Chronic heart failure, and its acute exacerbations, is one of the leading causes of hospitalization, costs and deaths in the United States. Annually, more than one million patients are hospitalized due to heart failure (HF) and this accounts for a total Medicare expenditure exceeding $17 billion. Clinical management of HF is expensive, and proposals to replace the traditional HF clinic model by reengineered integrated HF treatment centers to reduce these costs have been suggested. A cornerstone of HF management is having a reliable way of assessing patients'volume/fluid status. Specifically, assessment and early detection of the changes in lung water (CLW) is very important. However, a detailed literature review and interviews with more than 100 cardiologists revealed that, there is no reliable, non-invasive, low-cost and easy-to-use medical sensor for making these measurements. To overcome these bottlenecks in measuring the CLW, we propose the CPS technology which is a novel sensor based on radio frequency (RF) measurements on the patient's chest. CPS can non-invasively and accurately measure the CLW (demonstrated by animal experiments), cardiac waveforms, heart rate (HR), and respiration rate (RR) (demonstrated on a few male human subjects). It is worth noting that the proposed technology, although based on RF measurements, is different from others that are based non-contact, radar-type measurements. These radar measurements based techniques encounter strong surface reflections, and hence seem inadequate and were not used for any at depth measurements such as lung water content. The main objective of this study is to assess and validate the accuracy of the CPS in measuring the CLW, and other vital signs in a clinical setting with HF patients. The vital signs measured by CPS will be compared to those obtained from right heart catheterization and other standard monitoring procedures. This project will be conducted in collaboration with the University of Hawaii John A. Burns School of Medicine (biostatistics), College of Engineering (CPS technology development), and Queen's Medical Center (clinical experiments).
A cornerstone of heart failure (HF) management is having a reliable way of assessing patients'volume/fluid status. Specifically, assessment and early detection of the changes in lung water (CLW) is very important. However, currently available sensors to assess the volume status are either highly invasive or indirect, constituting a significant bottleneck in the management of HF, hence the high costs (exceeding 17 billion/year). The full development of the Cardio-Pulmonary Stethoscope (CPS) is very significant since multiple vital signs including heart rate, respiration rate, cardiac waveform and more importantly changes in lung water (CLW) will be extracted from a single non-invasive radio frequency measurement. Successful completion of this project will provide a new diagnosis modality to a wide array of medical doctors including cardiologists and help enable improved efficiency of healthcare delivery, decrease the costs of HF, provide continuous monitoring to capture rare, transient and evanescent events, and in supporting a variety of in-field and emergency military applications. The developed sensor platform can be an investigative tool for further illness diagnosis as well as extracting important cardiac parameters such as the stroke volume.
|Celik, Nuri; Gagarin, Ruthsenne; Huang, Gui Chao et al. (2014) Microwave stethoscope: development and benchmarking of a vital signs sensor using computer-controlled phantoms and human studies. IEEE Trans Biomed Eng 61:2341-9|