Research Project
9409408
Summary/Abstract Hypertension is a leading cause of excess cardiovascular morbidity and mortality, and remains a signi cant national problem, with approximately one third of all adults having high blood pressure (BP). BP monitoring has high diagnostic and prognostic value as an important marker of cardiovascular disease. Static BP snapshots, which are typically obtained via sphygmomanometry during doctor's-oce visits, have documented reliability issues, the causes of which include \white-coat hypertension and poor technique. As a result, electronic oscillometric devices that are worn on the upper arm and are designed for self blood pressure measurement (SBPM) have seen widespread adoption; however, these devices also su er from poor reliability as measurements are seldom performed according to the speci ed guidelines (e.g., measurements taken with the patient seated, arm cu maintained at heart level, arm cu kept stationary, and no talking or leg crossing). Auscultatory or oscillometric cu -based ambulatory BP monitors (ABPMs) that can be worn in home settings and provide regular automated measurements over 24 h periods|and, most importantly, during sleep|have become the clinical standard, reportedly providing more accurate and reliable results. However, these devices still require the patient to follow the same guidelines as SBPMs, yield intermittent measurements only (e.g., every 15-30 min during the day, every 30-60 min at night), and are found by many patients to be obtrusive and uncomfortable. The proposed Cardiovascular Hemodynamics Processing System (CHAMPS ) will be a reliable, easy-to-use, and comfortable (i.e., non-cu -based) continuous (i.e., beat-to-beat) ambulatory BP monitor (cABPM) that can operate around the clock, even during activities of daily living (ADL). This new class of BP monitor will be an important addition to clinical practice, accurately and unobtrusively assessing individuals with established or suspected hypertension, even during movement and without uncomfortable cu in ations. CHAMPS provides accurate BP estimates without restricting users' mobility, body postures, or arm elevations. In the proposed SBIR Phase I e ort, Barron Associates seeks to demonstrate proof-of-concept for CHAMPS via rigorous evaluation of a new algorithm that obviates the need for repeated calibrations traditionally associated with pulse transit time (PTT)-based systems. CHAMPS beat-to-beat BP estimates may be used directly or averaged over arbitrary intervals (e.g., to mimic conventional ABPMs). In Phase I, CHAMPS systolic, diastolic, and mean arterial BP estimates obtained during rest, di erent postures and arm elevations, and treadmill exercise will be compared directly with criterion BP measurements obtained using a clinical laboratory system speci cally designed for application in cardiac stress and exercise testing. Comparisons between CHAMPS BP estimates and criterion measurements will be obtained in each participant during two 50-min test periods separated by 24-h to demonstrate the ability of CHAMPS to provide accurate BP estimates without recalibration. CHAMPS will ful ll the need for an ergonomic, accurate, reliable, and low-cost cABPM for use in healthcare and clinical research. _
