Pharmaceutical company Johnson & Johnson collaborated with Apple to launch a study to analyse whether an iPhone and Apple Watch can accurately detect stroke symptoms, to reduce cases of the life-threatening medical condition and test the validity of digital health tools.

In a statement, Johnson & Johnson said participants in the Heartline Study will wear an Apple Watch equipped with a heart-rate sensor, and use iPhone 6s and later models running iOS 12.2 onwards to access an electrocardiogram (ECG) app.

With those tools, the study aims to see whether atrial fibrillation, a common form of irregular heart rhythm, can be detected early and provide warning before a stroke occurs.

Johnson & Johnson cited US Centers for Disease Control and Prevention figures which estimate between 2.7 million and 6.1 million people in the country have atrial fibrillation.

Myoung Cha, Apple head of health strategic initiatives said: “The Heartline Study will help further understanding of how our technology could both contribute to science and help improve health outcomes”.

Apple launched a Research app in 2019 in which users can contribute data to medical studies on heart, hearing and women’s health.