Mr. Been (Humanetics) presented document GTR9-1-08 on the status of the FlexPLI development. He mentioned that slight changes have already been made to the presentation and that a revised version will be shared (document GTR9-1-08r1).

Mr. Been concluded his presentation stating that Humanetics is working to find a final solution to meet both certification procedures – especially the inverse test corridors are not always met – with the same FlexPLI assembly. Mr. Been finally requested all attendees of the IG GTR9-PH2 to support Humanetics with providing test capacity and legforms that have already been delivered to the customers.

Mr. Zander (BASt) wondered why issues only occur with the inverse test but are not seen with the pendulum test. Mr. Been replied that there were further changes to the bone core material (change from polyester to vinyl ester material), to the rubber layers in front of the tibia (elongated to the full length of the tibia) as well as to the assembly of the rubber parts holding the tibia and femur segments on the bone core. These changes may affect the performance. In addition, the corridors had been defined with prototypes assembled with the old bone core material, using only three impactors for the inverse test procedure. Mr. Zander replied that, however, the changed properties of the impactors had already been considered within the activities of the TEG and that serial production legs previously had issues with both, the pendulum as well as the inverse certification test. In addition, for defining the inverse test corridors three legforms had been tested in two labs while just two impactors were tested in one lab for definition of the pendulum corridors. So, for him further deviations are hard to understand.

Mr. Kolb wondered what will happen if an impactor does not meet the pendulum test requirements already after its final assembly. Mr. Been responded was not aware of related issues. As worst case, Humanetics would need to disassemble and reassemble the impactor, maybe replacing parts for the impactor.

Mr. Knotz (Concept Technologies) asked how it is assured that the overall impactor assembly still meets all criteria when just one single part (specifically one bone part) is replaced. Mr. Been answered that replacing parts is common and that also other dummy assemblies have to be regularly certified. Mr. Knotz however wondered whether it influences the final performance of the impactor. Mr. Been said that there should not be a risk with this but customers can double check the re-assembled legform at their test lab to assure that the performance is still okay. Customers would be able to directly compare the performance before and after any modification. Dr. Konosu added that according to the experience collected in Japan there also are no issues with replacement of the bones and the impactor performance after this.

Mr. Bilkhu (OICA) asked whether there are experiences with the glass fiber material on how many scratches, how many wear marks can be accepted until the bone core needs to be replaced. Mr. Been pointed to the presentation announced for agenda item 9.1 that may provide some answers for this. Later, Mr. Bilkhu also wondered whether the production process due to machining could also influence the performance of the bone core material (or the impactor respectively) but this is not seen by Humanetics.

Some further discussion came up on the build levels of the impactors. Mr. Hohmann (OICA) as well Dr. Ries (OICA) wondered whether all impactors have the same build level: According to the document TEG-138 it was distinguished between FlexPLI’s produced “before” and “after” April 2010 when comparing the certification test results. Mr. Been replied that besides the prototypes all legforms were equipped with bone cores made of vinyl ester and therefore should have the same performance. The only difference was the kind of data acquisition system used including the number of channels. However, he also noted that the bone core material from the 22 currently available serial production legforms was taken from four different batches.

The secretary Mr. Kinsky reminded the group that Humanetics had supplied for an earlier meeting of the former Technical Evaluation Group (TEG) a table with all modifications to the legform that were brought in during the production. This table mentions amongst others the change of the glue to affix the strain gauges as a possible source of major deviations. Mr. Been will double check this together with his colleagues. The document mentioned above will be added to the documentation of this meeting as document GTR9-1-10.

According to the explanation of the chair, detailed information on the current build level of impactors will provide evidence to the participants of the IG and the user of the impactor.

This information is also needed and important to be known as the tests planned within this informal group in future shall be performed with several impactors of the same build level.

The discussion was finally concluded for the time being with the request to Humanetics to provide detailed information regarding the build level of the individual impactors produced. Humanetics will prepare this information.

Mr. Yamakawa (OICA) asked whether there are issues with the recyclability of the FlexPLI since this was on the agenda during the last WP.29 session to be a potential problem for the WorldSID dummy (also produced by Humanetics). Mr. Been answered that this is a specific WorldSID issue since one of the components contains mercury. He can of course not guarantee that the environmental friendliness is not an issue in 10 years or so but currently no problems are seen by Humanetics for the materials used for producing the flexible legform impactor.