Patrick Joseph Flaherty - US grants

In the US, heart failure affects over 6 million people and is the most common cause of hospitalization. New technologies are needed to enable in-home monitoring and treatment of patients at risk of developing acute decompensated heart failure. Early symptom detection will help clinicians reduce disease progression and prevent hospitalization. Current home-based management relies on monitoring weight gain, but weight alone does not accurately gauge the fluid accumulation that predicts worsening of heart failure. Atrial fibrillation, a heart rhythm abnormality associated with stroke, hospitalization, and 2-fold higher risk of death, is also common in heart failure patients. Because atrial fibrillation symptoms can be vague, intermittent, and short lasting, atrial fibrillation detection requires continuous monitoring--a challenge in ambulatory patients. A device that can measure vital signs (including heart rate, respiration rate, and tidal volume), intrathoracic fluid status (using thoracic bioimpedance) and heart rhythm will both detect atrial fibrillation and promote quick and accurate identification of the early stages of acute decompensation in chronic heart failure patients. Thus, the goal of this work is to develop a novel device for in-home monitoring of heart failure patients who are at risk of developing acute decompensated heart failure. The system will consist of a bioimpedance monitor (a wearable vest with dry electrodes--no adhesives, gels or wetting required) to detect trending to acute decompensated heart failure and of a smart-watch to measure atrial fibrillation. These components will require the development of novel sensor and information technologies, wearable monitors, signal processing algorithms, and telecommunication systems. The long-term goal of this project is to enable in-home monitoring of patients at risk of catastrophic cardiovascular events in order to provide prompt, targeted intervention, reduce symptom progression and avert preventable hospitalization. A wireless cardiac monitoring system that will be comfortable to wear, easy to use, cost effective, and feasible for home use with ambulatory patients will be developed. The system will provide patients and their healthcare providers with early warnings about cardiac decompensation and serious but difficult-to-detect arrhythmias, which can empower patients and caregivers, improve quality of life, and reduce health care costs.

This project aims to: 1) develop reuseable carbon-black and polydimethylsiloxane (CB/PDMS) electrodes that capture bioimpedance and electrocardiogram data; 2) develop hardware and algorithms for acute decompensated heart failure detection, resulting in a wearable monitor with embedded CB/PDMS electrodes; 3) develop hardware and algorithms for atrial fibrillation detection using a smart watch; and 4) evaluate the performance and usability of both detection systems in a prospectively recruited cohort study. The clinical study will target populations, including patients with psychosocial or cognitive limitations, that are at high risk for acute decompensated heart failure and atrial fibrillation progression but that typically are omitted from clinical studies. The central hypothesis is that an innovative bioimpedance monitor with re-usable, non-wetted bioimpedance electrodes embedded in a wearable vest device used in conjunction with a smart watch will continuously collect and transmit key physiologic data. Devices running decision-support algorithms will analyze this data to identify patients with emergent acute decompensated heart failure symptoms that require prompt attention. A second hypothesis is that a wrist-based continuous monitoring device will provide unobtrusive and acceptable 24-hour heart rhythm monitoring and will augment data collected by the bioimpedance monitor. Heart rhythm, vital signs, and intrathoracic fluid accumulation measurements will be collected via 24-hour data recordings. This data will be used to develop a robust clinical decision support algorithm that accurately detects atrial fibrillation and early acute decompensated heart failure.