Microbial inactivation and effects of interrelated factors of intense pulsed light (IPL) treatment for Pseudomonas aeruginosa

- The double Weibull model accurately describes IPL inactivation curves.
- Energy incidents were compared with the fluence for the first log reduction values.
- IPL energy incident is higher for a lower pulse repetition rate or longer width.
- Energy efficiency of the IPL fluence for different pulse conditions was discussed.

Intense pulsed light (IPL) inactivation of Pseudomonas aeruginosa for different pulse repetition rates (2-15 Hz) and widths (0.15-1.5 ms) were described using the double Weibull model and their energy incidents were compared. The values of the regression coefficient (R2), RMSE (root mean sum of squared errors), accuracy factor (Af), and bias factor (Bf) strongly suggested that the model provided a good fit to the data, and they were coupled with the fluence for the first log reduction (FR) to compare the energy incidents of different treatments. The incident was higher for a lower pulse repetition rate or a longer pulse width. Moreover, in order to examine the effects of interrelated factors on the IPL fluence in terms of energy efficiency, we proposed several terms: the VF value is defined as the increase in the voltage required for a 1-J/cm2 increase in the fluence, and the zprr and zpw values are defined as the increases in repetition rate and width of the pulses, respectively, that result in one unit increase in the VF value. By using these terms, the effects of pulse repetition rate and width on the IPL fluence were analyzed and predicted for further investigation.