Miftahurrohman, Asni Tafrikhatin, J. sumarah, and El Vionna Laellyn Nurul Fatich. “Design and Construction of a NodeMCU-Based Heart Rate and Blood Oxygen Level Monitoring Device With Blynk Application Output”. Jurnal E-Komtek (Elektro-Komputer-Teknik), Vol. 9, no. 2, Jan. 2026, pp. 642-50, doi:10.37339/e-komtek.v9i2.2927.