Fet Meaning

Fet Meaning

(F ield E ffect T ransistor) One of two major categories of transistor; the other is bipolar. FETs use a gate element that, when charged, creates an electromagnetic field that changes the conductivity of a silicon channel and turns the transistor on or off. FET is an acronym for federal excise tax. It refers to the tax imposed by the federal government on tires used on the road with a maximum load capacity greater then 3500 pounds. Generally this applies to medium truck tires and heavy duty trailer tires. Do I pay FET on farm and forestry tires?
FET, Field Effect Transistor, Tutorial Includes:
FET basicsFET specsJFETMOSFETDual gate MOSFETPower MOSFETMESFET / GaAs FETHEMT & PHEMTFinFET technology
The field effect transistor, FET is a key electronic component using within many areas of the electronics industry.
 The FET used in many circuits constructed from discrete electronic components in areas from RF technology to power control and electronic switching to general amplification.
However the major use for the field effect transistor, FET is within integrated circuits. In this application FET circuits consume much lower levels of power than ICs using bipolar transistor technology. This enables the very large scale integrated circuits to operate. If bipolar technology was used the power consumption would be orders of magnitude greater and the power generated far too large to dissipate from the integrated circuit.
Apart from being used in integrated circuits, discrete versions of field effect transistors are available both as leaded electronic components and also as surface mount devices.
Field Effect Transistor, FET historyBefore the first FETs were introduced into the electronic components market, the concept had been known for a number of years. There had been many difficulties in realising this type of device and making it work.
Some of the early concepts for the field effect transistor were outlined in a paper by Lilienfield in 1926, and in another paper by Heil in 1935.
 The next foundations were set in place during the 1940s at Bell Laboratories where the semiconductor research group was set up. This group investigated a number of areas pertaining to semiconductors and semiconductor technology, one of which was a device that would modulate the current flowing in a semiconductor channel buy placing an electric field close to it.
During these early experiments, the researchers were unable to make the idea work, turning their ideas to another idea and ultimately inventing another form of semiconductor electronics component: the bipolar transistor.
 After this much of the semiconductor research was focussed on improving the bipolar transistor, and the idea for a field effect transistor was not fully investigated for some while. Now FETs are very widely used, providing the main active element in many integrated circuits. Without these electronic components electronics technology would be very different to what it is now.
Note on Field Effect Transistor Invention & History:The field effect transistor took many years to develop. The first ideas for the concept appeared in 1928, but it was not until the 1960s that they started to become widely available. 
Read more about the  Field Effect Transistor Invention & History
 Field Effect Transistor – the basicsThe concept of the field effect transistor is based around the concept that charge on a nearby object can attract charges within a semiconductor channel. It essentially operates using an electric field effect - hence the name.
The FET consists of a semiconductor channel with electrodes at either end referred to as the drain and the source.
A control electrode called the gate is placed in very close proximity to the channel so that its electric charge is able to affect the channel. 
In this way, the gate of the FET controls the flow of carriers (electrons or holes) flowing from the source to drain. It does this by controlling the size and shape of the conductive channel.
 The semiconductor channel where the current flow occurs may be either P-type or N-type. This gives rise to two types or categories of FET known as P-Channel and N-Channel FETs.
In addition to this, there are two further categories. Increasing the voltage on the gate can either deplete or enhance the number of charge carriers available in the channel. As a result there are enhancement mode FET and depletion mode FETs.
 As it is only the electric field that controls the current flowing in the channel, the device is said to be voltage operated and it has a high input impedance, usually many megohms. This can be a distinct advantage over the bipolar transistor that is current operated and has a much lower input impedance.
FET circuitsField effect transistors are widely used in all forms of circuit from those used in circuits with discrete electronic components, to those employed in integrated circuits.
Note on Field Effect Transistor Circuit Design:The field transistor transistors can be used in many types of circuits although the three basic configurations are common source, common drain (source follower) and common gate. The circuit design itself if fairly straightforward and can be undertaken quite easily.
Read more about  Field Effect Transistor Circuit Design
As the field effect transistor is a voltage operated device rather than a current device like the bipolar transistor, this means that some aspects of the circuit are very different: the bias arrangements in particular. However electronic circuit design with FETs is relatively easy - it is just a bit different to that using bipolar transistors.
Using FETs, circuits like voltage amplifiers, buffers or current followers, oscillators, filters and many more can all be designed, and the circuits are very similar to those for bipolar transistors and even thermionic valves / vacuum tubes. Interestingly valves / tubes are also voltage operated devices, and therefore their circuits are very similar, even in terms of the bias arrangements.
Field Effect Transistor typesThere are many ways to define the different types of FET that are available. The different types mean that during the electronic circuit design, there is a choice of the right electronic component for the circuit. By selecting the right device it is possible to obtain the best performance for the given circuit.
FETs may be categorised in a number of ways, but some of the major types of FET can be covered in the tree diagram below.
There are many different types of FET on the market for which there are various names. Some of the major categories are delayed below.
Junction FET, JFET: The junction FET, or JFET uses a reverse biased diode junction to provide the gate connection. The structure consists of a semiconductor channel which can be either N-type or P-type. A semiconductor diode is then fabricated onto the channel in such a way that the voltage on the diode affects the FET channel. 
 In operation this is reverse biased and this means that it is effectively isolated from the channel - only the diode reverse current can flow between the two. The JFET is the most basic type of FET, and the one that was first developed. However it still provides excellent service in many areas of electronics. 
Read more about  . . . . junction field effect transistor, JFET.

Insulated Gate FET / Metal Oxide Silicon FET MOSFET: The MOSFET uses an insulated layer between the gate and the channel. Typically this is formed from a layer of oxide of the semiconductor. 
The name IGFET refers to any type of FET that has an insulated gate. The most common form of IGFET is the silicon MOSFET - Metal Oxide Silicon FET. Here, the gate is made of a layer of metal set down on the silicon oxide which in turn is on the silicon channel. MOSFETs are widely used in many areas of electronics and particularly within integrated circuits. 
The key factor of the IGFET / MOSFET is the exceedingly gate high impedance these FETs are able to provide. That said, there will be an associated capacitance and this will reduce the input impedance as the frequency rises.
Read more about  . . . . Metal Oxide Silicon FET, MOSFET.

Dual Gate MOSFET: This is a specialised form of MOSFET that has two gates in series along the channel. This enables some considerable performance improvements to be made, especially at RF, when compared to single gate devices.
The second gate of the MOSFET provides additional isolation between the input and output, and in addition to this it can be used in applications like mixing / multiplication.

MESFET: The MEtal Silicon FET is normally fabricated using Gallium Arsenide and is often referred to as a GaAs FET. Often GaAsFETs are used for RF applications where they can provide high gain low noise performance. One of the drawbacks of GaAsFET technology results from the very small gate structure, and this makes its very sensitive to damage from static, ESD. Great care must be taken when handling these devices. 
Read more about  . . . . MESFET / GaAsFET.

HEMT / PHEMT: The High Electron Mobility Transistor and Pseudomorphic High Electron Mobility Transistor are developments of the basic FET concept, but developed to enable very high frequency operation. Although expensive, they enable very high frequencies and high levels of performance to be achieved.

FinFET: FinFET technology is now being used within integrated circuits to enable higher levels of integration to be achieved by allowing smaller feature sizes. As higher density levels are needed and it becomes increasingly difficult to realise ever smaller feature sizes, FinFET technology is being used more widely.
Read more about  . . . . FinFET.

VMOS: VMOS standard for vertical MOS. It is a type of FET that uses a vertical current flow to improve the switching and current carrying performance. VMOS FETs are widely used for power applications. 
Although there are some other types of field effect transistor that may be seen in the literature, often these types are trade names for a particular technology and they are variants of some of the FET types listed above.
FET specificationsApart from selecting a particular type of field effect transistor for any given circuit, it is also necessary to understand the different specifications. In this way it is possible to ensure that the FET will operate to the required performance parameters.
FET specifications include everything from the maximum voltages and currents permissible to the capacitance levels and the transconductance. These all play a part in determining whether any particular FET is suitable for a given circuit or application.
Read more about  . . . . FET specifications and datasheet parameters.

Field affect transistor technology can be used in a number of areas where bipolar transistors are not as suitable: each of these semiconductor devices has its own advantages and disadvantages, and can be used to great effect in many circuits. The field effect transistor has a very high input impedance and is a voltage driven device and this opens it up to being used in many areas.
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Also found in: Dictionary, Thesaurus, Legal, Acronyms, Encyclopedia, Wikipedia. FETFarlex Partner Medical Dictionary © Farlex 2012
FET Medical Dictionary for the Health Professions and Nursing © Farlex 2012
field effect transistor ,

FETA transistor that uses electricity to permit or to block conduction through a semiconductor channel. 
technique (tek-nek') [Gr. technikos, pert. to a craft] 1. A systematic procedure or method by which an involved or scientific task is completed.
2. The skill in performing details of a procedure or operation.
3. In radiology, the various technical factors that must be determined to produce a diagnostic radiograph, e.g., kilovoltage, milliamperage, time of exposure, and source-image receptor distance.
Alexander technique See: Alexander techniqueaseptic techniqueA method used in surgery to prevent contamination of the wound and operative site. All instruments used are sterilized, and physicians and nurses wear caps, masks, shoe coverings, sterile gowns, and gloves. The technique is adapted at the bedside, e.g., during procedures, and in emergency and treatment rooms. 
bisecting angle techniqueA dental radiographic technique that requires placement of the film as close as possible to the teeth, causing the film to rest against the crown; visualization of a bisector, which bisects the angle formed by the long axis of the teeth and the film; and positioning of the central ray perpendicular to the bisector. The image produced is distorted in a buccolingual direction Synonym: short-cone technique See: Cieszynski's rule
Buteyko breathing technique See: Buteyko breathing techniquecompensatory technique1. The use of modified procedures or assistive devices to enable the successful performance of tasks by persons with a disability.
2. Any altered pattern of movement in patients with limited mobility in which synergistic muscles are recruited and used to perform movements that would usually be performed by other muscle groups.
crossed finger techniqueA hazardous method of opening an unconscious patient's mouth by placing the thumb and index finger of a gloved hand on opposite rows of teeth and spreading the jaw open.
depilatory techniqueAny of several temporary procedures to remove hair from the body, including shaving, plucking, chemicals, or hot wax. If chemical depilation is used, care must be taken to avoid skin irritation. The wax treatment involves application of molten wax, which is allowed to cool; then, when the wax is pulled away, the hair comes with it. Permanent depilation is accomplished by electrolysis of each hair follicle. This time-consuming process is done by an electrologist trained in the technique. 
 See: electrolysis; hirsutismenzyme-multiplied immunoassay technique Abbreviation: EMIT
An enzyme immunoassay based on a mixture of analyte and enzyme substrate such that no immobile phase is necessary.
 See: enzyme immunoassay; cloned enzyme donor immunoassayforced expiration techniqueA type of cough that facilitates clearance of bronchial secretions while reducing the risk of bronchiolar collapse. One or two expirations are forced from average to low lung volume with an open glottis. A period of diaphragmatic breathing and relaxation follows. 
forced expiratory technique Abbreviation: FET
The use of sudden exhalations to clear the airways of secretions.
immunomagnetic techniqueThe use of magnetic microspheres to sort, isolate, or identify cells with specific antigenic markers.
long-cone techniqueParalleling technique.minimal leak technique Abbreviation: MLT
A method of determining the appropriate cuff inflation volume on endotracheal tubes (ETT). The ETT cuff is inflated until no respiratory sounds are heard. The cuff is then deflated slightly until sounds are heard. Excessive cuff inflation volume may lead to necrosis of the trachea, and excessive leaking may render oxygenation and ventilation ineffective or allow aspiration of large particles from the oral cavity. 
Mohs chemosurgery technique See: Mohs chemosurgery techniquePapillon techniqueA radiation therapy for rectal cancer in which the radiation source is placed directly into the distal bowel, in contact with the tumor.
paralleling techniqueA dental radiographic technique that requires placement of the film parallel to the teeth and positioning of the central ray perpendicular to the teeth. The orientation of the film, teeth, and central ray produces a radiograph with minimal geometric distortion. Synonym: long-cone technique; right-angle technique
preclinical techniqueIn dentistry, the use of manikins, mechanical articulator, artificial or extracted teeth, and the dental instruments and materials to study and master the techniques of clinical dentistry.
projective techniqueAny of several forms of psychological assessment or evaluation. The subject's comments about the results or products of ambiguous activities and tasks that encourage self-expression are evaluated and interpreted to determine indications of his unconscious needs, thoughts, or concerns. 
push-bang techniqueThe elimination of a kidney stone from the proximal ureter by flushing it distally and then fragmenting it with lithotripsy.
right-angle techniqueParalleling technique.Seldinger technique See: Seldinger techniqueshort-cone techniqueBisecting angle technique.sighted guide techniqueA means of assisting a blind person to navigate unfamiliar situations. A sighted person offers assistance and, if it is accepted, taps the blind person on the hand and offers an arm for support. The sighted person then walks just ahead of and to the side of the blind person to help avoid potential hazards. 
forced expiratory technique Abbreviation: FET
The use of sudden exhalations to clear the airways of secretions.
time (tim) The interval between beginning and ending; measured duration.
activated partial thromboplastin time Abbreviation: APTT
A laboratory test to measure the intrinsic pathway of coagulation. In health, the APTT is about 16 to 40 sec, depending on the laboratory methods used. Prolonged PTT may indicate cirrhosis of the liver, disseminated intravascular coagulation, blood clotting factor deficiencies (VIII, IX, X), decreased levels of fibrinogen in the blood, von Willebrand's disease, or the presence of a lupus anticoagulant. 
arise timeIn sleep medicine, the time when a person gets out of bed after sleeping as opposed to the time a person becomes alert and awake after sleep.
association timeFets Luck Meaning

See: association testbackup timeIn radiography, the time setting selected before an automated exposure, usually 150% of the anticipated total exposure time for projection.

FETA transistor that uses electricity to permit or to block conduction through a semiconductor channel. 
technique (tek-nek') [Gr. technikos, pert. to a craft] 1. A systematic procedure or method by which an involved or scientific task is completed.
2. The skill in performing details of a procedure or operation.
3. In radiology, the various technical factors that must be determined to produce a diagnostic radiograph, e.g., kilovoltage, milliamperage, time of exposure, and source-image receptor distance.
Alexander technique See: Alexander techniqueaseptic techniqueA method used in surgery to prevent contamination of the wound and operative site. All instruments used are sterilized, and physicians and nurses wear caps, masks, shoe coverings, sterile gowns, and gloves. The technique is adapted at the bedside, e.g., during procedures, and in emergency and treatment rooms. 
bisecting angle techniqueA dental radiographic technique that requires placement of the film as close as possible to the teeth, causing the film to rest against the crown; visualization of a bisector, which bisects the angle formed by the long axis of the teeth and the film; and positioning of the central ray perpendicular to the bisector. The image produced is distorted in a buccolingual direction Synonym: short-cone technique See: Cieszynski's rule
Buteyko breathing technique See: Buteyko breathing techniquecompensatory technique1. The use of modified procedures or assistive devices to enable the successful performance of tasks by persons with a disability.
2. Any altered pattern of movement in patients with limited mobility in which synergistic muscles are recruited and used to perform movements that would usually be performed by other muscle groups.
crossed finger techniqueA hazardous method of opening an unconscious patient's mouth by placing the thumb and index finger of a gloved hand on opposite rows of teeth and spreading the jaw open.
depilatory techniqueAny of several temporary procedures to remove hair from the body, including shaving, plucking, chemicals, or hot wax. If chemical depilation is used, care must be taken to avoid skin irritation. The wax treatment involves application of molten wax, which is allowed to cool; then, when the wax is pulled away, the hair comes with it. Permanent depilation is accomplished by electrolysis of each hair follicle. This time-consuming process is done by an electrologist trained in the technique. 
 See: electrolysis; hirsutismenzyme-multiplied immunoassay technique Abbreviation: EMIT
An enzyme immunoassay based on a mixture of analyte and enzyme substrate such that no immobile phase is necessary.
 See: enzyme immunoassay; cloned enzyme donor immunoassayforced expiration techniqueA type of cough that facilitates clearance of bronchial secretions while reducing the risk of bronchiolar collapse. One or two expirations are forced from average to low lung volume with an open glottis. A period of diaphragmatic breathing and relaxation follows. 
forced expiratory technique Abbreviation: FET
The use of sudden exhalations to clear the airways of secretions.
immunomagnetic techniqueThe use of magnetic microspheres to sort, isolate, or identify cells with specific antigenic markers.
long-cone techniqueParalleling technique.minimal leak technique Abbreviation: MLT
A method of determining the appropriate cuff inflation volume on endotracheal tubes (ETT). The ETT cuff is inflated until no respiratory sounds are heard. The cuff is then deflated slightly until sounds are heard. Excessive cuff inflation volume may lead to necrosis of the trachea, and excessive leaking may render oxygenation and ventilation ineffective or allow aspiration of large particles from the oral cavity. 
Mohs chemosurgery technique See: Mohs chemosurgery techniquePapillon techniqueA radiation therapy for rectal cancer in which the radiation source is placed directly into the distal bowel, in contact with the tumor.
paralleling techniqueA dental radiographic technique that requires placement of the film parallel to the teeth and positioning of the central ray perpendicular to the teeth. The orientation of the film, teeth, and central ray produces a radiograph with minimal geometric distortion. Synonym: long-cone technique; right-angle technique
preclinical techniqueIn dentistry, the use of manikins, mechanical articulator, artificial or extracted teeth, and the dental instruments and materials to study and master the techniques of clinical dentistry.
projective techniqueAny of several forms of psychological assessment or evaluation. The subject's comments about the results or products of ambiguous activities and tasks that encourage self-expression are evaluated and interpreted to determine indications of his unconscious needs, thoughts, or concerns. 
push-bang techniqueThe elimination of a kidney stone from the proximal ureter by flushing it distally and then fragmenting it with lithotripsy.
right-angle techniqueParalleling technique.Seldinger technique See: Seldinger techniqueshort-cone techniqueBisecting angle technique.sighted guide techniqueA means of assisting a blind person to navigate unfamiliar situations. A sighted person offers assistance and, if it is accepted, taps the blind person on the hand and offers an arm for support. The sighted person then walks just ahead of and to the side of the blind person to help avoid potential hazards. 
forced expiratory technique Abbreviation: FET
The use of sudden exhalations to clear the airways of secretions.
time (tim) The interval between beginning and ending; measured duration.
activated partial thromboplastin time Abbreviation: APTT
A laboratory test to measure the intrinsic pathway of coagulation. In health, the APTT is about 16 to 40 sec, depending on the laboratory methods used. Prolonged PTT may indicate cirrhosis of the liver, disseminated intravascular coagulation, blood clotting factor deficiencies (VIII, IX, X), decreased levels of fibrinogen in the blood, von Willebrand's disease, or the presence of a lupus anticoagulant. 
arise timeIn sleep medicine, the time when a person gets out of bed after sleeping as opposed to the time a person becomes alert and awake after sleep.
association timeFets Luck Meaning See: association testbackup timeIn radiography, the time setting selected before an automated exposure, usually 150% of the anticipated total exposure time for projection.
bleeding timeThe time required for blood to stop flowing from a small wound or pinprick. It is assessed using one of several techniques. Depending on the method used, the time may vary from 1 to 3 min (Duke method) or from 1 to 9 min (Ivy method). The Duke method consists of timing the cessation of bleeding after the earlobe has received a standardized puncture. The Ivy method is done in a similar manner following puncture of the skin of the forearm. The validity of this test to predict clinically significant bleeding has been questioned. 
bowel transit timeThe length of time it takes for food (or a marker dye) to pass through the gastrointestinal tract, from ingestion to defecation. It is shorter in conditions such as malabsorption and more prolonged in constipation. 
circulation timeThe time required for a drop of blood to make the complete circuit of both the systemic and pulmonary systems. Circulation time is determined by injecting a substance into a vein and timing its reappearance in arteries at the injection point. The blood with the contained substance must pass through veins to the heart and through the right atrium and ventricle, through the pulmonary circuit to the lungs, and back through the left atrium and ventricle, and then out through the aorta and arteries to the place of detection. Dyes such as fluorescein and methylene blue and substances such as potassium ferrocyanide and histamine have been used as tracers. Average circulation time is about 1 min. Circulation time is reduced in anemia and hyperthyroidism and is increased in hypertension, myxedema, and cardiac failure. Circulation time may also be measured by injecting into a vein a substance that can be tasted when it is transported to the tongue. The normal circulation time from an arm vein to the tongue is 10 to 16 sec. In the aorta, the blood flows at a speed of approx. 30 cm/sec.
clot retraction timeThe time required following withdrawal of blood for a clot to completely contract and express the serum entrapped within the fibrin net. The normal time is about 1 hr. Clot retraction depends on the number of platelets in the specimen. 
coagulation timeThe time required for a small amount of phlebotomized blood to clot. This can be determined by collecting blood in a small test tube and noting elapsed time from the moment blood is shed to the time it coagulates. 
cold ischemia time Abbreviation: CIT
The time that an organ surgically removed for transplantation remains in a chilled perfusion solution before engraftment.
cycle timeThe period between regular events, e.g., inflations of an automated blood pressure monitor.
doubling timeThe length of time needed for a malignant tumor cell population to double in size.
door-to-balloon timeThe delay between the arrival at a hospital of a patient with an acute myocardial infarction and the opening of the patient's obstructed vessel by percutaneous coronary intervention. The delay should be 90 min or less for optimal outcomes. 
dwell timeThe length of time a therapeutic substance will be retained in the body.
euglobulin lysis timeA test that determines how rapidly blood clots dissolve. It is used to identify diseases such as disseminated intravascular coagulation, and to monitor the effect of thrombolytic drugs, such as streptokinase and the recombinant enzyme tissue plasminogen activator. 
What Does Fet Stand Forforced expiratory time Abbreviation: FET
The time required to forcibly exhale a specified volume of air from the lung.
gestation time See: pregnancy for tableintestinal transit timeThe speed with which consumed food passes through the gut. It is slowed by anticholinergic agents (such as tricyclic antidepressants) and by neuropathic diseases of the stomach or intestines, e.g., diabetes mellitus. Many agents increase intestinal transit, including erythromycin and nonabsorbable laxatives. 
into-bed timeIn sleep medicine, the time when a person lies down for his or her major sleep time of the day as opposed to other periods of sleep.
kaolin cephalin time Abbreviation: KCT, KCCT
A laboratory test to measure the health of the intrinsic pathway of coagulation (the function of clotting factors VII, IX, XI, and XII). When a prolonged kaolin cephalin clotting time does not normalize after the addition of normal plasma, a lupus anticoagulant is present in the blood. 
longitudinal relaxation timeT1 time.lost timeIn occupational health, the number of hours, days, or weeks that an employee does not appear for work, as a result of illness, injury, absenteeism, workers' compensation, or unpaid leave.
median lethal timeThe time required for half of a population to die after exposure to ionizing radiation.
partial thromboplastin timeThe time needed for plasma to clot after the addition of partial thromboplastin. It is used to test for defects of the clotting system. 
prothrombin time Abbreviation: PT
The time it takes for clotting to occur after thromboplastin and calcium are added to decalcified plasma. The test is used to assess levels of anticoagulation in patients taking warfarin, to determine the cause of unexplained bleeding (as in patients with hemophilia), or to assess the ability of the liver to synthesize blood-clotting proteins. 
 See: international normalized ratioquiet time1. The time between measurable events, e.g., in respiratory care, the time between inspiration and expiration.
2. A time of silent reflection, thought, or prayer.
reaction timeThe period between application of a stimulus and the response.
real timeMoment-to-moment or second-to-second dynamic. It is used, e.g., of imaging technologies that take moving pictures rather than static images of body structures. 
recovery time1. The time between the end of an anesthetic infusion and the opening of a patient's eyes.
2. The time between the end of an anesthetic infusion and the patient's ability to oxygenate and ventilate without mechanical assistance.
reptilase time Abbreviation: RT
A test to identify hypofibrinogenemia or dysfibrinogenemia in plasma.
response time1. The delay between the first administration of a medication and the onset of or recovery from its effects.
saturation timeThe time required for the arterial blood of a person inhaling pure oxygen to become saturated.
screen timeThe number of hours that a person spends each day in front of a computer, or watching movies or television, or playing video games.
setting timeThe time required for a material to polymerize or harden, as in dental amalgam, cement, plaster, resin, or stone.
spin lattice relaxation timeT1 time.spin-spin relaxation timeT2 time.T1 timeThe time it takes for a proton that has been stimulated by radiofrequency (RF) energy to relax back into its usual alignment in tissue. Each tissue in the body has its own distinguishing relaxation time and its own distinctive energy emission after stimulation with RF energy. These physical characteristics of tissues are exploited in magnetic resonance imaging to create pictures of body structures. 
 Synonym: longitudinal relaxation time; spin lattice relaxation timeT2 timeThe time it takes for neighboring, radiofrequency-stimulated protons to relax relative to other protons in tissue (rather than relative to the magnetization provided by a magnetic resonance imaging (MRI) device). The T2 time varies from tissue to tissue. This is exploited in MRI to help generate contrast between adjacent tissues, e.g., between the white matter and grey matter of the brain, or between tissues with high fat content as opposed to those with high water content. Synonym: spin-spin relaxation time; transverse relaxation time
taipan snake venom timeA test to determine the presence of lupus anticoagulant in a blood specimen. The test relies on the mixing of venom from snakes of the genus Oxyuranus with dilute phospholipid and can be used even in patients receiving warfarin anticoagulation. 
template bleeding timeA bedside test to determine the presence of abnormal delays in blood clotting, in which a small cut is made in the skin, and the time it takes for bleeding to stop is measured.
time in the therapeutic range Abbreviation: TTR
An estimate of the average time that a medication is dosed with optimal efficacy and safety. The term is usually used with respect to anticoagulants such as warfarin but can apply to any agent whose drug levels are monitored. 
thermal death timeThe time required to kill a bacterium at a certain temperature.
transverse relaxation timeT2 time.turn-around time, turnaround time Abbreviation: TATSa Ka Fet Meaning
The time it takes to process an order, carry it out, and report the results, e.g., the time between ordering and reporting laboratory test results.Patient careIn the rushed environment of contemporary hospitals, especially in emergency departments and intensive care units, TAT can be a problem between physicians and nurses who order lab tests and the laboratorians who complete them and report the results. At the bedside, TAT starts with the ordering of the test. In the lab it begins when the specimen or the order for the test is received; next it is processed; and, finally, the results are reported to the clinician. Decreasing TAT without sacrificing the quality of reported results makes timely modifications in treatment possible; it requires careful planning at the bedside, a rapid system of specimen transport, an easy-to-use order entry system and log, and an efficient laboratory with well-trained professional staff.
forced expiratory time Abbreviation: FETFet Meaning Medical
The time required to forcibly exhale a specified volume of air from the lung.
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