Systems and methods for humidity control

Inventors

Leonard, Scott A. • Kate, Meghan H.

Assignees

Vapotherm Inc

Abstract

Systems, methods, and devices for humidifying a breathing gas using a vapor transfer unit are presented. The method includes providing a first vapor transfer unit having a gas passage and a liquid passage, delivering a liquid to the liquid passage, delivering a gas to the gas passage, humidifying the gas by delivering vapor from the liquid in the liquid passage to the gas in the gas passage, exiting the humidified gas outside the vapor transfer unit at first relative humidity and at a high gas flow rate, and reducing the gas flow rate through the first vapor transfer unit to less than a low gas flow rate, while preventing the relative humidity from exceeding the first relative humidity by more than an acceptable margin.

Core Innovation

The invention provides a system for humidifying a breathing gas that includes a housing with a liquid inlet, a liquid outlet, a gas inlet, and a gas outlet, and a vapor transfer compartment disposed within the housing. The vapor transfer compartment includes a first gas passage coupling the gas inlet to the gas outlet, a liquid passage coupling the liquid inlet to the liquid outlet, and a permeable membrane separating the first gas passage and the liquid passage.

In addition to the vapor transfer compartment, the system includes a bypass gas passage disposed externally to the housing and coupling the gas inlet to the gas outlet. The bypass gas passage is configured to receive a fraction of the gas received by the gas inlet, and the bypass gas passage is configured to automatically alter the fraction of gas passed through the bypass gas passage.

The fraction of gas passed through the bypass gas passage is solely a function of fixed dimensions of the bypass gas passage, without requiring other variable control. The disclosed approach addresses behavior in which low gas flow rates can lead to excessive relative humidity and condensation risk, while higher gas flow rates require maintaining adequate humidity, by automatically adjusting the bypassed fraction as the delivered gas flow rate varies.

Claims Coverage

The partial content identifies two independent claims: one directed to a humidifying system and one directed to a method of humidifying breathing gas. Across these independent claims, the core inventive concept comprises a vapor transfer compartment with a permeable membrane separating gas and liquid passages combined with an externally disposed bypass gas passage that automatically alters the bypass fraction solely based on fixed bypass dimensions; the method claim further adds the delivery of breathing gas at a gas flow rate and the humidifying step within the vapor transfer compartment.

Both independent claims center on combining membrane-based vapor transfer humidification inside a housing with an externally disposed bypass gas passage. In the system and method, the bypass fraction is automatically altered while being solely determined by fixed bypass dimensions, thereby integrating a fixed-geometry, flow-responsive bypass split with the permeable-membrane humidification function.

Stated Advantages

Documented Applications