[New-ITS] Complexity Measures

[Grahame Grieve]

Thomas Beale wrote:
> Grahame Grieve wrote:
>> so, sticking to time series, for the moment,
>> HL7 already has PIVL<T>. So the idea seems to be
>> that you would reuse this on ActRelationship,
>> and create some kind of PIVL_ACT_RELATIONSHIP
>> which specialises ActRelationship and adds
>> recurrence : PIVL<TS>, and has 1..* target {ordered}.
>>
>> You might need to restructure ActRelationship
>> a little, but this would mean that you had
>> a single act relationship pointing to a sequence
>> of Acts all with the same relationship semantics,
>> differing by their time in an ordered manner.
>>   
> don't forget - what is needed is that at each time point you can have as 
> large a data structure as you want, detailing what was measured at that 
> point. Example is Apgar - 6 data points per time point, or BP, 2 or more 
> items per time point; ECG - 12 values per time point...

well, it points to act- you can't get larger than that ;-)

> Would the structure you suggest be intuitive in a design environment, on 
> the screen etc?

Well, I think that if you are in the RIM world, then
it's intuitive.

>> Where would you use a structure like this in
>> existing HL7 models? I kind of drew a blank
>> except perhaps in clinical Statement? Really
>> it belongs in areas that HL7 hasn't really modeled,
>> in investigative procedure reports (where frequently
>> they are presented as regular but they actually
>> aren't).
>>   
> well, and many lab observations (OGTT an obvious example), and many 
> point of care observations (nearly all vital signs in hospital are 
> time-based), and many others besides (Apgar, orthostatic BP and so on). 
> These are all basic measurements.

yes, this is the area of templates, so HL7 hasn't devoted
much attention to modelling them - nor has CfH, I think

>> It would seem that a more useful pattern was an
>> ActRelationship with more than one target, where
>> there was some ability to mark the target with
>> some arbitrary differentiating information, such
>> as a date, so you could do an irregular series of
>> {investigations, appointments, etc}

> History in openEHR copes with irregular series, and even series of mixed 
> point and interval values. But a "series" of investigations, 
> appointments etc is not a time-series in the scientific measurement 
> sense, it is a sequence of events in social/business time, not a series 
> of measured values of a phenomenon. WHat you are suggesting is no doubt 
> also useful, but is a different thing altogether.

just from working a lab, I know that there's nominal time series, and
the actual sequence of measurement

> But in any case, you seem to be suggesting trying to make some 
> contortions on existing RIM classes to make them perform this simple 
> pattern - it sounds complex already!

I don't think you are being fair here. If you adopt the RIM paradigm,
then I don't think it's sounds as complex as it might to someone
who automatically assumes that the RIM is overly complex

Grahame