ORIGINAL PAPER A Novel Handheld Device for Use in Remote Patient Monitoring of Heart Failure Patients—Design and Preliminary Validation on Healthy Subjects Luca Pollonini & Nithin O. Rajan & Shuai Xu & Sridhar Madala & Clifford C. Dacso Received: 3 March 2010 / Accepted: 17 May 2010 # Springer Science+Business Media, LLC 2010 Abstract Remote patient monitoring (RPM) holds great promise for reducing the burden of congestive heart failure (CHF). Improved sensor technology and effective predictive algorithms can anticipate sudden decompensation events. Enhanced telemonitoring systems would promote patient independence and facilitate communication between patients and their physicians. We report the development of a novel hand-held device, called Blue Box, capable of collecting and wirelessly transmitting key cardiac parameters derived from three integrated biosensors: 2 lead electrocardiogram (ECG), photoplethysmography and bioelectrical impedance (bioim- pedance). Blue Box measurements include time intervals between consecutive ECG R-waves (RR interval), time duration of the ECG complex formed by the Q, R and S waves (QRS duration), bioimpedance, heart rate and systolic time intervals. In this study, we recruited 24 healthy subjects to collect several parameters measured by Blue Box and assess their value in correlating with cardiac output measured with Echo-Doppler. Linear correlation between the heart rate measured with Blue Box and cardiac output from Echo- Doppler had a group average correlation coefficient of 0.80. We found that systolic time intervals did not improve the model significantly. However, STIs did inversely correlate with increasing workloads. Keywords Remote patient monitoring . Congestive heart failure . Cardiac output . Electrocardiography . Photoplethysmography . Systolic time intervals Introduction Congestive heart failure (CHF) remains a leading cause of death in industrialized countries. Despite advances in medical treatment, an estimated 250,000–300,000 CHF patient are hospitalized in the United States each year for symptoms caused by low cardiac output (CO) [1]. Although the events that cause acute decompensation are multifactorial, the common pathway associated with decreased ventricular function, autonomic dysfunction and fluid retention [2]. Ultimately, the physiological response is precipitated by a fall in cardiac output. Key physiologic parameters of heart failure decompen- sation include altered systolic time intervals (STI), which are accepted as an indicator for cardiac deficiencies including CHF [3–5]. For instance, there is clear evidence for the inverse correlation of STI with internal indices of myocardial performance [6]. Additional clinical parameters such as QRS complex duration, pulse wave duration, and bioimpedance have been investigated as independent predictors of CHF readmission [7–10]. Prior research has focused on one or more of these parameters as potential predictors of decompensation in clinical settings [11]. An estimated 50%–66% of CHF hospitalizations are preventable with improved remote patient monitoring (RPM) [12]. A recent meta-analysis concluded that RPM L. Pollonini (*) : C. C. Dacso College of Technology, University of Houston, Houston, TX, USA e-mail: lpollonini@uh.edu L. Pollonini : N. O. Rajan : S. Xu : C. C. Dacso Abramson Center for the Future of Health, Houston, TX, USA N. O. Rajan : S. Xu : C. C. Dacso Methodist Research Institute, Houston, TX, USA S. Madala Indus Instruments, Webster, TX, USA J Med Syst DOI 10.1007/s10916-010-9531-y