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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.

‘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.

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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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Dirt to the Rescue

Posted January 27, 2015 12:00 AM by Chelsey H

I'm a firm believer in the old adage "God made dirt, dirt don't hurt," and it turns out that dirt might soon be saving lives.

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A novel microfluidic device is used to grow soil bacteria by researchers in Boston and Bonn, Germany. The researchers say they have identified a new type of antibiotic that kills the bacteria that cause pneumonia, staph, and blood infections. Backyard dirt might have yielded the most powerful antibiotic discovered in decades.

This is a timely discovery. Last year the World Health Organization predicted that a "discovery void" for new antibiotics could lead to an era in which minor injuries and common infections become deadly again.

The antibiotic, named teixobactin, has yet to be tested in people, but it cured mice of pneumonia, staph, and blood infections. It was discovered using a new technology for soil prospecting that was developed by a biologist at Northeastern University in Boston, which used a two-inch-long microfluidic chip that acts as a portable diffusion chamber.

The research team diluted dirt made mud to capture a single soil microbe in each of 306 tiny holes on the chip's surface. The bacteria was put in a tub of dirt and therefore "tricked" into growing colonies robust enough to be transferred to a petri dish. From there they were tested to see if they produced antibiotics.

9 comments; last comment on 02/03/2015
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Medieval Hygiene

Posted January 27, 2015 12:00 AM by Chelsey H

It's romantic to think about being a prince or princess in medieval times. The pageantry and chivalry seem almost idealistic…but once I start to really think about what it was like to live back then I realize that I'm much happier in a world with plumbing and deodorant. In case you were wondering, here are some down-right medieval hygiene practices.

Privies and garderobe - Tudor houses had toilets made from a bowl with a slab of wood and a hole carved at the top. Builders set the toilet into a recess of a cupboard-like area called a garderobe. In castles, the wood covers a hole in the floor that took the waste straight into the moat. Poor people relieved themselves wherever they could and just buried the waste in cesspits in their cellars or outside.

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Bathing in the same water - Public baths were popular in the 13th century. Since firewood (and therefore hot water) was a "hot commodity," bathing became expensive so whole families and friends would share a bath or just remain dirty.

Laundry - Since few were bathing they had to at least wash their clothes. Laundry detergent at the time consisted of a mixture of lye made of ashes and urine in order to remove stains and clean their clothes. Oh, and some people never bothered to change or clean their clothes anyway.

Make up - Ceruse was used as foundation for men and women because it gave them a smooth, pale look. It also contained a heavy amount of lead that seeped into the body and poisoned them. Also, even the wealthy had brown teeth. Many would chew herbs, rinse, and rub their teeth with cloth to try to clean and freshen their breath.

Lice - Nits and lice were so common that many wealthy people would shave their hair and wore periwigs instead. Unfortunately, even the wigs would be infested with nits, especially during plagues.

No forks - Some members of the church condemned using forks citing that God gave people fingers for a reason. Bread was used to wipe faces and fingers.

Nose-gays - A small bouquet of flowers or sachet of herbs was used to keep the smells (often from cesspits) at bay while walking through a crowd. It was usually held in the hand or pins on the wrist. This is also the inspiration for "pocket full of posies" in the loving (but pretty morbid) child's rhyme "Ring around the Rosie."

Infection from rushes - Rushes or straws were often used to cover up the natural dirt floor of a building. This was one of the biggest sources of infection since many people only changed the top layer of rushes.

Bird droppings on the bed - Without proper protective roofing it was common for bugs, pests, and even bird droppings to fall on to the clean bedding. The canopy bed was invented to keep everything from falling from the room on to the bed.

Chamber pots - Containers used to collect urine during the night. To top off the bathroom routine was the fact that toilet paper didn't exist yet. Poor people used leaves or moss, while the rich used lamb's wool.

So there you go - from morning to night, the life of a medieval person was tough and smelly. But they did develop some ingenious solutions to ease their troubles!

7 comments; last comment on 01/31/2015
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No Food Beyond This Point

Posted January 02, 2015 12:00 AM by Chelsey H

New Year's resolutions almost always seem to include "eat healthier" and "exercise more" (at least mine always do!). But have you ever thought about fasting?

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Intermittent fasting has no definite length of time. It can be anywhere from fasting for 14 hours at a time to fasting for a couple days a week, as long as you are restricting food consumption during specified periods. The goal is to consume little to no calories during the "fasting" periods and eat normally during the "feasting" times. (I'm already hungry thinking about this.)

But don't start fasting yet since it can have a major impact on your workout.

Your body uses glycogen, or stored carbohydrates, for fuel during exercise except when glycogen reserves are depleted, such as when you've been fasting. Your body is then forced to find and burn other energy sources, such as fat. In one study done by British Journal of Nutrition, men who ran before eating breakfast burned up to 20% more fast than those who ate before their run.

When your body can't burn glycogen, it reverts to breaking down protein for fuel. So you may shed more fat when exercising, but you may also lose muscle. Not only will this loss of muscle result in loss of strength, it will slow your metabolism and make losing weight harder in the long run. This happens because as your body tries to prevent starvation it adapts to the number of calories you give it.

Fasting regularly, therefore, causes your body to burn fewer calories per day to ensure you have enough every to stay upright and breathing. One study showed that fasting every other day for 22 days resulted in a 5% drop in the subject's metabolic rate (about 83 calories). Plus exercising while your stomach is rumbling just isn't a pleasant feeling, you'll probably feel weak and not have the energy to push your self during the workout.

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If you're still a fan of intermittent fasting then just be sure to structure your workouts so you can still get results and be safe. For example, keep cardio low-intensity if you've been fasting and go high-intensity after meals. This ensures that you have enough glycogen to fuel your workout. Also, follow up a tough workout with a carb-rich snack. Other things to keep in mind include what you're eating while you're "feasting." Regular protein is vital to muscle synthesis throughout the day as well as right after a workout so your meals should include 20 to 30 grams of high-quality protein every four hours while you're awake. During your feast time take advantage of snacks and aim for a meal that combines fast-acting carbohydrates with a blood-sugar-stabilizing protein and eat a high-protein post-workout snack.

I don't think I'm going to be fasting any time soon since I'm all about snacks! Guess I'll have to fulfill my New Year's resolution another way.

5 comments; last comment on 01/03/2015
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A Gluten Story, Part 2

Posted December 16, 2014 12:00 AM by Chelsey H

Gluten can be eaten by itself and has become a common substitute for meat and tofu. It is particularly popular in Asia, where is goes by the name seitan and is often steamed, fried, or baked.

An interesting twist to this story comes when we start looking at the amount of gluten added to industrially made bread. (To read part 1, please visit here. ) Most of the bread in the U.S. is made by replacing hydration, fermentation, and kneading with artificial additives and huge industrial mixers. Image Credit

In the nineteenth century steel rollers and industrial mills replaced stones in the wheat grinding process. Steel was fast, efficient, and easy to maintain. Millers discarded the germ and the bran in the wheat kernel, along with most of the vitamins, fiber, and most of its healthy fats.

Most bakers include an additive called vital wheat gluten, made by washing wheat flour with water until the starches dissolve, to strengthen the dough and help the load rise. According to the New Yorker, "In general, the higher the protein content of wheat, the more gluten it contains." Vital wheat gluten is a powdered, concentrated form of gluten that is found naturally in all bread. The extra gluten is added to provide the strength and elasticity necessary for it to endure industrial mixing. Image Credit

Chemically, vital wheat gluten is identical to regular gluten - but some worry it's a crutch to add storage and functionality to the final product. Even though it doesn't add flavor it's added to pastas, snacks, cereals, and even some cosmetics. According to scientists at The Bread Lab in Washington, it makes bread taste like mush.

The FDA defines bread as being made of flour, yeast, and a moistening ingredient, usually water. Bleached flour uses chemicals like acetone peroxide, chlorine, and benzoyl peroxide (still to be determined if bread will treat your breakout). Other possible ingredients include shortening, sweeteners, ground dehulled soybeans, coloring, and potassium bromate.

It's not possible to manufacture, package, and ship large amounts of industrially made whole-grain bread without adding something to strengthen the dough. Even "healthy" whole-wheat breads are packed with gluten under various ingredient names such as "whole-wheat flour, water, wheat gluten, and wheat fiber." Image Credit

There is a gluten-free movement happening in America. Sales of gluten-free products have doubled in the past five years and more than two hundred million dishes were ordered gluten free (also in the past 5 years?). While products started out only being sold in small boutique stores, they are now easily found in popular nation-wide chains. But the diet can be unhealthy, loaded with ingredients such as rice starch, cornstarch, tapioca starch, and potato starch. These contain highly refined carbohydrates and release at least as much sugar into the bloodstream as the foods given up. When it comes down to it, when the good things that sell food (salt, fat, and gluten) are removed more of another is added to keep it tasty. Gluten-free cake is still cake.

Although "gluten-free" is probably just another fad diet, large-scale, long-term testing should be done to look at the effect of added gluten in American diets but we won't have the answer for years. In the meantime, those who do have celiac disease have options, because who wants to go their whole life without pizza?

This blog is adapted from "Against The Grain"

7 comments; last comment on 12/22/2014
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