STIMULATION OF EXCITABLE TISSUES - Design and Development of Medical Electronic Instrumentation - page 314

TABLE 7.1 Typical Parameters Used in Various Clinical Applications Involving the Stimulation of Tissues with Electrical Currents

Clinical Typical Method of Typical Typical Current

Application Current Delivery Waveform or Voltage

Cardiac pacing Implanted electrodes in contact with 0.1- to 2-ms capacitor-discharge 0.1 to 8 V peak delivered

heart; electrode impedance pulse with charge-balancing from 5- to 10-µF

250 Ω to 1 kΩ phase capacitor

Gelled skin-surface electrodes placed Balanced biphasic current pulse 50 to 200 mA with 30-V

on chest; electrode impedance 50 Ω 20 to 40 ms in duration compliance

Cardiac defibrillation Implanted electrodes in contact with Biphasic capacitor discharge 2 to 10 A with capacitor

heart; electrode impedance 30 to 60 Ω 5 to 10 ms in duration bank charged to 1kV

Gelled skin surface electrodes placed Monophasic or biphasic 30 to 40 A with capacitor

on chest; electrode impedance capacitor-discharge pulse bank charged to 3kV

50 to 100 Ω 5 to 10 ms in duration

Cardiomyoplasty Platinum-iridium wire electrodes Burst of capacitive discharge pulses 0.1 to 8 V peak delivered

sewn across skeletal muscle a few with charge-balancing phase, from 5- to 10-µF

centimeters apart, looped under the 0.06 to 1.0 ms in duration; 1 to capacitor

nerve branches that run along the 16 pulses per burst, at a pulse

surface of the muscle; electrode repetition rate of 10 to 60 Hz;

impedance 50 to 100 Ω burst delivered in synchrony with

cardiac activity at a burst-to-beat
ratio of 1 : 1 to 1 : 16

Electroventilation Temporary electroventilation with 0.8-s bursts of balanced monophasic 200 mA to 1.5 A with up to

gelled anterior axillary skin-surface pulses 10 µs in duration at 35 Hz 1500-V compliance

electrodes; impedance 250 Ω to 1 kΩ
Implanted electrodes in contact with 0.8-s bursts of balanced biphasic 1 to 10 mA with

phrenic nerve or innervation point current pulses 1 to 10 ms in 12-V compliance

of diaphragmatic muscles duration or (phrenic nerve) 25 to

100 ms in duration (muscles);
repetition rate 30 Hz

Diagnostic stimulation Bipolar pair of 2- to 5-mm-diameter Monophasic current pulses 50 µs 0 to 100 mA with up to

of peripheral nerves spherical dry electrodes with to 2 ms in duration 400-V compliance

interelectrode distance of 2 to 5 mm
applied to skin over target nerve

Diagnostic stimulation Bipolar pair gelled electrodes 50-µs-wide transformer-isolated 100 to 1000 V with a

of brain (cortex) and (or corkscrew electrodes for square wave maximum current of

spinal cord intraoperative monitoring) 1.5 A (at a rate of

with interelectrode distance current rise of 0.1 A/µs)

of 7 cm applied to skin

Pain relief Implanted electrodes in contact Monophasic or biphasic pulses 0.1 to 12 V peak

with spinal cord or targeted 210 µs in duration delivered

peripheral nerve to block the at 30 to 80 Hz

sensation of pain
Gelled skin-surface electrodes Monophasic or biphasic pulses 10 to 150 mA with

(impedance 200 Ω to 1 kΩ) placed 50 to 150 µs in duration 150-V compliance

on painful region; often known delivered at 10 to 150 Hz

as transcutaneous electrical nerve
stimulation (TENS)

Vagus nerve Implanted electrodes in contact Monophasic current pulses 0.25 to 35 mA with

stimulation (VNS) with vagus nerve; electrode (with charge-balancing phase) 12-V compliance

impedance 1 to 7 kΩ 130 to 1000 µs in duration

delivered at 30 Hz for 30 s
every 5 minutes