Comparative Performance of High-End and Economical Stethoscopes in Automated Auscultation

Blood pressure measurement is a vital procedure in assessing cardiovascular health. Automated auscultation is being developed to detect Korotkoff sounds that determine systolic and diastolic blood pressure. The quality of the stethoscopes influences the accuracy of this development. This study aims to evaluate and compare the performance of a high-end (Littmann) and an economical (ABN) stethoscope in detecting Korotkoff sounds for blood pressure measurements using the automatic auscultation method. The study used a mixed design, combining between-subject and within-subject approaches. This comparative experimental study involved 85 respondents with three repetitions of measurements, resulting in a total of 255 data for each stethoscope. The suitability of the measurements was evaluated based on the international accuracy standards AAMI/ANSI/ISO and BHS and analyzed using non-parametric statistical test. The results showed that ABN had an average systolic measurement error of 4.4 ± 4.8 mmHg with a percentage of agreement of 75%, 91%, and 95% at thresholds 5, 10, and 15 mmHg. Meanwhile, Littmann showed a lower average systolic error of 3.4 ± 3.5 mmHg with an agreement of 80%, 96%, and 98%. For diastolic measurements, both stethoscopes showed similar mean errors of 4.1 ± 4.1 mmHg. Paired analysis revealed a significant difference in manual systolic pressure, while diastolic measurements showed no significant difference between ABN and Littmann. Overall, although both stethoscopes met the established accuracy standards, Littmann was superior in consistency and accuracy of systolic measurements, which are important in evaluating Korotkoff sounds in blood pressure measurements using automatic auscultation. However, ABN can still be considered a reliable alternative, particularly for diastolic pressure measurement.