AOD4184A Symbol Min Typ Max Units BV DSS 40 V V DS=40V, V GS=0V 1 T J=55°C 5 I GSS ±100 nA V GS(th) Gate Threshold Voltage 1.7 2.1 2.6 V I D(ON) 120 A 5.8 7 T J=125°C 9.6 12 7.6 9.5 mΩ. FET — can mean:.Falkirk Environment Trust.Family Effectiveness Training.Fast Expression Templates.Federation of Environmental Technologists.FET.
In this section:
Foot problems are common in people with diabetes. You might be afraid you’ll lose a toe, foot, or leg to diabetes, or know someone who has, but you can lower your chances of having diabetes-related foot problems by taking care of your feet every day. Managing your blood glucose levels, also called blood sugar, can also help keep your feet healthy.
How can diabetes affect my feet?
Over time, diabetes may cause nerve damage, also called diabetic neuropathy, that can cause tingling and pain, and can make you lose feeling in your feet. When you lose feeling in your feet, you may not feel a pebble inside your sock or a blister on your foot, which can lead to cuts and sores. Cuts and sores can become infected.
Diabetes also can lower the amount of blood flow in your feet. Not having enough blood flowing to your legs and feet can make it hard for a sore or an infection to heal. Sometimes, a bad infection never heals. The infection might lead to gangrene.
Gangrene and foot ulcers that do not get better with treatment can lead to an amputation of your toe, foot, or part of your leg.A surgeon may perform an amputation to prevent a bad infection from spreading to the rest of your body, and to save your life. Good foot care is very important to prevent serious infections and gangrene.
Although rare, nerve damage from diabetes can lead to changes in the shape of your feet, such as Charcot’s foot. Charcot’s foot may start with redness, warmth, and swelling. Later, bones in your feet and toes can shift or break, which can cause your feet to have an odd shape, such as a “rocker bottom.”
What can I do to keep my feet healthy?
Work with your health care team to make a diabetes self-care plan, which is an action plan for how you will manage your diabetes. Your plan should include foot care. A foot doctor, also called a podiatrist, and other specialists may be part of your health care team.
Include these steps in your foot care plan:
Tips to Take Care of Your Feet
- Check your feet every day.
- Wash your feet every day.
- Smooth corns and calluses gently.
- Trim your toenails straight across.
- Wear shoes and socks at all times.
- Protect your feet from hot and cold.
- Keep the blood flowing to your feet.
- Get a foot check at every health care visit.
Check your feet every day
You may have foot problems, but feel no pain in your feet. Checking your feet each day will help you spot problems early before they get worse. A good way to remember is to check your feet each evening when you take off your shoes. Also check between your toes. If you have trouble bending over to see your feet, try using a mirror to see them, or ask someone else to look at your feet.
Look for problems such as
- cuts, sores, or red spots
- swelling or fluid-filled blisters
- ingrown toenails, in which the edge of your nail grows into your skin
- corns or calluses, which are spots of rough skin caused by too much rubbing or pressure on the same spot
- plantar warts, which are flesh-colored growths on the bottom of the feet
- warm spots
If you have certain foot problems that make it more likely you will develop a sore on your foot, your doctor may recommend taking the temperature of the skin on different parts of your feet. A “hot spot” can be the first sign that a blister or an ulcer is starting.
Cover a blister, cut, or sore with a bandage. Smooth corns and calluses as explained below.
Wash your feet every day
Wash your feet with soap in warm, not hot, water. Test the water to make sure it is not too hot. You can use a thermometer (90° to 95° F is safe) or your elbow to test the warmth of the water. Do not soak your feet because your skin will get too dry.
After washing and drying your feet, put talcum powder or cornstarch between your toes. Skin between the toes tends to stay moist. Powder will keep the skin dry to help prevent an infection.
Smooth corns and calluses gently
Thick patches of skin called corns or calluses can grow on the feet. If you have corns or calluses, talk with your foot doctor about the best way to care for these foot problems. If you have nerve damage, these patches can become ulcers.
If your doctor tells you to, use a pumice stone to smooth corns and calluses after bathing or showering. A pumice stone is a type of rock used to smooth the skin. Rub gently, only in one direction, to avoid tearing the skin.
Do NOT
- cut corns and calluses
- use corn plasters, which are medicated pads
- use liquid corn and callus removers
Cutting and over-the counter corn removal products can damage your skin and cause an infection.
To keep your skin smooth and soft, rub a thin coat of lotion, cream, or petroleum jelly on the tops and bottoms of your feet. Do not put lotion or cream between your toes because moistness might cause an infection.
Trim your toenails straight across
Trim your toenails, when needed, after you wash and dry your feet. Using toenail clippers, trim your toenails straight across. Do not cut into the corners of your toenail. Gently smooth each nail with an emery board or nonsharp nail file. Trimming this way helps prevent cutting your skin and keeps the nails from growing into your skin.
Have a foot doctor trim your toenails if
- you cannot see, feel, or reach your feet
- your toenails are thick or yellowed
- your nails curve and grow into the skin
If you want to get a pedicure at a salon, you should bring your own nail tools to prevent getting an infection. You can ask your health care provider what other steps you can take at the salon to prevent infection.
Wear shoes and socks at all times
Wear shoes and socks at all times. Do not walk barefoot or in just socks – even when you are indoors. You could step on something and hurt your feet. You may not feel any pain and may not know that you hurt yourself.
Check the inside of your shoes before putting them on, to make sure the lining is smooth and free of pebbles or other objects.
Make sure you wear socks, stockings, or nylons with your shoes to keep from getting blisters and sores. Choose clean, lightly padded socks that fit well. Socks with no seams are best.
Wear shoes that fit well and protect your feet. Here are some tips for finding the right type of shoes:
- Walking shoes and athletic shoes are good for daily wear. They support your feet and allow them to “breathe.”
- Do not wear vinyl or plastic shoes, because they do not stretch or “breathe.”
- When buying shoes, make sure they feel good and have enough room for your toes. Buy shoes at the end of the day, when your feet are the largest, so that you can find the best fit.
- If you have a bunion, or hammertoes, which are toes that curl under your feet, you may need extra-wide or deep shoes.1 Do not wear shoes with pointed toes or high heels, because they put too much pressure on your toes.
- If your feet have changed shape, such as from Charcot’s foot, you may need special shoes or shoe inserts, called orthotics. You also may need inserts if you have bunions, hammertoes, or other foot problems.
When breaking in new shoes, only wear them for a few hours at first and then check your feet for areas of soreness.
Medicare Part B insurance and other health insurance programs may help pay for these special shoes or inserts. Ask your insurance plan if it covers your special shoes or inserts.
Protect your feet from hot and cold
If you have nerve damage from diabetes, you may burn your feet and not know you did. Take the following steps to protect your feet from heat:
- Wear shoes at the beach and on hot pavement.
- Put sunscreen on the tops of your feet to prevent sunburn.
- Keep your feet away from heaters and open fires.
- Do not put a hot water bottle or heating pad on your feet.
Wear socks in bed if your feet get cold. In the winter, wear lined, waterproof boots to keep your feet warm and dry.
Keep the blood flowing to your feet
Try the following tips to improve blood flow to your feet:
- Put your feet up when you are sitting.
- Wiggle your toes for a few minutes throughout the day. Move your ankles up and down and in and out to help blood flow in your feet and legs.
- Do not wear tight socks or elastic stockings. Do not try to hold up loose socks with rubber bands.
- Be more physically active. Choose activities that are easy on your feet, such as walking, dancing, yoga or stretching, swimming, or bike riding.
- Stop smoking.
Smoking can lower the amount of blood flow to your feet. If you smoke, ask for help to stop. You can get help by calling the national quitline at 1-800-QUITNOW or 1-800-784-8669. For tips on quitting, go to SmokeFree.gov.
Get a foot check at every health care visit
Ask your health care team to check your feet at each visit. Take off your shoes and socks when you’re in the exam room so they will remember to check your feet. At least once a year, get a thorough foot exam, including a check of the feeling and pulses in your feet.
Get a thorough foot exam at each health care visit if you have
Red Spots On Feet
- changes in the shape of your feet
- loss of feeling in your feet
- had foot ulcers or an amputation in the past1
Ask your health care team to show you how to care for your feet.
When should I see my health care provider about foot problems?
Call your health care provider right away if you have
- a cut, blister, or bruise on your foot that does not start to heal after a few days
- skin on your foot that becomes red, warm, or painful—signs of a possible infection
- a callus with dried blood inside of it,which often can be the first sign of a wound under the callus
- a foot infection that becomes black and smelly—signs you might have gangrene
Ask your provider to refer you to a foot doctor, or podiatrist, if needed.
References
[1] American Diabetes Association. Microvascular complications and foot care. Diabetes Care. 2016;39(Suppl. 1):S78.
Clinical Trials
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.
What are clinical trials, and are they right for you?
Clinical trials are part of clinical research and at the heart of all medical advances. Clinical trials look at new ways to prevent, detect, or treat disease. Researchers also use clinical trials to look at other aspects of care, such as improving the quality of life for people with chronic illnesses. Find out if clinical trials are right for you.
What clinical trials are open?
Clinical trials that are currently open and are recruiting can be viewed at www.ClinicalTrials.gov.
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases(NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.
The NIDDK would like to thank David Armstrong, DPM, MD, PhD, University of Arizona College of Medicine
FET stands for 'Field Effect Transistor' it is a three terminal uni polar solid state device in which current is control by an electric field.
FET can be fabricated with either N- Channel or P- Channel, for the fabrication of N-Channel JFET first a narrow bar of N-type of semiconductor material is taken and then two P-Type junction are defused on opposite sides of it's middle part, called channel. The two regions are internally connected to each other with a signal lead, which is called Gate terminal. One lead is called Source terminal and the other is called Drain terminal.Construction of FET
P-Channel JFET is similarly is constructed except that it use P- type of bar and two N- types of junctions.
Source:-
It is the terminal through which majority carriers are entered in the bar, so it is called Source.
Drain:-
It is the terminal through which the majority carriers leads the bar, so it is called the drain terminal.
Gate:-
These are two terminals which are internally connected with each other and heavily doped regions which form two PN-Junctions.
Working / Operation FET or JFET
Gate are always in reverse biased, hence the gate current IG is practically zero. The source terminal is always connected to end of the drain supply, which provides the necessary carrier, in N- Channel JFET Source terminal is connected to the negative end of the drain voltage source. The electrons flow from source to drain through the channel from D to S is started,
the current ID increases as VDS is increased from zero on ward. This relation ship between VDS and ID continuous till VDS reaches certain value called 'Pinch OFF' VPO.
When VDS is equal to zero and VGS is decreased from zero, the gate reverse bias increases the thinks of the region, as the negative value of the VGS is increase a stage cones when the two dip lections regions touch each other, in this conduction the channel is said to be Cut OFF.
JFET as Amplifier
One of the application of the JFET is an Amplifier, it amplified the weak signal connected in the Gate terminal , the input is always reversed biased, a small change in the reverse bias on the gate produce large change in the drain current, this fact make JFET capable of amplifing the weak signals
Working / Operation
When negative signal is applied at in put of the amplifier, the gate bias is increase, duplication layer is decrease, Channel resistance is increase, ID is decreased, Drop across Load Resistor is decreases, and the positive signal is present at output through C2.
When the positive signal is applied at the input the action will be the wise versa
This seen that there is phase inveration between the input signal at the gate and the output signal at the drain.
Application of JFET
JFET is used at large scale in amplifiers circuits, analog switches; it is also used in AGC system, voltage regulators, buffer amplifiers.
MOSFET
The MOSFET is sub divided in to two types,
- DE-MOSFET
- E only MOSFET
DE- MOSFET
This MOSFET could be operating in both duplication and Enhancement mode. By Changing the Polarity o VGS, when VGS is negative for the N-Channel DE- MOSFET is operate in depletion mode, however with positive gate voltage it operates in an Enhancement mode.
E- Only MOSFET
This MOSFET Operates in the only Enhancement mode. It differs only in construction from the DE- MOSFET in that there exists no channel between the drain and source.
DE-MOSFET Construction
Like JFET it has source, Gate and Drain, However its gate is insulated from its conduction channel by an ultra thin metal oxide. Insulating film usually silicon dioxides (SiO2), because of this insulating property MOSFET is also known as Insulated Gate Field Effect Transistor (IGFET). In DE-MOSFET we can apply both the positive and negative voltages at gate terminal because the gate terminal is isolated from the channel.
DE-MOSFET Working / Operation
Depletion Mode
When VGS=0 electrons can flow freely from source to drain through the conduction channel, When a negative voltage is applied at gate terminal, it depletes the N- channel and its electrons by inducing positive charges in it. Grater negative voltage on the gate, grater is the reduction in the number of electrons in the channel which increase the conduction. In fact too much negative gate voltage cut off the channel, thus with negative gate voltage a DE-MOSFET behaves like a JFET, for this reason negative gate operation of DE-MOSFET is called Depletion mode Operation.
Enhancement Mode
In circuit diagram the drain current flows from source to drain even with zero gate bias, when positive voltage is applied to the gate, the input gate capacitor is able to create pre- electrons in the channel which increase the ID. Pre- electrons are induced in the channel by the capacitor action, these electrons are added to the other ready electrons for the conduction, which increase the number of electrons and these electrons increase the conductivity of the channel.
As positive gate voltage increases the number of induced electrons is increased which increase the conductivity of channel from source to drain, this way the current is also increased. The positive gate operation of the DE-MOSFET is known as enhancement mode.
On Fitness Mag
Application of MOSFET
MOSFET have wide application in field of electronics some of these application are given below.
On Feet Have White Spots
- As input amplifier in oscilloscope, electronic volt meter, and other measuring and testing equipment because they have high input resistance.
- It is used In logic circuits for fast switching.
- It is also used in TV receiver.
- It is used in computer circuits.
- In high frequency amplifiers.