Abstract: Apparatuses and methods for determining particle shed rates of implantable or inter-dwelling devices are disclosed. Durability test apparatuses with integrated particle counters produce time-dependent particle shed rate profiles. The apparatuses are designed to accommodate pulsatile flow, resembling a heartbeat at the implantable device. In an embodiment, the pulsatile flow is converted to a steady flow before fluid enters the integrated particle counter.

Abstract: Method and apparatus are disclosed for obtaining flow information of a conductive fluid by detecting the streaming potential and analyzing the resultant signal. In a particular embodiment for detecting abnormal blood velocities in the arterial tree, the apparatus includes a flexible sensor having two fixedly spaced apart electrodes and a common mode signal electrode. Each sensor electrode is connected to an input of a differential amplifier and the common electrode is connected to the common input of the differential amplifier. The output signal from the differential amplifier, after filtering and amplification is provided to a recorder or oscilloscope so that it can be compared with the normal or average signal.A particular embodiment of the method is used to detect blood flow abnormalities, either too fast or too slow compared with most healthy individuals of the same age.