Table 1.

Comparison of blood leakage sensor candidates

Type	General Feature	General Problems	Other Information
Electrical sensor (Conductivity/Impedance change)	Simple structure, cheap equipment	Low accuracy, impermeable to air	Limit of detection: 10 μL−1 mL [4]
Optical sensor	High accuracy	Impermeable to air, causes physical discomfort	Sensitivity: 4 × 10−6 blood concentration in volume [2]
Camera (visual and IR)	High accuracy	Psychologically uncomfortable
Pressure-sensitive sheet	Simple structure, cheap equipment	Impermeable to air
Blood-flow rate sensor	Simple structure, cheap equipment	Delayed detection