U.S. District Court Judge Ann D. Montgomery last week ruled in favor of Maplewood-based 3M Company in a trademark infringement lawsuit that the company filed against a California businessman.

In its suit-filed in June 2009 in U.S. District Court in Minnesota-3M accused Pradeep Mohan of trademark infringement, counterfeiting, and unfair competition related to the sale of stethoscopes.

Since 1942, 3M has sold stethoscopes under the Littmann name. The company claimed in its lawsuit that the Littmann brand is “exceedingly strong, if not famous, being one of the best-known and most trusted brands in the medical field.”

The company received its Littmann trademark in 1963. It later began marketing its Littmann stethoscopes under the brand Master Cardiology-a name for which it received a trademark in 2007.

Mohan, who has done business under the names Kila Labs and Lautenn Stethoscopes, has sold stethoscopes on his own Web site, as well as on third-party sites including Amazon.com and eBay.

3M accused Mohan of using its trademarks “to deceive and confuse” people into buying the products with the belief that they are in some way affiliated with 3M. Mohan allegedly sold stethoscopes under the Master Cardiology name, displayed 3M and the Littmann trademarks on his Web site, and sold a variety of other products that infringed on 3M's trademarks.

Following a four-day trial, the judge ruled in favor of 3M, ordering Mohan to stop infringing on 3M's patents. 3M was awarded “reasonable attorneys fees” but was denied its request for statutory damages. The order states that the defendant is entitled to a jury trial through which the appropriate damages may be determined.

Montgomery wrote in her order that the evidence indicates that Mohan's stethoscopes are of significantly lower quality than 3M's. Additionally, she said that the “quick and effortless nature” of online shopping makes it easier for consumers to become confused, and Mohan “deliberately and continuously” infringed on 3M's trademarks.

The judge also called attention to the fact that the product is a medical device, and it's in the public interest to halt trademark infringement-because confusion about the product's quality by medical professionals could result in harm to patients.

“The Littmann brand is synonymous with outstanding quality and acoustic performance,” Ingrid Blair, 3M's vice president of patient assessment, said in a statement. “While 3M takes infringement of any of its intellectual property very seriously, it is especially important that purchasers of health care products such as stethoscopes receive authentic products.”

3M is among Minnesota's 10-largest public companies based on its revenue, which totaled $23.1 billion in 2009.