Dr. John Lang
Convener, ISO/TC194/WG14
Smith & Nephew Group Research Center
York Science Park
Heslington, York YO1 5DF
UK                                                   February 27, 1997


Dear Dr. Lang,

Thank you for sending a draft document of MATERIAL CHARACTERIZATION.  
We members of the domestic committee for TC194 discussed the aim of WG14 
including the BSI proposal.  
The following is our consensus for WG14 obtained in the discussion:

(1)  We find the process named "MATERIAL CHARACTERIZATION" in a Flow Chart 
     Annex C of ISO 10993-1.  The aim of the process is to answer the 
     question "Is material same as in an existing commercially available 
     device ?", we read so in the chart.  
     In the reviewing process of premarketing approval of medical devices 
     in Japan,  it is very important to identify whether the materials 
     used in a device are same as in the approved devices of similar 
     clinical use, too.

(2)  We think, for the purpose above, we need the data set sufficient 
     for identifying or specifying material rather than the detailed 
     methods of chemical, physical and mechanical characterization of 
     material. 

(3)  Therefore, we propose to standardize DATA SET FOR IDENTIFYING MATERIAL 
     first.

I attached a format of MATERIAL MASTER FILE that is under discussion for the 
purpose of  filing the existing materials used in the approved devices 
in Japan.  
Also I have heard that FDA has a similar plan for preparing 
IMPLANT MATERIALS/DEVICES COMPENDIUM DATA SHEET.  

(4)  Therefore, we think it appropriate to consider 
     EXISTING MATERIALS DATABASE.

                                                 Yours sincerely,



                                                 Akitada Nakamura, Ph.D.
cc/ Donald Marlowe (FDA/CDRH)
Encl.