Physiologic and Extracorporeal Shock Wave Lithotripsy (ESWL) data were collected before, during and after ESWL from four patient groups employing different anesthetic techniques (epidural anesthesia, general anesthesia with low-volume conventional mechanical ventilation or with unsynchronized high frequency jet ventilation (HFJV) or with HFJV synchronized to the heart rate). The primary goal was to determine if synchronized HFJV had any beneficial effects. A synchronization unit was fabricated that triggered one HFJV breath, per heart beat, delivered 30 milliseconds after the shock wave. This allowed only expiratory motion during shock wave administration. Results were analyzed using one-way analysis of variance, Students t-tests and chi-square tests with significance at p 0.05. Results showed that renal stone excursion was significantly less in HFJV groups and that significantly more patients required re-treatment in non-HFJV groups. No results indicated that synchronizing HFJV had any further benefits than unsynchronized HFJV.