title: Development of an accurate oscillometric blood pressure device for low resource settings.
abstract: OBJECTIVE
  To assess and develop an accurate blood pressure measurement device for use in low resource settings and by untrained staff, according to the World Health Organisation guidelines.
  
  
  METHODS
  Ninety-nine adults were recruited to validate the device according to the International Protocol of the European Society of Hypertension. All participants provided written informed consent. Patients with an arrhythmia or unclear Korotkoff sounds were excluded. Nine sequential same-arm measurements were taken from each participant alternating between the test device and mercury sphygmomanometry. Differences between the test device and observers were evaluated according to the criteria of the International Protocol and the Association for the Advancement of Medical Instrumentation.
  
  
  RESULTS
  The device failed the first assessment of the oscillometric function and required modification to both the deflation rate and the algorithm to fulfil the International Protocol criteria. It then achieved an acceptable mean difference of -0.7 (4.7) mmHg for systolic and -2.0 (4.6) mmHg for diastolic pressure (oscillometric function) and -1.9 (3.8) mmHg and -0.9 (3.3) mmHg for systolic and diastolic pressures, respectively (auscultatory function).
  
  
  CONCLUSIONS
  The Microlife 3AS1-2 is a semi-automated upper arm device with features consistent with low resource requirements. We successfully developed this device for accurate blood pressure measurement in adults according to the International Protocol, through adjustment of the deflation rate and algorithm. The accuracy and user-friendly design of this low-cost device makes it a highly valuable monitor in clinical practice, particularly in low resource settings and for use by untrained staff.
authors.affiliation: Maternal and Fetal Research Unit, Division of Reproduction and Endocrinology, King's College London, St Thomas' Hospital, London, UK.
authors.forename: Annemarie
authors.initials: A
authors.lastname: de Greeff
authors.forename: Hannah
authors.initials: H
authors.lastname: Nathan
authors.forename: Nina
authors.initials: N
authors.lastname: Stafford
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Shennan
mesh_terms: D000328:Adult; D000465:Algorithms; D001132:Arm; D001795:Blood Pressure Determination / Q000295:instrumentation*; D002138:Calibration; D003971:Diastole; D004867:Equipment Design / Q000295:instrumentation*; D006295:Health Resources; D006801:Humans; D009991:Oscillometry / Q000191:economics* / Q000295:instrumentation*; D017410:Practice Guidelines as Topic; D015203:Reproducibility of Results; D012955:Societies, Medical; D019722:Sphygmomanometers / Q000592:standards; D013599:Systole; D014159:Transducers