Since I have planned a multidisciplined symposium on ESP-Technical,Medical and Business English, I would like to invite your suggestion on topics specified
It is better you develop your own ESP course based upon your context and level. There are two good books ESP by Hutchinson and Waters and Developments in ESP by Dudley-Evans and John. You may like to refer to TESOL Quality Audit Framework: Benchmarking for Curriculum Improvement by Jawaid, A. especially chapters 6 and 7. I hope it helps!
For both medical and technical English: The role of specialist vocabulary in curriculum design. This article (though about Engineering English) may give you some ideas: http://www.u.arizona.edu/~karaj/pages/Reviews/Mudraya2006.pdf
For medical English I think you need to specify for whom (e.g. doctors versus nurses versus administrative staff). For doctors (especially general practitioners) using English two crucial issues are: a) asking effective questions (when interacting with patients and diagnosing) and b) building a relationship with the patient (showing care/empathy) through English.