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Articles from 2011 In May

New NMR Spectroscopy Method Could Lead to Future Diagnostic Devices

Standard nuclear magnetic resonance (NMR) spectroscopy requires the use of a very high magnetic field created by large superconducting magnets cooled by liquid helium. Because this method is unwieldy and expensive, it cannot translate into small medical diagnostic devices. Now, however, an article posted at published by the Institute of Physics (London) reports that a group of researchers at the Nuclear Science Division at the University of California, Berkeley has learned how to perform NMR spectroscopy without magnets. As a result of their work, small personalized medical spectrometers may not be so far off, after all.

Currently the size of a room, nuclear magnetic resonance spectroscopy could eventually dispense with large magnets and accommodate small diagnostic devices.

Conventional NMR works by bombarding a sample with radio waves and measuring the energy absorbed or emitted when nuclei flip between two states: spin-up and spin-down. Because the same nuclei in different parts of a molecule have slightly different transition frequencies, measuring these frequencies allows researchers to work out the location of particular atoms in the molecule. To resolve different frequencies, bigger magnetic fields are better.

While nuclear spins interact with the magnetic field, they also interact with one other. Known as J-coupling, this interaction results in signals that can provide a great deal of information about a sample's chemical structure.

The Berkeley scientists' achieve this type of spin coupling by employing parahydrogen-induced polarization, which transfers a special kind of polarization to the sample molecule, enhancing the signal. Uniquely, their method accomplishes this transfer in zero field. The researchers also use a technique known as an optical atomic magnetometer to measure the faint magnetic fields. This technique, which does not require refrigeration, can also be employed at zero field.

The team has demonstrated the viability of its technique by distinguishing between several similar hydrocarbon molecules. Its success points the way toward future NMR technology that is smaller and less costly than today's NMR spectrometers.

Swivel Casters Designed for Light Loads

A range of light-duty swivel casters is available for a variety of applications, including use with carts, dollies, medical equipment, furniture, mobile stands, and displays. The Flexello brand D-Series is offered in four wheel sizes (2, 3, 4 and 5 in.) with load capacities that range from 110 to 220 lb. per caster. Available in top-plate and bolt-hole models with a choice of rubber and nylon wheels, the casters have a plain bearing designed for light loads. All casters in the series can be ordered with an optional foot brake.

The Revvo Caster Company, Inc.
West Seneca, NY, 716/675-9609

Sintering System Features 400-W Fiber Laser

An improved version of a direct metal laser-sintering system is available with a 400-W fiber laser for faster and more uniform processing, among other changes. The higher-power laser on the EOSINT M 280 can melt more metal powder per second than the previous-model EOSINT M 270, increasing build time and productivity. The new model also has a taller maximum building height (325 mm) and an optimized gas management system. The EOSINT M 280 can run either nitrogen or argon atmospheres in the chamber. The system also features part property profiles for standardized part manufacture.


Munich, Germany, +49 89 893360

Boston Scientific Accidentally Paid Sales Rep $200K; Company Wants it Back

 A sales rep from Boston Scientific was apparently paid  $200,000 more than he was supposed to be paid, due to an administrative mistake. The device maker is suing Michael J. McCormick to get the funds back. From the Pioneer Press:

The company said it offered to remedy the situation by offering McCormick a new employment agreement that would account for the overpayment, which Boston Scientific says came to $200,605.46. But McCormick rejected the proposal, the lawsuit claims, and contacted the company earlier this month to say he was resigning.

I guess that means he won't be getting a fun, "Bank Error in Your Favor" card. (h/t MassDevice)

— Thomas Blair


Study: Medtronic Spine Product Connected to Male Sterility

According to a Stanford University study that's been making waves over the last few days, a biological agent from Medtronic that is used in back surgeries may be linked to a condition that causes sterility in men. From the Web site MedPage Today

The Stanford team found that in their patients use of recombinant human bone morphogenetic protein-2, or BMP-2—marketed as Infuse by Medtronic—was associated with a measurable rate of retrograde ejaculation, a condition that causes sterility.

Earlier research did not link the product with the condition, but then, that research was performed by doctors with financial ties to Medtronic. And, as they say, therein lies the rub. Because the clinical trials that were performed in order for the product to gain FDA approval did find evidence of a connection. According to MedPage Today, a clinical trial from 2002 found that "five of 78 men treated with BMP-2 developed the retrograde ejaculation compared with one of 68 men who received the standard hip bone graft," while "in another arm of the clinical trial, an additional six of 57 men (10.5%) treated with BMP-2 also developed retrograde ejaculation."  

This is casting doubt on the relationship between the device company and the researchers who have vouched for the product. From the Milwaukee Journal Sentinel

...last year alone Medtronic paid more than $6 million in royalties to a handful of doctors who over the last nine years co-authored papers about Infuse without cautioning that it was linked to male sterility.

The paper notes that none of the royalties were directly tied to the product.

In addition to the Stanford researchers, a Croatian doctor has been challenging the safety of the Medtronic product.

What do you think? Does this taint research about the safety of a product that is performed by people with financial ties to the company that makes that product? Or is this just a case of researchers drawing conclusions that may be in opposition to each other but which are equally morally tenable?

— Thomas Blair


Threaded Receptacles Are Precision Machined Using a Brass Alloy

Custom socket receptacles are available in threaded or tapped versions. They can be implemented in specialized applications that require a nonsoldered, field-replaceable interconnect, such as a socket location terminated on a metal plate. Tapping the interior back hole of a receptacle allows for screw attachment of threaded mating pins. The receptacles are precision machined using brass alloy and press-fit assembled with a high-reliability beryllium copper contact. They are available in 36 different sizes, accommodating mating pins that range in diameter from 0.008 to 0.102 in.

Mill-Max Manufacturing Corp.
Oyster Bay, NY, 516/922-6000

Wire EDMs Increase Company’s Capacity

A company recently added wire electrical discharge machines (EDMs). The five Sodick AG400L wire EDMs bring the company’s total to 43. They will enable it to continue to provide competitive delivery times for clients. The company is one of the largest wire EDM facilities in the United States, with locations in Waukesha, WI, and Cary, IL.
Xact Wire EDM Corp.
Waukesha, WI

Students Test Stent Material in Simulated Arteries

Device designers are likely familiar with achieving very different results when testing components in vivo, compared with those obtained in vitro. A team of students at Michigan Technological University (Houghton, MI) have made advances in testing stent materials both inside and outside the body, however, by testing materials in the aortas of rats. This method has enabled them to create a way to replicate what happens to manmade devices inside a simulated blood vessel.

Michigan Tech Stent Testing
Students created a simulated artery environment to get in vivo results for stent material testing. Image credit: Marcia Goodrich/ Michigan Technological University

An interdisciplinary senior design team at Michigan Tech, funded by medical device manufacturer Boston Scientific, implanted tiny wires in the aortas of rats, subjects much smaller than the rabbits and pigs traditionally used for stent testing. Over time, the wires became coated by calcium and phosphorus, and eventually a layer of cell tissue. Next, the team created a cell culture medium chemically similar to blood by using iron, magnesium, and a protein involved in blood clotting called fibrin. The same wire samples were placed in containers inside an incubator; flow chambers were used to create circulatory fluid flow over the coated wires.

The wire corrosion results were the same in the rats and in the fibrin mixture. "In the past, in vivo and in vitro corrosion rates have always been different," says Jaroslaw Drelich, an associate professor of materials science and engineering and the group's coadvisor. "These appear to be identical."

According to Jeremy Goldman, an associate professor of biomedical engineering and the team's other coadvisor, Boston Scientific is impressed so far with the results obtained by the students. The company is particularly interested in investigating bioabsorbable stents, which are absorbed into the body over time.

"The rat model could help reduce reliance on large animals. And the students' in vitro model might make it possible to reduce the use of animals overall," Goldman says. "They've done cutting-edge work. For undergraduates to accomplish this shows a high level of effort and dedication."

Theft of Boston Scientific Devices Likely an Anomaly

Image from iStockPhoto.

The theft, which happened in April, was widely reported, with the company alerting customers to keep an eye out for the devices. According to the company, the devices were labeled “sterile” despite the fact that they were never sterilized, making them a potential health risk to patients, if they ever end up being used.

Does this latest incident mean that thieves are going to turn their attention to sophisticated medical devices? Is this the beginning of a crime wave, a spree of thefts involving implantables and prosthetics?

Not likely, says Richard Lincoff, who leads the medical devices practice at business consulting firm Cognizant (Teaneck, NJ). Lincoff says that he doesn’t “hear a lot about theft in our industry” when it comes to Class II and Class III devices. “I’m sure it occurs,” he says, but by their nature, those types of products “are much more difficult to move.”

There are a number of reasons, he says, for thieves to avoid looting such devices. Because of the way they are purchased in the United States—from highly regulated and well-known sales outfits—it would be very difficult for a third-party thief to find someone willing to buy them.

This is in contrast to pharmaceuticals, which are more intensely targeted by thieves. Pharmaceuticals can be resold much more easily on a secondary market that features high levels of demand, making them much more valuable. 

“Medical devices, people don’t swallow them, they don’t give you a high, and they can be tracked, because they have serial numbers,” Lincoff says. “And they do break down, and so how are you going to get them fixed?” He points out that off-market medical devices would not, obviously, come with access to any sort of customer service.

Medical devices are also closely tracked in case they need to be recalled, which would also make them easy to recognize if they’re stolen and illicitly resold.

“Take a product like a hemoanalyzer,” Lincoff says. “If you stole one of those, well, you’re dealing with $50,000 or more of equipment. Most of the parts in there have numbers, and those numbers are associated with that particular instrument. So if you were going to sell it on the hot market, you’d have to find some sleazy lab. But once they called it in to get it fixed because those things are pretty difficult—they’d be in trouble.”

These barriers would seem to put a natural limit on the market for stolen medical devices, says Barry Tarnef, a senior risk specialist with insurance firm Chubb Group (Warren, NJ).

“I wouldn’t think that the secondary market, if you will, for stolen medical devices would be as good as the secondary market for other stolen products,” Tarnef says. “There are other things that are easier to sell, and there’s a wider range of people that want them. People looking for medical devices are probably a very small niche.”

The threat of theft is such a small concern for manufacturers of Class II and III devices, Lincoff says, that many don’t even take any kind of extra security measure to protect their supply chains.

“The best tracking that you can have is because it is an asset that must be tracked,” Lincoff says. “So the very fact that they are tracking it. . . allows them, if something would happen, to announce ‘Here’s the following numbers, and this is why they’re gone.’”

“The industry makes products that are more difficult to use, and that in itself provides some protection,” he says.

However, just because there wouldn’t seem to be an obvious reason to steal medical devices doesn’t mean companies shouldn’t at least be aware of the possibility. For instance, devices are at risk of being lifted if they’re connected to, packaged with, or even just traveling next to pharmaceuticals.

“I think that just generally speaking, probably all cargo in transit is probably almost equally vulnerable,” Tarnef says. 

“If you’ve got, let’s say, a medical device shipment that happens to be comingled with a pharmaceutical shipment, even though your product may not be the target, if the load gets stolen, your product is now out of your care, custody, and control,” Tarnef says. “So that, certainly, would be an issue.”

Devices that are meant to be consumed or are easier to sell, such as many Class I devices, would also be at risk.

Additionally, there is the possibility that a thief is not deterred by the poor market and heavy tracking of more sophisticated devices.

“I’m not sure that’s common knowledge among the cargo thieves,” Tarnef says of product tracking. “Even if it is, [thieves] might be able to find a market that might be either off-market or outside the country.” While there may not be very many people interested in buying those devices, Tarnef says, “you only need one person to buy it. So if one person has a market or can find a market for whatever you stole. . . whether it’s serialized or not, maybe they can do it.”

Whatever the motive, a theft is still a problem.

“If a load is stolen, whether it was stolen by somebody who actually actively targeted that load, or [someone] who just stole it because it was an opportunity theft, at the end of the day, does it really matter to the medical device manufacturer?” Tarnef says. “I think not.”

Medical device makers may not have to prepare for a sudden rise in theft, but Tarnef says security is still something they should pay attention to.

“How do they protect their product from physical damage?” Tarnef says. “Maybe theft and pilferage becomes another thing to think about.”

With regard to the stolen Boston Scientific devices, a company representative said there are no updates to report. A list of the stolen items, complete with pictures and serial numbers, was published shortly after the theft.

Artificial Collagen-Based Wound-Care Tissue Promotes Vascular Growth

Scientists from Cornell University (Ithaca, NY) have developed an artificial wound-care tissue that promotes vascular growth. The new material could encourage healthy skin to invade the wound area, hasten healing, and reduce the need for surgery.

Known as a dermal template, the material was engineered in the lab of Abraham Stroock, an associate professor of chemical and biomolecular engineering and member of the Kavli Institute for Nanoscale Science, in collaboration with Jason A. Spector, assistant professor of surgery at Weill Cornell Medical College.

Measuring about the size of a dime and exhibiting the consistency of tofu, the template is made from Type 1 collagen, a biocompatible material that contains no living cells, thus reducing concerns about immune system response and rejection. The material promotes the in-growth of a vascular system to the wounded area by providing a template for growth of both skin tissue and blood vessels.

The template was fabricated using tools at the Cornell NanoScale Science and Technology Facility to contain networks of microchannels that promote and direct the growth of healthy tissue into wound sites. While dermal templates have been created previously, current versions do not efficaciously encourage growth of healthy tissue because they lack the microchannels developed by the Cornell researchers. A key finding of the study is that the healing process responds strongly to the geometry of the microchannels within the collagen because they guide healthy tissue and vessels to grow toward the wound in an organized and rapid manner.