Digital twin of the human body may forecast health decline before it happens

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 18 through 80 years at enrollment. * Able and willing to provide written informed consent. * Able to understand study instructions and comply with protocol assessments. * Able to complete the standardized physiologic resilience challenge safely, with a customary assistive device or protocol-permitted accommodation when needed. * Clinically stable at screening, with no significant acute change in health status or prescribed medication regimen during the preceding 30 days, unless determined by the investigator not to affect participant safety or study measurements. * Willing to undergo multimodal physiologic monitoring and use study-provided or compatible wearable equipment. * Meets the criteria for one of the following prespecified cohorts: 1. Reference Health Cohort: Generally healthy adult without an unstable or clinically significant condition expected to prevent safe completion of the protocol or materially impair interpretation of the reference measurements. 2. Stable Cardiometabolic Cohort: Adult with one or more stable cardiometabolic conditions or risk factors, which may include controlled hypertension, dyslipidemia, obesity, prediabetes, or stable type 2 diabetes, without recent acute cardiometabolic decompensation. 3. Stable Respiratory or Mobility Cohort: Adult with a stable chronic respiratory condition or mobility-related functional limitation, without a recent exacerbation, acute injury, or acute functional decline that would make protocol assessments unsafe. * Participants meeting criteria for more than one clinical cohort will be assigned according to the prespecified cohort-classification hierarchy. * Participation in optional biospecimen collection requires separate consent; declining optional biospecimen collection will not otherwise exclude an eligible participant. Exclusion Criteria: * Inability or unwillingness to provide informed consent. * Acute illness, febrile illness, or suspected communicable infection at the time of assessment. * Hospitalization, major surgery, or clinically significant acute medical event within 30 days before enrollment, unless reviewed and cleared by the investigator. * Unstable cardiovascular disease, including recent acute coronary syndrome, decompensated heart failure, uncontrolled clinically significant arrhythmia, or symptomatic severe valvular disease. * Acute respiratory exacerbation, unstable oxygen requirement, or resting respiratory status that the investigator determines would make the challenge unsafe. * Resting blood pressure, heart rate, oxygen saturation, or other screening measurement outside the protocol-defined safety limits after repeat assessment. * Recent syncope, recurrent unexplained falls, acute musculoskeletal injury, or another condition that would prevent safe standing, walking, or recovery monitoring. * Neurologic, cognitive, psychiatric, visual, hearing, or communication impairment that would prevent informed consent or reliable completion of study procedures despite reasonable accommodation. * Known intolerance to required wearable sensors, electrodes, adhesives, or monitoring procedures that cannot be addressed using an approved alternative. * Participation in another clinical study or exposure to an investigational intervention that, in the investigator's judgment, could confound study measurements or increase risk. * Any medical, functional, or behavioral condition that the investigator or designated medical monitor determines would create an unacceptable risk or compromise the scientific validity of the collected data.