Determining likelihood of an adverse health event based on various physiological diagnostic states

A method comprising:

• obtaining, via a plurality of electrodes on a housing of an implantable medical device (IMD) implanted subcutaneously in a patient, one or more subcutaneous tissue impedance measurements of interstitial fluid in an interstitium of a subcutaneous space of the patient wherein the plurality of electrodes are positioned within 5 centimeters (cm) apart on the housing;
• determining, by processing circuitry of a computing device, a respective one or more values for each of a plurality of physiological parameters, the plurality of physiological parameters including:
• a first period of time subcutaneous tissue impedance parameter determined from the one or more subcutaneous tissue impedance measurements of interstitial fluid measured over the first period of time, and
• a second period of time subcutaneous tissue impedance parameter determined from the one or more subcutaneous tissue impedance measurements of the interstitial fluid measured over the second period of time, the first period of time is up to 7 days, and the second period of time is up to 30 days;
• determining, by the processing circuitry, a diagnostic state for each of the physiological parameters based on the respective values, the diagnostic states defining a plurality of evidence nodes for a probability model;
• and
• applying, by the processing circuitry, the plurality of evidence nodes to the probability model to determine a probability score indicating a likelihood that the patient (a) is experiencing an adverse health event or (b) is likely to experience the adverse health event within a predetermined amount of time.

A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause one or more processors to at least:

• obtain, via a plurality of electrodes on a housing of an implantable medical device (IMD) implanted subcutaneously in a patient, one or more subcutaneous tissue impedance measurements of interstitial fluid in an interstitium of a subcutaneous space of the patient, wherein the plurality of electrodes are positioned within 5 centimeters (cm) apart on the housing;
• determine a respective one or more values for each of a plurality of physiological parameters, the plurality of physiological parameters including:
• a first period of time subcutaneous tissue impedance parameter identified from the one or more subcutaneous tissue impedance measurements of interstitial fluid measured over the first period of time, and
• a second period of time subcutaneous tissue impedance parameter determined from the one or more subcutaneous tissue impedance measurements of the interstitial fluid measured over the second period of time, the first period of time is up to 7 days, and the second period of time is up to 30 days;
• determine a diagnostic state for each of the physiological parameters based on the respective values, the diagnostic states defining a plurality of evidence nodes for a probability model;
• and
• apply the plurality of evidence nodes to the probability model to a probability score indicating a likelihood that the patient (a) is experiencing an adverse health event or (b) is likely to experience the adverse health event within a predetermined amount of time.