The ornamental design for a keyboard for an ultrasonicobservation device for an endoscope, as shown and described.
FIG. 1 is a front perspective view of a keyboard for an ultrasonic observation device for an endoscope, showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines in the drawings are included for the purpose of illustrating portions of the keyboard for an ultrasonic observation device for an endoscope that form no part of the claimed design.