Monday, June 28, 2010

I bought a Kindle the other day. One of the reasons was I found I wasn’t reading as many books as I used to. I thought about why? Well, one reason is eye strain. Without realizing it, I was tiring more when reading printed pages. As a result, I found reasons not to sit down and spend a couple hours reading. But the other week I bought a Kindle and am amazed at the improvement I now have in reading stamina. I had heard Kindles were easier on the eyes than printed books, but really thought it was just marketing hype. Well, for me it isn’t.

So what is eye strain? Several muscles control the eyes, moving them in back and forth and converging to focus at various distances. In addition to the actual muscles that move the eyes are the facial muscles that control the lids. Like any muscle they can fatigue. Our eyes were really designed to see far away and at different focal lengths. But if we look at one focal length for sustained periods of time (as I do during TV football season), we essentially produce a repetitive strain injury to the muscles. This results in aching eye muscles and/or even dry-feeling eyes. A trick I’ve adopted to relieve this problem is to stop every ten minutes or so and look away, at a corner of the room, or at something out the window. The problem, of course, is remembering to do this. In any event, I love my new Kindle. If you’ve ever thought of owning one, seriously consider it. They’re seriously fun.

Friday, June 18, 2010

A strange pain disorder called Causalgia can occur when the nerves that run from the spinal cord to the limbs are partially damaged, especially when the damage involves the bundles of nerves to the arms called the brachial plexus. Partial damage can come from accidents (that stretch the shoulder away from the neck, literally pulling some nerve fibers apart), from hand surgery, or from war injuries. A more recent name for the disorder is Complex Regional Pain Syndrome.
The pain is burning, constant, and usually involves the hand or foot. Sensory stimulation, such as rubbing the area, can worsen the pain. The pain usually is adjacent to any neurological deficit if there is one. Meaning that the pain may not be located in a region of numbness, but adjacent to it.

What makes this pain syndrome so different from other forms of chronic pain is that changes can occur in the skin and bones of the affected limb. The skin can become swollen and red because of loss of the normal tone of the blood vessels. In fact, comparing the temperature of the affected limb compared to the other normal limb is one aid to making the diagnosis (thermography). Abnormal sweating can also be seen. Interestingly, in some case patchy osteoporosis can be shown on X-rays of the limb in as little as three weeks from onset.

The cause is not really understood, but because of the vascular and skin changes, it has been suggested that the sympathetic nervous system is involved. In severe cases nerve blocks to the sympathetic ganglia in the base of neck can provide enough pain relief so that aggressive physical therapy can be started. Cigarette smokes are at much higher risk for developing the painful disorder than non-smokers.

Monday, June 14, 2010

I worked for a couple of medical device companies. One of the was Northstar Neuroscience. It was based a very cool concept. We developed a small battery powered electrode that could be implanted on the motor area of stroke victim’s brain. The system could be turned on to provide a tiny electrical current to the brain while the patient was participating in physical therapy. Guess what? It worked. Patients who were partially paralyzed on one side of their body regained a remarkable amount of movement. But timing is everything and before we could commercialize the device and obtain FDA approval, the stock market ran into a brick wall and there was no way the company could continue without another stock offering, so it went under. Actually, Saint Jude bought the technology but never really did anything with it.

The thing I loved about working at Northstar was all the bright energetic minds. I’m happy to say that many of the engineers and thinkers migrated from Northstar to another start-up company, NeuroVista. What they’re working on is a really cool sensor that is able to predict when a person with epilepsy is going to have a seizure.

There is a genetic line of dogs that have seizures and the company has successfully tried the device on the seizure-prone dogs with good success. Enough so that the company is starting their first clinical trial on humans in Australia. Check them out at

If you’re interested, check out a recent interview that was broadcast on Australian TV:

Sunday, June 6, 2010

Here’s one from the Whatever-Happened-To department: Cryonics. The idea was that a life could be suspended if lowered to subzero temperatures (typically at -196 degrees F ) for an indefinite period of time. The rationale being that people who are considered dead by current legal or medical definitions may not necessarily be dead according to more stringent definitions of death. So, cryopreserved them until they can someday be recovered by using highly advanced technology that is presently not available. Because most chemical reactions slow with decreasing temperature, it stands to reason that lowering a tissue’s temperature will place it in a state of suspended life. Presently cryopreservation is can be done for sperm (for future in vitro fertilization) and other biological tissues such as blood and stem cells.

According to their website, Alcor, ( is a foundation established in 1972 in California. Their mission is to enhance the cryonics movement. In 1987 Alcor “cryopreserved” its first human.

Interesting subject. It contains all the stuff I love to mull over when thinking up plots. On the other hand, the scientist in me always asks, “Whoa, what are some of the risks, the basic problems in biology?” There are several, making the physiology complicated. When tissues are cooled slowly, water migrates out of cells and ice forms in the extracellular space. Too much extracellular ice can cause crush injury to the cell membrane. Also, moving water out of the cell can cause dehydration damage. Although some tissues can tolerate some extracellular ice, most can’t tolerate ice inside the cell. To mitigate some of these problems, tissue can be flash frozen. In 1963 Peter Mazur, at Oak Ridge National Laboratory in the USA, showed that lethal intracellular freezing could be avoided if cooling was slow enough to permit sufficient water to leave the cell during progressive freezing of the extracellular fluid. That rate differs between cells of differing size and water permeability: a typical cooling rate around 1°C/minute is appropriate for many mammalian cells after treatment with cryoprotectants such as glycerol or dimethyl sulphoxide, but the rate is not a universal optimum. Even so, problems arise when trying to thaw frozen tissue.

The issues go on and on, and to me the bottom line is the process is not ready for prime time.