Clinical Calculators and Physiology Simulators

The calculators run competing equations side by side where clinicians use more than one: four QT corrections, four body surface area formulas, and CKD-EPI 2021, MDRD and Cockcroft-Gault on the same creatinine. A dose or a threshold can depend on which one a hospital adopted, so you can see how far they disagree for the same inputs.

Each bedside calculator carries the same caution on its page. Its reference ranges are typical, and your laboratory’s may differ. The unit on the report decides what goes in: American and Indian reports mostly use mg/dL, while British, Canadian and Australian reports use mmol/L or µmol/L.

What is a clinical calculator?

A clinical calculator turns a measurement from the bedside or the laboratory into a derived value through a published equation: a blood pressure into mean arterial pressure, a creatinine into an estimated GFR, a QT interval into a rate-corrected QTc. Each calculator here names its equation and source, so the result can be checked against a textbook.

Physiology simulators, for the mechanism behind a number

The simulators model a textbook system rather than a patient. The cardiac cycle lines up pressures, volume, valves and the ECG on a Wiggers diagram; the rhythm simulator sweeps a lead II strip through the heart blocks, atrial fibrillation and flutter; the spirometry simulator draws obstructive and restrictive flow-volume loops; and the oxygen dissociation curve shifts with pH, carbon dioxide, temperature and 2,3-BPG.

Each one shows the mechanism a calculated value depends on, so you can watch a fall in pH shift the oxygen curve or a dropped beat appear on the strip.

Anatomy in 3D, and the neurological maps

The anatomy explorers are 3D models built from the BodyParts3D meshes: peel the full body from skin to skeleton, hide the heart wall to see the valves, or take the brain apart into named gyri, deep structures and ventricles.

Two diagrams sit beside them for the neurological examination. The dermatome map lights each spinal root’s band of skin from C2 to S5 with its myotome and reflex, and the visual field explorer shows the defect a lesion causes at each point from the optic nerve to the visual cortex.

Practice questions and test statistics

The lab and clinical practice set generates QTc, MAP, A-a gradient, corrected calcium and osmolality questions, marks each answer when you press Check and shows the working, with every answer computed by the calculator it came from.

The sensitivity and specificity tool covers the other half of reading a result: how moving a test’s cut-off trades one against the other, and how prevalence sets the positive predictive value.