0.02
0.015
0.01
Real part
Imaginary part
10
4
10
6
10
8
10
10
Frequency (Hz)
0.005
0
−0.005
−0.01
−0.015
Electrical field (V/m)
12
10
Real part
Imaginary part
10 6
10
8
10
10
Relative permittivity
8
6
4
2
0
10
4
101
Pulsed Electric Fields in Biological Cells and Membranes
Figure 2.15 A nanosecond rectangular pulse with a 10 7 V/m electric field, transformed into
the frequency domain.
Frequency (Hz)
Figure 2.16 Relative permittivity of cell membrane as a function of frequency.
in all cases, and the field amplitude was adjusted each time to ensure a constant total
energy. As seen from Figure 2.17, the highest TMP is predicted for the subnanosecond
pulse duration, with progressive decreases for the longer 2-ns and 4-ns pulses. Physically,
this occurs because for shorter pulses, the frequency spectrum of the waveform shifts to
a higher range. Because the dielectric constant at higher frequencies decreases, the effective charging time constant of the membrane (∼ε/σ) is reduced. This enables quicker
0.015
0.01
Real part
Imaginary part
10
4
10
6
10
8
10
10
Frequency (Hz)
0.005
0
−0.005
−0.01
−0.015
Electrical field (V/m)
12
10
Real part
Imaginary part
10 6
10
8
10
10
Relative permittivity
8
6
4
2
0
10
4
101
Pulsed Electric Fields in Biological Cells and Membranes
Figure 2.15 A nanosecond rectangular pulse with a 10 7 V/m electric field, transformed into
the frequency domain.
Frequency (Hz)
Figure 2.16 Relative permittivity of cell membrane as a function of frequency.
in all cases, and the field amplitude was adjusted each time to ensure a constant total
energy. As seen from Figure 2.17, the highest TMP is predicted for the subnanosecond
pulse duration, with progressive decreases for the longer 2-ns and 4-ns pulses. Physically,
this occurs because for shorter pulses, the frequency spectrum of the waveform shifts to
a higher range. Because the dielectric constant at higher frequencies decreases, the effective charging time constant of the membrane (∼ε/σ) is reduced. This enables quicker