Brandaris 128 ultra-high-speed imaging facility: 10 years of operation, updates, and enhanced features

Abstract

The Brandaris 128 ultra-high-speed imaging facility has been updated over the last 10 years through modifications made to the camera's hardware and software. At its introduction the camera was able to record 6 sequences of 128 images (500 × 292 pixels) at a maximum frame rate of 25 Mfps. The segmented mode of the camera was revised to allow for subdivision of the 128 image sensors into arbitrary segments (1-128) with an inter-segment time of 17 μs. Furthermore, a region of interest can be selected to increase the number of recordings within a single run of the camera from 6 up to 125. By extending the imaging system with a laser-induced fluorescence setup, time-resolved ultra-high-speed fluorescence imaging of microscopic objects has been enabled. Minor updates to the system are also reported here.

Ultra-fast bright field and fluorescence imaging of the dynamics of micrometer-sized objects

“…A recent update of the Brandaris system reported on the improvement on fluorescence imaging at above 1 Mfps rate, among other improvements such as region of interest selection mode and segment selection mode. 25 We present the development of a high speed bright field and fluorescence imaging system that further improves on the sensitivity, spatial resolution, and computer control, that synchronizes light source for bright field and laser fluorescence imaging, and that incorporates external waves such as US. Special emphasis is put on in vitro and in vivo fluorescence imaging where photon availability is limited and high sensitivity is required.…”

Combined optical sizing and acoustical characterization of single freely-floating microbubbles

“…2,3 The nonlinear radial dynamic response of single microbubbles exposed to ultrasound, especially to long burst excitations, are of great interest for developing imaging and drug delivery strategies. [4][5][6] Previous studies using acoustical or optical techniques to determine the microbubble response to ultrasound excitation, have demonstrated a myriad of nonlinear behaviors specific to lipid-coated microbubbles. These behaviors include asymmetric oscillation due to buckling and rupture of the lipid shell, 7 subharmonic emission, 8 and compression-only behavior.…”

“…12 Optical methods have been employed using (ultra) highspeed cameras to capture the instantaneous microbubble vibrations. 13,14 However, the frame rate is generally less than 25 Mfps, 5,6,8 and the recording time is restricted by the frame rate and the number of recorded frames unless complex timing schemes are used. 15 Techniques in which isolated microbubbles are manipulated or confined within a capillary or a flow channel can overcome these limitations to some degree.…”

Monodisperse bubbles and droplets for medical applications

“…1.10B, and provides valuable information on the shell viscoelastic properties. Recent advances in ultra high-speed fluorescence microscopy, some performed at frame rates exceeding 20 million frames per second 77,78 , have revealed new insight in lipid shedding, drug release 14 and drug uptake mechanisms 52,81 and valuable information for bubble-mediated medical applications.…”

“…The optical visualization of a sample of microbubbles under the microscope is relatively straightforward, but the real-time visualization of the bubble dynamics upon insonation with a 2-MHz ultrasound pulse is quite challenging and it requires high-speed imaging at a frame rate near 10-20 million frames per second. Several camera systems [76][77][78] are capable or reaching such high frame rates and in addition acquire a high number of frames of 100 or more. A higher number of frames allows for the measurements of the bubble response at various acoustic parameters, such as pressure 79 and frequency 80 , or both 75 .…”