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MRI switch and coil

Basic Information

Students: Vincent Eurasto, Tapio Leppänen, Tuomas Haajanen, Mohammad Shahidul Islam Ahmed

Project manager: Vincent Eurasto

Instructor: Janne Holma

Starting date: 25.2.2022

Completion date: 3.6.2022

A novel accessible magnetic resonance imaging (AMRI) device is being developed at Aalto

University. This device uses much lower magnetic fields than traditional MRI machines, which

allows using the equipment, for example, inside an ambulance. This project aimed to create two parts

to the radiofrequency (RF) system of the AMRI device. The objectives were to develop an active

transmit/receive switch and an RF coil. The switch is used to control the RF coil, which transmits and

receives magnetic fields to and from the sample that is inside the coil. The switch was built using PIN

diodes which are an excellent choice for RF switching applications. If a sufficient forward bias

voltage is applied over a PIN diode, an AC signal can pass through the diode with minimal losses,

which is ideal, especially during the receive mode. The purpose of the RF coil is to perform as an

antenna for transmitting and receiving signals. The coil needed to have an elliptical shape that fits

well around the abdomen or lungs of a middle-sized human. In addition, the coil needed to have a

design, which allows opening the coil, to set the coil on a patient or a sample easily. Furthermore, the

transmit and receive modes of the RF system rely heavily on the phenomena of electrical resonance,

and thus, a resonator circuit must be designed for the coil. In this project work, a prototype of the

active switch was successfully developed and tested profoundly in both transmit and receive modes.

Additionally, the casing for the coil was built using 3D printing techniques and the windings for the

coil were made using Litz wire. In the end, the coil was measured to have low resistance which was

one of the desired characteristics. However, the development of the resonator circuit of the coil was

left out of the project mainly due to a lack of time.

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PDF File Business_aspects_3-02.pdf Jun 08, 2022 by Vincent Eurasto
PDF File Final_gala_poster_3-03.pdf Jun 08, 2022 by Vincent Eurasto
PDF File Final_report_2022_mri_switch_and_coil_3-02.pdf Jun 08, 2022 by Vincent Eurasto
PDF File Pitch_presentation_3-02.pdf Jun 08, 2022 by Vincent Eurasto
PDF File Project_plan_3-02.pdf Jun 08, 2022 by Vincent Eurasto
PDF File Project_Work_presentation_3-02.pdf Jun 08, 2022 by Vincent Eurasto
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