Medical Device Daily

DUSSELDORF, Germany — Draeger Medical had a home team advantage at Medica 2007 here last week, just a few hours drive south from headquarters in Lubeck.

The company's wide exhibition stand took up an even larger footprint with the "Friends of Draeger" crowding the adjacent aisles, visiting customers, distributors and subcontractors.

To get a view of the products, a visitor worked through the wall of bodies and a language barrier to arrive on the stand, only to discover the product grouped in three successive circles.

Facing out from the stand was a display of the current lineup of products from Draeger, from natal incubators to intensive care units for adults, and finally to assisted breathing equipment for the assisted living center.

Draeger generated $4.2 billion in 2006 on sales of machine-assisted breathing machines, the monitors and the information systems needed to both control the therapy and provide data on the patient's progress.

In 2008, the company is marking its 100th anniversary of entering the U.S. market with its "resuscitating machines" that immediately proved their worth during a spectacular mining accident.

Once at the booth, the customer saw a inner facing row of upcoming products updates for products and a demonstration of the Infinity Acute Care System that ties them together across hospitals.

It was not until arriving inside the inner circle that a visitor came across a novel work-in-progress at Draeger, electro-impedance tomography, a new technique for diagnostic imaging.

"True radiation diagnosis seems to have come to an end of development, but this technology opens new possibilities," said Michael Bender application specialist for intensive care with Draeger.

Imaging from electro-impedance technology is based on emitting an ultra-low voltage signal into the body and capturing modifications to these pulses. Unlike radiated images that show up on treated film, the data from the received signals needs to be interpreted much like MRI.

The potential for creating a medical image using electro-impedance was first shown 20 years ago and since then studies have shown a highly significant correlation with images obtained by other techniques.

"This is absolutely new and we have the patent," said Bender.

"Our focus is specifically on the ventilated patient and 10 years ago we began developing a clinical application using this technology," he said. "About five years ago we decided to bring it to the bedside."

Key to acquiring the images is a belt worn on the thorax carrying 16 electrodes for emitting or capturing signals. Where a typical configuration of such electrodes requires assigning a separate cable to each electrode with the resulting thick mass of cables, the belt used by Draeger features serial linkage of the emitter-detector pairs. Two mono-lead cables link eight electrodes each.

"It comes in a variety of sizes from baby to XXL," Bender said.

Electrodes, using the same low-range voltage as an EEG, are put in direct contact with the skin using natural body humidity, rather than gels.

"It takes about five minutes for an untrained caregiver to set up a patient in the bed, compared to 20 minutes using single electrodes set up by trained staff," he noted.

Two paired electrodes are used for a signal pulse while the other 14 serve as detectors, the next pair then fire and the process continues around the belt, with an average 50 signal pulses per second.

The detected signals are processed by algorithms to filter out the ambient noise that includes the frequencies of electrical transmissions by other equipment operating near the bedside, or those emanating from the patient, such the micro volts generated by each heart beat.

The advantage for bedside acquisition of the images is an immediate picture of how well an inhaled gas is being absorbed without a need to take the patient for computed tomography or magnetic resonance imaging scans, and without the radiation.

"Some of these patients are extremely fragile and the belt is a far more convenient way to monitor the condition," according to Bender.

The graphical image used for the demonstration at Medica was called a tidal view. The image was intuitive, as it showed two lung-like shapes, much like an image from the Weather Channel, where an empty lung shows as dark blue with circles of orange, yellow and finally red expanding as the lung fills with air.

Like a weather map, the distribution changes between the shallow breathing of the upper lung and the deeper intake of the lower regions.

The readings are real-time, with immediate changes seen when the Draeger employee rigged with the electrode belt either laughed or answered a question.

Other graphic views could be shown that depict global impedance or zoom to specific region to examine regional impedance.

Using EIT, respiration therapies in the future can be better understood, Bender said, their effectiveness measured and the recovery of patients more closely monitored than can be imagined today.

While the technology and the Draeger application have been proven, the product remains in a research mode and is still far upstream from commercial distribution.