Transonic Files Suit Against Fresenius for Infringement of Its Hemodialysis Access Flow Measurement Patents.

Business Editors/Health/Medical Writers

ITHACA, N.Y.--(BUSINESS WIRE)--Nov. 17, 2003

Transonic Systems Inc. announced today that it filed a lawsuit against Fresenius USA Inc. and Fresenius Medical Care Inc. for infringement of Transonic's US patent numbers 5,685,989 and 6,514,419. These patents protect Transonic's "Krivitski Method" of measuring access flow during dialysis, using blood line reversal and indicator dilution principles. According to papers just filed in Federal District Court in San Francisco, CA, Transonic claims that the on-line clearance (OLC) access flow measurement which Fresenius recently integrated in its 2008K Dialysis Delivery Machine infringes the Krivitski measurement approach as protected under US patent law.

According to Mr. Cornelis Drost, President of Transonic: "We approached Fresenius several times to attempt to avoid this dispute, and it is very unfortunate that Fresenius has instead chosen to disregard our intellectual property rights. Our patents protecting Dr. Krivitski's pioneering contribution to the hemodialysis patient community are very important to the company. We have spent millions of dollars in bringing this method to market, and Transonic will vigorously enforce its patents to protect its rights. Transonic realizes that the dialysance method has not been independently validated, and we would not want to block scientific inquiry. Researchers wanting to perform such independent validation studies may contact Transonic for a temporary license for the duration of those studies." Transonic is represented in this dispute by intellectual property law firm Knobbe, Martens, Olson & Bear.

The blood line reversal method of measuring access blood flow, which is the subject of the '989 and '419 patents, was invented by Transonic's Senior Scientist Dr. Nikolai Krivitski in 1994. His invention led to breakthrough improvements in the management of stenotic disease in the hemodialysis access. Approximately 300,000 USA patients have lost functionality of their kidneys, and a well-functioning dialysis access (A/V shunt or fistula) is their link to life as it facilitates hemodialysis. Research studies using the Transonic ultrasound access flow monitor quickly revealed that flow-based surveillance of the access, coupled with minimally-invasive procedures to restore flow, would lead to reduced patient morbidity and hospitalization and prolonged life of the hemodialysis access shunt. The "Krivitski Method" was incorporated in the "Dialysis Outcome Quality Initiative" guidelines published by the National Kidney Foundation in 1997 as the preferred method for surveillance of patients during their routine dialysis treatment.

Transonic manufactures and sells a broad range of blood flow measurement devices for intraoperative surgery, hemodialysis and biomedical research, and provides embedded flow measurement solutions to manufacturers of medical devices.

For more information go to www.transonic.com.