Passive, proportional measurement of oxygen and carbon dioxide consumption for assessment of metabolic parameters

US12419539B2 · kind B2 · utility

Assignees

• Massachusetts Institute of Technology · US
• The Government of the United States, as represented by the Secretary of the Army · US

Inventors

• Holly McClung · Westborough, US
• Reed Hoyt · Framingham, US
• Lawrence M. Candell · Arlington, US
• Joseph M. Mahan · Beverly, US
• Gary A. Shaw · Westford, US
• Andrew M. Siegel · Arlington, US
• Robert L. Standley · Acton, US
• Kyle J. Thompson · Boulder, US

Key dates

• Filing date: Aug 11, 2022
• Grant date: Sep 23, 2025
• Expiry date: Mar 3, 2043

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61M16/0808
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A conventional flow tube for a metabolic cart is usually a straight length of pipe whose inner diameter is fixed by the respiratory burden imposed by the flow tube on the user, with a smaller diameter imposing a higher respiratory burden. The ratio of the straight flow tube's length to diameter is fixed by fluid dynamics, so increasing the flow tube's diameter causes the flow tube's length to increase. As the flow tube gets longer, it exerts more torque on the user's neck and jaw, creating discomfort. Reducing the flow tube's length causes an undesired increase in the respiratory burden but increasing the flow tube's diameter to reduce the respiratory burden makes the flow tube less comfortable, making the flow tube unconformable, hard to breathe through, or both. Bending the flow tube makes it possible to increase the flow tube's propagation length without increasing the flow tube's lever arm length.