Equity by construction

You are not a deviation from someone else’s average.

Intuitive Pathos builds physiological monitoring designed around each person’s own baseline rather than a population mean that was never built to include them. The aim is fairness built into the mathematics rather than promised in a policy, and it has to be measured group by group before anyone can claim it.

See it for yourself

One heart rate. Three different verdicts.

A resting heart rate of 92 bpm sits comfortably inside the textbook adult range. For one of the two people below, it is the clearest warning of the day. Drag the reading, or jump to a scenario.

One resting heart rate, judged three ways A horizontal scale of resting heart rate from 40 to 120 beats per minute. The conventional adult reference range, 60 to 100, is drawn as a wide band. Beneath it sit two people's own habitual baselines: Person A rests at 84 to 96 beats per minute, Person B at 50 to 60. A single reading, which you can move along the scale, is compared against all three at once. At 92 beats per minute it is unremarkable for the population and ordinary for Person A, while standing 32 beats per minute beyond anything Person B's own body normally does. Population range 60–100 Person A baseline 84–96 Person B baseline 50–60 +32 bpm 40 60 80 100 120 resting heart rate, beats per minute 92 bpm

A population range answers “is this normal for people in general?” It cannot answer “is this normal for this person?” The same reading can sit inside the reference range and inside Person A’s baseline while being a large departure from Person B’s, and a reading the range flags can be exactly what Person B’s body does every night. That departure from a person’s own baseline is the signal that matters, and it is the one a population reference misses. Figures are illustrative; the 60–100 bpm band is the conventional adult resting range, not a claim about any individual.

The problem

Reference ranges carry the history of who was measured.

Nearly every physiological threshold in routine use is a population statistic: a range derived from some cohort of people, at some point in time, under some set of conditions. When the person in front of you resembles that cohort, the range works. When they do not, the range quietly stops being a measurement and starts being an assumption.

The failure is not that clinicians are careless. It is that the instrument itself encodes a comparison the clinician did not choose and often cannot see. A patient whose resting physiology sits at one end of a distribution can deteriorate substantially and still read “normal.” Another can be flagged, worked up, and labeled for being exactly who they have always been.

Both are errors of the same kind: a person compared against a distribution they were never part of.

Deviation
A statistical distance from a population mean. An observation about a distribution.
Deviance
A judgment that something is wrong with the person. An observation about a human being.
The conflation
Treating the first as evidence of the second. It is the oldest category error in measurement, and it is built into the tools.

This is not a hypothetical: reference-range and sensor bias are documented in the peer-reviewed literature; see the disparity case.

A number can be normal and still be wrong.

Normal for the population. Wrong for the person in front of you. Every reference range in routine use is capable of both at once.

The framework

Four principles, built into the mathematics.

These are not values we aspire to. They are constraints the system is constructed from, which is why we call it equity by construction.

Deviation is not deviance

01: the founding constraint

Statistical distance from a population mean is not, by itself, pathology. A body that runs differently from the average is reporting a fact about a distribution, not a defect in a person. Our within-subject methods are designed so that distance from the mean is never, on its own, grounds for an alert.

The per-subject baseline

02: your reference range is you

Every subject accumulates a within-subject reference distribution: what their physiology does across time, rest, activity and recovery. Change is then measured against that, so the question the within-subject comparison asks is “what is different for you?” rather than “how unlike other people are you?”

Yang/Yin symmetric fairness

03: equal and opposite

Departures above baseline (Yang) and departures below it (Yin) are treated as equal and opposite. Monitoring systems have a long habit of instrumenting one direction well and the other poorly: agitation over withdrawal, hyperactivity over shutdown, the loud failure over the quiet one. Symmetric treatment is designed to remove that asymmetry in the within-subject comparison, before it reaches a threshold or an alarm.

Architectural impossibility

04: some harms should be unrepresentable

A protection enforced by policy can be waived, misconfigured or forgotten. A protection enforced by architecture cannot. Where a harm is serious enough, we design it to be something the system has no way to express, rather than something it is asked not to do. Examples include comparing a person to a demographic cohort, moving identifiable physiology off a device, and letting a non-clinical product emit a clinical conclusion.

Read the framework in full

Symmetry

The quiet failure counts the same as the loud one.

Most monitoring is asymmetric by accident. The signals that get instrumented are the ones that are easy to see, easy to chart, and historically the ones that disrupted a ward. The person who becomes withdrawn, slowed, flat or unresponsive generates less noise, and so, in a system tuned by noise, less attention.

Symmetric fairness means the model does not have a preferred direction. A given magnitude of departure from a person’s own baseline carries the same weight whether it points up or down.

Symmetric treatment of departures above and below baseline A horizontal per-subject baseline runs across the middle. Equal-sized departures are drawn above in warm color and below in cool color, mirrored exactly, showing that both directions are weighted identically. YOUR OWN BASELINE Yang: elevated Yin: suppressed EQUAL MAGNITUDE, EQUAL WEIGHT
In the within-subject comparison, departure above and below a person’s own baseline is designed to be weighted identically.

End to end

What the system is designed to do.

  1. Observe

    Continuous physiological signal from each subject, gathered over time in the setting the product is designed to serve.

  2. Learn the subject’s own baseline

    Build a within-subject reference distribution over time. This is the comparison set. It belongs to one subject and is never swapped for a cohort average.

  3. Look for a change in state

    The Wu mathematics primitives, namely memory coefficient, critical slowing down, λ* criticality, and sliding-window regime detection, look for a system changing state.

  4. Report symmetric, direction-honest deviation

    The within-subject output is designed to be expressed as departure from the subject’s own baseline, with elevated and suppressed weighted equally and the direction preserved.

  5. Federate what is safe to federate, and nothing else

    The federation contract is designed so that model improvement can be shared across deployments. What may cross the boundary and what may never cross it is expressed in the type system of the client rather than in a configuration setting.

Product family

One substrate. Many settings where a baseline matters.

The same primitives are designed to serve a critical-care unit, a veterinary clinic, a field team and a living room, because “compare this subject to themselves” is not a clinical idea. It is a measurement idea.

All products and their regulatory status

Where to go next

Start from where you stand.

Clinicians & health systems

What a per-subject baseline changes at the bedside, what the regulatory posture is today, and what we will and will not claim.

Clinical overview

Investors & partners

The architecture of the moat, the product family, the layering strategy, and an honest statement of stage.

Platform thesis

Government & defense

Capability statement, operator-state monitoring, data-sovereignty posture, and how to contract with us.

Capability statement

Everyone else

The idea in plain language: why being different from average is not the same as being unwell, and why that distinction is worth building.

The idea

Why this exists

Every nurse has watched someone be told they were fine because their numbers matched a stranger’s. And watched someone else be treated as a problem for being exactly who they had always been.

Intuitive Pathos was founded by a registered nurse after about ten years at the bedside, not in a lab. The framework came out of the specific, repeated experience of watching measurement instruments answer the wrong question, and of noticing that the error was systematic, directional, and fixable in the mathematics rather than in the vigilance of tired people.

About the founder and the company

What has happened lately

Talk to us

If you have a population your instruments keep getting wrong, we should talk.

Clinical partnerships, veterinary and research deployments, government contracting, or investment: the conversation starts the same way.