Abstract
In the roller-pump-driven cardiopulmonary bypass system, inadvertent kinking or bending of the blood stream tube may cause abrupt changes in circuit pressure and produce fatal damage to the system and/or a patient. To avoid this type of hazard, we invented equipment with which CPB circuit pressure could be used to regulate the rotation cycle of the roller pump. After checking its efficacy in vitro, we investigated its clinical usefulness and safety in 598 cardiovascular surgical CPB cases. In 596 of them, our equipment was used as a safety guard both in the inlet and outlet circuit of the CPB system, and in the remaining two as a constant flow modulator. For the former purpose, our equipment worked promptly and immediately produced an appropriate alarm. No harmful changes in circuit pressure were observed. The restoration of the CPB system was also prompt and smooth after resolving any kinks or bends in the tubes. In the latter cases, satisfactory constant blood flow could be maintained. In conclusion, our pressure-feedback regulator equipment could offer safe and effective management of CPB. Furthermore, it can be useful in the further automation of the CPB system.
