Blood Pressure Cross-Country Cross-Language Cross-Paradigm (Demo) IG
0.2.1 - ci-build

Blood Pressure Cross-Country Cross-Language Cross-Paradigm (Demo) IG, published by FO. This guide is not an authorized publication; it is the continuous build for version 0.2.1 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/frankoemig/bloodpressure/ and changes regularly. See the Directory of published versions

Information Models

Blood pressure measurements appear to be obiously simple. However, discussions reveal that the details allow for interpretations. The only way out is an exact definition in form ob class diagrams.

Base Model

The aforementioned details are now aggregated in form of classes and linked together. The important items are in bold:

Blood Pressureidentifierinterpretation: codelocation: codeposition: codemethod: codeexertion: code|quantitycuffType: codecuffSize: codeconsciousness: codetilt: integercuffType: codecuffSize: codedateTime: instant|periodcomment: stringBlood Pressure Valuevalue: integerunit = mm[Hg]referenceRange: rangeinterpretation: codeSystolic BPDiastolic BPMean Arterial PressurePulse PressureReference Rangelow : integerhigh: integerage: rangeBody Weightnecessary tointerpretthe measurementMedicationAuthorPerformerRecorderSubjectnormallythe patient110..10..10..110..*10..1

To simplify abstract classes are introduced.

Spot vs. Average

In principle, different individual measurements are performed. They can be used and aggregated into an average value:

SpotsystolicdiastolicunittimestampAveragesystolicdiastolicunitperiodcount0..*

Calculation

The pulse pressure is the result of a calculation of systolic and diastolic values:

measuredcalculatedaggregatedSystolicDiastolicPulse PressureAverageperiodcountValuevalueunittimestampReference Rangelowhigh110..*

Interpretation

The interpretation of values depends on certain context details:

MedicationMedicationrelevantirrelevantBlood PressureBody Weightnecessary to interpretthe measurement, butin the sense of overweightExertionPositioningCuff Sizenormally, the cuffsoize does not matter,but in rare circumstancesit is relevant to know(eg. too small for an athletic person)0..*
  • some medication reduces the blood pressure to protect against strokes etc.
  • physical exertions like riding a bike increases the blood pressure
  • the positioning of the body has a direct impact on the result
  • …

Equivalence of Models

Pre- vs. Post-Coordination

An important topic taht normally does not belong into such a guide is the translation of pre-coordinated concepts to/from appropriate post-coordinated terms. The following table should help with that although the best presentation and appropriate details are still to be elaborated.

post-coordinated base addt'l details
in rest and sitting standard no addt'l details
in rest and standing standard position = standing
walking standard position = walking + exertion = 25W
jogging standard position = walking + exertion = 100W
biking uphill standard position = sitting + exertion = 200W
… … …

In principle, a function like this one is necessary:

f(pre-coordination) = Base(concept) + Set(attributeValue)

The problem is that this function is self-defining and recursive in the sense of a taxonomy.