Medical tools

For those who have never suffered from a bout of vertigo, the condition might evoke thoughts of Alfred Hitchock and a dizzying fear of heights. Those people would be misguided.

Imagine instead that, for anywhere from 20 seconds to 2 minutes, you are both falling and spinning, and yet you are also lying perfectly still in bed. It is not only nauseating and terrifying, but the disconnect is also completely frustrating.

Millions of people around the world are thought to suffer from one of a number of balance disorders, some of which are still poorly understood (do the problems stem from the ear, brain, or some combination of the two?). However, a new device could help those who suffer from one such problem, called Meniere's disease, avoid symptoms the moment an attack begins.

The implantable device consists of a cochlear implant and a processor with new software and electrode arrays designed by University of Washington researchers who specialize in head and neck surgery, signal processing, brainstem physiology, and vestibular neural coding.

It has been designed specifically to treat Meniere's disease--which affects an estimated 615,000 people in the U.S., typically between ages 40 and 60 and which typically affects one ear--because the disease is well understood. (The attacks result from rupturing of the inner-ear membrane, causing a sensation of spinning in the direction of the failing ear.)

The most common way for those with Meniere's to fight the symptoms of a vertigo attack is to lie very still for hours or, in severe cases, to elect for surgery that essentially shuts off that ear altogether, permanently affecting hearing and balance.

"We have a variety of existing treatments for Meniere's disease, and any time there's a variety it's because none of them are optimal," says Dr. Jay Rubinstein at UW's Department of Otolaryngology-Head and Neck Surgery, who himself has never experienced vertigo--"other than from drinking too much in college"--but who for years has seen first-hand how debilitating it can be. "In theory this is potentially an optimal therapy that could really change how we treat Meniere's."

The device, implanted last week in a 56-year-old patient who is the first of 10 to be involved in the first clinical trials, is essentially an override, Rubinstein explains. "It doesn't change what's happening in the ear, but it eliminates the symptoms while replacing the function of that ear until it recovers."… Read more

When I came to after getting my wisdom teeth removed in college, the nausea was actually worse than the pain in the back of my mouth. Every time my mother stepped on the gas on the ride home, I had to lean out the window, just in case.

Postoperative nausea is not only common (a 2002 study shows that 30 percent of all patients and 70 percent of high-risk patients experience post-op vomiting), it's often rated worse than postoperative pain.

Relief may have arrived via Reletex, a new prescription-only neuromodulation device worn on the wrist that is noninvasive and … Read more

It sounds counterintuitive--that light, so often considered the culprit in skin cancer, might also play a role in its treatment. But researchers at the University of California at Irvine are using light-emitting diodes to improve a cancer therapy that they hope to use to treat skin cancer.

The technique is called photodynamic therapy (PDT), and is approved by the Food and Drug Administration to treat both esophageal and lung cancer. Light-absorbing chemicals are injected into tumors and then exposed to light, which prompts the chemicals to generate oxygen radicals that destroy cancer cells.

The technique has the potential to treat … Read more

Physicists at the National Institute of Standards and Technology, along with researchers at the German national metrology institute, say they've successfully tracked a human heartbeat with NIST's mini atom-based magnetic sensor, a development that might one day lead to readings more precise than currently possible using electrocardiograms.

The key advantage to using the magnetic signals of the heartbeat, says principal investigator John Kitching, is that they "are not affected at all while propagating from the source--the heart, say--to outside the body because the body is essentially transparent to magnetic fields." Electrical signals, on the other hand, &… Read more

It all started more than 25 years ago, when James C. Tilton, a scientist at NASA's Goddard Space Flight Center, began investigating a novel way to analyze the pixels that comprise digital images.

He devised an algorithm that took image segmentation (grouping pixels at different levels of detail) to a whole new level; he not only found regional objects, but also grouped spatially separate objects into region classes. In other words, applied to a satellite image, it could not only identify and separate lakes of varying depths, but could recognize lakes as a class of objects spatially distinguishable from, say, trees.

He calls this Recursive Hierarchical Segmentation, and it has been used to analyze Earth-imaging data from NASA's Landsat and Terra spacecraft to improve snow and ice maps, find potential locations for archeological digs, etc. It is now being applied to medical imaging to improve mammograms, ultrasounds, digital x-rays, and more.

"My original concept was geared to Earth science," says Tilton, who was at first skeptical that his algorithm could enhance, say, mammography. "I never thought it would be used for medical imaging."

Then he processed cell images and saw details not visible in unprocessed displays of those images. "The cell features stood out real clearly, and this made me realize that Bartron was onto to something."

Bartron Medical Imaging, based out of Connecticut, has since developed the new MED-SEG system, which the FDA recently cleared for use by trained professionals to process images alongside other images, though stipulated that the system should not (at least yet) be used for primary image diagnosis.

Bartron, which first studied the software through Goddard's Innovative Partnerships Program Office, licensed the patented technology in 2003 to create a system that would differentiate hard-to-see medical image details. It then began to work with doctors to analyze CT scans, MRIs, ultrasounds, etc.… Read more

In 2007, Marva Lorde of Mississauga, Ontario, suffered a heart attack that resulted in 10 days in the intensive care unit, angioplasty, and pacemaker implantation, only to be followed by another cardiac arrest in 2008.

Now 61, she has become the first person in Canada (and among only a handful in the world) to be implanted with a longer-lasting left ventricular assist device (LVAD).

The device, called DuraHeart by Terumo Heart, was first implanted in clinical trials in the U.S. in 2008 and is also being used in Germany. It's designed for long-term cardiac support to reduce the … Read more

You know that stern voice at the end of drug advertisements that runs through the list of possible side effects as quickly (and sometimes comically) as possible? "Possible side effects include nausea, anxiety, an erection that lasts more than four hours, and in rare cases, death."

This wide range of possibilities exists in large part because drugs and dosages have yet to be personalized, and while there are established standard reactions to those drugs and dosages, our bodies are ultimately genetically unique.

Enter the emerging realm of personalized medicine, a method that uses information about an individual to … Read more

How'd you like to check your pulse, respiration, and blood pressure as you brush your teeth in the mirror each morning? A PhD candidate at the Harvard-MIT Division of Health Sciences and Technology is working to make this a reality in the near future.

Electrical and medical engineering student Ming-Zher Poh has already used low-res Webcam imaging to measure the human pulse. He's now working on adding respiration, blood oxygen levels, and blood pressure to the list--all by having people simply peer into a camera or, for those who'd rather multitask, into a mirror in front of that camera.

The system works by measuring the slightest variations in brightness produced by blood flow through blood vessels in the face. Poh used public-domain software to identify facial positions in any given image and break that information into separate red, green, and blue portions of the video images.

To deal with both movement in front of the lens as well as different ambient light, Poh adapted a method known as ICA (Independent Component Analysis)--a signal-processing technique originally developed to extract a single voice from a room of conversations--to find the pulse signal amid all the video noise.

Initial results of the project, which Poh conducted with Media Arts and Sciences Professor Rosalind Picard and Media Lab student Daniel McDuff, were outlined in May in the journal Optics Express.

The pulse results turned out to be pretty reliable when compared with measurements taken by an FDA-approved monitoring device.… Read more