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Author Archives: P.T.R. Rupprecht
Fast z-scanning using a voice coil motor
We just published a paper on fast remote z-scanning using a voice coil motor. For 2P calcium imaging. It’s a nice paper with some interesting technical details. The starting point was the remote z-scanning scheme used by Botcherby et al. (2012) from … Continue reading
Posted in Calcium Imaging, Imaging, Microscopy, Neuronal activity
Tagged Calcium Imaging, laser scanning microscopy, Microscopy, Scanning
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Modulating laser intensity on multiple timescales (x, y and z)
In point-scanning microscopy and especially when using resonant scanners, the intensity of the beam is typically modulated using a Pockels cell. For resonant scanning, the dwell time per micrometer is not constant along the scanned line, and one wants either to … Continue reading
Posted in Calcium Imaging, Imaging, Microscopy
Tagged Calcium Imaging, laser scanning microscopy, Microscopy, Scanning
1 Comment
Deep learning, part III: understanding the black box
As many neuroscientists, I’m also interested in artificial neural networks and am curious about deep learning networks. I want to dedicate some blog posts to this topic, in order to 1) approach deep learning from the stupid neuroscientist’s perspective and 2) to get a feeling … Continue reading
Undistort/unwarp images for resonant scanning microscopy
For image acquisition using a resonant scanning microscope, one of the image axes is scanned non-linearly, following the natural sinusoidal movements of the resonant scanner. This leads to a distortion of the acquired images, unless a online correction algorithm or … Continue reading
Posted in Calcium Imaging, Microscopy
Tagged Calcium Imaging, laser scanning microscopy, Microscopy, Scanning, zebrafish
1 Comment
Deep learning, part II : frameworks & software
As many neuroscientists, I’m also interested in artificial neural networks and am curious about deep learning networks. I want to dedicate some blog posts to this topic, in order to 1) approach deep learning from the stupid neuroscientist’s perspective and 2) to get a feeling … Continue reading
Deep learning, part I
As many neuroscientists, I’m also interested in artificial neural networks and am curious about deep learning networks, which have gained a lot of public attention in the last couple of years. I’m not very familiar with machine learning, but I want to dedicate some blog … Continue reading
Point spread functions
One way to characterize the quality of one’s microscope is to measure the point spread function (PSF), that is the image that is created by a point source (which can be a fluorescent bead smaller than the expected size of the … Continue reading
Aphantasia
A couple of days ago, during a hiking tour close to Luzern, I met a medical doctor from Israel who decided to join me for my hike for the rest of the day. After some time, when I made fun of … Continue reading
EODs for kHz imaging
J. Schneider et al., and S. Hell recently published a paper on STED microscopy, using EODs (electro-optical deflectors) to scan 512 x 512 pixels at frame rates of 1000 Hz. Compared to AODs, EODs offer the costumer-friendly advantage of not dispersing … Continue reading
A pockels cell with a broken crystal
In a 2P microscope, pockels cells are employed for fast control of the laser beam intensity. I use it for both switching off the laser beam during turnarounds of the resonant scanner, between two frames if they are not immediately one after … Continue reading
A blog about neurophysiology 