SCS & Electrical Engineering 101
What metrics do we use for SCS - ANS-Volt (volts), milliamps (mA), kOhoms (Ohms),
microseconds (us), Hertz (Hz)
Voltage - ANS-The electrical pressure that causes free electrons to travel through an
electrical circuit. It is measured in volts (V is abbreviation for Voltage)
Current - ANS-Flow - the amount of electrical charge moving past a given point in an
electrical circuit per unit of time. Current is measured in Amperes or Amps (I is the
abbreviation for current; mA is shorthand for thousandths of an amp) 1mA=0.001 A; the
current is what we generate is what stimulates the nerve
Resistance - ANS-That characteristic of a medium which opposes the flow of electrical
current. It is measured in Ohms - resistance in SCS comes in many forms: lead,
contact, tissue... (R is the abbreviation for Resistance)
What's another way to express Resistance? - ANS-Impedance
Ohm's Law - ANS-Voltage = Current x Resistance; V=I x R; I=V/R; R=V/I
Control - ANS-A process where an output is measured and adjusted to a target value
(ex: cruise-control, temperature control, voltage control, current control)
What are the four characteristics of Electrode Polarity? - ANS-1. At least one positive
2. At least one negative
3. Current flows from positive to negative through the tissue
4. Tissue has resistance
What happens when there are changes in resistance? - ANS-Total current level will
change and voltage control systems cannot control the current to each contact when the
resistance in the tissue changes for any number of contacts
Anode - ANS-Positive +
Cathode - ANS-Negative -
What metrics do we use for SCS - ANS-Volt (volts), milliamps (mA), kOhoms (Ohms),
microseconds (us), Hertz (Hz)
Voltage - ANS-The electrical pressure that causes free electrons to travel through an
electrical circuit. It is measured in volts (V is abbreviation for Voltage)
Current - ANS-Flow - the amount of electrical charge moving past a given point in an
electrical circuit per unit of time. Current is measured in Amperes or Amps (I is the
abbreviation for current; mA is shorthand for thousandths of an amp) 1mA=0.001 A; the
current is what we generate is what stimulates the nerve
Resistance - ANS-That characteristic of a medium which opposes the flow of electrical
current. It is measured in Ohms - resistance in SCS comes in many forms: lead,
contact, tissue... (R is the abbreviation for Resistance)
What's another way to express Resistance? - ANS-Impedance
Ohm's Law - ANS-Voltage = Current x Resistance; V=I x R; I=V/R; R=V/I
Control - ANS-A process where an output is measured and adjusted to a target value
(ex: cruise-control, temperature control, voltage control, current control)
What are the four characteristics of Electrode Polarity? - ANS-1. At least one positive
2. At least one negative
3. Current flows from positive to negative through the tissue
4. Tissue has resistance
What happens when there are changes in resistance? - ANS-Total current level will
change and voltage control systems cannot control the current to each contact when the
resistance in the tissue changes for any number of contacts
Anode - ANS-Positive +
Cathode - ANS-Negative -
