Myoguide Stimulation Location

Multi-segmented sites, such as the hand and foot, can require the use of stimulation to identify the correct injection sites. EMG itself cannot separate the different fingers, or toes, as they all emit EMG signals. Stimulation will evoke a twitch response and identify the digit.

Myoguide’s powerful integrated stimulator can challenge the injection site and invoke a twitch response. Stimulation location is essential in these areas. The site is located by palpation during digit movement. The hypodermic needle electrode is inserted, and the patient is asked to move the digit in question (if possible).

The site is reinforced as EMG is evoked when the movement is initiated. Stimulation through the same needle will confirm the injection site is related to that digit by evoking a muscle contraction. Stimulation parameters can be changed easily with several pulse widths, frequency of pulse presentation, and constant current level.

Stimulation evokes movement of the digit, as a twitch response, and is achieved at a very comfortable stimulation current. Stimulation can be presented continuously in order to simplify the clinician’s work. A bright yellow panel light illuminates when actively stimulating.

Clinicians can easily activate the stimulation PAUSE feature, to halt stimulation, by pressing two “arrow” buttons together (indicated by the panel pause graphic). The yellow light will extinguish when the system is paused and the status on the display will indicate “Stimulation Pause”.

This is a very convenient way to halt stimulation yet retain all the stimulation parameters. This is useful while repositioning the needle to an improved location. Any button press will switch the stimulator back to the previously parameters and will continue stimulation.

Stimulation location (Estim) can also be used to help locate nerves and motor endplates. This is best approached only with stimulation that can be adjusted in 0.1mA steps, as these anatomical structures can be quite sensitive to even 1 mA of stimulation current.

Myoguide can present narrower pulse widths to further reduce the stimulation presented to the sites. These features provide a wide variety of choices as to how stimulation pulses are presented according to clinical demands.