PharmPK Discussion - Convolution and Deconvolution techniques to assess Bioavailability.

PharmPK Discussion List Archive Index page
• On 20 Dec 1995 at 13:52:51, "Nishit Modi" (modi.-a-.gene.com) sent the message
`David,Wagner-Nelson is considered a specialized (read limited ?) form ofdeconvolution. Limited to a single compartment analysis with first orderabsorption.  Application of convolution of deconvolution does not requirea compartmental assumption.  Other assumptions do apply.Deconvolution can be used to characterize the absorption profile (andhence assess bioavailability) among other things.  And deconvolutiondoes not require that an intravenous administration to be applied.  Itdepends on the question!Nishit Modi.`
Back to the Top

• On 10 Jan 1996 at 13:09:08, "Steven L. Shafer" (Steven.Shafer.aaa.Forsythe.Stanford.Edu) sent the message
`Dear David:I consider LR and WN as parametric forms of deconvolution. However,I also consider conventional nonlinear regression to be a method ofparametric deconvolution when it is used to identify a dispositionfunction.Best regards,Steve Shafer`
Back to the Top

• On 19 Jan 1996 at 11:14:32, Maria Durisova (exfamadu.at.savba.savba.sk) sent the message
`For  the  linear  dynamic  system  defined  by the weightingfunction  WF(t),  input  function  I(t)  and output functionO(t), the system output can be expressed by Eq.1O(t)=f1(I(t), WF(t)),                              (1)where t represents time.The  function f1  is  the convolutory  integral.The system  weighting function and  the system input  can beexpressed in the form of Eq.2  and Eq.3, respectivelyWF(t)=f2(I(t), O(t))                               (2)I(t)=f3(WF(t), O(t)).                              (3)The  methods  for  determination  of  the  system  weightingfunction  and the  system input   on the  basis of  Eq.2 andEq.3, respectively, are called  deconvolution methods.The  Wagner-Nelson method  enables to  determine the  systeminput I(t) if the mathematical  model of drug elimination isknown and  if the system  output O(t) can  be measured afterextravascular administration.  This method enables  to reachthe  same result  as does  Eq.3 but  it does  not employ theproperties  of  the  convolutory  integral.  It follows thenthat,  in   principle,  the  Wagner-Nelson   method  is  nota deconvolution method.  However, it is obvious  that if theknown  mathematical model  of the  drug elimination  has theweighting function  WF(t), then the same  result is obtainedwhether  the  deconvolution  method  based  on  Eq.3  or theWagner-Nelson method is used.Dedik Ladislav                DEDIK.-a-.KAM1.VM.STUBA.SKDurisova Maria                exfamadu.aaa.savba.sk`
Back to the Top

 Want to post a follow-up message on this topic? If this link does not work with your browser send a follow-up message to PharmPK@lists.ucdenver.edu with "Convolution and Deconvolution techniques to assess Bioavailability." as the subject Support PharmPK by considering my eBooks

Copyright 1995-2014 David W. A. Bourne (david@boomer.org)