ISG image-guided therapy systemto get new optical tracking sensors

October 25, 1995

Firm announces search for chief executiveISG Technologies will soon integrate a different tracking systeminto Viewing Wand, the Mississauga, Ontario, firm's image-guidedsurgery tool. The wand, which is distributed worldwide by ElektaInstruments

Firm announces search for chief executive

ISG Technologies will soon integrate a different tracking systeminto Viewing Wand, the Mississauga, Ontario, firm's image-guidedsurgery tool. The wand, which is distributed worldwide by ElektaInstruments of Sweden, includes a multi-jointed articulated armwith a neurosurgical probe mounted on the end (SCAN 5/4/94). Butin the future, perhaps as early as next spring, users of ViewingWand will have an alternative to the arm made possible by opticaltracking sensors developed by Northern Digital of Waterloo, Ontario,under an alliance between the firms formalized earlier this month.The new technology will allow freehand, 3-D tracking of one ormore probes in virtual space.

"We are not replacing the arm and saying to customersthat the only thing you can do now is optical sensing. We aregiving them an option," said Boyd Kalnay, business directorof surgical navigation for ISG.

That option, however, will be very appealing. The most obviousadvantage will be that the sensors, when integrated into ViewingWand, will allow greater freedom of movement.

Infrared emitting diodes, attached to the probe and at keypoints on the patient, will allow a bank of lightweight cameras,probably mounted on a floor stand, to update the computer on thevirtual location of patient and surgical instrument. The updateswill be translated into virtual space in the context of a 3-Dmodel of patient anatomy, either the brain or sinus, constructedfrom CT or MR data. On the current systems, the position of thatvirtual probe in the context of surrounding tissue is regularlyupdated by sensors at the joints that record movements made bythe surgeon.

Aside from increasing the surgeon's freedom of movement, opticalsensors will permit more than one surgical instrument to be tracked,allowing the use of several different probes.

"It will be easier (to change instruments) using the freehandsystem," Kalnay said.

By marking several instruments with the infrared emitting diodes,the changeover might be accomplished by simply picking up thenew probe.

That ease of use is still some months in the future, at leastfor users in the U.S. ISG has not yet received clearance for aversion of Viewing Wand integrated with the new optical technology,but plans to submit such a request to the Food and Drug Administrationin time for the agency to make a decision before next year's Aprilmeeting of the American Association of Neurological Surgeons.

When available for sale in the U.S., the technology will beready for integration into new systems in place of the arm, dependingon customer preference. Existing users also will be able to orderthe freehand technology as an upgrade for their Viewing Wands,Kalnay said.

In other ISG news, the company last month reported financialresults for its fourth quarter and 1995 fiscal year (end-June).ISG's revenues for the year were $16.5 million, up 10% comparedto $15 million in sales in 1994. The firm's net loss for the yearwas $2.1 million, an increase of 31% compared to a $1.6 millionloss last year.

For the fourth quarter of 1995, ISG had revenues of $4.9 millionand a loss of $278,000, compared to sales of $4.9 million anda profit of $156,000 in the same period in 1994.

ISG chairman and CEO Michael Greenberg said the company hasbegun a search for a new president and CEO to strengthen its managementteam. Greenberg will continue as chairman.