Convex Sensor Plate for Stable Blood Flow Measurement

The invention inverts the conventional contact configuration by making the contact surface convex rather than flat. This allows the sensor device to be attached with minimal pressure while maintaining stable optical coupling, as the convex shape naturally concentrates the contact area and ensures reliable signal detection without requiring excessive fastening force that would constrict capillary vessels.

The contact surface is designed with non-uniform geometry, specifically a convex shape with a predetermined curvature radius. This local quality change concentrates the contact interaction at specific points rather than distributing pressure across a flat surface, enabling stable attachment with reduced overall pressure on the capillary vessels.

The contact surface is pre-formed with a specific convex geometry and predetermined curvature radius during manufacturing. This preliminary action ensures that when users attach the device themselves, the optimal contact configuration is already established, eliminating the need for users to adjust or flatten the contact surface manually, thus ensuring consistent measurement quality across different users.

The invention specifies a predetermined curvature radius for the convex contact surface, transforming the contact geometry from a variable parameter (flat surface requiring user adjustment) to a fixed parameter (convex surface with defined curvature). This parameter change ensures that the device achieves optimal attachment state automatically upon application, regardless of user skill or pressure applied.