A triage system from voice acoustics to colour-coded blood-biomarker prediction in microgravity: validation of α-Curve v7.0 with 41 longitudinal recordings from ISS crew

<title>Abstract</title> <p> Background Microgravity perturbs human physiology through multiple mechanisms — fluid shift, electrolyte imbalance, cardiovascular deconditioning and neuromuscular change — yet obtaining blood samples in space is severely constrained. We developed and tested a triage system that, using a seven-dimensional acoustic deviation vector (the α-Curve) grounded in the Sommerfeld fine-structure constant α = 1/137.036, generates colour-coded pathology predictions for 13 blood biomarkers from voice recordings alone, and we evaluated it in International Space Station (ISS) crew. Methods Primary data comprised 41 sustained /u/ vowel recordings from three crews (M1 = 17, M2 = 9, M3 = 16) who transitioned to the ISS on 19 January 2025. Individual pre-flight quarantine reference recordings (n = 4) were collected for M2 and M3 on 9 January 2025. Acoustic features (F₀, jitter, shimmer, HNR, CPP) were extracted in Python (numpy, scipy); the α-Curve was computed as a seven-dimensional deviation vector (λ _i = log(x _i /baseline _i ) × 137.036, pathological direction only). For each subject the v7.0 engine produced a sigmoid-based colour score (green &lt; 0.25, yellow 0.25–0.50, orange 0.50–0.70, red ≥ 0.70) for 13 blood biomarkers (Na, K, Mg, Ca, glucose, CRP, ferritin, procalcitonin, Hgb, TSH, troponin, NT-proBNP, creatinine). Secondary data comprised a systematic literature validation of 22 publications (total n = 51,234 patients + controls). Results In crew M3 the quarantine→ISS comparison revealed a marked cardiovascular escalation pattern: jit_n rose 1264% (1.00→13.64), HNR fell 50.2% (0.57→0.28), F₀ rose 21.1% (89.5→108.4 Hz) and CPP fell 52.9% (5.44→2.56 dB). A strong positive Pearson correlation was observed between mission day and jit_n in M3 (r = + 0.732, p &lt; 0.001). Across all ISS recordings (n = 35), jit_n × HNR (r = − 0.635), jit_n × alpha_n_top (r = − 0.611), HNR × alpha_n_top (r = + 0.596) and jit_n × shim_n (r = + 0.553) were significant at p &lt; 0.001. Applied to the ISS M3 data, the v7.0 engine returned |Λ| = 207.3 (high–moderate deviation) and an ORANGE flag for Na, NT-proBNP and troponin — triage decision: ORANGE, same-day specialist evaluation. A forest-plot meta-synthesis of the 22 studies (n = 51,234) supported the v7 correlations. Conclusions The Sommerfeld-α-based seven-dimensional acoustic deviation vector is a sensitive, calibrated indicator of systemic physiological disturbance in microgravity. By producing colour-coded biomarker alerts from voice without blood sampling, the v7.0 system may assist triage in space medicine, telehealth and resource-limited settings. Using colour categories rather than numerical estimates softens literature uncertainties and offers a safe framework for clinical decision support. Multi-centre prospective validation is recommended. </p>