# Waveforms of Therapeutic Currents

Original Editor - Rafet Irmak

Top Contributors - Admin, Rafet Irmak, Rachael Lowe and Kim Jackson

## Waveforms of Therapeutic Currents

Therapeutic currents are, special electric currents that are applied to human body for healing the body. Generally these are defined by using voltage-time chart of the current which can be seen in the oscilloscope screen. This page summaries the waveform of common therapeutic currents.

## Fundamental Terms

### Oscilloscope

An ossiloscope is an instrument which is used to observe voltage changes during time in electric circuits.

### Signal Generator

A signal generator is an instrument which generates electrical signals at given waveform, frequency and amplitude. Electrotherapy equipment is a kind of signal generator which generates therapeutic signal waveforms in safe frequency and amplitude.

### Frequency

Frequency is a term which describes how many times a waveform repeat it self per second by signal generator.

#### A 100 Hz Sine Wave Figure 2: Signal generator settings for sine wave at 100 Hz frequency and 1V peak amplitude. Figure 3: Ossiloscope screen shot for sine wave at 100 Hz frequency and 1V peak amplitude.

#### A 500 Hz Sine Wave Figure 4: Signal generator settings for sine wave at 500 Hz frequency and 1V peak amplitude Figure 5: Osiloscope screen shot for sine wave at 500 Hz frequency and 1V peak voltage amplitude.

#### A 1000 Hz Sine Wave Figure 6: Signal generator site for sine wave at 1000 Hz frequency and 1V peak amplitude Figure 7: Osciloscope screen shot for sine wave at 1000 Hz frequency and 1V peak voltage amplitude.

### Peak Amplitude

The term peak amplitude defines the highest positive or negative value of a waveform. In therapeutic currents peak amplitude generally defines the highest value of the voltage during time.

### Peak to Peak Amplitude

The term peak to peak amplitude defines the amplitude between the highest negative to highest positive value. Peak to peak amplitude of a sine wave is equal to two times peak value of a sine wave.

### Mean Amplitude

The term mean amplitude defines mean value of a waveform. In therapeutic currents mean amplitude is a quantity in terms of voltage. Peak amplitude of a sine wave has different mean amplitude value. Mean amplitude of a sine wave is equal to 0.637 x Peak Amplitude.

#### Peak and Mean Amplitude of 100 Hz and 1 Volt Sine Wave Figure 9: Osciloscope screen shot for peak and mean amplitudes of a 100 Hz 1 Volt sine wave.

Peak and Mean Amplitude of 1000 Hz (1KHz) and 10 Volt Sine Wave Figure 11: Osciloscope screen shot for peak and mean amplitute of a 100 Hz, 10V sine wave.

Peak and Mean Amplitude of 1000 Hz (1KHz) and 20 Volt Sine Wave Figure 12: Signal generator parameters for Peak and mean amplitude of a sine wave  at 100 Hz  and 20V. Figure 13: Osciloscope screen shot for peak and mean amplitute of a 100 Hz, 20V sine wave.

### Square Waveform

Square waveform is a common therapeutic waveform. Interrupted galvanic current and TENS are forms of Square waveform. The main parameter of a square waveform is duty cycle. It defines the time ratio when voltage is higher or lower then zero and when voltage is equivalent to zero.

#### 20% Duty Cycle Square Waveform

50% Duty Cycle Square Waveform

75% Duty Cycle Square Waveform Figure 21: Osciloscope screen shot for 1V, 100Hz, 75% duty cyclesquarewaveform