A system for monitoring pressure within a volume defined by a wall has a housing and a manometer coupled to the housing having fluid therein. The manometer is coupled to the volume and has a fluid level corresponding to a pressure within the volume. A pressure sensor is coupled to the housing and is coupled to volume. The pressure sensor generates a pressure signal corresponding to the pressure within the volume. A controller is coupled to the pressure sensor and is programmed to compare the pressure signal to a threshold and programmed to generate an indicator based on comparing.

A microfluidic pressure sensor may include a reference chamber, a sensed volume, a microfluidic channel connecting an interior of the reference chamber to an interior of the sensed volume, a volume of liquid contained and movable within the microfluidic channel while occluding the microfluidic channel and a sensor to output signals indicating positioning of the volume of liquid along the microfluidic channel. Positioning of the volume of liquid along microfluidic channel indicates a pressure of the sensed volume.

A microfluidic pressure sensor may include a reference chamber, a sensed volume, a microfluidic channel connecting an interior of the reference chamber to an interior of the sensed volume, a volume of liquid contained and movable within the microfluidic channel while occluding the microfluidic channel and a sensor to output signals indicating positioning of the volume of liquid along the microfluidic channel. Positioning of the volume of liquid along microfluidic channel indicates a pressure of the sensed volume.

An optofluidic flow meter to determine a rate of fluid flow in a flow member includes: the flow member; a primary fluid conduit disposed in the flow member and that receives a fluid; a secondary fluid conduit disposed in the flow member; and a fiber optic comprising a fiber Bragg grating interposed between a first flow region of the primary fluid conduit and a second flow region of the secondary fluid conduit and that: physically distorts relative to a pressure differential between the primary fluid conduit and the secondary fluid conduit; and produces a shift in a Bragg wavelength in response to a physical distortion due to the pressure differential.

An optofluidic flow meter to determine a rate of fluid flow in a flow member includes: the flow member; a primary fluid conduit disposed in the flow member and that receives a fluid; a secondary fluid conduit disposed in the flow member; and a fiber optic comprising a fiber Bragg grating interposed between a first flow region of the primary fluid conduit and a second flow region of the secondary fluid conduit and that: physically distorts relative to a pressure differential between the primary fluid conduit and the secondary fluid conduit; and produces a shift in a Bragg wavelength in response to a physical distortion due to the pressure differential.