Philips Medical Systems
category
waveform parameters
Defibrillation Waveform
specifications
Biphasic truncated exponential. Waveform parameters are automatically adjusted as a function of patient defibrillation impedance. In the diagram at left, D is the duration of phase 1 and E is the duration of phase 2 of the waveform, F is the interphase delay (500 µs), and Ip is the peak current.
The HeartStart delivers shocks to load impedances from 25 to 180 ohms. The duration of each phase of the waveform is dynamically adjusted based on delivered charge, in order to compensate for patient impedance variations, as shown below:
|
| adult defibrillation |
|
|
| |
load | phase 1 | phase 2 | peak | delivered |
| |
resistance (Ω) | duration (ms) | duration (ms) | current (A) | energy (J) |
| |
25 | 2.8 | 2.8 | 65 | 128 |
| |
50 | 4.5 | 4.5 | 40 | 150 |
| |
75 | 6.25 | 5.0 | 30 | 155 |
| |
100 | 8.0 | 5.3 | 24 | 157 |
| |
125 | 9.65 | 6.4 | 21 | 159 |
| |
150 | 11.5 | 7.7 | 18 | 160 |
| |
175 | 12.0 | 8.0 | 16 | 158 |
| |
| pediatric defibrillation |
|
| E | ||
(using M5072A infant/child | ||||||
| ||||||
load | phase 1 | phase 2 | peak | delivered |
| |
resistance (Ω) | duration (ms) | duration (ms) | current (A) | energy (J) |
| |
25 | 4.1 | 2.8 | 28 | 35 |
| |
50 | 5.1 | 3.4 | 20 | 46 |
| |
75 | 6.2 | 4.1 | 15 | 52 |
| |
100 | 7.2 | 4.8 | 12 | 54 |
| |
125 | 8.3 | 5.5 | 10 | 56 |
| |
150 | 9.0 | 6.0 | 9 | 57 |
| |
175 | 9.0 | 6.0 | 8 | 55 |
| |