Fluid level detector for an infusion fluid container

A fluid level sensor assembly in combination with an infusion fluid containing device, comprising:

• a rigid walled container having an interior volume, and at least a container side wall defining a portion of the interior volume, the side wall being made of a translucent material,
• a fluid level detector including a light sensor array and a light source;
• a clamp that securely clamps the fluid level detector in place on the container, to minimize movement during use of the infusion container and fluid level sensor assembly;
• the light sensor array positioned vertically relative to the side wall, and configured to sense light at various points vertically along the light sensor array;
• the light source positioned vertically relative to the side wall, and configured to project light linearly through a vertical portion of the side wall;
• wherein the light source and the light sensor array are spaced apart, such that light emitted from the light source may be projected into the container and towards the sensor array;
• wherein an incidence angle α of the light source relative to the side wall is such that a light beam projected by the light source into the container illuminates a portion of the light sensor array when passing through air in the interior volume, and a light beam projected by the light source into the container does not illuminate the light sensor array when passing through fluid in the interior volume due to reflection of the light beam when the light beam intersects a side wall/fluid interface;
• and
• wherein when infusion fluid is absent in a vertical location of the container, the light sensor array outputs a signal based on a presence of light at a sensor location adjacent the vertical location corresponding to the absence of fluid at the vertical location, and when infusion fluid is present at a given vertical location in the container, the light sensor array output reflects an absence of light at a sensor location adjacent the given vertical location due to the presence of infusion fluid at the given vertical location.