#$%^&*AU2019101517A420200312.pdf#####ABSTRACT A method of removing or reducing bioburden from an interior surface of a medical instrument, the method comprising the step of bringing an ultrasonic energy waveguide into proximity with said interior surface and applying ultrasonic energy to said interior surface thereby to remove or bioburden on said surface.1/1 8 3 7 6 2 4 5 1 FIGURE 1