BOTHELL, WA - February 21, 2007 - Sonosite, Inc. (Nasdaq:SONO), the world leader in hand-carried ultrasound, today announced it has filed a patent infringement lawsuit against Zonare Medical Systems, Inc. in the US District Court for the Central District of California Southern Division. In its complaint, Sonosite asserts that Zonare has infringed Sonosite's U.S. Patent No. 5,722,412 (the '412 Patent) through its sales of its z.one ultrasound platform. Sonosite's '412 patent covers a portable ultrasound system weighing less than ten pounds. The complaint seeks unspecified monetary damages and a court injunction against future infringement by Zonare.

"The company's technology covered by the '412 patent is one of our core assets in the innovation and creation of the hand-carried ultrasound market that we have founded and led since 1999," said Kevin M. Goodwin, Sonosite President and CEO. "After thoroughly examining the issues, we were convinced that we had to move aggressively to protect and enforce our intellectual property.

About Sonosite
Sonosite, Inc. (www.sonosite.com) is the innovator and world leader in hand-carried ultrasound. Headquartered near Seattle, the company is represented by eight subsidiaries and a global distribution network in over 90 countries. Sonosite's small, lightweight systems are expanding the use of ultrasound across the clinical spectrum by cost-effectively bringing high performance ultrasound to the point of patient care. The company employs over 500 people worldwide.