Low Field NMR Signal Electronics

Basic information

Project ID: AEE-2017-38

Students: Tiia Huttunen, Ville Luntinen, Tommi Koskinen, Olli Mäkinen, Otto Aho

Project manager: Tiia Huttunen

Instructor: Raimo Sepponen

Other advisors: Matti Linnavuo

Starting date: 5.1.2017

Completion date: 29.5.2017

Objective

This work demonstrates a low-field NMR spectrometer prototype that can successfully detect the ¹H NMR signal from a small water sample, using a permanent magnet of 10 mT. A signal-to-noise ratio of approximately 20 is achieved.

The purpose of the work is to serve as a blueprint for future development of a full-scale low-field MRI device in Aalto University Health Factory. Low-field MRI may offer a compelling alternative to the more common MRI devices that utilize superconducting magnets and high field strengths. Using low fields, costs can be kept lower and the electronics simplified, albeit with some trade-offs in resolution and signal-to-noise ratio. Our prototype serves as an early stage small-scale prototype that can be utilized in gradually scaling the system towards a full-scale MRI device. The prototype is expected to prove useful in for example studying the homogeneity of the permanent magnet, as well as providing an initial design of the required signal electronics.

The realized spectrometer prototype is intended for laboratory use in the school premises. It comprises of original circuits realized by the authors as well as commercial products such as signal generators and power sources. Design, realization and testing of the spectrometer is described in detail.

The presented work was done as part of Aalto University’s Project Work course of spring 2017. Insights are therefore also given from the point of view of project management and learning goals of the course.

Summary of results

A working low-field NMR spectrometer prototype was designed, built and demonstrated. Using a permanent magnet of ~10 mT, the FID signal of ¹H was successfully obtained using the prototype. Our work can serve as the blueprint for the long-term goal of developing the device closer to a full-scale MRI device.

Documents

Poster

Finalreport38_Low-FieldNMR_E80022017.pdf