The RFoF1P4MED is a miniature active electro-optical wide-band sensor system for induced voltage measurements. It was jointly developed with our Z43 partner organization ZMT Zurich MedTech AG (ZMT) and allows medical implant immunity testing for compatibility with magnetic resonance imaging (MRI) environments in a precise and easy manner.

RFoF1P4MED is compatible with MRI systems up to 7T. With the ability to acquire the complex-valued voltage signals in the frequency range from 10 MHz – 1 GHz, RFoF1P4MED fulfills all probe requirements stated in ISO 10974 Clause 15 for Tier 3 evaluations.



TDS RFoF1P4MED is composed of one RFoF1PMED voltage probe, an RFo1PF4MEDFOI fiber-optic interconnect, and a TDS Remote Unit. An RFoF1P4MEDCU calibration unit is used for on-site calibration and verification.


The TDS RFoF1P4MED system is optimized RF voltage measurements in EM-hostile and EM-sensitive environments:

  • ISO 10974 Clause 15 for Tier 3 evaluations
  • Fully differential voltage measurements in EM-hostile environments
Basic Configuration

The basic configuration of a TDS RFoF1P4MED system is composed of:

TDS Remote Unit

TDS Remote Unit specifications:

  • input: TDS MU8 optical interconnect
  • output: 3.5mm RF connector
  • frequency range: 100kHz (10Hz) to 6 GHz
  • P1dB: > 0 dBm
  • return loss: > 10 dB
  • power and control: USB

Specifications of the TDS RFoF1P4MED transducer:

  • frequency range: 10 MHz (10 Hz) to 1 GHz
  • dynamic range: 50 μV - 7 V (peak)
  • sensor size: 2 × 2 × 4  mm2
  • impedance: 300 kΩ
Software TDS RFoF1P4MED comes with a remote control capability via SCPI commands over the USB link for measurement and test automation.
Calibration Calibration is performed in SPEAG's ISO17025-certified calibration laboratory.

S21 measurement with RFoF1P4MED CU

Standard Compatibility

TDS RFoF1P4MED can be used for tests in compliance with:

  •  ISO 10974 Clause 15 for Tier 3
Unique Features  

Frequency range

Active optical technology



10 MHz (10 Hz) - 1 GHz

non-disturbed signal transmission with unparalleled dynamic range

flat wideband  RF signal transmission

sensor size 2 × 2 × 4  mm2


Wide-band sensors

Miniature transducer

Fully isolated using optical technology

Fully differential

MRI compatible

ability to cover a wide frequency range with one voltage probe

no loading of the device under test

no parasitic pickup, full signal integrity, 100% trusted results

optical isolation provides unparalleled differential measurement performance

no magnetic material in the probe allows easy use in clinical systems

Compatibility DASY8 Module AIMD, ZMT MITS, ZMT piX
Product History see Product Lifetime

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