Abstract: A device and method to position a cannula or a catheter for nerve block are provided for use with a unipolar cannula (10), which is electrically insulated around its axial length. The device includes a stimulation device (20) to generate an electrical signal, an electrically conductive bare stimulation electrode (12) provided on a distal end of the unipolar cannula (10) and a skin electrode (14), which can be applied to a body surface (26) of a patient with an electrically conductive contact. The stimulation electrode (12) and the skin electrode (14) can be connected to the stimulation device (20), so that the electrical signals are routed from the stimulation electrode (12) through a patient's body (28) to the skin electrode (14).

Abstract: A light pointer (16) is mounted on the proximal end of a cannula (10) by use of an adapter (14) for positioning the cannula (10) that is inserted into a body by use of an ultrasonic head. The light pointer (16) emits a light beam (18) in a direction axially parallel to the cannula (10). When the cannula (10) is inserted, the light beam (18) produces a light spot on the bodily surface on which the ultrasonic head is placed.

Abstract: Methods and systems for determining the proper placement of an epidural catheter prior to administration of anesthetic is described. In a preferred embodiment, an aqueous fluid is introduced into an epidural catheter that has been inserted into the spine of a subject. Motor reactions by the subject in response to electrical current applied through the aqueous solution is monitored. By monitoring the motor response with respect to electrical stimulation, the proper placement of an epidural catheter can be differentiated from the placement of the catheter in subarachnoid, subcutaneous or epidural intravascular placement. Additionally, in the preferred embodiment, a wire is disposed within the catheter tube to facilitate the passage of electric current. However, to avoid electrochemical reaction of the wire with the aqueous solution and/or the subject's dural tissue, the wire does not extend completely to the distal end of the catheter tube.