LEDs and Medicine: Diffuse Optical Tomography Uses LEDs to Scan Brain

A look at current DOT testing

A look at current DOT testing

According to a report in BioOptics World, scientists at the Washington School of Medicine in St. Louis, Missouri have developed a new way to study the brain, diffuse optical tomography (DOT), a new non-invasive technique that relies on LEDs rather than magnets or radiation. While still experimental, it offers promise for a new non-invasive test for the human brain.

While it looks primitive now, DOT scans use LED light to measure brain activity. For a DOT scan, a subject wears a cap composed of many light sources and sensors connected to cables. A DOT cap covers two-thirds of the head and involves shining LED lights directly into the head. DOT images show brain processes taking place in multiple regions and brain networks, like those involved in language processing and self-reflection (daydreaming). It also avoids radiation exposure and bulky magnets required by positron emission tomography (PET) and magnetic resonance imaging (MRI) respectively.

DOT works best for patients with electronic implants that can be problematic with MRI testing such as pacemakers, cochlear implants, and deep brain stimulators (used to treat Parkinson’s disease). The magnetic fields in MRI may disrupt either the function or safety of implanted electrical devices while DOT doesn’t impact these types of devices.

How does DOT work? According to author Joseph Culver, Ph.D., associate professor of radiology, DOT can detect the movement of highly oxygenated blood flows to the parts of the brain that are working harder when the neuronal activity of a region in the brain increases. He told BioOptics World that, “It’s roughly akin to spotting the rush of blood to someone’s cheeks when they blush.”  According to the magazine, DOT works by detecting light transmitted through the head and capturing the dynamic changes in the colors of the brain tissue.

DOT has a lot of potential benefits for medicine concerning the brain.  Since DOT technology does not use radiation, doctors could monitor progress of patients using multiple scans performed over time without worry. It could be useful for patients recovering from brain injuries, patients with developmental disorders such as autism, and patients with neurodegenerative disorders such as Parkinson’s.

Currently, a full-scale DOT unit takes up an area slightly larger than a phone booth, but Culver and his team have built versions of the scanner mounted on wheeled carts. The DOT device is designed to be portable, so it could be used at a patient’s bedside in the hospital or at home, in a doctor’s office, or even in the operating room in the future.

For more details about DOT, visit:

BioOptics World, DIFFUSE OPTICAL TOMOGRAPHY ABLE TO SCAN THE BRAIN WITHOUT RADIATION, MAGNETS, http://www.bioopticsworld.com/articles/2014/05/diffuse-optical-tomography-able-to-scan-the-brain-without-radiation-magnets.html

Nature, Mapping distributed brain function and networks with diffuse optical tomography, http://www.nature.com/nphoton/journal/v8/n6/full/nphoton.2014.107.html (registration required)

 

 

LEDs Making a Difference in Medicine

Special LED-based luminous ceiling lighting by Philips

Special LED-based luminous ceiling lighting by Philips

There have been quite a few stories lately about how LEDs are making a difference in medical settings. Here are a few cases where LEDs are making a difference with infection control, intensive care unit lighting and in medical research for brain disorders.

Controlling the spread of infection through mobile devices in hospitals

The statistics about hospital acquired infections (HAIs) are staggering.  According to the US Centers for Disease Control, HAIs inpact more than a million people a year in the US alone and are linked to nearly 100,000 US deaths per year.  More than 50 percent of healthcare workers admit to using mobile devices during direct physical contact with patents and yet only 8 percent say that actually clean them.  According to Hospital and Health Networks, 65 percent of doctors believe that the increased use in mobile devices in the healthcare environment leads to the spread of disease.

Sensor Electronic Technology, Inc. (SETi) plans to unveil a new line of disinfection cases for phones, tablet computers and other mobile devices at Medica tradefair in Dusseldorf, Germany, November 20 23, 2013. Using SETi’s UV LEDs, the disinfection cases are the world’s first fully portable disinfection units and are designed to be carried with the mobile device as a protective case as well as a disinfection system.

Using LED lighting to help critically ill patients

Special LED-based luminous ceiling lighting by Philips has been introduced into clinical use by the Charité Campus Virchow Clinic in Berlin as part of a unique stress-reducing concept called Parametric Spatial Design. Simulating energizing daylight to comfort critically ill patients, Parametric Spatial Design uses the area above a patient bed to create sky-like visuals mimicking daylight customized to the needs of individual patients.

Clinical research has shown that factors like loud noise, inappropriate lighting conditions and social isolation can increase the risk of patients in intensive care slipping into a shock-like state.

Philips played a significant role in designing this innovative concept.  The luminous ceiling from Philips combines a natural, dynamic rhythm of daylight and the effects of gentle colorful light and visual content to create a soothing environment for patents. It incorporates 15,400 LEDs and extends from the ceiling onto the wall in front of a patient’s bed, filling a patient’s field of vision.

Shining Light on Brain Disorders

Researchers at Washington University School of Medicine in St. Louis (WUSTL) are using tiny, electronic devices that include an LED to identify and map neural circuits in the brain especially those that target specific populations of brain cells that malfunction in depression, pain, addiction and other disorders.

The team’s work has been recognized with a rare grant called EUREKA (Exceptional, Unconventional Research Enabling Knowledge Acceleration) that funds high-risk/high-reward projects from the National Institutes of Health (NIH) which awards only 12 to 18 such grants each year.

The WUSTL team will develop specialized, optically sensitive G-protein-coupled receptors on brain cells that will make it possible to control cell signaling in the brain with light.  Combining these new receptor tools with the wireless micro-LED devices implanted in a mouse brain should enable researchers to learn about molecular and cellular events that underlie stress, addiction and depression.  The researchers hope to isolate and map the brain networks involved in stress by studying how the mice interact in their cages.

The team developed the special wireless micro-LED devices with researchers at the University of Illinois in Urbana-Champaign.  Many researchers use optogenetic techniques to isolate pathways in the mouse brain, but those animals are often tethered to wires.  The team at WUSTL can observe animals that are able to move freely because the LED devices that they developed are portable and wireless.

For Further Reading

LED Journal, Using UV LEDs to Control the Spread of Hospital Acquired Infections, http://www.ledjournal.com/main/markets/applications/using-uv-leds-to-control-the-spread-of-hospital-acquired-infections/

Philips News Release, Luminous ceiling from Philips simulates daylight to comfort critically ill patients in Intensive Care, http://www.newscenter.philips.com/main/standard/news/press/2013/20131024-Luminous-ceiling-from-Philips-simulates-daylight-to-comfort-critically-ill-patients-in-Intensive-Care.wpd#.UoPhB_mtmSo

Bioscience Technology, Tiny Devices Can Shine Light on Brain Disorders,  http://www.biosciencetechnology.com/news/2013/11/tiny-devices-can-shine-light-brain-disorders#.UoY5bhqtmSq