists and biomedical engineers. In Computer Science, EMG is also used as middleware in gesture recognition towards allowing the input of physical action to a computer as a form of human-computer interaction. Clinical uses EMG testing has a variety of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroencephalography
Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex and allocortex. It is typically non-invasive, with the EEG electrodes placed along the scalp (commonly called "scalp EEG") using the International 10-20 system, or variations of it. Electrocorticography, involving surgical placement of electrodes, is sometimes called " intracranial EEG". Clinical interpretation of EEG recordings is most often performed by visual inspection of the tracing or quantitative EEG analysis. Voltage fluctuations measured by the EEG bioamplifier and electrodes allow the evaluation of normal brain activity. As the electrical activity monitored by EEG originates in neurons in the underlying brain tissue, the recordings made by the electrodes on the surface of the scalp vary in accordance with their orientation and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrocorticography
Electrocorticography (ECoG), or intracranial electroencephalography (iEEG), is a type of electrophysiological monitoring that uses electrodes placed directly on the exposed surface of the brain to record electrical activity from the cerebral cortex. In contrast, conventional electroencephalography (EEG) electrodes monitor this activity from outside the skull. ECoG may be performed either in the operating room during surgery (intraoperative ECoG) or outside of surgery (extraoperative ECoG). Because a craniotomy (a surgical incision into the skull) is required to implant the electrode grid, ECoG is an invasive procedure. History ECoG was pioneered in the early 1950s by Wilder Penfield and Herbert Jasper, neurosurgeons at the Montreal Neurological Institute. The two developed ECoG as part of their groundbreakinMontreal procedure a surgical protocol used to treat patients with severe epilepsy. The cortical potentials recorded by ECoG were used to identify epileptogenic zones †... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrooculography
Electrooculography (EOG) is a technique for measuring the corneo-retinal standing potential that exists between the front and the back of the human eye. The resulting signal is called the electrooculogram. Primary applications are in ophthalmological diagnosis and in recording eye movements. Unlike the electroretinogram, the EOG does not measure response to individual visual stimuli. To measure eye movement, pairs of electrodes are typically placed either above and below the eye or to the left and right of the eye. If the eye moves from center position toward one of the two electrodes, this electrode "sees" the positive side of the retina and the opposite electrode "sees" the negative side of the retina. Consequently, a potential difference occurs between the electrodes. Assuming that the resting potential is constant, the recorded potential is a measure of the eye's position. Principle The eye acts as a dipole in which the anterior pole is positive and the posterior pole is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electro-olfactography
Electro-olfactography or electroolfactography (EOG) is a type of electrography (electrophysiologic test) that aids the study of olfaction (the sense of smell). It measures and records the changing electrical potentials of the olfactory epithelium, in a way similar to how other forms of electrography (such as ECG, EEG, and EMG) measure and record other bioelectric activity. Electro-olfactography has been used for decades to advance the basic science of smell, although the advances in molecular biology Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physi ... in recent decades have expanded olfactory science beyond the knowledge that the electrical recordings of electro-olfactography alone could provide. Electro-olfactography is closely related to electroantennography, the electrography ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroretinography
Electroretinography measures the electrical responses of various cell types in the retina, including the photoreceptors ( rods and cones), inner retinal cells ( bipolar and amacrine cells), and the ganglion cells. Electrodes are placed on the surface of the cornea (DTL silver/nylon fiber string or ERG jet) or on the skin beneath the eye (sensor strips) to measure retinal responses. Retinal pigment epithelium (RPE) responses are measured with an EOG test with skin-contact electrodes placed near the canthi. During a recording, the patient's eyes are exposed to standardized stimuli and the resulting signal is displayed showing the time course of the signal's amplitude (voltage). Signals are very small, and typically are measured in microvolts or nanovolts. The ERG is composed of electrical potentials contributed by different cell types within the retina, and the stimulus conditions (flash or pattern stimulus, whether a background light is present, and the colors of the stimulus a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronystagmography
Electronystagmography (ENG) is a diagnostic test to record involuntary movements of the eye caused by a condition known as nystagmus. It can also be used to diagnose the cause of vertigo, dizziness or balance dysfunction by testing the vestibular system. Electronystagmography is used to assess voluntary and involuntary eye movements. It evaluates the cochlear nerve and the oculomotor nerve (CN III). The ENG can be used to determine the origin of various eye and ear disorders. Technique and results Electrodes applied around the eyes record eye movements using the corneo-retinal potential. Some portions of the ENG measure a patient's ability to track a moving stimuli while others observe the presence of nystagmus. The vestibular system monitors the position and movements of the head to stabilize retinal images. This information is integrated with the visual system and spinal afferents in the brain stem to produce the vestibulo-ocular reflex (VOR). ENG provides an objective assess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrocochleography
Electrocochleography (abbreviated ECochG or ECOG) is a technique of recording electrical potentials generated in the inner ear and auditory nerve in response to sound stimulation, using an electrode placed in the ear canal or tympanic membrane. The test is performed by an otologist or audiologist with specialized training, and is used for detection of elevated inner ear pressure (endolymphatic hydrops) or for the testing and monitoring of inner ear and auditory nerve function during surgery. Clinical applications The most common clinical applications of electrocochleography include: * Objective identification and monitoring of Ménière's disease and endolymphatic hydrops (EH) * Intraoperative monitoring of auditory system function during surgery on the brainstem or cerebellum * Enhancement of Wave I of the auditory brainstem response, particularly in patients who are hard of hearing * Diagnosis of auditory neuropathy Cochlear physiology The basilar membrane and the hair cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroantennography
Electroantennography or EAG is a technique for measuring the average output of an insect antenna to its brain for a given odor. It is commonly used in electrophysiology while studying the function of the olfactory pathway in insects. The technique was invented in 1957 by German biologist Dietrich Schneider and shares similarities with electro-olfactography.{{Citation , editor-last=Glatz , editor-first=Richard , year=2015 , title=Molecular Basis of Olfaction. Volume 130 of Progress in Molecular Biology and Translational Science , publisher=Academic Press, page=ix , url=https://books.google.com/books?id=LFOZBQAAQBAJ&pg=PR9 , isbn=978-0128029138 , postscript=. Method Electroantennography is usually performed either by removing an antenna from the animal and inserting two chlorided silver wires for contact onto the two ends and amplifying the voltage between them while applying an odor puff to see a deflection as in the figure, or by leaving the animal intact and inserting a ground w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
