Validation of a Novel Oscillometric-Based Algorithm for Determination of the Ankle-Brachial Index

Study Overview
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Brief Summary
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Peripheral arterial disease (PAD) is a highly prevalent medical condition. Patients with PAD are usually diagnosed on the basis of the ankle-brachial index. The ankle-brachial index is the ratio of ankle pressure to arm pressure after measurement of blood pressures in the arms and legs using a Doppler device. The need for dedicated equipment and trained personnel, along with the time required to perform the test, have been identified as barriers to widespread implementation of ankle-brachial index screening. The use of automated oscillometric devices for blood pressure measurement has been applied to leg pressure measurement and determination of the ankle-brachial index with variable success. It will be beneficial to investigate a reliable oscillometric-based procedure that can accurately measure leg pressures for the ankle-brachial index across the entire spectrum of PAD severity. In a previous pilot study completed in 2009 (IRB 08-823), the investigators gathered data from N=60 subjects which allowed for mathematical analysis of oscillometric waveforms derived from the lower extremities as compared to Doppler-based measurements of blood pressure. We used signal processing analysis and regression techniques to develop a two-step algorithm which will allow for accurate interpretation of oscillometric waveforms in normal/mild vs. moderate/severely diseased limb and accurate calculation of ankle pressure across the spectrum of peripheral artery disease severity. This proposed project will validate this novel oscillometric ABI algorithm in a population of patients who have been identified as at risk for PAD and for whom screening ABI has been recommended by multiple professional organizations (AHA/ACC and American Diabetes Association). Arm, ankle, and toe pressure measurements will be made in the supine position using Doppler, oscillometric methods, and a photoplethysmographic sensor. The ankle-brachial index and toe-brachial index will be calculated.

Official Title
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Validation of a Novel Oscillometric-Based Algorithm for Determination of the Ankle-Brachial Index

Conditions
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Peripheral Arterial Disease

Intervention / Treatment
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* Device: Blood Pressure Measurement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: At least 70 years of age At least 50 years of age with a history of diabetes mellitus or tobacco smoking (>100 cigarettes in their lifetime) Ambulatory Outpatient Exclusion Criteria: Unable to give informed consent Unable to lie supine for at least 15 minutes Known non-compressible vessels on prior laboratory studies (ABI>1.3 on either side)

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Suspected Arterial Disease<br>Patients with known or suspected arterial disease and patients screened using AHA/ACC criteria for P.A.D. | Device: Blood Pressure Measurement<br>* Systolic blood pressures will be obtained from each limb using Doppler, oscillometric, and photoplethysmographic (PPG) modalities.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Peripheral, Arterial, Vascular