Who Owns Littmann?

The stethoscope itself dates to 1816 and René Laennec's rolled paper tube in Paris, improved for commercial production by George Cammann a year later. For 150 years the basic acoustic design barely changed, until Dr. David Littmann, a Harvard Medical School professor and international authority on electrocardiography, began redesigning it in the early 1960s.

Littmann's 1961 journal article described what became the combination chestpiece: an open bell for low-pitched sounds and a stiff diaphragm for high-pitched sounds, with short single-lumen tubing and a lighter frame. He patented the design in 1963 and, with Gus Machlup, founded Cardiosonics to manufacture a physician's model and a nurse's model.

3M bought Cardiosonics in April 1967, and Littmann himself stayed on as an adviser. The first Littmann stethoscopes under 3M launched in the early 1970s, and the line became the reference standard of the industry. Tunable diaphragm technology, letting clinicians switch between bell and diaphragm modes by pressure alone, was patented by 3M and became the brand's signature feature.

Successive generations followed: the Classic II Pediatric, Lightweight II S.E., and Cardiology III, then the Classic III with oil- and alcohol-resistant tubing, and the Cardiology IV introduced during the brand's 50th anniversary year in 2017. Electronic models, including the Littmann Electronic Model 3200 and the CORE digital stethoscope with amplification and Eko AI integration, extended the line into digital auscultation.

The April 2024 Solventum spin-off made Littmann part of a standalone health care company for the first time in nearly six decades, with the brand positioned as one of Solventum's flagship medical-surgical assets.