A few immediate thoughts:
1. SI’s general design philosophy for device modelling is unclear.
As the briefing note indicates, a number of device-relevant attributes have already been introduced. These ‘grammatically’ apply to the entire << 260787004 |Physical object| domain but (quite reasonably) are only ‘sensibly’ relevant to a smaller number of device types.
This ‘container’ exercise takes a different approach, introducing new attributes, specifying that they apply to a much narrower domain (plus reorganising the content to conform).
Both approaches (define globally and only use where appropriate (probably by template-level constraints) vs. define locally) are valid, but - at this very early stage in SCT device modelling - there is an opportunity to adopt a single approach and use it consistently. The new proposed attributes (‘has additive’, ‘has separator’ and ‘intended content’) are unlikely only to be applicable to ‘specimen container’ type devices, so will need to be restated (possibly with definition, cardinality and range modifications) as and when they are applied to other device types. By contrast, if they were also specified at the level of ‘physical object’ they could be declared mandatory or profiled out/ignored (using e.g. template specifications) as needed (which is broadly what happens in other parts of the terminology).
If, on the other hand, SI wishes - in the long term - to specify multiple device type domains (of which I imagine there will be many), then there is an opportunity to rework the published attributes now so that we can understand what general design philosophy is planned. We then might reasonably expect (the many) device model specifications to be simultaneously ‘grammatical’ and ‘sensible’ (with considerably less need for template profiling for each device type).
2. The briefing note title refers to ‘changes…to the physical object MRCM…’.
a. sorry to be pedantic, but whilst it is not wrong to say that the MRCM will change, the proposal is a conceptual one - it is the ‘SNOMED CT physical object concept model’ to which the proposed changes would apply. The MRCM is simply a machine readable rendering of certain elements of the ‘concept model’.
b. The ‘Has additive’ attribute proposal names two domains (‘Container’ and ‘Specimen’). As such the briefing note is also a proposal to ‘change the SNOMED CT specimen concept model’ and should be presented as such. It is likely, for example, that the current usage definition for ‘specimen substance’ (“…the type of substance, pharmaceutical/biologic product, or physical object of which a specimen is comprised…”) will need to change in order to exclude ‘specimen additives’ which would be handled by an alternative means).
3. Links
The briefing note contains a number of links beginning “https://nl-authoring.ihtsdotools.org/…”. I am unable to reach the pages they specify. If the content is valuable for reviewing the proposal please could it be made available?
Thanks Ed