20
To help ensure patient safety and prevent cross contamination, reusable electrodes and stimulators must be
properly cleaned and maintained. This maintenance includes cleaning before use on each patient. Always follow
the specific instructions that accompany these patient contacting devices (e.g., electrodes, probe tips) and your
institution's guidelines for cleaning patient contacting devices. --
To help ensure patient safety and prevent infections when using sterile supplies such as needle and corneal
electrodes, always follow the manufacturer’s instructions and your institution's guidelines regarding use of
these devices.
Table 1: Example of Minimum Stimulus Electrode Sizes
Minimum Stimulus Electrode sizes
Resistance
(Ohms)
Max Current
Used (mA)
Stim Duration
(uS)
Rate (Hz)
Surface Area
(cm2)
Required Diameter of disc
(mm)
2000
25
100
2
0.001
0.357
4000
25
100
2
0.002
0.505
4000
25
100
5
0.005
0.798
4000
50
100
2
0.008
1.009
4000
100
100
2
0.032
2.018
4000
100
500
2
0.160
4.514
4000
100
1000
2
0.320
6.383
4000
100
1000
100
16
45.135
Legend:
• Resistance - is the impedance of the stimulus electrodes in ohms
• Maximum current used - is the maximum stimulus intensity that you plan to use
• Stimulus duration - is the maximum stimulus duration you plan to use
• Rate - is the maximum stimulus rate you plan to use
• Surface area - is the surface area required for each electrode to not exceed 0.25 W/cm2
• Required diameter of disc - is the minimum diameter of the electrode
(to not exceed 0.25 W/ cm2 assuming a round disc)
The Surface Area = ((maximum current/1000)2 *(resistance) * (duration/1000000) * (rate)) / 0.25
The Required Diameter of disk = 20 * square root (surface area/3.14159) millimeters (mm)
System Installation and Operation
Inspect the system prior to first startup and frequently prior to usage for damaged components. Tighten any
loose connections.
Inspect the power cord often for fraying or other damage. DO NOT operate the apparatus if the power cord or
plug is damaged.
The potential for electrical shock is present if device covers are removed. Refer servicing to qualified personnel.
If the system is dropped or otherwise mishandled, check all system functionality and conduct an electrical safety
test before resuming use.
