US Patent 9913656 Ultrasonic surgical instruments

An ultrasonic surgical blade comprises a solid blade body defining an axis. The solid blade body comprises a first length, a proximal end, and a distal end. The solid blade body is configured to acoustically couple to an ultrasonic transducer. The ultrasonic surgical blade further comprises a treatment region and a first edge at the distal end of the solid blade body. The ultrasonic surgical blade comprises an inner concave surface. The inner concave surface comprises a cavity extending proximally from the distal end of the solid blade body along the axis. The cavity terminates at a proximal end of the inner concave surface. The inner concave surface is configured to cause fluid droplets to converge along the axis when the fluid droplets collide with the inner concave surface to enhance visibility of a surgical site.