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Phosphenes
A phosphene is the phenomenon of seeing light without light entering the eye. The word ''phosphene'' comes from the Greek words ''phos'' (light) and ''phainein'' (to show). Phosphenes that are induced by movement or sound may be associated with optic neuritis. Phosphenes can be induced by mechanical, electrical, or magnetic stimulation of the retina or visual cortex, or by random firing of cells in the visual system. Phosphenes have also been reported by meditators (called '' nimitta''), people who endure long periods without visual stimulation (the prisoner's cinema), or those who ingest psychedelic drugs. Causes Mechanical stimulation The most common phosphenes are pressure phosphenes, caused by rubbing or applying pressure on or near the closed eyes. They have been known since antiquity, and described by the Greeks. The pressure mechanically stimulates the cells of the retina. Experiences include a darkening of the visual field that moves against the rubbing, a diffus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prisoner's Cinema
Prisoner's cinema is the phenomenon of a "light show" of various colors that appear out of the darkness. The light has a form, but those that have seen it find it difficult to describe. Sometimes, the cinema lights resolve into human or other figures. The phenomenon is reported by prisoners confined to dark cells and by others kept in darkness, voluntarily or not, for long periods of time. It has also been reported by truck drivers, pilots, and practitioners of intense meditation. Astronauts and other individuals who have been exposed to certain types of radiation have reported witnessing similar phenomena. Scientists believe that the cinema is a result of phosphenes combined with the psychological effects of prolonged lack of exposure to light, and others have noted a connection between the form the lights take and neolithic cave paintings. Popular culture The pilot episode for the original ''Twilight Zone'' series, "Where Is Everybody?," depicts elaborate, fully realistic hallu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain–computer Interface
A brain–computer interface (BCI), sometimes called a brain–machine interface (BMI), is a direct communication link between the brain's electrical activity and an external device, most commonly a computer or robotic limb. BCIs are often directed at researching, Brain mapping, mapping, assisting, Augmented cognition, augmenting, or repairing human Cognitive skill, cognitive or Sensory-motor coupling, sensory-motor functions. They are often conceptualized as a human–machine interface that skips the intermediary of moving body parts (e.g. hands or feet). BCI implementations range from non-invasive (EEG, Magnetoencephalography, MEG, MRI) and partially invasive (ECoG and endovascular) to invasive (microelectrode array), based on how physically close electrodes are to brain tissue. Research on BCIs began in the 1970s by Jacques Vidal at the University of California, Los Angeles (UCLA) under a grant from the National Science Foundation, followed by a contract from the Defense Adva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Pressure
Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" refers to the pressure in a brachial artery, where it is most commonly measured. Blood pressure is usually expressed in terms of the systolic pressure (maximum pressure during one Cardiac cycle, heartbeat) over diastolic pressure (minimum pressure between two heartbeats) in the cardiac cycle. It is measured in Millimetre of mercury, millimetres of mercury (mmHg) above the surrounding atmospheric pressure, or in Pascal (unit), kilopascals (kPa). The difference between the systolic and diastolic pressures is known as pulse pressure, while the average pressure during a cardiac cycle is known as mean arterial pressure. Blood pressure is one of the vital signs—together with respiratory rate, heart rate, Oxygen saturation (me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braille
Braille ( , ) is a Tactile alphabet, tactile writing system used by blindness, blind or visually impaired people. It can be read either on embossed paper or by using refreshable braille displays that connect to computers and smartphone devices. Braille can be written using a slate and stylus, a braille writer, an electronic braille notetaker or with the use of a computer connected to a braille embosser. For blind readers, braille is an independent writing system, rather than a code of printed orthography. Braille is named after its creator, Louis Braille, a Frenchman who lost his sight as a result of a childhood accident. In 1824, at the age of fifteen, he developed the braille code based on the French alphabet as an improvement on night writing. He published his system, which subsequently included musical notation, in 1829. The second revision, published in 1837, was the first Binary numeral system, binary form of writing developed in the modern era. Braille characters are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Prosthesis
A visual prosthesis, often referred to as a bionic eye, is a visual device intended to restore functional vision in those with partial or total blindness. Many devices have been developed, usually modeled on the cochlear implant or bionic ear devices, a type of neural prosthesis in use since the mid-1980s. The idea of using electrical current (e.g., electrically stimulating the retina or the visual cortex) to provide sight dates back to the 18th century, discussed by Benjamin Franklin, Tiberius Cavallo, and Charles LeRoy. Biological considerations The ability to give sight to a blind person via a bionic eye depends on the circumstances surrounding the loss of sight. For retinal prostheses, which are the most prevalent visual prosthetic under development (due to ease of access to the retina among other considerations), patients with vision loss due to degeneration of photoreceptors (retinitis pigmentosa, choroideremia, geographic atrophy macular degeneration) are the best c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity
Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of either a positive or negative electric charge produces an electric field. The motion of electric charges is an electric current and produces a magnetic field. In most applications, Coulomb's law determines the force acting on an electric charge. Electric potential is the Work (physics), work done to move an electric charge from one point to another within an electric field, typically measured in volts. Electricity plays a central role in many modern technologies, serving in electric power where electric current is used to energise equipment, and in electronics dealing w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blindness
Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception. In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficulties with normal daily tasks, including reading and walking. The terms ''low vision'' and ''blindness'' are often used for levels of impairment which are difficult or impossible to correct and significantly impact daily life. In addition to the various permanent conditions, fleeting temporary vision impairment, amaurosis fugax, may occur, and may indicate serious medical problems. The most common causes of visual impairment globally are uncorrected refractive errors (43%), cataracts (33%), and glaucoma (2%). Refractive errors include near-sightedness, far-sightedness, presbyopia, and astigmatism (eye), astigmatism. Cataracts are the most common cause of blindness. Other disorders that may cause visual problems include age-related macular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or a gas). In electrochemical cells, electrodes are essential parts that can consist of a variety of materials (chemicals) depending on the type of cell. An electrode may be called either a cathode or anode according to the direction of the electric current, unrelated to the potential difference between electrodes. Michael Faraday coined the term "" in 1833; the word recalls the Greek ἤλεκτρον (, "amber") and ὁδός (, "path, way"). The electrophore, invented by Johan Wilcke in 1762, was an early version of an electrode used to study static electricity. Anode and cathode in electrochemical cells Electrodes are an essential part of any battery. The first electrochemical battery was devised by Alessandro Volta and was aptly named the Voltaic cell. This battery consisted of a stack of copper and zinc electrodes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otfrid Foerster
Otfrid Foerster (; 9 November 1873 – 15 June 1941) was a German neurologist and neurosurgeon, who made innovative contributions to neurology and neurosurgery, such as rhizotomy for the treatment of spasticity, anterolateral cordotomy for pain, the hyperventilation test for epilepsy, Foerster's syndrome, the first electrocorticogram of a brain tumor, and the first surgeries for epilepsy. He is also known as the first to describe the dermatomic area, dermatomes (an area of skin that is supplied by a single pair of dorsal nerve roots), and he helped map the motor cortex of the cerebrum. Life Foerster was born in Breslau (now Wrocław) to Richard Foerster (classical scholar), Richard Foerster, and studied in the Maria Magdalenen Gymnasium, graduating 1892. From 1892 to 1896 he studied medicine in Freiburg, Kiel and Breslau, obtaining his licensure by state examination in 1897 and his doctorate in the same year. Upon completion of the doctoral studies, he spent two years studying a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurology
Neurology (from , "string, nerve" and the suffix wikt:-logia, -logia, "study of") is the branch of specialty (medicine) , medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the Human brain, brain, the spinal cord and the peripheral nervous system , peripheral nerves. Neurological practice relies heavily on the field of neuroscience, the scientific study of the nervous system, using various techniques of neurotherapy. IEEE Brain (2019). "Neurotherapy: Treating Disorders by Retraining the Brain". ''The Future Neural Therapeutics White Paper''. Retrieved 23.01.2025 from: https://brain.ieee.org/topics/neurotherapy-treating-disorders-by-retraining-the-brain/#:~:text=Neurotherapy%20trains%20a%20patient's%20brain,wave%20activity%20through%20positive%20reinforcement International Neuromodulation Society, Retrieved 23 January 2025 from: https://www.neuromodulation.com/ Val Danilov I (2023). "The O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Frigate Méduse (1810)
''Méduse'' was a 40-gun frigate of the French Navy, launched in 1810. She took part in the Napoleonic Wars during the late stages of the Mauritius campaign of 1809–1811 and in raids in the Caribbean. In 1816, following the Bourbon Restoration, ''Méduse'' was armed en flûte to ferry French officials to the port of Saint-Louis, in Senegal, to formally re-establish French occupation of the colony under the terms of the First Peace of Paris. Through inept navigation by her captain, Hugues Duroy de Chaumareys, who had been given command after the Bourbon Restoration for political reasons and even though he had hardly sailed in 20 years, ''Méduse'' struck the Bank of Arguin off the coast of present-day Mauritania and became a total loss. Most of the 400 passengers on board evacuated, with 146 men and 1 woman forced to take refuge on an improvised raft towed by the frigate's launches. The towing proved impractical, however, and the boats soon abandoned the raft and its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
