Since 1984 Dirkjan has been involved in the device development, certification project management of 75 (inter)national device companies and regulatory affairs and quality assurance of medical devices. After his PhD, he held positions as (1) manager R&D for a company developing and manufacturing implants and as (2) notified body product review co-ordinator and regulatory auditor. Since 2008, as QA/RA manager / consultant for manufacturers of medical devices, Dirkjan has been responsible for the planning and implementation of quality management systems per EN ISO 13485:2012, EN ISO 13485:2016, Directive 93/42/EEC, Regulation (EU) 2017/745 on medical devices and 21 CFR Part 820. Dirkjan was responsible for, and involved with, the regulatory approvals of product portfolio in the EU and USA
Dirkjan is specialized in the area of biocompatibility, design control, risk management, clinical evaluation, implantable devices, devices based on pharmaceutical technologies and polymeric medical devices.
Dirkjan is co-inventor of device-related patents, was member of Dutch Committee on Standardisation of Biocompatibility and Biological Testing.