Lateral Flow Device with Inclined Sample Pad for Multiplexed Testing

The patent transitions from a conventional horizontal arrangement of multiple test strips to a three-dimensional stacked configuration. Multiple test strips are arranged vertically in different layers, with each strip positioned at a different height. The sample is applied to the top layer and flows downward through gravity and capillary action, ensuring uniform distribution across all strips. This vertical stacking in the z-dimension resolves the sample distribution problem while maintaining simultaneous detection of multiple analytes.

The patent employs a nested structure where multiple test strips are positioned within a housing that provides vertical stacking. Each test strip is contained within its own plane, and the strips are nested vertically one above another. The housing structure guides the sample flow from the top strip downward through intermediate layers to the bottom strip, creating a nested configuration that ensures even sample distribution while enabling multiplexed detection.

The patent uses a single sample application area located at the top of the vertical stack, but resolves the distribution problem by utilizing the vertical dimension. The sample application area is positioned above all test strips, and sample flow is directed downward through gravity and capillary wicks that extend to each strip. This vertical arrangement allows one sample application area to uniformly distribute sample to multiple strips without increasing horizontal complexity.

The patent introduces intermediate capillary wicks or flow channels as mediators between the single sample application area and the multiple test strips. These intermediaries are positioned vertically and transport sample from the top application area down to each test strip in sequence. This intermediary structure enables uniform sample distribution across all strips while maintaining a simplified single-point sample input design.

The patent distributes the sample volume requirement across the vertical dimension rather than concentrating it horizontally. By arranging test strips in vertical layers, each strip receives an appropriate amount of sample as the liquid flows downward through controlled capillary channels. This vertical distribution prevents sample overload at any single location while ensuring all strips receive sufficient sample for accurate testing.

The patent segments the sample flow path into multiple vertical stages, with each stage corresponding to a test strip layer. The sample is divided and distributed to different strips at different vertical levels through separate capillary channels or wicks. This segmentation of the flow path ensures that each test strip receives an optimized sample volume appropriate for its detection requirements, preventing overload while maintaining sensitivity.

The patent nests multiple conventional test strips within a single housing structure, with each strip maintaining its individual functionality while being vertically stacked. This nested configuration allows multiple targets to be detected simultaneously using standard test strip technology, achieving multiplexed detection without requiring complex custom-designed strips. The housing integrates the multiple strips into a unified device that remains simple to operate.

The patent creates a multi-functional device by combining multiple test strips in a vertical stack, where each strip can detect different analytes. The unified housing and single sample application area provide universal functionality for simultaneous detection of multiple targets. This approach maintains operational simplicity while achieving the versatility of multi-analyte detection through the vertical stacking configuration.