Introduction

Modern medical imaging systems, ranging from MRI and CT scanners to PET and SPECT, demand exceptional reliability, precision, and uptime. These systems operate in environments where high-energy fields, radiation scatter, and electromagnetic interference are common. Such conditions increase the risk of Single Event Upsets (SEUs), bit-level errors caused by energetic particles interacting with semiconductor devices.

This article introduces SEUs, explores their relevance across multiple imaging modalities, and presents PolarFire® SoC technology, as implemented in SundanceDSP’s SMO1 and SOM1-SOC modules, as a robust solution for engineers designing next-generation medical platforms.

What Is a Single Event Upset (SEU)?

An SEU is a transient fault caused by high-energy particles (e.g., cosmic rays, alpha particles) striking sensitive regions in semiconductor materials. These interactions can flip bits in memory or logic circuits, leading to unpredictable behavior without damaging the hardware.

SEU Mechanism in Electronics

In medical environments, SEUs may occur due to:

• Radiation scatter from X-ray or gamma sources
• Electromagnetic interference from MRI magnets and RF pulses
• Cosmic ray exposure in mobile or high-altitude diagnostic units

Particle-Based Imaging Modalities and SEU Risk

Several advanced imaging systems rely directly on particles or radiation-emitting tracers, increasing the likelihood of SEU events in nearby electronics:

Positron Emission Tomography (PET)

• Particles Used: Positrons
• Mechanism: Radioactive tracers emit positrons that annihilate with electrons, producing gamma photons.
• SEU Risk: Gamma emissions can induce soft errors in control and processing electronics.

Single Photon Emission Computed Tomography (SPECT)

• Particles Used: Gamma photons
• Mechanism: Radiotracers emit gamma rays, detected by rotating cameras.
• SEU Risk: High-energy photons may affect FPGA logic or memory near detectors.

Magnetic Particle Imaging (MPI)

• Particles Used: Superparamagnetic iron oxide nanoparticles (SPIONs)
• Mechanism: SPIONs respond to magnetic fields and are tracked to form images.
• SEU Risk: Strong magnetic fields and switching gradients can induce transient faults.

Radiotheranostics

• Particles Used: Alpha, beta, and gamma emitters
• Mechanism: Combines diagnostic imaging with targeted radiation therapy.
• SEU Risk: Proximity to therapeutic radiation increases SEU exposure.

Nanoparticle-Enhanced Imaging

• Particles Used: Metallic or polymeric nanoparticles
• Mechanism: Used as contrast agents in CT, MRI, and ultrasound.
• SEU Risk: Indirect, but enhanced imaging fields may elevate soft error rates.

FPGA Architecture and SEU Susceptibility

Most FPGAs used in embedded systems rely on SRAM-based configuration memory, which is volatile and highly susceptible to SEUs. These devices require constant power to maintain their configuration and often rely on external scrubbing mechanisms to detect and correct errors.

SRAM-Based FPGA Vulnerabilities:

• Volatile configuration memory: susceptible to bit flips
• Higher power consumption
• Delayed boot time due to configuration loading
• Complex SEU mitigation strategies are required

PolarFire FPGA: A Non-Volatile, SEU-Resilient Alternative

Microchip’s PolarFire® FPGA and SoC family addresses these challenges with a fundamentally different architecture:

Key Advantages:

Feature	PolarFire FPGA
Configuration Memory	Non-volatile flash (SEU-immune)
Power Efficiency	Up to 50% lower than SRAM-based FPGAs
Instant-On Boot	No delay from configuration loading
SEU Mitigation	Inherent immunity in configuration and logic
Security	Hardware root of trust, secure boot, encryption

This architecture makes PolarFire ideal for mission-critical medical systems operating in radiation-prone environments.

Introducing SOM1 and SOM1-SOC

SundanceDSP’s SMO1 and SOM1-SOC modules integrate PolarFire SoC technology into small form factor, low-power, and instant-on platforms tailored for medical device manufacturers.

Module Highlights:

Feature	SMO1 / SOM1-SOC
Form Factor	Compact, ideal for embedded imaging systems
Processor	RISC-V cores with FPGA fabric
SEU Resilience	Inherent via PolarFire architecture
Boot Time	Instant-on for critical uptime
Power Profile	Optimized for fanless, low-thermal designs
Security	Built-in encryption and secure boot features

These modules are designed to accelerate the development of:

• MRI control systems
• CT scan data acquisition units
• PET and SPECT electronics
• Radiotherapy controllers
• Portable diagnostic platforms

Conclusion

SEUs represent a hidden but significant reliability risk in particle-based medical imaging systems. By adopting PolarFire SoC technology, engineers can build platforms that are inherently resilient to soft errors, while benefiting from low power, secure operation, and deterministic performance.

SundanceDSP’s SMO1 and SOM1-SOC modules offer a turnkey solution for medical OEMs seeking to enhance system reliability, reduce development time, and meet stringent regulatory standards.