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Biomedical Engineering

The Biomedical Engineering blog is the place for conversation and discussion about topics related to engineering principles of the medical field. Here, you'll find everything from discussions about emerging medical technologies to advances in medical research. The blog's owner, Chelsey H, is a graduate of Rensselaer Polytechnic Institute (RPI) with a degree in Biomedical Engineering.

Don't be Myopic About Going Outside

Posted April 17, 2015 12:00 AM by Chelsey H

I got my first pair of glasses when I was 14 years old because I couldn't read the board from the back of the classroom. I remember walking out of the store and being surprised that I was able to read the names of stored across the parking lot - I didn't know I should have been able to see them.

But I am hardly alone in needing glasses, and nearsightedness is reaching epidemic status. More than 2.5 billion people around the world will have myopia by 2020. This problem is especially prevalent in China, where 90% of teenagers are nearsighted.

Myopia, also called nearsightedness, is caused by a slightly elongated eyeball, which means that the light is focused just in front of the retina instead of on it. The danger of myopia comes when the deformation stretches and thins the inner parts of the eye, which increases the risk of retinal detachment, cataracts, glaucoma, and event blindness. Image Credit

A recent article in Nature magazine (very interesting read) points to an interesting hypothesis behind the cause of all the nearsightedness: kids are staying indoors for too long these days. The hypothesis is based on several studies showing kids who spent more time indoors had a higher risk of developing myopia. And before you get to bashing computers - it's not the lack of physical activity that's causing the problem, it's the lack of exposure to bright light.

The eye grows throughout childhood and outdoor light promotes eye growth. One researcher encourages kids to spend at least three hours a day exposed to bright light - the equivalent of sitting under a tree wearing sunglasses.

Unfortunately, if you're already nearsighted it's too late to fix it with sunlight. But going outside is probably good for you anyway.

11 comments; last comment on 04/22/2015
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Memories and Men

Posted April 07, 2015 12:00 AM by Chelsey H

Sometimes it's nice to have science back up what we (and by 'we' I mean women) already know - that women have better memories than men. Not only is a man's memory worse than a woman's, but the part of the brain that controls memories is smaller in men.

Dr. Clifford Jack of the Mayo Clinic and fellow researchers studied a group of 1,246 cognitively normal people between the ages of 30 and 95. Overall they found that while memory started to decline for both sexes at age 30, male memory was worse than females' overall, especially after age 40.

Image Credit

This is due, in part, to the hippocampus being smaller in men than women, especially after age 60. The hippocampus is the part of the brain that controls memory.

"It's true, women's brains are smaller than men's brains, but brain size scales with your height," Jack said. "And so if you correct for head size, which we did, women's hippocampus and verbal memory is better than men's."

The protective effects of hormones keep a woman's hippocampus larger, especially estrogen which has been shown to shield pre-menopausal women from hypertension, bone loss, and heart disease. Progesterone, luteinizing hormone, and blood volume also help increase and maintain a woman's memory. This goes away for some women over the age of 50, but they still have had a lifetime of protective advantage giving them a residual effect for a number of years.

Dr. Jack also noted that one unusual, and hopeful, finding of the study was that memory and brain-volume starts to decline in your 30s and continue through old age occur well before there is evidence of Alzheimer's disease.

This means that being forgetful at age 50 or 60 may just be evidence of your brain aging instead of evidence of early Alzheimer's disease.

Still, your brain is going to age. Experts agree that anyone can benefit and delay signs of neurodegeneration by maintaining a healthy lifestyle through exercise of the body and brain.

Doctors recommend that you keep learning. Learn a new language, develop a skill such as piano or guitar, and take up painting or drawing. And a half hour interval burst of aerobic exercise helps your brain significantly.

And even today, do you trust your memory?

13 comments; last comment on 04/10/2015
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Testing Biologics

Posted March 17, 2015 3:24 PM by Chelsey H

A new type of test could help researchers give a more accurate prediction of how patients might respond to biologics, such as the cancer drugs Herceptin and Avastin.

Biologics are manufactured in a living system such as a microorganism, plant, or animal cell. They are very large, complex molecules and many are produced using recombinant DNA technology. According to, "Drugs generally have well-defined chemical structures... By contrast it is difficult, and sometimes impossible, to characterize a complex biologic by testing methods available in the laboratory, and some of the components of a finished biologic may be unknown." This makes biologics unpredictable not only in humans, but in various parts of a patient's body.

Biologics affect cell interactions deep in the body, making testing in petri dishes inadequate for observing all the side effects. Because these medicines are specific to humans, they can cause severe reactions that don't materialize in animal studies.

FASEB Journal recently published a new, more reliable test which only requires blood from one donor. Researchers from Imperial College in London isolated stem cells from a donor's blood and then grew endothelial cells in a petri dish to recreate the conditions in the blood vessels. Once the endothelial cells were established, the researchers took white blood cells from the same donor and combined them to recreate the unique donor's blood vessel conditions. Image Credit

The new method of combining cells from a single donor's blood can better predict whether a new drug will cause a severe immune reaction in humans.

1 comments; last comment on 05/07/2015
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Winter Blues

Posted March 06, 2015 12:00 AM by Chelsey H

It's no secret that this was a rough winter for the Northeast and I am very tired of talking about the weather. With March approaching there is hope for warm weather (and mud!) but not before we all still face the winter blues.

This winter has affected my mood more than previous winters. A condition called seasonal affective disorder, or SAD is a type of depression which manifests as sad, anxious, or "empty" feelings, feelings of hopelessness, guilt, restlessness, and irritability. It can also lead to loss of interest in activities previously enjoyed, fatigue or decreased energy, difficulty sleeping or oversleeping, and changes in weight.

The specific causes of SAD are unknown but researchers have been able to link several factors to the disorder. One reason is the lack of sunlight. Winter sunrise is later and winter nights are longer. This can cause melatonin, the hormone regulating sleep and wake cycles, to overshoot into the day leading to grogginess for several hours. Serotonin is one of the many brain chemicals that affect mood and also varies seasonally. Lower levels are common in the winter.

So how can you beat winter blues?

Light therapy is a common and inexpensive treatment. You sit a few feet from a specially designed bright light, which mimics outdoor light. It's not a proven form of therapy but it does appear to cause a change in brain chemicals linked to mood. It also has been shown to result in headaches, mild nausea, and trouble sleeping.

Antidepressants are recommended for severe symptoms and may take a few weeks to fully kick in.

Psychotherapy is a more natural route. It can help you identify and change negative thoughts and behaviors that may be making you feel worse, learn healthy ways to cope with SAD, and how to better manage stress.

Prevention is the best medicine.

Sometimes the simplest solutions are the best. Going for a walk, even in the cold, can help to get enough light exposure - especially if it's within the first few hours of waking up. Of course, working out can help decrease stress and anxiety, which can increase symptoms of SAD.

Socializing is also a huge benefit to lifting the winter blues. It's easy to want to hibernate when it's cold and dark outside but it's important to connect with those around you!

Hopefully spring is right around the corner - I've seen enough robins to think that we'll see the sun again soon!

18 comments; last comment on 03/10/2015
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‘Smart’ Test for HIV

Posted February 22, 2015 12:00 AM by Chelsey H

A paper published in the journal Science Translational Medicine describes how a $34 smartphone attachment rapidly and accurately detected the presence of HIV and syphilis antibodies in drops of blood taken from pregnant women. Ninety-six people took part in the study done in Rwanda and demonstrated that laboratory-quality diagnostics can be run on a pocket-sized device that works well in field conditions.

The attachment is approximately the size of the phone itself, is made of plastic, and uses disposable cartridges costing just pennies. A worker loads a blood sample which mixes with reagents in microscale channels with the cartridge. Gold nanoparticles then bind to antibodies and silver nanoparticles form a film around the gold particles.

The silver film blocks light transmitted through the finished sample, indicating the test results within 15 minutes. The results are automatically loaded into the phone's storage. Image Credit

Over the past few years the research group has miniaturized the technology, reduced its power requirements, and integrated it with everyday mobile devices. The tiny amount of current in a smartphone's audio jack is all that's needed to power the sensing and data management. A specially created software records the results of tests and uploads those results to a server.

"This work is a proof of how technology can improve diagnosis and care, making it faster and simpler and cheaper without compromising the existing quality," says Sabin Nsanzimana, the manager of the sexually transmitted disease division at Rwanda's Ministry of Health.

The group is planning a larger-scale field trial and sees far broader implications for smartphone-based diagnostics. The technology can be used for a variety of different applications and provides easy, inexpensive, and accurate ways to test for diseases in developing countries.

1 comments; last comment on 02/22/2015
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Another Win for 3D Printing

Posted February 15, 2015 3:14 PM by Chelsey H

A little girl named Violet was born with a rare defect called a Tessier facial cleft. The defect left a fissure in her skull, but doctors have found a way to use 3-D printing to help during the complicated surgeries.

A Tessier facial cleft caused a large growth over Violet's left eye, setting her eyes very far apart. She also had no cartilage in her nose. The bones that normally join to form the fetal face had not fused properly.

Before the operation, Dr. Meara at Boston Children's Hospital wanted a more precise understanding of Violet's skull so he had a colleague print him a 3-D model of Violet's skull, based on magnetic resonance imaging (MRI) pictures.

Image Credit

The model helped the doctor decide the surgical options and discuss his treatment plan with Violet's family. Additional printouts allowed Dr. Meara to rotate the model skull in directions he could not manage with a picture and would not attempt with a patient on the operating table. It also allowed him to cut and manipulate the plastic model to determine the best way to push her eye sockets more than an inch closer together.

Experiments with the models showed the doctor where bones would touch and where problems may occur throughout the surgery, even allowing him to consult the model during the surgery, which went as planned.

The surgical simulation program has been shown to improve team communication and trust, lift confidence before extremely complex operations, and shorten a patient's time under anesthesia.

Models such as the ones used by Dr. Meara are transforming medical care by giving surgeons new perspective and opportunities to practice complex procedures. Hospitals are also printing training tools and personalized surgical equipment.

Watch the amazing story in the video here.

2 comments; last comment on 02/18/2015
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