Abstract: This invention provides a support device that allows the adjustable, yet rigid placement of a probe or other medical instrument against a region of interest/treatment on a patient. The system and method of rigid fixation, positioning, and adjustment contemplated herein is useful for a broad array of medical procedures including, but not limited to, ultrasound-guided anesthetic delivery. In an exemplary embodiment of the present invention, a flexible armature is attached to a rigid stand placed upon the floor, or attached to another stable surface such as a bed rail, wall, ceiling or piece of equipment. A joint connects the armature to an instrument holder able to accommodate and rigidly attach an ultrasound sensing probe or other medical device. The medical device then remains rigidly attached to the described invention during the procedure. Furthermore, this set position is resistant to minor patient motion or other disturbances.