Dr. David Schaafsma, PhD has over 25 years of experience in Optical Systems, Microscopy, Fluorescence & Spectroscopy, Optical Materials, Lasers, Optoelectronics, Sensors, and Data Acquisition. Dr. Schaafsma specializes in multi-disciplinary projects primarily for the medical device field, involving optics, electronics, software, and sensors. He has worked in diverse areas such as semiconductor manufacture, telecommunications, and biotechnology. Dr. Schaafsma has been offering expert witness services for over 10 years. He has been retained as an expert in several areas of expertise, from angioplasty catheters to retinography cameras to optical microscopes of various stripes. Dr. Schaafsma is available for consulting, testing, analysis, inspection, reports (opinion), deposition, and trial testimony.
"Experts.com is proud to announce its new member Dr. David Schaafsma. With over 25 years of experience in Optical Technology, Dr. Schaafsma is available as an expert witness and consultant in matters relating to optical engineering intellectual property patent dispute, medical device personal injury, and product performance loss of business issues. "
Software Engineer Architect Expert Witness Howard Cohen
Howard J. Cohen, PhD, has over 30 years of experience in Software Engineering, Architecture and Implementation. He possesses particular expertise in Algorithms, Relational Databases, Graphical User Interfaces (GUIs) and Software Applications in general. His experience has been in a broad spectrum of technology, in several languages, in a wide variety of applications, and on multiple platforms. Dr. Cohen's background includes Electronic Design Automation, Bioinformatics, Digital Cartography, Banking Systems for Foreign Exchange Traders, and many more. He is the co-inventor on approximately 120 patents.
Dr. Cohen has over 15 years of experience as an Expert Witness. He possesses excellent written and verbal communications skills, including the ability to express himself well in interpersonal contacts, make presentations to large audiences, explain complex concepts clearly, and write well on levels ranging from the scientific to end user documentation. He is available to analyze complex systems, to write clearly about technical issues, and communicate face-to-face in a manner appropriate for any audience to understand the issues, the technology and the point of view. Dr. Cohen has been deposed and testified at arbitration hearings and in Federal Court.
Dr. David W. Riley is an Extrusion Analysis & Plastics Rheological Consultant. Dr. Riley has spent over nineteen years as a consultant in the field of Plastic Processing. He has over forty years of experience in developing Polymer Defect Technology and fifteen years in developing the field of Plastic and Polymer coefficient of friction related to the feed section of the extruder.
Areas of Expertise:
Analytical Instrumentation Adaptation to Processing Equipment
Extrusion Equipment: Design & Analysis of Production
Expert Witness – Patent infringement (intellectual property all categories)
Expert Witness – Medical physics, supervision of (medical physicist, dosimetrist, radiation therapist, radiologic technologist)
Expert Witness - Termination of employment
Michael S. Gossman, M.S., DABR, FAAPM, is a Board Certified Qualified Expert Medical Physicist, an honorary Fellow of the American Association of Physicists in Medicine (AAPM), and the Chief Medical Physicist & Radiation Safety Officer (RSO) in Radiation Oncology at a clinic in Indiana. Chief Gossman is directly and ultimately responsible for all technical and scientific aspects of cancer treatment. He directly supervises and oversees efforts from staff medical physicists, dosimetrists, radiation therapists and x-ray technologists.
Chief Gossman is the highest ranking scientist in medicine and has been in the field for 24 years. Chief Gossman's expertise involves the safe, effective and precise delivery of radiation to achieve the therapeutic result prescribed in patient care by radiation oncologists striving to treat cancer patients with particle accelerators and radioactive material.
Extra-professionally, Chief Gossman is retired as the Interim Editor-in-Chief and Editorial Board Member for the Medical Dosimetry Journal, Editorial Board Member for the Journal of Applied Clinical Medical Physics, served four years as a Medical Consultant to the U.S. Nuclear Regulatory Commission, and was a veteran Accreditation Site Reviewer for both theAmerican College of Radiology (ACR) and the American College of Radiation Oncology (ACRO). He was a 2-term Ohio River Valley Chapter President of the AAPM, and was also formerly a Graduate School Professor of Clinical Medical Physics at Wright State University.
As an expert in radiation safety, dosimetry, detector measurements, particle accelerator and radioactive material calibrations, and radioactive material handling, Chief Gossman is a highly respected medical physicist by medical physicists nationally. He is also the owner of Regulation Directive Medical Physics, which he created as a consulting company, providing services for medical physics, dosimetry, medical device testing, and expert witness efforts.
Medical expert witness
Review of: medical event, malpractice, and misadministration
Investigation and audits
Independent medical evaluation of the probable deterministic effects of radiation exposures
Facility practice vs. standards review
Accelerator acceptance testing & commissioning
Peer review of the Chief Medical Physicist
Calibration of medical accelerators
Calculation of time and dose for treatment
Handling, shipping, receiving, and storing radioactive material
Calibrating radioactive material
Interpretation of bioassay results and other data related to radiation exposure
Calculation of internal and external radiation doses, as necessary
Cochlear implants, via direct electrical stimulation of the auditory nerve, allow the restoration of hearing and speech recognition in both adults and children having sensorineural deafness. These devices typically contain both extemal components (speech processor, microphone, transmitter) and intemal components (including the cochlear stimulator and electrode array), which are surgically placed under the skin behind the ear and in the cochlea.
Inadequate research exists regarding testing of a ventricular assist device (VAD) for susceptibility to radiation damage. Specifically, minimal data are available to radiation oncologists prescribing treatment plans for patients with an implanted VAD. As the number of implanted devices increases, patients requiring radiation at tissue sites near or at the device will increase.
Abstract. Object: Where no society-based or manufacturer guidance on radiation limits to neuromodulation devices is available, this research provides the groundwork for neurosurgeons and radiation oncologists who rely on the computerized treatment plan clinically for cancer patients.
Abstract-The medical community is advocating for progressive improvement in the design of implantable cardioverter-defibrillators and implantable pacemakers to accommodate elevations in dose limitation criteria.
Since the first commercial multichannel cochlear implant was marketed by Cochlear in 1985 (1), use of the device has grown exponentially. As of mid-2010, more than 188,000 people worldwide have received a cochlear implant system (2). Recent developments in the manufacturing of cochlear implants by the market leader, Cochlear Limited (based in Australia), have resulted in an aim to provide electronically stable models (3).
Abstract -- In order to determine a mouse's dose accurately and prior to engaging in live mouse radiobiological research, a tissue-equivalent tumor-bearing phantom mouse was constructed and bored to accommodate detectors. Comparisons were made among four different types of radiation detectors, each inserted into the mouse phantom for radiation measurement under a 6 MV linear accelerator beam.
As promulgated by the Nuclear Regulatory Commission, packaging regulations for radioactive material are confusing (e.g., “activity” vs “contained” activity vs “total” activity). As a consequence, medical physicists are forced to secondguess the intent of the regulations.
Recent improvements to the functionality and stability of implantable pacemakers and cardioverter-defibrillators involve changes that include efficient battery power consumption and radiation hardened electrical circuits. Manufacturers have also pursued MRI-compatibility for these devices
Vascular access ports are used widely in the administering of drugs for radiation oncology patients. Their dosimetric effect on radiation therapy delivery in photon beams has not been rigorously established. In this work, the effects on external beam fields when any of a variety of vascular access ports were included in the path of a high energy beam are studied. This study specifically identifies sidescatter and backscatter consequences as well as attenuation effects.
Authors: Todd Pawlicki, et al; Editors; Michael Gossman (Ch. 19), et al
This comprehensive work highlights benefits of quality techniques, approaches to implementation, and guidelines for specific quality assurance steps related to equipment and procedures used in radiotherapy. After an overview of manufacturing and engineering techniques, the text addresses quality and safety issues in radiotherapy from both the physician and physicist viewpoints.