In human communication it many times is clear what is meant. Of course Cardiac Output = 2 liters / minute means 2 liters of blood and not Oxygen. In both cases the unit is liters of something per period of time; many times for instance: liters / minute or liters / day, etc. We are always tempted to pre-/post-coordinate and make the unit Liters (blood) or liters (O2).
In my SIAMM way of modelling I abstain as much as possible from pre- and post-coorodinated codes. The unit is generically a volume/time period specialised as liters/minute In the archetype the context must make it clear that it is about the Cardiac Output of Blood. In this way, making these choices, the Boundary problem between structure and coding system is avoided. Gerard Freriks +31 620347088 [email protected] Kattensingel 20 2801 CA Gouda the Netherlands > On 5 Sep 2018, at 09:48, David Moner <[email protected]> wrote: > > I agree with Ivar. In fact, UCUM has the unit /min to represent frequencies > without a numerator unit. > > El mié., 5 sept. 2018 a las 9:39, Ivar Yrke (<[email protected] > <mailto:[email protected]>>) escribió: > 1/min, definitely! > > > > Cardiac output is measured as liters/minute. Liters of what? We could have > used the unit liters{blood}/minute, but I have never seen that done. It is > considered obvious from the context. Likewise with other units. Velocity is > measure as meters/second, not meters{travelled}/second. One could argue that > meters{travelled} makes it clear that it is not meters{altitude}, but that is > generally considered obvious from the context. > > > > For some reason there is this temptation to add a fictive unit ({beats}, > {count} etc.) when the number itself is unit less. This is not necessary. The > context is always sufficient, just like in the cases that have a unit. Let us > cut through the unclarity of UCUM and keep it simple and basic. > > > > My argument is probably influenced by my background as a physicist. But if no > one has objected to 1/min in pulse/heartbeat, then I see no reason to deviate > from the basics in ECG or to modify pulse/heartbeat. > > > > Vennlig hilsen > > Ivar Yrke > > Senior systemutvikler > > DIPS AS > Telefon +47 75 59 24 06 > > Mobil +47 90 78 89 33 >
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