UPC, Vall d’Hebron and UAB researchers design an app to help assess the severity of symptoms in chronic fatigue syndrome

UPC, Vall d’Hebron and UAB researchers design an app to help assess the severity of symptoms in chronic fatigue syndrome

The images at the top show the interface of the app installed on a mobile device. It allows the records to be obtained under controlled conditions.

UPC, Vall d’Hebron and UAB researchers design an app to help assess the severity of symptoms in chronic fatigue syndrome

From left to right: researchers Juan Ramos Castro, Rosa Maria Escorihuela, Lluís Capdevila, José Alegre and Jesús Castro

Vall d’Hebron, a member of the European Network on CFS/ME

In Catalonia, it is estimated that there are currently between 350,000 and 500,000 people affected by chronic fatigue syndrome/myalgic encephalomyelitis, and 2 out of 3 of them are women. Worldwide, a prevalence of between 17 and 25 million people with this disease is estimated. In addition, these numbers are predicted to double by 2030 due to persistent COVID-19, a condition in which patients have similar symptoms. This is known as postviral chronic fatigue syndrome, which has been previously described in other coronaviruses (SARS-CoV-1 and MERS) and other viruses such as Ebola, Epstein-Barr and cytomegalovirus.

Severe fatigue is the main symptom of CFS/ME, in addition to problems with immediate memory, speed of information processing and concentration, and intolerance to physical/mental exercise, pain and dizziness. This syndrome can be very disabling, but there are currently no diagnostic biomarkers or specific treatment options, so it is important for experts in the field to work in a coordinated way to improve the care and management of these patients.

In this sense, José Alegre and Jesús Castro, both from Vall d'Hebron, are members for Spain in the European Network on Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (EUROMENE), which includes 55 professionals from 22 European countries. A consensus document on therapeutic and diagnostic approaches for this syndrome was recently published in the journal Medicina.

The technology uses a chest strap connected to a mobile app that measures heart rate variability. Researchers have shown that heart rate variability is related to the severity of fatigue in women with chronic fatigue syndrome/myalgic encephalomyelitis.

Sep 07, 2021

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a disabling disease in which people have great difficulties carrying out their daily activities. Despite its high prevalence, there are still no effective tools for its diagnosis, monitoring and treatment. To better understand and stratify fatigue, as well as to promote follow-up of these patients, the Universitat Politècnica de Catalunya · BarcelonaTech (UPC), Vall d'Hebron and the Universitat Autònoma de Barcelona (UAB)  have developed a mobile application that may be useful in assessing the severity of fatigue in this syndrome, especially in women. The results of the study in which this technology was tested have been published in the journal Sensors..

The technology developed by UPC and UAB researchers consists of a chest strap with a sensor for measuring cardiac hemodynamic variables that is connected to a mobile app via Bluetooth. The mobile application allows the heart rate variability to be recorded and monitored and the analysed results to be shared with medical staff who supervise patients.

Specifically, the study analysed the relationship between heart rate variability and the severity of symptoms in women and men with CFS/ME. This parameter is closely related to the heart rate, that is, the heart’s number of beats per minute. However, the time that passes between two consecutive beats is not always exactly the same; small differences that fall within a normal range can be detected, and this is what is known as heart rate variability (HRV).

In previous studies published in the  Journal of Translational Medicine, HRV had already been related to the assessment of the severity of fatigue in women with CFS/ME. “Specifically, we observed that this variability was lower in patients with CFS/ME, especially in the most disabling cases”, explains Jesús Castro, coordinator of the chronic fatigue syndrome/myalgic encephalomyelitis laboratory of the Rheumatology group at the Vall d'Hebron Research Institute (VHIR). Having a high variability is considered positive, as it is an indicator of the proper functioning of the autonomic nervous system. “In this work we wanted to verify the relationship between HRV and the syndrome in both women and men with CFS/ME compared to healthy controls and its usefulness for monitoring patients”, adds Castro.

In line with previous studies, it was found that HRV measurement with mobile app technology could predict the severity of disabling fatigue in patients with chronic fatigue syndrome/myalgic encephalomyelitis. This was especially observed in the case of women, but the relationship was not as clear in the case of men. “We demonstrated that the use of the app would be especially useful for monitoring women suffering from this syndrome, who clearly have a lower heart rate variability compared to healthy women”, says Rosa M. Escorihuela, from the Department of Psychiatry and Legal Medicine at the UAB. Thus, HRV would be a good predictive marker of the severity of fatigue during the clinical course of the disease.

The study was carried out with 77 patients with CFS/ME (32 men and 45 women) and their results were compared with those of a control group. The HRV evaluation was carried out in three sessions lasting five minutes, separated by between one and three weeks and under controlled conditions.

The study was carried out in part thanks to the R&D project PID2019-107473RB-C21, coordinated by researchers from the UPC and the UB and funded by the Ministry of Science and Innovation.

An improved non-invasive technology
Juan Ramos Castro, from the Electronic and Biomedical Instrumentation group and the Department of Electronic Engineering at the UPC, explains that “the experience of the UAB and UPC research groups has made it possible to correct the most important limitations of this technology, such as errors in measuring cardiac variability due to the incorrect placement of the chest strap and/or the patient moving and breathing during recording, and to obtain the records under controlled conditions, which reduces the influence of other external factors. The results of the analysis are stored in a single and secure server and can be consulted through a specific platform”. Dr. Lluís Capdevila, a researcher at the Department of Basic, Developmental and Educational Psychology and the Sports Research Institute at the UAB, adds that “it is a non-invasive technology that is easy to use by patients or users, through a mobile device. In this way, they can perform self-assessments in ecological situations and can be monitored in real time”.

Dr. Capdevila comments, “the system originated in and has been used successfully for real-time monitoring and follow-up of the relationship between physical effort and recovery, both in athletes and in the general population. For example, sports clubs such as FC Barcelona (the women’s basketball and soccer sections) and New York City FC have used the system, as well as national teams such as those of the Spanish Basketball Federation, the Spanish Field Hockey Federation (men and women) and the Spanish Federation of Mountain Sports and Climbing”.