rdc-Observation-CGM-calibrated

CGM Calibration status

The CGM value in the observation resource will be considered when extension: calibration-status = calibrated [Refer Example above]

if the extension: calibration-status = uncalibrated then it will be not considered as a valid entry, below is the calibration status representation for the same.

    {
        "url": "https://roche.com/fhir/iop/StructureDefinition/ext-CalibrationStatus",
        "valueString": "uncalibrated"    
    }

CGM Flags

The CGM Flags are values that denotes certain conditions like if the value is High or low for the CGM values measured, If the CGM values have any flags it will be marked in the CGM Flags extension, if there are no flags for a particular value it is denoted with X as shown in below sample.

So in the below valueSampledDate example below the data values have these flags HI; X; X; LO associated:

• 100 -> HI is the flag associated
• 99 -> X is represented stating no flag association
• 89 -> LO & CALIBRATION REQUIRED (multiple flags are associated to single CGM value)
• 89 -> LO is the flag associated

"valueSampledData": {
    "origin": {
        "value": 0,
        "unit": "mg/dL",
        "system": "http://unitsofmeasure.org",
        "code": "mg/dL"
    },
    "interval": "60000", // Time interval of the data
    "intervalUnits": "ms" // Time interval unit
    "dimensions": "1", // Hardcorded value in FHIR
    "data": "100 99 89 89", // CGM data values
    "extension": [
        {
            "url": "https://roche.com/fhir/iop/StructureDefinition/ext-SampledDataTimestamps",
            "valueString": "2020-10-14T02:01:00+01:00 2020-10-14T02:02:00+01:00 2020-10-14T02:03:00+01:00 2020-10-14T02:04:00+01:00"
        },
        {
            "url": "https://roche.com/fhir/iop/StructureDefinition/ext-CGMFlags",
            "valueString": "HI; X; X; LO"
        }
    ]
}

Notes

1. CGM Device resource needs to be send first.
2. Once the Device resource in place, CGM Data resource can be shared as it has a reference to the Device (CGM) resource.