The WEK-SAR calorimetric SAR measurement phantom—an MRI SAR phantom and whole-body SAR measurement device—consists of a fiber-optic temperature measurement system and the SAR phantom itself.

The temperature measurement range of the fiber-optic system is 15°C to 45°C, with a maximum permissible error of ±0.1°C. It complies with the Calibration Specification for Medical Magnetic Resonance Imaging Systems (JJF 2151—2024).

The SAR phantom is scanned using a body coil. The scanning sequence and parameters are configured according to the clinically standard Spin Echo (SE) sequence parameters. The number of scans is increased such that the scanning process continues until either the total scanning duration reaches a minimum of 2 hours or the temperature rise within the SAR phantom reaches 4°C, at which point the scan is terminated.

 

This utility model relates to a "calorimetric" SAR value measurement device based on the principle of fiber-optic thermometry, comprising a phantom for calorimetric SAR measurement and a fiber-optic temperature measurement unit.

The phantom features an elliptical cross-section with a platform situated on its upper surface; this platform is tangential to the outer diameter of the ellipse's minor axis. An inlet port is provided on the platform, and the interior of the phantom is filled with a solution possessing average electromagnetic characteristic parameters consistent with those of human torso tissue.

The phantom described in this utility model is characterized by its compact overall volume and low mass, facilitating ease of transport. Furthermore, it eliminates the need to measure an equivalent load and allows for the direct measurement of SAR values ​​without requiring the disassembly of the outer casing.

The device is capable of real-time monitoring of temperature fluctuations within the solution inside the phantom, the MRI scanning room, and the MRI scanning bore; it also enables the recording and export of temperature monitoring data, thereby demonstrating broad applicability.


 

Features:

• Comprises a phantom designed for "calorimetric" SAR value measurement and a fiber-optic temperature measurement system.
• The phantom is constructed from acrylic material and features an elliptical cross-section. A platform is situated across the upper section of the phantom, positioned tangentially to the outer diameter of the ellipse's minor axis. This platform is equipped with three equally spaced filling ports, arranged symmetrically along the central axis of the phantom.
• The fiber-optic temperature measurement system consists of multiple fiber-optic temperature probes, a main measurement unit, and a computer pre-loaded with temperature monitoring software; the computer communicates with the main measurement unit via a serial port.
• The phantom is supplied with two types of lids: a standard sealing lid, and a second lid featuring a central through-hole designed for the insertion of the fiber-optic temperature probes.
• During transport, the phantom is sealed using the standard sealing lid; for SAR value measurements, this is replaced with the lid featuring the through-hole.

The fiber-optic temperature transmitter features a wall-mounted or DIN-rail installation design.

This product offers unique technical advantages for temperature measurement in specialized environments characterized by high voltage and intense electromagnetic interference.

Notably, the fiber-optic temperature sensor utilized within the transmitter employs no electrical connections between its temperature-sensing hotspot and its signal reception unit; this enables long-term operation with exceptional accuracy and stability, thereby significantly expanding its scope of application.

Furthermore, the fiber-optic temperature transmitter effectively mitigates the risks associated with high-voltage circuit breakers or cable terminations operating under excessive heat—conditions that can shorten their service life, lead to burnout, or compromise the safe operation of switchgear cabinets.

The transmitter boasts high accuracy and sensitivity, is resistant to high voltage and corrosion, supports remote monitoring, and offers a long service life. Its compact size simplifies maintenance and ensures safe transportation. Moreover, its internal modular design features a layout that is both aesthetically pleasing and functionally sound.