Stress Test ElectrocardiographCardiMax FX-8400 The FX-8400 has a large 8-inch widescreen LCD offering unparalleled ease of use for checking patient data, as well as clear, accurate ECG wavefo... ElectrocardiographCardiMax FX-8322R Installation of the optional software FP-805S will enable the FX-8322R to perform stress test ECG examination on an Ergometer or Treadmill.