"Our measurement system is an almost unique system, based on non-intrusive, imaging flow measurement technique, called Particle tracking velocimetry. The name is due to the measurement of the velocities of the Particles, tracked in the three-dimensional measurement volume of turbulent flow. The measurement allows investigating the physics of flow in a variety of scientific and engineering applications, ranging from biological fluids in aortas and brain to flows with heat transfer from microelectronic chips, multiphase flows with Particles and polymers, etc. The technique is at the state-of-the-art of the present experimental fluid dynamics research due to its three dimensional abilities and an approach of tracking Particle trajectories for relatively long time. The system looks like the above image, shown in courtesy of Dr. Jochen Willneff, IGP, ETHZ: "

The DVR Express line of frame grabbers are equipped with onboard disk controllers that link directly to the hard drives. There are several advantages to this method. First, the data travels directly to the recording medium, effectively skipping the PC architecture, which is a source of instability and data bottlenecks. Second, the data is ready for post processing and review immediately after recording. Third, a single PC can be scaled to run multiple high speed cameras simply by adding more DVR Express cards. All of these attributes enables a flexible solution for any recording application.

We have assembled a resonant scanning 2-photon system based on previous systems designed by Ian Parker (UC Irvine) and Mike Sanderson (UMass Worcester). The original design functioned as a confocal system but more recent incarnations extend the technology (and actually simplify the design) for 2-photon excitation and 4-channel collection using the Raven video card.

When building our instrument, we were greatly aided by an incarnation of a distortion correction filter that was built into Video Savant with using base code from Mike Sanderson. In conjunction with Bitflow Raven data acquisition cards, our system can process up to 60 full frames per second (we typically use a 30 fps however). Video Savant is a software package that acquires images from PMTs or cameras. In this case, the programmers at Video Savant were extremely helpful in writing a custom GUI to control data acquisition as well as driving a Prior XY stage and a PIFOC high-speed piezzo-electric Z-drive of the type we first used to obtain 4D data in widefield and confocal applications). This code simplifies data handling and creates indexed files that can be read in ImageJ, Bitplane or Metamorph (or standard Windows image viewers) for analysis.