Vitacore Research Collaborative

Publications

Preprints & working papers.

Vitacore publishes preprint-first on arXiv, bioRxiv, or medRxiv, followed by peer-reviewed journal submission with open-access preference. The June 2026 sprint comprises three theoretical and perspective papers.

2026 sprint

  • Technical Note in preparation

    Towards a Formal Signal Processing Specification for Photon-Counting CT Radiomics: Addressing the Feature Instability Problem through Signal Chain Characterisation

    Walker A. · Vitacore Research Collaborative · 2026

    Photon-counting CT (PCCT) represents the most significant hardware transition in clinical CT in five decades, yet radiomics pipelines built on conventional-CT signal characteristics remain formally unvalidated for PCCT data. This Technical Note applies formal signal-chain analysis to the PCCT radiomics pipeline, deriving theoretical stability conditions for IBSI feature classes under PCCT acquisition parameter variation and validating these conditions against published 2023–2025 phantom-study findings.

    Preprint
    arXiv · eess.SP, cross-listed physics.med-ph
    Journal
    European Radiology Experimental (Springer Nature, open access)
    • signal processing
    • radiomics
    • PCCT
    • IBSI
    • formal methods
  • Opinion in preparation

    Spatial Transcriptomics Cell Type Deconvolution as a Blind Source Separation Problem: A Formal Signal Processing Framework

    Walker A. · Vitacore Research Collaborative · 2026

    Twenty or more spatial-transcriptomics deconvolution algorithms have been published with inconsistent benchmark results. None has been derived from formal signal-separation theory. This Opinion frames deconvolution as a blind source separation problem, derives identifiability conditions, maps existing algorithms to their BSS equivalents, and proposes principled algorithm selection criteria based on formal signal-model assumptions.

    Preprint
    bioRxiv · Bioinformatics
    Journal
    Briefings in Bioinformatics (Oxford University Press)
    • bioinformatics
    • spatial transcriptomics
    • blind source separation
    • identifiability
  • Perspective in preparation

    Information-Theoretic Limits of Circulating Tumour DNA Detection: A Signal Detection Theory Framework for Clinical Threshold Specification

    Walker A. · Vitacore Research Collaborative · 2026

    Clinical detection thresholds for ctDNA assays are set empirically without theoretical foundation. This Perspective applies the Neyman-Pearson framework and Shannon information theory to derive the minimum detectable tumour fraction in closed form as a function of sequencing depth and error rate, calculate the channel capacity of ctDNA sequencing assays, and situate current clinical assays relative to theoretical limits.

    Preprint
    medRxiv · Oncology
    Journal
    npj Precision Oncology (Nature Portfolio)
    • oncology
    • ctDNA
    • information theory
    • signal detection

Prior work

Earlier publications by the Founding Research Director, prior to the establishment of Vitacore Research Collaborative.

  • 2018 · Walker A. et al. Real-time trauma scoring and survival prediction using wearable physiological sensing. IEEE EMBC 2018.
  • 2017 · Walker A. et al. ECG classification with HL7-FHIR interoperability for wearable clinical telemetry. IEEE conference paper.