Accuracy Assessment of an Automatic Blood Pressure Measurement Device in Adult Volunteers

The research team has developed an automatic blood pressure monitor (Sphygmo) to be used for the monitoring and diagnosis of pre-eclampsia in pregnant women, particularly in low-resource settings where current monitoring is limited. 90 adult volunteers will be enrolled by researchers at Rice University. The participant will be seated in a comfortable chair with arm at heart level. Arm circumference will be measured and a blood pressure cuff will be placed on the arm. The cuff will be inflated and blood pressure measurements will be taken by a commercially available device and by the Sphygmo device. Blood pressure measurements from both devices will be recorded. The participant's blood pressure will be measured up to 9 times with a waiting period of 45-60 seconds between each measurement. The results of this study will be used to optimize the blood pressure detection algorithm and thus further develop the device.

Participants enrolled in the study will have their blood pressure measured multiple times with both the GE Dinamap Procare commercial blood pressure monitor and Sphygmo, the experimental blood pressure monitoring device.

Men and women over the age of 18 will have their blood pressure measured with both the Sphygmo: Automatic Blood Pressure Monitor device and the GE Dinamap ProCare automatic blood pressure monitor.

A team of engineers from Rice University has recently developed Sphygmo, an ambulatory, low-cost blood pressure monitor for use in the diagnosis and management of pre-eclampsia in low-resource hospitals.

This commercially available gold standard blood pressure monitor will be used as a control to assess the accuracy of the Sphygmo device.

Mean difference of systolic and diastolic blood pressure readings between Sphygmo device and the gold standard sphygmomanometer.

Blood pressure was measured an average of 9 times for each participant during their single visit and the mean of these measurements was recorded and used for analysis. The measurement period lasted approximately 30-45 minutes.

Percentage of Sphygmo Readings That Were With < 5 mmHg, < 10 mmHg, and < 15 mmHg of the Readings by the Gold Standard Sphygmomanometer.

The British Hypertension society defines a specific criteria for the accuracy of a sphygmomanometer. Devices are graded according to the cumulative percentage of readings that have an absolute difference between the more favorable observer's mercury sphygmomanometer readings and the test device of < 5 mmHg, < 10 mmHg, and < 15 mmHg. A letter grade of "A" requires that over 60%, 85%, and 95% were achieved in the < 5 mmHg, < 10 mmHg, and <15 mmHg categories, respectively. A letter grade of "B" requires that over 50%, 75%, and 90% were achieved in the < 5 mmHg, < 10 mmHg, and <15 mmHg categories, respectively. The test device achieved a grade of (B/B) with the validation data from this study.

Blood pressure was measured an average of 9 times for each participant during their single visit and the mean of these measurements was recorded and used for analysis. The measurement period lasted approximately 30-45 minutes.

Inclusion Criteria: 18 years of age or older Willing and able to provide informed consent Exclusion Criteria: Unable to provide informed consent