Vlad Negnevitsky

Power supply of the OCRA console

Hello OCRA and Tabletop community, In this blog post I want to share our console power supply for the OCRA Tabletop MRI System. The console is driven by a Mean Well RT-50C switching mode power supply with a universal 110/230V AC input and +15V, -15 and +5V DC outputs. To connect the power supply to…

26 Apr

Gradient Coils for the OCRA Tabletop MRI System

Hello OCRA and Tabletop community, In this blog post I want to share our gradient coil design for the OCRA Tabletop MRI System. Gradients fields are necessary to encode spatial information to the spin signal. As the origin of the spin signal is the homogeneous magnetic field (B0) it is possible to variate this field…

08 Mar

Relax2.0, a graphical user interface for OCRA

Hello OCRA and Tabletop community, In this blog post, I will share the news about the first GitHub publication of my Relax2.0 graphical user interface (GUI) for OCRA. Relax2.0 is based on the original OCRA server for the Red Pitaya by Thomas Witzel and the PyQt GUI Relax by David Schote. Relax2.0 can be downloaded…

18 May

Testing the transmit and receive functionality of the OCRA Tabletop MRI System

Hello OCRA and Tabletop community, In this blog I will guide you on how to test the RF functionality of the OCRA Tabletop MRI System. We will test the functionality for receiving RF spin signals (RX) and transmiting RF pulses (TX). For the tests you need a pickup loop coil. The coil can be build…

18 Apr

RF-Coil for the OCRA Tabletop MRI system

Hello OCRA and Tabletop community, In this short blog I will share my radiofrequency (RF) -coil design for our OCRA Tabletop MRI system. The coil is a simple solenoid design. To make it sensitive to the measurement (Larmor) frequency it is built as an electrical resonator with parallel capacitance. To match its impedance to a…

15 Dec

Small Scale 600W Gradient Power Amplifier

Hello OCRA and Tabletop Community, I would like to introduce the low-cost 4-channel 600 W Gradient Power Amplifier (GPA) for our OCRA Tabletop MRI system. Basically, the GPA converts a voltage input coming for example from the OCRA1 (see blog post from Marcus) into currents to supply gradient coils. The GPA can handle gradient sequences (pulsed…

Porting RP-125 FPGA bitstream features to RP-122

My name’s Vlad Negnevitsky, and I’ve been working on OCRA part-time since mid-2019 on behalf of the MRILab at i3m in Valencia, Spain. I’m not an MRI physicist, and I’ll mainly be discussing the technical side of OCRA. OCRA is a multi-level project, bringing together lots of fun engineering at the electronics/hardware, FPGA firmware, embedded…

Author: Vlad Negnevitsky