Skip to main content

AccuQT - Accurate QT Correction for ECG Analysis

Tampere University
Duration of project1.1.2021–30.6.2022
Area of focusHealth, Technology


In the electrocardiogram (ECG), the QT interval, the time between the beginning of the Q wave and the end of the T wave, is an essential metric to assess cardiac health. Therefore, the QT interval must be measured as accurately as possible. The problem is the fact that the QT interval depends on the heart rate (RR intervals) in a complex fashion. This dependence must be computationally corrected. This dependence must be removed as accurately as possible. For this purpose, various QT correction models have been proposed but with limited success. The present correction formulas in clinical use date back to 1920’s and often produce erroneous results, leading to unnecessary examinations and wrong diagnoses. Currently, there is no general consensus on which QT correction method to use in clinical practice.


We have discovered the dynamical dependence between the RR and QT intervals by employing the concept of transfer entropy (Potapov et al., 2018). As a follow-up to this discovery, we have developed a novel QT correction method, AccuQT, that computes the corrected QT intervals precisely during the ECG measurement (Räsänen et al., 2021). The method dynamically adapts to a multitude of previous RR intervals and gives the true QT correction as an output. According to tests AccuQT has a superior detection rate for abnormal QT times and it overperforms all the other QT correction methods. The goal of the present project is to validate this technology for large clinical datasets and prepare for commercialization.



  • Superior performance in comparison with all the previous QT correction methods.
  • Independence of models or approximations: uses only the measured raw QT and RR intervals as input and gives the corrected QT intervals as output.
  • Straightforward to implement to any ECG, handheld or wearable device that records QT and RR intervals.
  •  Makes QT interval evaluations meaningful on a much broader scale than what has been possible so far.


  • Clinical ECG measurement and QT assessment: potential to become a new standard in the field.
  • Cardiotoxicology in all phases of pharmaceutical development (pre-clinical and clinical)
  • Risk assessment through QT measurement in wearable devices.

Further Details

Potapov et al., Information transfer in QT-RR dynamics: Application to QT-correction, Sci Rep 8, 14992 (2018),

Räsänen et al., Towards Accurate and Model-Free QT Correction, Comp. Cardiol. 2021.

Patent accepted in Finland in 2020 (FI128598B), USA in 11-2021 (No. 11213241) and EPO in 2022. Pending in Japan, Canada, Australia, China and India.

Funding source

Novo Nordisk Fonden Pioneer Innovator Grant


Coordinating organisation

Tampere University