Coding for Hybrid III String Pot Chest

[dparent]

Greetings,

I'm writing to request additional codes, but I'm not sure what would be best. Here's the scenario...

There are variants of the 50th male and 5th female Hybrid III dummy with a "string pot chest", which measures the displacement of four locations on the anterior rib cage relative to the spine. To measure these four quadrants (upper left, upper right, lower left, lower right), there are eight string pots mounted to the spine. For each location, two string pots are attached to the rib at the anterior location and attached to opposite sides of the spine at the posterior location. So, each location has a "straight" (e.g. left rib to left of spine) and "cross" (e.g. left rib to right of spine) string pot.

In case it helps, I'm attaching a diagram that shows a cross-section of the dummy's chest looking down.

For the "straight" channels, these correspond to the X-axis of the dummy, so the codes might be: ??CHSTLEUPH3DSXP, ??CHSTLELOH3DSXP, ??CHSTRIUPH3DSXP, ??CHSTRILOH3DSXP

However, for the "cross" channels, these do not correspond to the Y-axis of the dummy, so setting the axis character to "Y" would be misleading. In this case, would it be best to add a new axis designation ("C" for "cross"), or to use "LL/LU/RL/RU" as FL1 and add maybe "CR" for FL2?

Thanks for your assistance!

- Dan

[DiVe]

Hi Dan,
I would like to share my thoughts on the new measurement.

I would fully agree to your proposal for the straight measurements:
??CHSTLEUPH3DSXP, ??CHSTLELOH3DSXP, ??CHSTRIUPH3DSXP, ??CHSTRILOH3DSXP

For the cross or transverse measurements I would stay with these codings but modify the measurement direction. In principle the ISO Code should describe the location of the sensor.
So I would choose the side from the string pot location (pot on the right side of the spine -> RI;pot on the left side of the spine -> LE).
The coding then could be
??CHSTLEUPH3DSCP, ??CHSTLELOH3DSCP, ??CHSTRIUPH3DSCP, ??CHSTRILOH3DSCP

My concern for the cross or across string pots is that the "C" might look very similar to the available "0" in the coding. So an alternative could be to use "T" for transverse.
??CHSTLEUPH3DSTP, ??CHSTLELOH3DSTP, ??CHSTRIUPH3DSTP, ??CHSTRILOH3DSTP

You as a native speaker might decide better if transverse is a good selection here.

Kind regards,
Dirk

[dparent]

Dirk,

Thanks for the quick response. I see your point that "C" might look like "0" - however, I don't think this is an issue because as long as it differentiates from "X" or "Y" then it's clear to the user that the measurement is not in a defined anatomical direction. For the same reason, "T" would also be an appropriate option, so using either "C" or "T" as the measurement direction would work just fine. So, I'll leave this distinction up to the experts!

Thanks,

- Dan

[DiVe]

Dear Dan,
we discussed your request on our recent task Force meeting. Actually we realized that several new alternative for multipoint chest deflection measurement are discussed (Rib Eye, IRTRACC). As we suggest that the string pot variant is one more possible candidate for a future intrumentation for this measurement, we would like to not include a new coding in the official database at this point. Nevertheless we see no problem if you code the direction of your measurements with a special coding ( like "C" or "T"). On the other hand in many applications the people use the "0" if the X,Y,Z is not applicable.

We also discussed about the Main Location coding for your purpose. We suggest that the measurement taken by the string pots is converted to the "real" X and Y displacements at the various measurement locations (end points on the ribs).
Therefore it might be helpful to code the string pot measurements according to their end points on the ribs like:
??RIBSLEUPH3DSXP and ??RIBSLEUPH3DS0P
??RIBSLELOH3DSXP and ??RIBSLELOH3DS0P
??RIBSRIUPH3DSXP and ??RIBSRIUPH3DS0P
??RIBSRILOH3DSXP and ??RIBSRILOH3DS0P

And then after the calculation express the calculated Chest Deflection with "CHST" as Main Location:
??CHSTLEUPH3DSX? and ??CHSTLEUPH3DSY?
??CHSTLELOH3DSX? and ??CHSTLELOH3DSY?
??CHSTRIUPH3DSX? and ??CHSTRIUPH3DSY?
??CHSTRILOH3DSX? and ??CHSTRILOH3DSY?
(I left the filtering open her, as I am not sure about your processing).

Please keep us updated on your development so we can prepare official codes betimes.
Kind regards,
Dirk

[derpmann]

Dear Dan,

please see http://www.iso-mme.org/forum/viewforum.php?f=122 !

Regards

Peter