Author Response: Pressure Wave Dosimetry for “Retinal Ganglion Cell Damage in an Experimental Rodent Model of Blast-Mediated Traumatic Brain Injury”

We would like to thank Lund and Rule ¹ for their interest in our work and their helpful suggestions to more thoroughly characterize the blast wave that we generated in our system. ² In order to accomplish that goal, we designed pressure measurement software coupled with a high-frequency pressure sensor (model 102B16; PCB Piezotronics) and signal conditioner (model 482C05; PCB Piezotronics, Depew, NY). Using this software we have been able to successfully characterize the total blast pressure in our system (Fig.A) adjacent to the animal holder at the level of the head (Fig.B). 

Figure

 

Example of a blast profile with the positive duration shaded gray (A). The design of the padded animal holder (arrow points to where the mouse head is located) and the blast wave pressure sensor ([B] arrowhead) are shown.

We now report measurements, obtained by using this system, of the intensity of our blast wave, which was 149.8 ± 2.09 kPa at the gauge (n = 13 blast responses; mean ± SEM). The total duration of the total pressure in our system (blast wave + wind gust) was approximately 10 to 15 ms, similar to that reported by Goldstein et al. ³ We feel that our blast exposure paradigm results in a phenotype that best reflects ocular injury after a traumatic brain injury, as recently described. ⁴ The authors raise an interesting point regarding the complexity of the blast wave responses experienced in our blast tank. It is likely in our system that the subjects experience a complex blast wave. It is also entirely likely, however, that veterans or civilians exposed to blast waves also experience complex blast waves.