Apparatus and method for detecting liquid level in a clear or partially clear container
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Publication Number
US-12491330-B2
Publication Date
2025-12-09
Expiration Date
Abstract
A trap bowl is provided to accumulate liquid droplets from a filter, as a liquid content. The trap bowl includes a transparent vertical prism. The transparent vertical prism includes a face that forms a vertical transparent surface facing against a content of the section. The face can provide a first angle of total reflection when content of the section is a type of gas, and a second angle of total reflection when the content of the section is the liquid content. A light source may emit a light beam incident on the face at an angle of incidence. The angle of incidence results in reflection of the light beam, striking the light receiver, when the face has the first angle of total reflection, and results in refraction of the light beam, missing the light receiver, when the face has the second angle of total reflection.
Core Innovation
The invention relates to a ventilator breathing-circuit filter-trap apparatus for filtering water vapor and/or liquid from a gas, with a trap bowl configured to accumulate liquid droplets from the filter as a liquid content. The trap bowl includes a transparent circular section that extends in a vertical direction, and an offset light source emits an angled light beam toward an outer surface of the transparent circular section at a defined point of incidence, with an offset light receiver located on an opposite side of the trap bowl from the light source.
The optical concept selects an optical index of refraction of the transparent circular section so that gas content versus liquid content produces different optical paths for the light beam. When gas content is against the transparent circular section, the light beam is refracted along a first path that travels through the trap bowl and is incident on the offset light receiver. When liquid content is against the transparent circular section, the light beam is refracted along a second path that travels through the trap bowl, exits the trap bowl, and misses the offset light receiver.
The arrangement supports optical non-contact liquid-level detection within a fill range by using different total-reflection conditions versus refraction into the liquid path when overfilled. The disclosure further describes trap bowl removal and attachment and installation verification using multiple receiver states, including proper installation, an over-maximum fill state, and a missing or misoriented trap bowl. The optical design analysis uses Snell’s law and total internal reflection concepts with exemplary optical indices to distinguish the refracted paths and receiver outcomes.
Claims Coverage
The disclosed claim set includes one independent claim (clm-00001). It covers four principal inventive features: a filter trap apparatus with a trap bowl having a transparent circular section extending vertically, an offset light source and an offset light receiver arranged on opposite sides, an optical-index selection that causes gas-versus-liquid-dependent refraction into distinct first and second paths, and a path behavior that ensures the first path is incident on the receiver while the second path misses the receiver.
Transparent trap bowl with vertical transparent circular section
A trap bowl configured to accumulate liquid droplets from the filter as a liquid content, the trap bowl comprising a transparent circular section that extends in a vertical direction.
Offset light source and opposite-side offset light receiver
An offset light source configured to emit a light beam incident on an outer surface of the transparent circular section at a point of incidence, and an offset light receiver located on an opposite side of the trap bowl from the offset light source.
Optical index selection for gas-versus-liquid refraction paths
An optical index of refraction of the transparent circular section is selected such that when a gas content is against the transparent circular section, the light beam is refracted along a first path, and when the liquid content is against the transparent circular section, the light beam is refracted along a second path.
Receiver-incidence versus receiver-miss path behavior
The first path travels through the trap bowl and is incident on the offset light receiver, and the second path travels through the trap bowl, exits the trap bowl, and misses the offset light receiver.
Independent claim coverage centers on using a transparent vertical trap-bowl section together with an offset light source and receiver and a selected optical index of refraction so that gas content produces a first refracted path incident on the receiver, while liquid content produces a second refracted path that exits the trap bowl and misses the receiver.
Stated Advantages
Enables non-contact liquid-level detection by distinguishing gas content versus liquid content using different refracted optical paths and receiver outcomes.
Supports detection over a proper fill range, including an over-maximum fill state where detection changes based on refractive behavior into the liquid path.
Allows verification of trap bowl installation or removal and detection of a missing or misoriented trap bowl using multiple optical receiver states.
Documented Applications
Integration into a therapy gas delivery system, including inhaled nitric oxide (iNO), with downstream gas sampling.
Use in a ventilator breathing circuit as a breathing-circuit filter-trap for monitoring fill state and related installation verification.
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