title: A New Cuffless Device for Measuring Blood Pressure: A Real-Life Validation Study.
abstract: Cuffless blood pressure (BP) monitoring devices, based on pulse transit time, are being developed as an easy-to-use, more convenient, fast, and relatively cheap alternative to conventional BP measuring devices based on cuff occlusion. Thereby they may provide a great alternative to BP self-measurement.
  
  
  
  The objective of our study was to evaluate the performance of the first release of the Checkme Health Monitor (Viatom Technology), a cuffless BP monitor, in a real-life setting. Furthermore, we wanted to investigate whether the posture of the volunteer and the position of the device relative to the heart level would influence its outcomes.
  
  
  
  Study volunteers fell into 3 BP ranges: high (>160 mmHg), normal (130-160 mmHg), and low (<130 mmHg). All requirements for test environment, observer qualification, volunteer recruitment, and BP measurements were met according to the European Society of Hypertension International Protocol (ESH-IP) for the validation of BP measurement devices. After calibrating the Checkme device, we measured systolic BP with Checkme and a validated, oscillometric reference BP monitor (RM). Measurements were performed in randomized order both in supine and in sitting position, and with Checkme at and above heart level.
  
  
  
  We recruited 52 volunteers, of whom we excluded 15 (12 due to calibration failure with Checkme, 3 due to a variety of reasons). The remaining 37 volunteers were divided into low (n=14), medium (n=13), and high (n=10) BP ranges. There were 18 men and 19 women, with a mean age of 54.1 (SD 14.5) years, and mean recruitment systolic BP of 141.7 (SD 24.7) mmHg. BP results obtained by RM and Checkme correlated well. In the supine position, the difference between the RM and Checkme was >5 mmHg in 17 of 37 volunteers (46%), of whom 9 of 37 (24%) had a difference >10 mmHg and 5 of 37 (14%) had a difference >15 mmHg.
  
  
  
  BP obtained with Checkme correlated well with RM BP, particularly in the position (supine) in which the device was calibrated. These preliminary results are promising for conducting further research on cuffless BP measurement in the clinical and outpatient settings.
authors.affiliation: Radboud University Medical Center, Department of Internal Medicine, Radboud University, Nijmegen, Netherlands.
authors.forename: Tessa S
authors.identifier: 0000-0001-5575-617X
authors.initials: TS
authors.lastname: Schoot
authors.forename: Mariska
authors.identifier: 0000-0002-0689-3669
authors.initials: M
authors.lastname: Weenk
authors.forename: Tom H
authors.identifier: 0000-0002-5401-8973
authors.initials: TH
authors.lastname: van de Belt
authors.forename: Lucien J L P G
authors.identifier: 0000-0002-8455-9367
authors.initials: LJ
authors.lastname: Engelen
authors.forename: Harry
authors.identifier: 0000-0003-0323-4876
authors.initials: H
authors.lastname: van Goor
authors.forename: Sebastian J H
authors.identifier: 0000-0002-6973-7540
authors.initials: SJ
authors.lastname: Bredie
mesh_terms: D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000295:instrumentation*; D002138:Calibration; D005060:Europe; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D011187:Posture / Q000502:physiology; D011674:Pulse
keywords: cardiovascular risk management; cuffless blood pressure monitor; hypertension; patient empowerment; wearable device