US Patent 7172555 Vascular testing system

A vascular sensing system includes blood flow restricting means, a sensor, and means for producing an output representing a return of blood flow after the blood vessel has been temporarily collapsed by the blood flow restricting means. The blood flow restricting means is capable of placement on a human toe having a blood vessel, and is capable of manipulating the blood vessel. The sensor is operably connected to the blood flow restricting means and is physically spaced from the toe. Further, a method of vascular sensing includes taking pressure measurements with an pressure cuff positioned on a toe, and conducting a waveform analysis of the pressure measurements to determine a return of blood flow pressure.