Engineering News

Second sight for
surgeons

Real-time imaging in the OR will speed healing,

cut health-care costs

Newton, MA--Magnetic-resonance imaging transformed diagnostic
medicine over the last two decades. Now, it's about to change surgery too, as
machines capable of real-time, high-resolution displays of internal topography
make their way into the operating room.

"This has the potential to revolutionize the operating room as it is known today," claims Dr. Ferenc Jolesz, director of the image-guided therapy program at Boston's Brigham and Women's Hospital.

Instead of the tunnel-vision views from endoscopes, so-called image-guided therapies let surgeons see beneath the surface of organs and view their instruments in spatially correct context. Such therapeutic imaging will expand the range of minimally invasive surgical procedures and thus help lower the personal and financial costs of health care. Doctors and engineers involved say that they're only beginning to explore these machines' potential.

Dual-doughnut design. Two experimental designs illustrate that promise. General Electric's Signa MRT (magnetic resonance therapy) system features "dual-doughnut" magnets that allows a surgeon access to a patient positioned between them. Using non-ferrous instruments chosen to be compatible with the body's magnetic characteristics, the doctor can view the patient's internal organs on an LCD screen within the magnetic field.

Kirby Vosburgh, manager of the Imaging and Visualization Laboratory at the GE R&D Center, Schenectady, NY, explains that the machine represents several breakthroughs in MR design. Along with the split, cryo-cooled, superconducting magnets, teams from the R&D Center; GE Medical Systems, Milwaukee, WI; GE's manufacturing operations; and clinicians developed unique radio-frequency pulse generating hardware and advanced electronics and software to speed data collation.

How fast is the Signa MRT? "We can drive it like an ultrasound machine," says Vosburgh. Using a probe as a geometric position indicator, surgeons can image any area of interest within the field. Selection and execution of the proper RF and gradient pulse sequences for a given area takes 1/30th of a second. "With a conventional machine that could take days," jokes Vosburgh. "It's real-time and interactive."

A machine at Brigham and Women's is being used initially to guide needle biopsies as well as "thermal therapies" for treating tumors by freezing or heating with a laser. On the horizon: completely non-invasive thermal therapy using RF or ultrasound energy focused on tumors while the MRT monitors temperature changes, preventing damage to surrounding healthy tissue.

According to Vosburgh, the "real" inventions will take place over the next few years when doctors develop entirely new procedures made possible by the MRT--advances such as spinal surgery on a seated patient. The machine's success depends on such discoveries. "If they can come up with procedures that are obviously better than anything else available, people will see this as cost-effective."

Meanwhile, in Cleveland, doctors are working with an experimental technique that superimposes real-time ultrasound images of surgical instruments onto fixed, pre-operative 3-D MR images to guide surgeons during operations. Developed by Picker International along with doctors from the Cleveland Clinic Foundation, the system is currently limited to cranial surgeries, since unavoidable motion in other parts of the body quickly render pre-op MR images inaccurate. Nevertheless, in 200 surgeries with the device, complications, hospital stays, and surgical costs each declined at least 30 percent compared with conventional procedures.

Now, it's about to be transformed into a more-widely applicable device called CAMIS--Computer Assisted Minimally Invasive Surgery. Working with the Air Force's Wright Laboratory and the Ohio Aerospace Institute, CAMIS researchers hope to give the system the ability to redraw MR images during surgery using ultrasound data.

"We'd effectively have real-time MR imaging without the MR equipment," explains James Leonard, Air Force project leader for CAMIS. The team's hopes rest on defense technologies for "sensor fusion" developed for applications like updating moving-map displays with radar information collected in flight.

In addition, the team is working on a helmet-mounted 3-D display that would give surgeons a virtual-reality view of the patient before them. Voice-recognition circuitry also under development would allow rotation of views without touching controls. Such systems would avoid the problem of doctors looking away to a screen and then reorienting themselves to the work at hand.

Leonard concedes that they're not there yet. "Sensor fusion isn't a solved problem," he says, "and we're still developing the inverse mapping functions to update the MR image." Still, he expects the system to emerge in some form within five years.

The potential for improved minimally invasive surgery is enormous. By one Air Force estimate, the ability to see without incisions could save this country $10 billion in health-care costs from quicker recoveries alone.


Kit jumpstarts designs for new medical bus

Julie Anne Schofield, Associate Editor

Bohemia, NY--A newly approved standard for a "Medical Information Bus" (MIB) will let bedside devices and hospital computers from multiple vendors interoperate without custom software or hardware interfaces. To help speed design of MIB medical equipment, ILC Data Device Corp. has developed an IEEE 1073 Prototype Development Kit.

Approved late last year, IEEE standard 1073 defines a data communication interface between bedside medical devices and hospital patient-care computers. The standard is based on the ISO Open System Interconnect (OSI) 7-layer model. Thus, it will provide plug-and-play operation from the connectors and cabling to software.

Today, data transfer is possible only through RS-232C ports. These ports are not standard on medical devices--people use the pins in different ways. Bob Kennelly at DDC claims you can blow up a laptop computer simply by plugging an infusion pump into it.

IEEE 1073 defines an active star topology that involves two types of communications stations: a device communication controller (DCC) and a bedside communication controller (BCC). A DCC provides an embedded 1073 into a bedside medical device such as an infusion pump or cardiac monitor. An external converter box interfaces with existing equipment.

DDC's kit includes an IEEE 1073 BCC board for an IBM PC, RS-232C to 1073 DCC converter box, cable assembly, medical-rated power supply, and software for the BCC board and converter box. It sells for $4,500. DCC's MIB port chipsets debut this spring. For more information about the IEEE 1073 standard, phone (908) 562-3800.


'95 forecast bright for America's OEMs

Sharon Machlis, Senior Editor

American manufacturers can look forward to another strong year in '95, as they are once again ex- pected to outshine the overall U.S. economy.

"The outlook for manufacturing continues to be quite good," says 3M Corporate Economist John McDevitt. "Technological innovation, creativity, improvements in quality, and focus on the customer will result in continued growth--regardless of who's in Washington."

McDevitt is projecting 2.5 to 2.75% real growth, adjusted for inflation; Cahners Economics predicts a similar rise of 2.2%, as the current business cycle matures.

That's a bit of a slowdown in the U.S. expansion, which was an estimated 3.5% in '94; but OEMs here should benefit from economic rebounds abroad. "More and more, U.S. manufacturers are finding that exports offer opportunities for growth that had previously been limited by small gains in domestic activity," according to the Cahners 1995 Economic Outlook.

As American manufacturers continue to make advancements in productivity and quality, exports are expected to soar. "By the year 2000, we should see a trade surplus of $5 billion," McDevitt predicts.

Industrial machinery. Aggressive capital-investment programs helped propel the industrial-machinery and equipment sectors to strong increases in the past two years. "Although some slowdown in growth is inevitable in 1995, most sectors will enjoy another good year," Cahners predicts. One top growth area: machinery for service industries and construction.

The electronics industry showed stronger-than-expected expansion in 1994, with component sales rising almost 18%. Cahners is expecting "a solid, if more moderate, expansion in mid-1995." Semiconductor sales should increase an overall 9%, while metal-oxide semiconductor microcomponents--including microprocessors--are predicted to rise 14%.

Two high-tech sectors Cahners expects to cool: Computer and office equipment, from almost 16% growth last year to 3.3% in '95; and communications equipment, from 22% last year to 3.5%. General test-and-measuring equipment should see 5% growth.

Post-Cold-War fallout. Defense electronics, which have seen a major slide following the breakup of the Soviet Union, should slow from an 8.8% decline in 1994 to a 6.1% drop this year. Aerospace, though, faces a shakeout as post-Cold-War mergers and cutbacks reshape the industry. "There's no indication that it's hit bottom," says James E. Challenger at Challenger Gray & Christmas, an agency which tracks job losses. "Over the last two years, they've seen more cuts than any other industry."

The auto industry should enjoy another year of respectable gains, with auto sales expected to rise 2.1% in '95 and light trucks--including popular minivans and sport-utility vehicles--increasing 3.8%.

And, consumer electronics should post a 5.9% growth in 1995, bringing shipments of household audio and video equipment to $13.3 billion.

Productivity boost. One of the most stunning achievements of U.S. manufacturing companies has been a steady increase in productivity, which rose about 5.5% last year, McDevitt notes. "Manufacturers have done a better job of managing their businesses than anybody anticipated," he maintains. "As a result, U.S. manufacturers are the envy of the world."


Heart-valve tool passes color test

Minneapolis--When it comes to surgical tools used to position heart-valve replacements, precision becomes a matter of life or death.

ATS Medical, Inc. faced a serious problem in producing such surgical implements. The high-temperature material it used to make these tools failed when it came to molding consistent colors in teal, maroon, and white. Also, the part exhibited a black speck marbling effect. Such defects can be catastrophic when you consider that the tool's size also indicates heart-valve size, and color indicates heart-chamber position.

The solution: switching to a precolored polysulfone compound supplied by RTP Co., Winona, MN, instead of a color concentrate. The result: improved dimensional stability, no material contamination, and the ability to undergo sterilization before and after performing a valve implant.


Urethane aids open-heart surgery

Buffalo, NY--In open-heart surgery, myocardial preservation--protecting the heart muscle--plays a critical role. An innovative tool, the Topical Cooling Device (TCD) made by the Ethox Corp., helps nurture this preservation. Lending an important assist in this effort: film made from urethane.

"Cooling protects the human heart during open-heart surgery," explains Mark Miller, product manager for COBE Cardiovascular, Inc., the Arvada, CO, company that markets the device. "When cooled, the heart's metabolic rate slows, the demand for oxygen is reduced, and the heart virtually stops. This process reduces stress on the heart muscle, and minimizes the potential of damaging the tissue."

During initial design stages, engineers considered making the TCD with polyvinyl chloride (PVC). Ultimately, they selected urethane because of its greater strength, flexibility, and efficiency in processing. "Flexibility was the driving force behind choosing urethane over PVC," says Bruce Tive, design engineer at COBE. "At low temperatures, urethane remains soft and flexible. Conversely, PVC can become so rigid that it could tear delicate muscle tissue."

For the TCD project, COBE selected urethane from JPS Elastomerics Corp., Northampton, MA. "JPS' urethane conforms well to the heart's shape and quickly goes from warm to cold and vice versa," Miller explains. "In addition, the material remains flexible at temperatures from 37C to 4C, which is deep hypothermia."

Purity proved another important factor in selecting urethane. "We required a virgin material that could be easily sterilized with ethylene oxide," Miller adds. "The JPS material has no plasticizers that can migrate out to weaken the original structure or contaminate the surgical setting."

How do customers feel about the TCD? "It has been widely accepted," says Miller. "In fact, we now have a large share of the market."


Spray process gives PEEK performance

Baltimore--Typically, coating components with polyetheretherketone (PEEK) requires two steps. First, the parts are sprayed with the PEEK powder, then they must be put through a heat cycle. Now, forget about step two.

Martin Marietta Laboratories has developed a way to apply PEEK to plastics, metals, and ceramics using a plasma spray-coating technique. "We can take the PEEK resin, put it in the hoppers, and in one step spray it and be finished," enthuses Greg Groff, a Martin Marietta engineer.

The process is not for neophytes, however. Groff cautions that the key to success lies in mastering the procedure. Groff spent more than five years varying process parameters in order to obtain the best results.

Did it pay dividends? Plasma spraying PEEK on various substrates provides "corrosion protection, wear resistance, and RF shielding," says Groff. "It's an excellent coating for pump liners and compressor parts."

Helping make the process more efficient is the use of Victrex PEEK, a product of Victrex USA Inc., West Chester, PA. "We experimented with a number of high-temperature resins before deciding on PEEK. It was by far the best for plasma spraying because of its flow, adherence, and coating properties," Groff relates.

The process offers another benefit: The plasma spray coating takes place in an environmentally controlled at-mosphere without using any carcinogenic materials.

Moreover, it is efficient and productive. "Everything is done robotically," Groff explains. "This means repeatability is excellent. You can be assured that the 500th part is the same as the first."


Engineering tools come to the operating room

Julie Anne Schofield, Associate Editor

Bohemia, NY--A newly approved standard for a "Medical Information Bus" (MIB) will let bedside devices and hospital computers from multiple vendors interoperate without custom software or hardware interfaces. To help speed design of MIB medical equipment, ILC Data Device Corp. has developed an IEEE 1073 Prototype Development Kit.

Approved late last year, IEEE standard 1073 defines a data communication interface between bedside medical devices and hospital patient-care computers. The standard is based on the ISO Open System Interconnect (OSI) 7-layer model. Thus, it will provide plug-and-play operation from the connectors and cabling to software.

Today, data transfer is possible only through RS-232C ports. These ports are not standard on medical de-vices--people use the pins in different ways. Bob Kennelly at DDC claims you can blow up a laptop computer simply by plugging an infusion pump into it.

IEEE 1073 defines an active star topology that involves two types of communications stations: a device communication controller (DCC) and a bedside communication controller (BCC). A DCC provides an embedded 1073 into a bedside medical device such as an infusion pump or cardiac monitor. An external converter box interfaces with existing equipment.

DDC's kit includes an IEEE 1073 BCC board for an IBM PC, RS-232C to 1073 DCC converter box, cable assembly, medical-rated power supply, and software for the BCC board and converter box. It sells for $4,500. DCC's MIB port chipsets debut this spring. For more information about the IEEE 1073 standard, phone (908) 562-3800.


Bausch & Lomb and IBM team up to deliver contact lenses

Rochester, NY--Although not apparent at first glance, there are many similarities between manufacturing microelectronics and optical devices. Both require clean environments with very few airborne particulates, and must be precise to tolerances measured in microns.

So, Bausch & Lomb's Contact Lens Div. decided work with IBM Micro-electronics to develop the PerformaSystem--a manufacturing and inventory-control system for B&L's next generation of soft contact lenses.

The Performa System uses B&L's patented FormCasttechnology to produce soft contact lenses in a highly automated fashion. Extremely precise molds create high-quality optical surfaces and exacting edges. Laser measurements and computerized in-line quality-control systems help ensure consistent lens quality and repeatability. IBM's PlantWorks serves as Performa's shop-floor control system.

To shorten the development cycle on the Performa System, IBM employed a paperless design process. Networked CAD systems linked designers in Rochester and Poughkeepsie, NY, allowing computer-based design reviews with 3-D kinematic models. This approach let B&L achieve a full-scale working prototype in eight months.


Cleaner stainless steel improves process components

Reading, PA--Switching to higher grades of stainless steel solved a host of manufacturing and performance problems for SAES Parker UHP Components, San Luis Obispo, CA, a manufacturer of fluid-handling equipment for ultra-pure-process applications. That success has led to the materials' specification in several soon-to-be published standards for the semiconductor manufacturing industry.

Super-Clean Quality (SCQ) stainless steel in 304 and 316L grades from Carpenter Technology Corp., Reading, PA, results from electroslag-remelting (ESR) and vacuum-induction-melting/vacuum-arc-remelting (VIM-VAR) processes respectively. Both processes dramatically reduce the incidence of inclusions and voids in the materials' microstructure.

Ron Hendry, a manufacturing-engineering consultant for SAES Parker, explains that levels of sulfur, calcium, copper, and other compounds had risen in conventional stainless steels as the volume of those materials produced from scrap steel grew over the last decade. The inclusions resulted in increasing numbers of weld failures, micro-pitting, and poor electro-polishing results.

Several factors led to the choice of SCQ steels for the Ultra-High Purity line of valves. "SCQ saves us inspection time," says Hendry. "The materials cost more, but it's small compared to the cost of reworks and rejects."

End users get more uniform products that can improve their processes. "In pharmaceuticals, for example, if you've cleaned out sub-surface contaminants, there's less chance of interference with chemical reactions," says Hendry.

Recognizing the need for higher quality stainless steels, the Semiconductor Equipment and Materials Institute (SEMI) recently published standards for steel pipes along the lines of Carpenter's SCQ product. Similar standards for bar stock should be published this spring.


HP unveils under-$1K printer/fax/copier

Newton, MA--Hewlett-Packard has jumped into the fledgling "merged-function" market with a single device that will print, fax, and copy--all for under $1,000.

"It's a threshold product. This is going to establish the marketplace for multi-function products for the home office," says Barry Tepper, senior industry analyst at BIS Strategic Decisions, a research and consulting firm in Norwell, MA.

The HP OfficeJet started with the company's inkjet-printer technology, according to product manager Donna Ogilvey; then, engineers designed a fax machine and "convenience copier" on top. The device is a full-fledged Deskjet-type printer, producing three pages per minute.

The copier is designed for workers at home who don't want to run to an outside photocopy store if they only need a few pages reproduced for their files. Because the OfficeJet uses a scanner for copying, it is substantially slower than conventional copiers, taking about 50 seconds to scan and produce a page; subsequent copies of that same page are quicker.

Why a three-in-one machine? Proponents say such systems save valuable deskspace in the at-home office; as well as cost less than buying a printer, fax machine, and personal copier separately. List price is $959. While a couple of other companies have announced such products, Tepper believes that HP's industry clout will make the devices more popular.

BIS Strategic Decisions estimates that more than $1 billion worth of "multi-function" products were sold in 1994, with half the purchases coming from low-end, home-office users. By 1998, the market should soar to $7.2 billion for all products, and $3.5 billion at the low end. Coming in the next generation of offerings, Tepper predicts: document scanning, a stronger PC link allowing faxes to be sent directly into the computer, and plain-paper printing.


Software helps control nuclear project

San Diego--Coordinating engineering work on three continents isn't easy. Just ask Didier Gambier, principal scientific advisor in the design of ITER (International Thermonuclear Experimental Reactor), the world's first nuclear fusion reactor.

When the San Diego-based Gambier goes to work, his colleagues in Japan, Germany, and Russia are going home.

"That's one of the things that could make concurrent engineering difficult on this project," he says. He uses process-management software.

Developed with funding from the U.S. Air Force and IBM, KI Shell integrates product data management with project data management. Users define processes, and identify the people who perform the work, the tasks they perform, and the requirements each task has to meet. The software converts the information into an electronic representation of the business process that works with existing applications.

Gambier and his team use the software as the front end for importing Dassault Systemes' CATIA and MacNeal Schwendler's MSC/PATRAN.

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