Reference

Glossary

Plain-language definitions of the clinical AI, regulatory, integration, and security terms used across VitaSignal - for clinicians, executives, compliance officers, and IT leaders.

Data & Integration

ADT: Admission, Discharge, and Transfer messages - real-time events about patient movement through a hospital.
De-identified Data: Data from which direct and indirect identifiers have been removed under HIPAA Safe Harbor or Expert Determination methods.
FHIR: Fast Healthcare Interoperability Resources, the HL7 standard for exchanging healthcare data. VitaSignal is evaluating FHIR R4 as a future site-specific mapping pathway. No production connector or conformance is currently claimed.
HL7v2: A long-established healthcare messaging standard widely used for ADT events and lab results in hospital EHR systems.
PHI: Protected Health Information - individually identifiable health information protected under HIPAA.

Security

Audit Log: A record of access or system activity. Whether it is tamper-evident, independently attested, or production-grade depends on the implementation; VitaSignal's current public environment does not claim those properties.
Evidence Layer: A research design pattern tying each illustrative output to its model version, input hash, and timestamp. Not an implemented production control.
RBAC: Role-Based Access Control - restricting system access based on a user's role and the principle of least privilege.
RLS: Row-Level Security - database-enforced rules that restrict which rows a given user or role can read or modify.
TLS 1.3: The current Transport Layer Security standard for encrypting data in transit between systems.

AI & Models

AUROC: Area Under the Receiver Operating Characteristic curve. A summary measure of how well a model separates two outcomes (e.g., high vs. low risk). 1.0 is perfect, 0.5 is random.
Calibration: How closely a model's predicted probabilities match observed outcomes. A well-calibrated 30% risk score means roughly 30 of 100 such patients experience the event.
Deterministic: Producing the same output from the same defined input and versioned process. Deterministic scoring and re-derivation are VitaSignal design goals. Implementation completeness and external verification have not been established.
Hallucination: When a generative AI produces information that is fabricated, unsupported, or not grounded in the approved source material. VitaSignal reduces this risk by keeping generative models out of the structured scoring path. Any LLM-assisted narrative, if used, remains separate from the recorded value and requires source grounding and human review. This design reduces but does not eliminate hallucination, omission, citation, interpretation, or transcription risk.
Model Card: A standardized document describing a model's intended use, training data, performance, limitations, and fairness characteristics.
Model Drift: Degradation of model performance over time as patient populations, workflows, or coding practices change. Drift may be evaluated through monitoring and recalibration studies.
Probabilistic: Producing varying outputs based on sampled likelihoods. Generative chatbots are probabilistic; their answers can shift across runs even with identical prompts.
SHAP: SHapley Additive exPlanations - a method for attributing a model output to individual input features, supporting explainability during research review.

Regulatory

BAA: Business Associate Agreement - a HIPAA-required contract between a covered entity (e.g., hospital) and a vendor that handles PHI on its behalf.
CMS: Centers for Medicare & Medicaid Services - U.S. federal agency that regulates and reimburses much of the U.S. healthcare system.
FDA Pre-Submission (Q-Sub): A formal meeting with FDA CDRH to obtain feedback on a proposed regulatory pathway before a full submission.
HIPAA: Health Insurance Portability and Accountability Act - U.S. law governing the privacy and security of protected health information.
IRB: Institutional Review Board - an independent committee that reviews and approves research involving human subjects.
SaMD: Software as a Medical Device - software intended to be used for medical purposes that performs those purposes without being part of a hardware device.

Clinical

CDS: Clinical Decision Support - software that provides clinicians with knowledge or patient-specific information to enhance care decisions.
Equity Monitoring: Prespecified review of model or data behavior across approved groups where sufficient data exist. Monitoring may identify variation requiring investigation. It does not certify fairness, prevent disparate impact, or establish equitable benefit.
Pre-market research prototype: VitaSignal software is a pre-market research prototype. The regulatory pathway is under evaluation. Not FDA cleared or approved. Not for clinical use.