Instrumentarium Imaging recently delivered 35 digital Exposcop 8000 "C-arm" x-ray imaging devices to 35 Polish hospitals from its factory in Germany for a contract with the Polish Ministry of Health.   . . .   Digital Descriptor Systems Inc., designer and marketer of digitized imaging systems and biometric identification solutions for the criminal justice and security markets, announced an agreement with privately held AuthenTec Inc. to sell its fingerprint matching system (FMS) to commercial markets. It previously had rights to sell FMS only to criminal justice markets.   . . .   Mark Melliar-Smith, a partner with Austin Ventures, has been appointed to Technitrol's board of directors. Melliar is the former president and CEO of International SEMATECH, a research and development consortium of 13 integrated circuit production companies.