Nearly 75 percent of users of Toshiba Corp.'s electronic endoscope have experienced problems with the product, according to the results of a survey made available Saturday.

The survey by the 94,000-member Japanese Medical and Dental Practitioners for the Improvement of Medical Care found that 33 of 45 surveyed users of Toshiba's endoscope, or 73 percent, have had trouble with the device.

Of the 33, 27 responded that the cause of the trouble was unknown, while 22 said the trouble could not be fixed despite requests to Toshiba.

While the survey also revealed that association members have experienced problems with other makers' endoscopes, the ratio of users reporting trouble was much lower than Toshiba's 73 percent.

The survey, conducted between June and July, asked the organization's members if they had experienced problems with endoscope manufacturers. There were 385 respondents.

The survey came after a lawsuit filed by a doctor seeking damages from Toshiba over claims that the company ignored his complaints regarding the endoscope.

The doctor, Koya Honda, who runs a Nagasaki clinic, is seeking 84.5 million yen in damages, saying Toshiba has not responded properly to his claim that the endoscope he purchased from them had a frosted lens, which impaired diagnosis.

The electronics maker filed a countersuit saying the frost is not a defect but was caused because the product was not cleaned in accordance with the instruction manual.

The issue is widely known, as Honda has publicized his complaint on the Internet.

A Toshiba spokesman said the company is not aware of the details of each incident.

"If there is trouble with our products, we will deal with it sincerely as in the past," the spokesman said.