According to the company, the AD5791 high-accuracy 20-bit digital-to-analog converter (DAC) provides four times greater accuracy and four times more resolution than competing converters. 1-ppm analog system design typically entails the complex engineering challenges involved with combining multiple lower-resolution DACs with a significant number of discrete components and support ICs—along with considerable development risk and costly amounts of engineering time—to optimise circuit parameters, minimise errors and design complex auto-calibration circuitry. The AD5791, with its 1-ppm resolution and accuracy, low noise (sub 1 ppm), fast refresh rates (1 us), and extremely low output drift (sub 1 ppm), significantly simplifies the design task, lowers development cost and reduces risk, the company claims.

The Atrato can monitor flow over a range of 200:1 and has accuracy better than ±1.5%. It features an easy-to-use design and USB interface.

Its unique clean-bore construction makes the device suitable for hygienic applications. The use of low-frequency ultrasound and advanced signal processing to interrogate the flow ensures high accuracy over a wide turndown range. In addition, the technology developed for the Atrato has the flexibility to provide the basis of a family of flowmeters suitable for an even wider range of flows and applications.

The product will receive its official launch at MEDTEC UK on 27 and 28 April at the NEC in Birmingham.

The glass and polymer fibre-optic cables, coaxial and symmetrical conducting cables and preassembled cable systems ensure efficient data and signal transmission as well as power supply for Siemens’ Magnetom Aera and Skyra generation devices. Leoni also developed multifunctional hybrid cables with a smaller outer diameter than previous models, thus reducing overall unit weight. A new mobile table designed to increase MR throughput is also fitted with Leoni cables.

Leoni’s data transmission cable for Siemens’ X-ray machines transmits high-resolution pictures from flat image detectors. Thanks to its flexible structure, it does not hinder the mobility of the C-arm.

The cable’s innovative hybrid structure includes shielded copper pairs, sensitive polymer and glass fibre conductors for rapid data transmission and cooling hoses to prevent the flat image detector from overheating. During tests conducted at the Leoni facility, the cable easily withstood 2,000,000 bending cycles, as required by Siemens AG’s Healthcare Sector.

“We are consolidating our position as a supplier for the healthcare sector,” Dr. Klaus Probst, CEO and President of Leoni AG is quoted as saying in a press release issued by the company. “We consider medical technology to be an important market of the future, which will need more and more high-quality cable systems.”

MIT engineers have designed this wearable ECG monitor that runs on very little power and could replace cumbersome devices now used to monitor heart patients. Image courtesy of Eric Winokur

From the Wire: The next wave of the electronics revolution will involve biomedical devices, say electrical engineers in MIT’s Microsystems Technology Laboratory (MTL) who are working on tiny, low-power chips that could diagnose heart problems, monitor patients with Parkinson’s disease or predict seizures in epileptic patients. Such wearable or implantable devices could transform the way medicine is practiced and help cut the costs of expensive diagnostic tests, says Dennis Buss, former vice president of silicon technology development at Texas Instruments.

“Microelectronics have the potential to reduce the cost of health care in the same way they reduced the costs of computing in the 1980s and communications in the 1990s,” says Buss, a visiting scientist at MIT. On a limited scale, this is already taking place. For example, one of the first successful applications of microelectromechanical systems (MEMS) to medicine was the development of US$10 disposable blood pressure sensors, which have been in use for over a decade and replaced sensors that cost hundreds of dollars.

The market for MEMS for biomedical applications is more than $1 billion, and that could grow close to 100-fold by 2015, according to a 2006 market report from MedMarket Diligence.

Beating hearts

The key to developing small wearable and implantable medical monitors is an ultra-low-power chip for interfacing to biomedical sensors, signal processing, energy processing and communications, developed by the research group of MTL Director Anantha Chandrakasan.

Ultimately, Professor Charles Sodini, one of the MIT researchers involved in the effort, and others at MTL hope to use that chip as the core of a device that can monitor a range of vital signs — heart rate, breathing rate, blood pressure, pulse oxygenation and temperature. For now, they’re starting with a monitor that measures and records electrocardiograms (ECGs).

An unobtrusive, comfortable ECG monitor that patients could wear as they go about their normal lives might offer a doctors a more thorough picture of heart health than the lab tests now used, says Collin Stultz, an MIT associate professor of electrical engineering and health sciences and technology and a cardiologist working on the project. Cardiologists can order up treadmill stress tests, MRIs and CT scans, among other diagnostics, but “all of these tests are done in contrived settings,” says Stultz. “Data obtained from more realistic, ‘at home’ settings may provide added information that can reveal potential problems.” Furthermore, standard tests can cost from a few hundred to a few thousand dollars.

Doctors often ask recent heart attack victims, and other patients suspected of having heart issues, to wear an ECG monitor as a Holter monitor for a few days. However, the device, which consists of several electrodes that stick to the chest, plus a bulky battery pack carried at the hip, is cumbersome and doesn’t have the memory to store much data.

In contrast, the new MIT monitor is an L-shaped device, about 4 inches along each side, that sticks to the chest and can be worn comfortably, with no external wires protruding. It can store up to two weeks of data in flash memory, and requires just two milliwatts of power. Eventually, the researchers hope to build chips that can harvest energy from the body of the person wearing the device, eliminating the need for a battery.

Doctors can use ECG data, which provides information on the electrical health of the heart, to help spot future problems. Stultz, working with MIT Professor John Guttag and recent PhD recipient Zeeshan Syed, has designed a computer algorithm that uses ECG data to assess risk of death in heart patients. They found that higher variability in heartbeat shapes in data recorded the day after a heart attack correlates with an eightfold increase in the risk of cardiac death within 90 days in some patient populations.

Currently that analysis can only be done after the data is downloaded from the chip, but eventually Stultz hopes to incorporate the algorithm into the chip itself. He envisions that the device could be equipped with an alarm that would alert the patient or doctor that a heart attack is imminent. It could also serve as an early detection system for longer-term problems, letting doctors know they may need to perform additional tests, alter the patient’s medication or perform surgery.

The researchers have built a prototype and plan to start testing the device in healthy subjects this spring, followed by trials in patients with cardiovascular disease.

New directions

While Stultz and colleagues are focusing on wearable devices, other MIT engineers are working on implantable electronics for medical monitoring. To do that, they need to overcome a significant challenge: how to run the device indefinitely without a battery that needs recharging. To solve that problem, Associate Professor Joel Dawson is working on a device that stores energy in an ultracapacitor, which doesn’t wear out like batteries do. He hopes to use the device, which would be about the size of a grain of rice, to measure tremors and shaking in patients with Parkinson’s disease.

Dawson is working on that project with neurologist Seward Rutkove of Beth Israel Hospital. That kind of collaboration between engineer and physician is exactly what Sodini would like to see happen with all of MTL’s biomedical projects. “We start out working with physicians so they can help define the problem, and they can start testing the devices in the clinic early in the process,” he says.

Other projects underway at MTL include tiny ultrasound devices and “lab on a chip” devices that can perform diagnostic tests on body fluids. Engineers are also working on the best ways to wirelessly transmit data from wearable or implanted devices to a cell phone or computer.

While those applications are promising, the future of biomedical electronics likely holds even more potential than we can imagine, says Buss.

“We will be using electronics in medical ways we don’t even conceive of yet,” he says. “When we started using cell phones, we had no idea we would be playing games and watching TV and surfing the Internet the way we do now.”

More information on the research is available from MIT.

The definition of “time of use” in Annex IX is as follows:

This new definition will directly affect devices classified as Class I and Class IIa based on Rule 5 – Devices used invasively in body orifices, Rule 6 – Surgically invasive devices for transient use and Rule 7 – Surgically invasive devices for short-term use. This means that certain devices that were considered Class I because they were for transient use (less than 60 minutes) could now be moved to Class IIa.

The biggest impact of the rule will be on products that, until now, were classified as short-term use devices. They suddenly would find themselves subject to Class IIb requirements, i.e. invasive devices used in body orifices that are not intended to be connected to an active device (Rule 5). Tracheal tubing was one example cited during the Afssaps meeting. Currently classified as a Class IIa product based on Rule 5, tracheal tubes could be reclassified as Class IIb devices. Long-term (as opposed to short-term) use implies the need to conduct additional biocompatibility tests, among other requirements.

Regulators and industry are waiting for a revision of the MEDDEV 2.4/1 guidelines for the classification of medical devices, which has not been revised since July 2001. Examples in Part 2 of the document might help to clarify this issue. Unfortunately, there is no word on when a revision might be forthcoming.

As manufacturers grapple with compliance, competent authorities inevitably will respond that they have had more than two years to prepare for implementation of the revising Directive’s amendments. We can counter, however, that the European Commission also had two years to publish its guidelines, notes Clément.

René Clément is co-chairman of MediMark Europe, which serves as an authorised representative for manufacturers of medical devices and IVD products. For more information about the firm, visit the company’s listing in the online Consultants Directory.

Knowing enough about the way light is scattered through materials would allow physicists to see through opaque substances, such as the sugar cube on the right. In addition, physicists could use information characterizing an opaque material to put it to work as a high quality optical component, comparable to the glass lens show on the left. Image courtesy of American Physical Society

From the Wire: Biological tissue and other opaque materials are opaque because the light that passes through them is scattered in complicated and seemingly random ways. A recent experiment conducted by researchers at ESPCI has shown that it’s possible to focus light through opaque materials and detect objects hidden behind them, provided you know enough about the material. The experiment is reported in the current issue of Physical Review Letters, and is the subject of Viewpoint in APS Physics by Elbert van Putten and Allard Moskof the University of Twente.

To demonstrate their approach to characterise opaque substances, the researchers first passed light through a layer of zinc oxide. By studying the way the light beam changed as it encountered the material, they were able to produce a numerical model called a transmission matrix, which included over 65 000 numbers describing the way that the zinc oxide layer affected light. They could then use the matrix to tailor a beam of light specifically to pass through the layer and focus on the other side. Alternatively, they could measure light emerging from the opaque material, and use the matrix to assemble of an image of an object behind it.

In effect, the experiment shows that an opaque material could serve as a high quality optical element comparable to a conventional lens, once a sufficiently detailed transmission matrix is constructed. In addition to allowing scientists to peer through paper or paint, and into cells, the technique opens up the possibility that opaque materials might be good optical elements in nano-scale devices, at levels where the construction of transparent lenses and other components is particularly challenging.

More information on the research is available from APS.

“Because of the increasing demands placed on the performance of polymeric materials and composites, we recognised the need to support our customers in this competitive market,” says Managing Director Mike Day. “Maintaining our highest service levels means we pursue long-term investments, ensuring our customers have access to the latest precision technology delivered with a fast turnaround.”

Noncontact extensometers enable productivity improvements compared with contacting methods, achieving ease of use with precision performance, according to the company. The technology is suited for batch testing, high temperature testing, use in harsh environments, high strain >100%, high-speed impact testing and the testing of very small (<1 mm) or delicate samples. Strain, shear strain, poisson’s ratio, modulus, proof stress, ultimate stress and ultimate failure strain can be measured by the instrument.

Smithers Rapra provides global customers with a  range of independent contract services, consultancy and research on all aspects of plastics and rubber materials. It has extensive on-site analytical, testing and processing laboratories with relevant areas that work to CGMP guidelines.

Consolidation of the company’s three healthcare packaging businesses—Rexam Pharma, Primary Packaging and Prescription—and the establishment of technical centres in Europe, the United States and, most recently, India are milestones that bode well for the company, according to Lewko. “We brought together our technical staff in technical centres near Lyon in La Verpillière to develop devices, and in Perrysburg, Ohio, in the United States to work on innovative closures and containers. That has worked out very well,” says Lewko. “The establishment of a single healthcare group lets us offer customer support across the board in terms of technology. Meanwhile, our global reach and local presence allow us to fulfil customer needs at all levels.”

The company’s newest technical centre is in Bangalore. It is a “high-end operation,” says Lewko, which may go against conventional wisdom. The company had been shipping closures and bottles to India from Europe and the United States, where they would be processed by customers and then shipped back to Europe or to the United States. “It just made no sense to continue doing that,” says Lewko. “Now we have a GMP-compliant facility with an ISO Class 8 cleanroom in India that can do the whole operation.” India’s indigenous healthcare market is evolving quite rapidly, he adds. “We are involved with a good number of domestic manufacturers and we are seeing a growing demand for more sophisticated products including devices.”

Back on the home front, the company continues to do R&D work on drug delivery devices. It is developing new nasal spray pumps, a new valve platform for metered dose inhalers, preservative-free multidose droppers, safety devices for prefilled syringes and multilayer technology for containers.

Honeybee larvae produce silk to reinforce the wax cells in which they pupate and now CSIRO scientists have produced this silk artificially. Image courtesy of CSIRO.

From the Wire: CSIRO scientist Dr Tara Sutherland and a research team have hand-drawn fine threads of honeybee silk from a ‘soup’ of silk proteins that they had produced transgenically. As strong as threads drawn from the honeybee silk gland, the fibres represent a significant step towards the development of coiled silk biomaterials, according to the researchers.

“It means that we can now seriously consider the uses of these biomimetic materials,” Dr Sutherland says. “We used recombinant cells of bacterium E. coli to produce the silk proteins which, under the right conditions, self-assembled into similar structures to those in honeybee silk,” she adds. “We already knew that honeybee silk fibres could be hand-drawn from the contents of the silk gland so used this knowledge to hand-draw fibres from a sufficiently concentrated and viscous mixture of the recombinant silk proteins. In fact, we had to draw them twice to produce a translucent stable fibre.”

Sutherland says numerous efforts have been made to express other invertebrate silks in transgenic systems but the complicated structure of the silk genes in other organisms means that producing silk outside silk glands is difficult.

“We had previously identified the honeybee silk genes and knew that that the silk was encoded by four small non-repetitive genes – a much simpler arrangement which made them excellent candidates for transgenic silk production.”

Possible practical uses for these silks would be tough, lightweight textiles, high-strength applications such as advanced composites for use in medical applications such as sutures, artificial tendons and ligaments.

More information on the research is available from CSIRO.

Parylene conformal coatings are ultra-thin, pinhole-free polymer coatings that can be used for a variety of surface treatment applications owing to their dry-film lubricity; thermal and UV stability; and  moisture, chemical and dielectric-barrier properties. Routinely used in the medical device sector, parylene can be used to treat products ranging from coronary stents to cochlear implants. Additionally, as nanotechnologies push their respective envelopes into ever smaller dimensions, performance reliability in the various environments these devices encounter has prompted many manufacturers to investigate parylene conformal coatings.

The seminars are designed to appeal to engineers in many disciplines, including R&D, design, manufacturing, quality, materials and electronics, as well as to those involved in regulatory affairs and product management.

The dates and locations of the seminars are below:

Munich, Germany; 26 March

Düsseldorf, Germany; 29 March

Paris, France;  23 April

Brussels, Belgium; 26 April

Birmingham, UK;  29 April