Introduction: Arterial hypertension is a key risk factor for cardiovascular diseases affecting 1
in 3 people worldwide, especially in developing nations where access to medical care is
limited. A smartphone application was developed to measure and track the blood pressure in
the general population, utilizing a photoplethysmography (PPG) waveform analysis algorithm
to measure blood pressure. Hypertensive disorders of pregnancy, including gestational
hypertension and pre-eclampsia, are associated with increased morbidity and mortality for
both mother and newborn.
Objectives: The objective of this study is to assess the performance of the OptiBP in a
population of pregnant women.
Patients: 10 pregnant women between 32 and 35 weeks of amenorrhea (WA) were included
and followed until delivery. Eligibility criteria included patients planned for a caesarian
section. Patients with conditions such as gestational hypertension or preeclampsia were
excluded.
Study procedure: Calibration of OptiBP’s algorithm was carried out after inclusion, followed
by repeated blood pressure measurements taken on the day of inclusion, on the day of
delivery, before the c-section, as well as after the c-section and every day until the mother
and newborn were released from the maternity unit.
At each visit, 3 valid pairs of blood pressure measurements (e.g., OptiBP measure paired with
a cuff measure) were recorded with not more than 8 attempts.
Methodology: Prospective, single-center study performed at CHUV University hospital in
Lausanne, Switzerland. An automatic cuff certified for a pregnant population with the existing
norm ISO 81060-2 was used as the control. Results were blinded to both trial participants and
the research team and were sent automatically offsite for storage and analysis. The accuracy
of OptiBP smartphone app in a population of pregnant women is expected to be similar as
compared to a general population and within the existing ISO 81060-2 norm.
Outcomes: The blood pressure measured by the app was then compared to the obtained
values of the automatic cuff. The mean difference and the standard deviation of the paired
values were compared to those obtained by the automatic cuff as reference calibration.
This study has been conducted in compliance with the protocol, the current version of the
Declaration of Helsinki, the ICH-GCP or ISO EN 14155 as well as all national legal and
regulatory requirements.