Biomedical Instrumentation

Archive for June, 2009

Dear friends! Lines of ultrasonic information are not generated in TV compatible format, consequently to use conventional TV monitors to display the image; some kind of scan conversion must be performed. The majorities of scanners digitize the image information and use a digital memory as a buffer store. The memory can be updated whenever necessary and can be read to give a standard video output.

Digitization of the echo information can be performed at a number of points in the signal dynamic range is about 20 db and the required digitization rate, about 1MHz. Both these criteria are easily met with readily available analog to digital converts. Alternatively, there is a growing interest in reducing the amount of undesirable information and digitization just after the radio frequency amplifier is becoming more popular. The dynamic range of 40 db and digitization rate of 10MHz would require expensive analog to digital converters. The advantage of digitization at this rate is that the phase information in the carrier is not lost and frequency changes can be used to modulate the image.

Because of the fairly low speed of the ultrasound in soft tissues and the requirements that all the echoes from the preceding pulse must be received before the next pulse can be delivered, the image line rate is limited. For penetration of 30cm, the maximum line rate is 5 KHz. With a frame rate of 20 frames per second for non-jerky real time imaging, the line density per frame is limited to 200. For some scanners, this trade-off between line rate, frame rate and line density produces a display with visible gaps between the lines of real ultrasonic information. Often these gaps are filled with lines calculated inside the machine by interpolation of real information. This improvement in aesthetic appearance does not affect the diagnostic accuracy.

Digital scan converters are microprocessor based and offer several additional benefits to the user. Alphanumeric information concerning the patient, date and equipment parameters such as transducer frequency, gain settings and location of the scan plane can be conveniently entered and displayed along with the ultrasound image. My dear friends! I am sure this article will enhance your knowledge regarding the digital scan converter.

Dear readers! Aging often brings financial and social losses with it. Being aware of this and preparing for it can help enable you to weather losses successfully. Financial planning is essential. Nearly everyone suffers a considerable loss of income in the retirement years, aggravated by inflation. It is important to have set aside enough money for retirement-to have the home paid for or adequate income to pay the rent-and to have insurance to cover unexpected medical and other expenses.

Another way to prepare is to plan an alternative living arrangement, should the responsibility for the present home become burdensome. A nursing home is not the only choice, and usually not the best one. Less than a third of older adults spend time in nursing homes, and those who do spend only a year there, on the average. There are many alternatives. Rather than leave it to their children to decide for them where they will live, older adults can decide for themselves. Financial preparations will not ward off the losses that take place in the emotional and social realms. These may be multiple. Old friends are lost because they die or move away; offspring move away also and may be too busy to write; income is lost upon retiring, as is status in the community.

Loss of control of the environment also occurs, such as finding that the home that was to be a haven in retirement now sits in the middle of a high-crime area, or that the familiar shops and fruit stands have closed. A person can develop a feeling of deep loneliness as the familiar environment shifts. A loss of identity may accompany retirement or the death of a spouse. The person who does not take positive steps to replace each loss can gradually become overwhelmed with loneliness. Depression is common in the elderly and can be severe.

Try to imagine how it would be to wake up tomorrow with all these changes having taken place at once. It might be wonderful to lie in the bed for a day, or two, or three. But imagine that the days stretch into weeks or months, and still, nothing pushes you to do your best, expand you mind, or accomplish things. My dear friends! I am sure this article will enhance your knowledge regarding the preparation for later life.

Dear friends! Fitness-minded people talk a lot about shin splints, stress fractures, tennis elbows, sprains, strains and an assortment of other anatomical hobo goblins. The Mini glossary of Sports Injuries lists the injuries that are mentioned most often. These and others can be avoided by following a proper program that builds fitness slowly. Many people could become marathon runners given enough time, but they could do it without joint damage only if they built slowly. Proper equipment and expert advice can help keep you safe. Be sure the expert is truly qualified, though.

Many employees of spas and health clubs lack knowledge and training, but freely offer advice that might lead to injury. Be consistent, too. While too little exercise leads to illness in later years, too much too soon presents a hazard to health and life today. A weekend athlete, who is sedentary all week and then exercises vigorously on weekends, invites injury, or even a heart attack, Vigorous and sudden demands on out of condition muscles, ligaments, and tendons lead to sprains and strains, and sudden demand can damage a weakened heart.

Take on a regular program of fitness to develop the strength that safe weekend play demands. If you have injured yourself, you have two options: to go to a health care provider, or to wait to see whether it clears up by it. Pain is your guide. If the pain diminishes during the first hours, chances are the injury is slight. If it increases or stays the same for several hours, you may have a serious condition that requires attention. Be alert to the dangers of overheating and dehydration. Heat is a byproduct of energy fuel breakdown, so muscles heat up during exertion; they are burning large amount of fuel.

The body attempts to maintain a normal temperature: blood penetrates the muscles and transports the heat to the skin, where the surrounding air and the evaporation of sweat can carry it away. On humid days, though, sweat does not evaporate well, heat builds up, and the body sweats copiously is an attempt to effect cooling. This lyte loses beyond a certain point compromise cellular functioning. It can even be fatal. My dear friends! I am sure this article will enhance your knowledge regarding the prevention of sport injuries and accidents.