The goal of the study was to compare the current gold standard blood pressure instrument (a mercury-filled sphygmomanometer with cuff and stethoscope) with the new experimental algorithm developed by HeartBeat Technologies Ltd. To that end, participants were recruited from Markham, Ontario and participated in a series of alternating blood pressure measurements over a period of 45 minutes. Comparisons were made between manual measurements and device measurements to determine the quality of the device readings. Measurements were taken by trained nurses and staff were consistent across the study duration.

The gold standard instrument for blood pressure measurement is a mercury-filled sphygmomanometer with cuff and stethoscope (Canadian Agency for Drugs and Technologies in Health; Canadian Electronic Library, 2012). However, such a device is not the most convenient for client self-monitoring or virtual (remote) care. Thus, there is a desire for an accurate, reliable alternative for the traditional mercury-containing sphygmomanometer.

HeartBeat Technologies Ltd. ("Heartbeat") has developed a novel approach to measuring blood pressure after an initial blood pressure reading using the conventional measurement method, supplemented by specific characteristics of a person (age, gender, height, weight, and heart rate), has established a "baseline measurement" for the person. The "novel approach" uses a finger pulse oximeter, the Contec CMS50EW device (Figure 1) (manufactured by Contec Medical Systems Co., Ltd., Shanghai, People's Republic of China). The finger pulse oximeter detects the changes in blood volume directly below the person's skin and indirectly measures oxygen saturation in the blood. The measurement is in the form of a photoplethysmogram (PPG) which is captured by the Contec oximeter and then, by Bluetooth technology, transmitted to a smartphone or tablet. A HeartBeat application, called MediBeat, on the smartphone or tablet then transmits the PPG to a server where a proprietary algorithm analyzes the baseline measurement for the person and the PPG to calculate the person's current blood pressure.

Heartbeat's intent is that the current blood pressure reading would then be made available to both the client and the health provider through separate web-based interfaces. Providers would be able to log onto the HeartBeat web-based application from anywhere to review and monitor the blood pressure of multiple clients, while clients can log onto the application to track their own measurements.

Inclusion Criteria:

• adult over 25 years of age

Exclusion Criteria:

• those who have heart arrhythmias,
• atrial fibrillations or atrial flutters,
• an inaudible Korotkoff sound,
• wounds of the upper arms/wrists, missing fingers, and/or
• an arm circumference of more than 55 cm will be excluded

For each participant, adverse event phenomena were monitored from the initial informed consent process and up to the remuneration process in the data gathering visit. This took approximately 45 minutes for each participant, during which they were continuously in the presence of trained medical professionals. Following this active assessment period, there was no follow-up conducted with participants, but participants were able to contact the research team with any concerns that may have arisen.

Adverse events or risks (for all-cause mortality, serious, or non-serious) were monitored throughout study duration, however, none were observed across the 94 study participants.