IEEE Engineering in Medicine and Biology Magazine最新文献

Obesity is one of the most prevalent chronic diseases globally, especially in the United States. While the United States gained an early lead in unnecessary weight gain, most other countries are quickly closing the gap. The latest U.S. National Health and Nutrition Examination Survey (NHANES, http://www.cdc.gov/nchs/nhanes.htm) documents that about one third of adults in the United States are now overweight [a body-mass index (BMI) between 25 and 30 kg/m2] and another one third (61 million) are considered obese (BMI >30 kg/m2). Being obese is a strong risk factor for cardiovascular diseases, type 2 diabetes, osteoporosis, some cancers, and depression. The economic impact of this condition is staggering: in 2008, more than 147 billion dollars were spent just in the United States for medical costs related to obesity. Time lost from work and spending on weight loss costs even more.

In recent years, noninvasive brain stimulation methods have been proposed as the next-generation technology to probe and eventually interfere with brain function. Transcranial magnetic stimulation (TMS) is a 20-year-old technique originally introduced to investigate nervous propagation along the corticospinal tract, spinal roots, and peripheral nerves in humans. TMS is extensively used in clinical neurophysiology, including rehabilitation and intraoperative monitoring.

Obesity is becoming increasingly common, with at least 400 million obese adults worldwide and the World Health Organization (WHO) projecting that this statistic will reach 700 million in another five years. Ironically, despite the fact that a majority of adults in developed nations are overweight or obese, society stigmatizes the obese severely. Still, obese people have more than just social motivations for losing weight; obesity commonly goes hand in hand with life-threatening comorbidities like cardiovascular disease and type 2 diabetes and some forms of cancer. It severely threatens quality of life, limiting the ability to move and work, navigate public places, and provide care for others and is a factor in musculoskeletal disorders like osteoarthritis. Both obesity and its comorbidities lead obese patients to hospitals at greater rates than patients of normal weight, and these factors, along with social pressures, motivate patients and their physicians to pursue solutions for obesity, its comorbidities, or both.

Writing about obesity research is a challenging task. While the rising obesity epidemic drastically raised public awareness of the problem, the causes behind the epidemic are still poorly understood. The etiology of obesity is a subject of ongoing scientific debate with widely varying views and strong opinions. Is it mostly genetic or environmental in nature? Is obesity caused by changes in our diet or changes in lifestyle and physical activity or both? Modern research literature quite often offers conflicting findings. Publications in popular media like the one in Time magazine add to the controversy by making quick and strongly worded summaries of academic research. Although the root causes of obesity remains a topic of active research, this review concentrates on the fundamental components of weight regulation in humans and their relative contribution to the energy equation. A better understanding of the energetics of obesity may provide some insight into the etiology of the obesity epidemic. The energetics of obesity also showcases an engineering challenge: development of techniques to accurately measure individual components of the energy equation.

Casual observation of any magazine rack or browsing the diet section of any bookshop provides convincing evidence that weight loss is of great interest to the U.S. population. Americans spend more than US$30 billion/year on weight-loss products, and the health cost of obesity was recently estimated to be as high as US$147 billion/year. Understanding the development of obesity and how excess weight can be lost requires knowledge of the physiological mechanisms by which the body uses food to provide fuel for metabolism and how the body copes with imbalances between fuel delivery and utilization.

There is only one U.S. president who is also a patentee. One might guess that the president is Thomas Jefferson, who invented many things and considered himself to be an inventor. Or, we might guess George Washington whose work as a surveyor and planter, not to mention commander-in-chief of the army, brought him into contact with the latest technology of the 18th century.