References

Customer Case: Zenicor Medical Systems

Zenicor Medical Systems is a Swedish medtech company providing solutions for remote cardiology diagnostics and stroke prevention. Cardiolund has provided Zenicor with a robust algorithm for detecting atrial fibrillation and other arrhythmias in ECG signals recorded using the Zenicor’s thumb-ECG system.

Cardiolund has developed a particularly robust algorithm to overcome the challenges of dealing with simplified ECG measurements performed at home. In addition to performing standard ECG measurements, the Cardiolund algorithm parses the ECG signals in detail providing markers of all important events.

Cardiolund’s algorithm also provides automatic classification of the ECG signal into one of 12 categories, summarising the algorithm’s interpretation of the signal. This classification can be used to separate signals without any deviations and those with severe disturbances from the rest. The remaining signals are divided into different categories relevant for different diagnoses including atrial fibrillation and pacemaker indication.

With this automatic classification, the attention of the cardiologist is focused to the cases of most importance resulting in considerable time savings. Preliminary results show that the algorithm sorts out 89% of the recorded signals which does not contain any relevant deviations thus providing a close to 90% workload reduction.

Zenicor is in a phase where they are expanding their market to countries in Europe, and with the help of Cardiolund’s algorithm they are positioning their system in the lead of competitors on all markets they enter.


Customer Case: Coala Life

Coala Life is a medtech company founded in Sweden that have developed a device for monitoring cardiac health. Their device is an event monitor that can perform both thumb ECG and chest ECG recordings, and it also records a phonocardiogram (PCG) along with the chest ECG.

The Coala Life system employs the Cardiolund ECG Parser for automated ECG analysis, they also employ a number of other custom signal analysis algorithms developed by Cardiolund.


Scientific Leadership

Cardiolund is at the leading edge of scientific research in analysis of ECG signals from patients with atrial fibrillation (AF). The algorithms we provide have root in extensive research carried out by Cardiolund and our research partners.

Our methodology related to atrial fibrillation has been presented and applied in the following scientific journal papers:

Scientific References

Rapid slowing of the atrial fibrillatory rate after administration of AZD7009 predicts conversion of atrial fibrillation.
Aunes M, Egstrup K, Frison L, Berggren A, Stridh M, Sörnmo L, Edvardsson N.
J Electrocardiol. 2014 May-Jun;47(3):316–23. doi:
10.1016/j.jelectrocard.2013.12.008. Epub 2013 Dec 18. (PubMed link)

Association between atrial fibrillatory rate and heart rate variability in patients with atrial fibrillation and congestive heart failure.
Corino VD, Cygankiewicz I, Mainardi LT, Stridh M, Vasquez R, Bayes de Luna A,
Holmqvist F, Zareba W, Platonov PG.

Ann Noninvasive Electrocardiol. 2013 Jan;18(1):41–50. doi: 10.1111/anec.12019.
Epub 2012 Nov 22. (PubMed link)

Decrease of the atrial fibrillatory rate, increased organization of the atrial rhythm and termination of atrial fibrillation by AZD7009.
Aunes-Jansson M, Edvardsson N, Stridh M, Sörnmo L, Frison L, Berggren A.
J Electrocardiol. 2013 Jan-Feb;46(1):29–35. doi:
10.1016/j.jelectrocard.2012.09.002. Epub 2012 Dec 6. (PubMed link)

Effects of dronedarone and amiodarone on atrial fibrillatory rate in patients with persistent atrial fibrillation.
John S, Salmas J, Kornej J, Löbe S, Stridh M, Sörnmo L, Hindricks G, Husser
D, Bollmann A.

Int J Cardiol. 2013 Sep 1;167(5):2354–6. doi: 10.1016/j.ijcard.2012.11.042.
Epub 2012 Nov 23. No abstract available. (PubMed link)

Analysis of atrial fibrillatory rate during spontaneous episodes of atrial fibrillation in humans using implantable loop recorder electrocardiogram.
Platonov PG, Stridh M, de Melis M, Urban L, Carlson J, Corbucci G, Holmqvist
F.

J Electrocardiol. 2012 Nov-Dec;45(6):723–6. doi:
10.1016/j.jelectrocard.2012.05.003. Epub 2012 Jun 12. (PubMed link)

Low atrial fibrillatory rate is associated with poor outcome in patients with mild to moderate heart failure.
Platonov PG, Cygankiewicz I, Stridh M, Holmqvist F, Vazquez R, Bayes-Genis A,
McNitt S, Zareba W, de Luna AB; MUSIC Trial Investigators.

Circ Arrhythm Electrophysiol. 2012 Feb;5(1):77–83. doi:
10.1161/CIRCEP.111.964395. Epub 2012 Jan 10. (PubMed link)

Left atrial appendage activity translation in the standard 12-lead ECG.
Platonov PG, Nault I, Holmqvist F, Stridh M, Hocini M, Haïssaguerre M.
J Cardiovasc Electrophysiol. 2011 Jun;22(6):706–10. doi:
10.1111/j.1540–8167.2010.01909.x. Epub 2010 Oct 6. (PubMed link)

A novel approach to propagation pattern analysis in intracardiac atrial fibrillation signals.
Richter U, Faes L, Cristoforetti A, Masè M, Ravelli F, Stridh M, Sörnmo L.
Ann Biomed Eng. 2011 Jan;39(1):310–23. doi: 10.1007/s10439–010–0146–8. Epub
2010 Aug 28. (PubMed link)

Letter by Platonov et Al regarding article, Dominant frequency of atrial fibrillation correlates poorly with atrial fibrillation cycle length
Platonov PG, Stridh M, Sörnmo L.
Circ Arrhythm Electrophysiol. 2010 Apr;3(2):e4; author reply e5. doi:
10.1161/CIRCEP.110.943274. No abstract available. (PubMed link)

Circadian variation in dominant atrial fibrillation frequency in persistent atrial fibrillation.
Sandberg F, Bollmann A, Husser D, Stridh M, Sörnmo L.
Physiol Meas. 2010 Apr;31(4):531–42. doi: 10.1088/0967–3334/31/4/005. Epub
2010 Mar 5. (PubMed link)

Right atrial organization and wavefront analysis in atrial fibrillation.
Richter U, Bollmann A, Husser D, Stridh M.
Med Biol Eng Comput. 2009 Dec;47(12):1237–46. doi: 10.1007/s11517–009–0540–2.
Epub 2009 Oct 15. (PubMed link)

A genotype-dependent intermediate ECG phenotype in patients with persistent lone atrial fibrillation genotype ECG-phenotype correlation in atrial fibrillation.
Husser D, Stridh M, Sörnmo L, Roden DM, Darbar D, Bollmann A.
Circ Arrhythm Electrophysiol. 2009 Feb;2(1):24–8. doi:
10.1161/CIRCEP.108.799098. (PubMed link)

Atrial fibrillatory rate and risk of stroke in atrial fibrillation.
Bollmann A, Husser D, Lindgren A, Stridh M, Härdig BM, Piorkowski C, Arya A,
Sörnmo L, Olsson SB.

Europace. 2009 May;11(5):582–6. doi: 10.1093/europace/eup062. Epub 2009 Mar

  1. (PubMed link)

Relation between atrial fibrillatory rate and markers of inflammation and haemostasis in persistent human atrial fibrillation.
Tveit A, Bollmann A, Seljeflot I, Husser D, Stridh M, Sörnmo L, Arnesen H,
Olsson SB, Smith P.

Thromb Haemost. 2009 Mar;101(3):601–3. No abstract available. (PubMed link)

Waveform characterization of atrial fibrillation using phase information.
Stridh M, Husser D, Bollmann A, Sörnmo L.
IEEE Trans Biomed Eng. 2009 Apr;56(4):1081–9. doi: 10.1109/TBME.2008.2006624.
Epub 2008 Oct 31. (PubMed link)

Spectral validation improves frequency tracking obtained by time-frequency analysis during atrial fibrillation.
Corino VD, Mainardi LT, Stridh M, Sornmo L.
Conf Proc IEEE Eng Med Biol Soc. 2008;2008:5733–6. doi:
10.1109/IEMBS.2008.4650516. (PubMed link)

Improved time–frequency analysis of atrial fibrillation signals using spectral modeling.
Corino VD, Mainardi LT, Stridh M, Sörnmo L.
IEEE Trans Biomed Eng. 2008 Dec;55(12):2723–30. doi:
10.1109/TBME.2008.2002158. (PubMed link)

Analysis of atrial fibrillation: from electrocardiogram signal processing to clinical management.
Sörnmo L, Stridh M, Husser D, Bollmann A, Olsson SB.
Philos Trans A Math Phys Eng Sci. 2009 Jan 28;367(1887):235–53. doi:
10.1098/rsta.2008.0162. Review. (PubMed link)

Fibrillatory rate response to candesartan in persistent atrial fibrillation.
Bollmann A, Tveit A, Husser D, Stridh M, Sörnmo L, Smith P, Olsson SB.
Europace. 2008 Oct;10(10):1138–44. doi: 10.1093/europace/eun195. Epub 2008 Jul

  1. (PubMed link)

Spatial characteristics of atrial fibrillation electrocardiograms.
Richter U, Stridh M, Bollmann A, Husser D, Sörnmo L.
J Electrocardiol. 2008 Mar-Apr;41(2):165–72. doi:
10.1016/j.jelectrocard.2007.10.006. (PubMed link)

Frequency tracking of atrial fibrillation using hidden Markov models.
Sandberg F, Stridh M, Sörnmo L.
IEEE Trans Biomed Eng. 2008 Feb;55(2 Pt 1):502–11. doi:
10.1109/TBME.2007.905488. (PubMed link)

A Gaussian mixture model for time-frequency analysis of atrial fibrillation electrocardiograms.
Corino VD, Mainardi LT, Bollmann A, Husser D, Stridh M, Sörmno L.
Conf Proc IEEE Eng Med Biol Soc. 2007;2007:271–4. (PubMed link)

Frequency tracking of atrial fibrillation using Hidden Markov Models.
Nilsson F, Stridh M, Sörnmo L.
Conf Proc IEEE Eng Med Biol Soc. 2006;1:1406–9. (PubMed link)

Atrial fibrillatory rate and risk of left atrial thrombus in atrial fibrillation.
Bollmann A, Husser D, Stridh M, Holmqvist F, Roijer A, Meurling CJ, Sörnmo L,
Olsson SB.

Europace. 2007 Aug;9(8):621–6. Epub 2007 Jun 29. (PubMed link)

Exercise testing for non-invasive assessment of atrial electrophysiological properties in patients with persistent atrial fibrillation.
Husser O, Husser D, Stridh M, Sörnmo L, Corino VD, Mainardi LT, Lombardi F,
Klein HU, Olsson SB, Bollmann A.

Europace. 2007 Aug;9(8):627–32. Epub 2007 Jun 26. (PubMed link)

Electrocardiographic characteristics of fibrillatory waves in new-onset atrial fibrillation.
Husser D, Cannom DS, Bhandari AK, Stridh M, Sörnmo L, Olsson SB, Bollmann A.
Europace. 2007 Aug;9(8):638–42. Epub 2007 Apr 30. (PubMed link)

Transthoracic tissue Doppler imaging of the atria to determine atrial fibrillation cycle length.
Bollmann A, Husser D, Stridh M, Sörnmo L.
J Cardiovasc Electrophysiol. 2007 Mar;18(3):E13–4. Epub 2007 Jan 30. No
abstract available. (PubMed link)

Validation and clinical application of time-frequency analysis of atrial fibrillation electrocardiograms.
Husser D, Stridh M, Cannom DS, Bhandari AK, Girsky MJ, Kang S, Sörnmo L,
Bertil Olsson S, Bollmann A.

J Cardiovasc Electrophysiol. 2007 Jan;18(1):41–6. (PubMed link)

Detection and feature extraction of atrial tachyarrhythmias. A three stage method of time-frequency analysis.
Stridh M, Bollmann A, Olsson SB, Sörnmo L.
IEEE Eng Med Biol Mag. 2006 Nov-Dec;25(6):31–9. Review. No abstract available.
(PubMed link)

Analysis of surface electrocardiograms in atrial fibrillation: techniques, research, and clinical applications.
Bollmann A, Husser D, Mainardi L, Lombardi F, Langley P, Murray A, Rieta JJ,
Millet J, Olsson SB, Stridh M, Sörnmo L.

Europace. 2006 Nov;8(11):911–26. Review. (PubMed link)

Electroatriography - time-frequency analysis of atrial fibrillation from modified 12-lead ECG configurations for improved diagnosis and therapy.
Husser D, Stridh M, Sörnmo L, Toepffer I, Klein HU, Bertil Olsson S, Bollmann
A.

Med Hypotheses. 2007;68(3):568–73. Epub 2006 Oct 9. (PubMed link)

Atrial fibrillatory rate and sinus rhythm maintenance in patients undergoing cardioversion of persistent atrial fibrillation.
Holmqvist F, Stridh M, Waktare JE, Sörnmo L, Olsson SB, Meurling CJ.
Eur Heart J. 2006 Sep;27(18):2201–7. Epub 2006 Sep 6. (PubMed link)

Frequency analysis of atrial fibrillation from the surface electrocardiogram.
Husser D, Stridh M, Sornmo L, Olsson SB, Bollmann A.
Indian Pacing Electrophysiol J. 2004 Jul 1;4(3):122–36. (PubMed link)

Atrial fibrillation signal organization predicts sinus rhythm maintenance in patients undergoing cardioversion of atrial fibrillation.
Holmqvist F, Stridh M, Waktare JE, Roijer A, Sörnmo L, Platonov PG, Meurling
CJ.

Europace. 2006 Aug;8(8):559–65. Epub 2006 Jul 10. (PubMed link)

Indices of electrical and contractile remodeling during atrial fibrillation in man.
Holmqvist F, Stridh M, Waktare JE, Sörnmo L, Roijer A, Meurling CJ.
Pacing Clin Electrophysiol. 2006 May;29(5):512–9. (PubMed link)

Prediction of sinus rhythm maintenance following DC-cardioversion of persistent atrial fibrillation - the role of atrial cycle length.
Meurling CJ, Roijer A, Waktare JE, Holmqvist F, Lindholm CJ, Ingemansson MP,
Carlson J, Stridh M, Sörnmo L, Olsson SB.

BMC Cardiovasc Disord. 2006 Mar 13;6:11. (PubMed link)

Comparison of atrial signal extraction algorithms in 12-lead ECGs with atrial fibrillation.
Langley P, Rieta JJ, Stridh M, Millet J, Sörnmo L, Murray A.
IEEE Trans Biomed Eng. 2006 Feb;53(2):343–6. (PubMed link)

Predicting spontaneous termination of atrial fibrillation using the surface ECG.
Nilsson F, Stridh M, Bollmann A, Sörnmo L.
Med Eng Phys. 2006 Oct;28(8):802–8. Epub 2006 Jan 25. (PubMed link)

Rapid fluctuations in atrial fibrillatory electrophysiology detected during controlled respiration.
Holmqvist F, Stridh M, Waktare JE, Brandt J, Sörnmo L, Roijer A, Meurling
CJ.

Am J Physiol Heart Circ Physiol. 2005 Aug;289(2):H754–60. (PubMed link)

Pilot study: Noninvasive monitoring of oral flecainide’s effects on atrial electrophysiology during persistent human atrial fibrillation using the surface electrocardiogram.
Husser D, Binias KH, Stridh M, Sornmo L, Olsson SB, Molling J, Geller C,
Klein HU, Bollmann A.

Ann Noninvasive Electrocardiol. 2005 Apr;10(2):206–10. (PubMed link)

Analysis of the surface electrocardiogram for monitoring and predicting antiarrhythmic drug effects in atrial fibrillation.
Husser D, Stridh M, Sornmo L, Platonov P, Olsson SB, Bollmann A.
Cardiovasc Drugs Ther. 2004 Sep;18(5):377–86. Review. (PubMed link)

Time-frequency analysis of the surface electrocardiogram for monitoring antiarrhythmic drug effects in atrial fibrillation.
Husser D, Stridh M, Sornmo L, Geller C, Klein HU, Olsson SB, Bollmann A.
Am J Cardiol. 2005 Feb 15;95(4):526–8. (PubMed link)

Determinants and prognostic significance of immediate atrial fibrillation recurrence following cardioversion in patients undergoing pulmonary vein isolation.
Husser D, Bollmann A, Kang S, Stridh M, Sornmo L, Olsson SB, Bhandari AK,
Cannom DS.

Pacing Clin Electrophysiol. 2005 Feb;28(2):119–25. (PubMed link)

Echocardiographic and electrocardiographic predictors for atrial fibrillation recurrence following cardioversion.
Bollmann A, Husser D, Steinert R, Stridh M, Soernmo L, Olsson SB, Polywka D,
Molling J, Geller C, Klein HU.

J Cardiovasc Electrophysiol. 2003 Oct;14(10 Suppl):S162–5. (PubMed link)

Frequency measures obtained from the surface electrocardiogram in atrial fibrillation research and clinical decision-making.
Bollmann A, Husser D, Stridh M, Soernmo L, Majic M, Klein HU, Olsson SB.
J Cardiovasc Electrophysiol. 2003 Oct;14(10 Suppl):S154–61. (PubMed link)

Sequential characterization of atrial tachyarrhythmias based on ECG time-frequency analysis.
Stridh M, Sörnmo L, Meurling CJ, Olsson SB.
IEEE Trans Biomed Eng. 2004 Jan;51(1):100–14. (PubMed link)

Detection of autonomic modulation in permanent atrial fibrillation.
Stridh M, Meurling C, Olsson B, Sörnmo L.
Med Biol Eng Comput. 2003 Nov;41(6):625–9. (PubMed link)

Non-invasive assessment of atrial fibrillation (AF) cycle length in man: potential application for studying AF.
Meurling CJ, Sörnmo L, Stridh M, Olsson SB.
Ann Ist Super Sanita. 2001;37(3):341–9. Review. (PubMed link)

Characterization of atrial fibrillation using the surface ECG: time-dependent spectral properties.
Stridh M, Sörnmo L, Meurling CJ, Olsson SB.
IEEE Trans Biomed Eng. 2001 Jan;48(1):19–27. (PubMed link)

Spatiotemporal QRST cancellation techniques for analysis of atrial fibrillation.
Stridh M, Sörnmo L.
IEEE Trans Biomed Eng. 2001 Jan;48(1):105–11. (PubMed link)

Attenuation of electrical remodelling in chronic atrial fibrillation following oral treatment with verapamil.
Meurling CJ, Ingemansson MP, Roijer A, Carlson J, Lindholm CJ, Smideberg B,
Sornmo L, Stridh M, Olsson SB.

Europace. 1999 Oct;1(4):234–41. (PubMed link)