Joshua 2.0 — Φ-Harmonic Neural State Monitor is a closed-loopbiofeedback system for actively guiding the autonomic nervoussystem toward a measurable state of phase coherence. The systemcombines a φ-harmonic frequency generator, a φ-resonancecorrelation detector, a multi-layer coherence integrator, athreshold response classifier, an autonomic balancecomputation, and a PID-controlled biofeedback cycle, operatingas a single closed-loop architecture (system components 101through 109) at a 10 Hz update rate. This paper documents the scientific foundations, mathematicalderivations, and system architecture underlying the invention,drawing on 48 peer-reviewed sources across heart-rate variabilityscience, signal processing, synchronization theory, controltheory, and biological-asymmetry analysis. PATENT AND PRIOR-DISCLOSURE NOTICE The system described in this paper is the subject of IsraeliPatent Application No. 320503, filed 25 April 2025 (prioritydate preserved). An amended Description, Claims, and AnnexureA were filed on 28 April 2026 with the Israel Patent Officethrough formal portal submission (request #70288, type 51) andcontemporaneously notified by email to the examinationdivision, in response to the Notice of Deficiencies of 17September 2025 (26 ק.פ.) and following the examiner interviewof 27 April 2026 (Reference 119100190). This paper is a scientific exposition of the same invention,prepared for academic and industrial reference. It does notexpand the subject matter of the patent application, does notconstitute an offer for sale, makes no medical claims, anddoes not represent that the application has been granted. The author retains all patent rights. Reproduction of themathematical derivations, system architecture, or componentspecification herein for the purpose of practising theinvention requires authorisation from the applicant. SAFETY AND SCOPE The system described herein is a wellness application forstress reduction, meditation practice, wellness monitoring,and athletic recovery training. It is not a medical device.It does not diagnose, treat, cure, or prevent any disease,and is not a substitute for medical care. copyright© 2025–2026 Yehudah Shilo Groskin. All Rights Reserved.Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0).