A novel method for conformity assessment testing of electrocardiographs for post-market surveillance purposes

1. Introduction

According to the Food and Drug Administration (FDA) [1] an electrocardiography is a medical device (MD) which creates, analyses, and displays electrocardiography data, and can provide information for identifying cardiac arrhythmias. These devices are classified according to the risk posed to a patient when the device is being used. According to the Medical Device Regulation (MDR) [2], ECGs are classified as Class IIa. This classification determines regulatory scrutiny to which devices are subjected to before placing on the market and Class II indicates that a medical device is of moderate to high risk and requires special controls.

As a type of medical device with a measuring function (MDMF), electrocardiographs are used to measure the electrical activity of the heart in order to identify any abnormalities [3]. Measurements of medical devices are carried out using sensors or measuring equipment of medical devices. The total degree of product quality is directly impacted by how well the MD’s sensors and measurement devices perform. Every pre-programmed setting for heart rate and ECG voltage signal amplitude has a designated function. Since the ECG is used to quickly identify cardiac issues and monitor overall heart health, any anomalies that arise during its usage will unavoidably have a detrimental impact on the patient. Given that the heart rate and voltage signal amplitude are factors in the evaluation of the electrocardiogram, which forms the foundation of their efficacy, post-market surveillance is concentrated on the accuracy of the determined values of the mentioned measuring quantities as well as the overall safety of the medical device.

Prior to its placement on the market, each ECG device is thoroughly tested and evaluated to avoid any faults in its function. However, upon market placement, the regulatory oversight is disharmonized and there are no standards indicating how it should be performed [4]. Regardless of the variations in types, all devices of this type perform the same function. Therefore, the end user is affected by the measured parameters. Measurements, therefore, have great impact in patient care and can be considered compliant, only if they can be controlled, i.e. if they can be traceable to internationally adopted standards of measurement. In order to ensure accuracy and safety of all ECG devices used in healthcare institutions, a methodology for their performance assessment must be established and developed.

This paper presents a novel methodology for conformity assessment of ECG devices during usage taking into account the International Organisation of Legal Metrology (OIML) approach defined for other types of medical devices that perform measurements. The presented novel method can be used by national regulators as a gold standard in defining regulatory framework considering conformity assessment of devices used in healthcare.

2. Method

To present the novel methodology, the accepted concept of OIML guidelines for other medical devices with measuring functions such as thermometers or sphygmomanometer was followed [5]. The method, developed under OIML recommendations, is reported as a coherent structure, through the following parts:

Definition of technical requirements for ECGs

During method validation, the performance assessment testing of ECGs was done by using two etalons, Fluke Biomedical ESA 620 electrical safety analyser [6] and Fluke Biomedical ProSim 8 Vital Signs Patient Simulator [7]. Both of these devices were periodically calibrated in EN ISO 17025 accredited laboratories [8]. The novel method was validated during the 2018–2021 time period. The presented data was analysed using a statistical approach.

3. Results and discussion

The results are presented in two parts. The first part consists of reporting the novel methodology for conformity assessment testing of ECGs and the second part consists of the validation report of this methodology done in real-time by inspection bodies in Bosnia and Herzegovina and Republic of Serbia.

4. Conclusion

Access to health is fundamental human right. However, various adverse event involving medical devices pose a risk to patients’ safety and well-being. The importance of safe and compliant medical devices has been especially demonstrated during COVID-19 pandemics [10]. Lately, regulators have been working in improving post-market surveillance of medical devices to ensure that number of incidents and adverse events including medical devices is lowered. Specifically, in the European Union, Medical Device Regulation (MDR) introduces the EUDAMED database [11, 12] containing all information regarding the adverse events associated with medical devices and reported by the end users that may be physicians, medical technicians or patients themselves. However, current databases collect information for each database from both voluntary sources and mandatory reports. Judging by the number of reported incidents involving medical devices it can be concluded that the limitations of the databases are that the data submitted include “incomplete, inaccurate, untimely, unverified, or biased data.” In addition, many use errors stay underreported and data format unknown. Moreover, current databases are limited to administrative data only including manufacturers and distributor data, vigilance and clinical studies data, hence the surveillance is not taking its full capacity. Also, baseline evidence for medical device safety and performance cannot be established due to lack of traceable data.

This paper lays out a novel methodology for conformity assessment testing of ECG device for post-market surveillance purposes. The novel methodology was developed based on OIML guidelines for technical and metrological characteristics and performance evaluation. Developed methodology has been validated by the work of two inspection bodies for medical devices working under the legal metrology framework which has been adopted for medical devices in Bosnia and Herzegovina and Republic of Serbia [13, 14]. The introduction of standardized conformity assessment method for testing of safety and performance of ECG device produced traceable, accurate, complete, verified, nonbiased and standardized data. All data resulting from the inspection carried out by independent appointed inspection bodies has been entered in database specially developed for this purpose – eLab [15]. This practice showed that significant cost-effectiveness can be achieved in management of maintenance in healthcare institutions because standardized data showed certain patterns for healthcare institutions.

The work demonstrated how standardized method for conformity assessment testing produces complete, accurate, verified, traceable and unbiased data. Following the trend of digital transformation and application of artificial intelligence, the researchers investigated application of artificial intelligence on this database [16, 17, 18, 19, 20]. The hypothesis of predictive management of maintenance of medical devices has been set up. Indeed, as medicine is shifting toward personalized medicine clinical engineering should follow the path of predictive approach.