Proposed Research. Systems Micro Technologies (SMT) proposes to research the feasibility and to establish the mechanisms of applying a novel radar-based monitor for early detection of cardiopulmonary arrest (CA) by showing that SMT's micropower frequency-modulated radar (MFMR) can detect changes in the following four physiological variables: heart rate, respiratory rate, cardiac output and respiratory tidal volume.
MFMR aims to enable continuous monitoring of these variables remotely, non-invasively and with no health risks to the patients. Problem/Opportunity. Cardiopulmonary arrest (CA), the leading proximate cause of in- hospital death in the US, can often be reversed or prevented with adequate intervention;however, in order to be effective, the life-saving activities have to start within minutes after CA. Two critical parameters that can reduce CA-mortality are expansion of the number of patients continuously monitored for the signs of CA and improving the reliability of monitoring by tracing more physiological variables. The innovative MFMR-based monitor proposed by SMT can achieve both of these effects by continuous remote and non-contact detection of changes in both the rates and output volumes of cardiac and respiratory activity of patients. MFMR's convenience and low operational cost will allow significant expansion of the types and numbers of patients subjected to continuous cardiopulmonary monitoring. Project Outline. SMT will build a prototype radar monitor using its currently existing MFMR unit (developed for non-medical purposes) as a starting point. The new prototype will be calibrated and undergo a series of performance tests. Once ready, the prototype will be used to validate the measurement of the four physiological variables of interest: absolute values of heart rate (HR) respiration rate (RR) and relative changes in cardiac ejection fraction (EF) and respiration tidal volume (Vt). Data processing and analysis algorithms will be developed to extract the values of these parameters from the radar reflection patterns. HR and EF monitoring will be validated using the Jaszczak beating heart phantom experiments. Simultaneous measurements of HR and RR, and detection of changes in Vt will be validated via patient studies at California Pacific Medical Center. Quantitative milestones for measurement of each of these parameters are defined. Success criteria formulated in terms of these milestones will have to be met in order to move to Phase 2 of the project. Benefits. If the feasibility for CA detection is confirmed, SMT will proceed to developing a marketable cardiopulmonary monitoring device for hospital and in-home use. The device will record data automatically and communicate it to the hospital patient alarm as well as communication system for further evaluation. The monitor will be used either as a single source of diagnostic information or as one of the components in a comprehensive patient evaluation when used in parallel with other methods. The proposed approach introduces major innovations that lead to three key benefits: The non-contact and convenient nature of SMT's radar allows it (1) to significantly expand the number of monitored patients, and (2) to reduce the time spent by caregivers;(3) SMT's radar can detect changes in cardiac output and respiration tidal volume, two important variables that are not commonly monitored now. This new diagnostic information can enable better understanding of the physiopathologies leading to CA.
Availability of reliable and convenient methods of continuous cardiopulmonary monitoring is critical for prevention of cardiac arrest mortality. Early detection of warning signs can prevent cardiopulmonary arrest deaths in many at-risk patients, both in the intensive care environment, in general hospital wards or at home. Remote, non-contact monitoring technology developed as the result of the proposed research will introduce a new paradigm in cardiopulmonary monitoring, potentially reducing the patient mortality from cardiopulmonary arrest and improving the patient's comfort while potentially even decreasing the cost of care.
