Disposable endoscopic camera: Size of a grain of salt

Tiny video cameras mounted on the end of long thin fiber optic cables, commonly known as endoscopes, have proven invaluable to doctors and researchers wishing to peer inside the human body.

Endoscopes can be rather pricey, however, and like anything else that gets put inside peoples' bodies, need to be sanitized after each use.

A newly-developed type of endoscope is claimed to address those drawbacks, by being so inexpensive to produce that it can be thrown away after each use – Mother Nature presumably would not approve. Not only that, but it also features what is likely the world's smallest complete video camera, which is just one cubic millimeter in size.

The prototype endoscope was designed at Germany's Fraunhofer Institute for Reliability and Microintegration, in collaboration with Awaiba GmbH and the Fraunhofer Institute for Applied Optics and Precision Engineering.

Ordinarily, digital video cameras consist of a lens, a sensor, and electrical contacts that relay the data from the sensor. Up to 28,000 sensors are cut out from a silicon disc known as a wafer, after which each one must be individually wired up with contacts and mounted to a lens.

In Fraunhofer's system, contacts are added to one side of the sensor wafer while it's still all in one piece. That wafer can then be joined face-to-face with a lens wafer, after which complete grain-of-salt-sized cameras can be cut out from the two joined wafers.

Not only is this approach reportedly much more cost-effective, but it also allows the cameras to be smaller and more self-contained – usually, endoscopic cameras consist of a lens at one end of the cable, with a sensor at the other.

The new camera has a resolution of 62,500 pixels, and it transmits its images via an electrical cable, as opposed to an optical fiber. Its creators believe it could be used not only in medicine, but also in fields such as automotive design, where it could act as an aerodynamic replacement for side mirrors, or be used to monitor drivers for signs of fatigue.

They hope to bring the device to market next year.

One sleepless night can induce insulin resistance in healthy people

1 sleepless night can induce insulin resistance in healthy people ScienceBlog.com

According to a new study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM), just one night of short sleep duration can induce insulin resistance, a component of type 2 diabetes.

"Sleep duration has shortened considerably in western societies in the past decade and simultaneously, there has been an increase in the prevalence of insulin resistance and type 2 diabetes," said Esther Donga, MD of the Leiden University Medical Center in The Netherlands and lead author of the study.

"The co-occurring rises in shortened sleep and diabetes prevalence may not be a coincidence. Our findings show a short night of sleep has more profound effects on metabolic regulation than previously appreciated."

Previous studies have found that reductions in sleep duration over multiple nights result in impaired glucose tolerance, but this is the first study to examine the effects of only a single night of partial sleep restriction on insulin sensitivity.

In this study, researchers examined nine healthy subjects, once after a night of normal sleep duration (approximately eight hours), and once after a night of four hours of sleep.

Insulin sensitivity of each study participant was measured using the hyperinsulinemic euglycemic clamp method. This method uses catheters to infuse glucose and insulin into the bloodstream and then determines insulin sensitivity by measuring the amount of glucose necessary to compensate for an increased insulin level without causing hypoglycemia.

"Our data indicate that insulin sensitivity is not fixed in healthy subjects, but depends on the duration of sleep in the preceding night," said Donga. "In fact it is tempting to speculate that the negative effects of multiple nights of shortened sleep on glucose tolerance can be reproduced, at least in part, by just one sleepless night."

Donga adds that further studies are needed to evaluate whether interventions aimed at improving sleep duration may be beneficial in stabilising glucose levels in patients with diabetes.

The article, "A single night of partial sleep deprivation induces insulin resistance in multiple metabolic pathways in healthy subjects," will appear in the June 2010 issue of JCEM.

To learn more about the Society and the field of endocrinology, visit their web site at www.endo-society.org.