Thermal Flow Sensing for Small-Conduit Occlusion Alarms

The patent employs asymmetric thermal conduction paths by positioning sensors at different distances from the thermal source (first sensor closer, second sensor farther). This asymmetric arrangement creates differential temperature measurements that are highly sensitive to small flow rates, resolving the contradiction by enhancing measurement precision through intentional asymmetry in sensor placement while maintaining a relatively simple overall device structure.

The patent transitions from single-point temperature measurement to multi-dimensional thermal field measurement by using multiple sensors positioned at different locations and distances from the thermal source. This dimensional expansion of measurement points enables accurate detection of small fluid flows through spatial temperature gradients, improving measurement precision without proportionally increasing device complexity.

The patent divides the measurement function into multiple independent sensors positioned at different locations relative to the thermal source. The first sensor measures temperature at a closer distance while the second sensor measures at a farther distance, creating segmented measurement points that together provide reliable flow detection. This segmentation improves reliability by enabling cross-validation and differential measurement while keeping each sensor component relatively simple.

The patent implements feedback-based flow detection by continuously monitoring temperature differences between multiple sensors and using this information to determine flow rate and detect occlusions. The system compares expected temperature profiles with actual measurements, providing reliable flow detection through feedback mechanisms that enhance accuracy without requiring complex hardware modifications.

The patent implements periodic pulsing of the thermal source instead of continuous operation. The thermal source is activated in periodic cycles, creating time-varying temperature fields that are measured by the sensors during each pulse cycle. This periodic action maintains measurement accuracy by providing sufficient thermal contrast while significantly reducing average energy consumption compared to continuous operation.

The patent employs dynamic thermal measurement by using time-varying temperature profiles created through periodic thermal source activation. The system measures temperature changes over time rather than relying on steady-state temperatures, enabling accurate flow measurement during transient thermal conditions. This dynamic approach maintains measurement precision while reducing energy consumption by limiting thermal source activation to necessary measurement intervals.