Request Expert

BLOOD-WETTED BIOMATERIAL; CARDIOVASCULAR PROSTHESES; ARTIFICIAL INTERNAL ORGANS. Expert has been involved in the design, development, and evaluation of extracorporeal and implantable artificial internal organs for many years, first with the artificial kidney (including hemodialyzers and those based upon selective absorption) and subsequently with many other membrane devices including artificial lungs (blood-gas exchangers), stents, and vascular prostheses. His expertise with respect to these devices involves fluid mechanics, transport phenomena, biocompatibility, and experimental approaches to evaluation. Most recently he has worked with specialized devices for separation of plasma and cells and also with devices to facilitate cellular immunotherapy. He has also developed technologies for separating rare cells (e.g. 1:100,000) from large cell populations.

Expert is familiar with related technologies and scientific areas, particularly from a quantitative and modeling perspective. His technical expertise includes methods for extracorporeal blood access, selection of biomaterials, control of thrombogenesis, and monitoring of equipment performance. His scientific areas include hemorheology, transport phenomena in blood, both homogeneous and heterogeneous reactions in blood (especially those related to cellular adhesion and thrombogenesis), and immunophysical phenomena, especially the interactions of T and B lymphocytes.

PROSTHETIC MATERIAL; BLOOD-COMPATIBLE MATERIAL. Expert has many years of involvement with the evaluation of hemocompatibility of biomaterials, the effects of shear on hemolysis, and other manifestations of cell damage by prosthetic devices. In addition, he also advises the Red Cross and other organizations concerning the processing of blood and other blood products, including blood filtration and the elimination of infectious vectors in transfusible products, especially via photochemical reactions.

GENETIC ENGINEERING. Expert is familiar with quantitative modeling of recombinant and fused cells, downstream processing of hybridoma and recombinant products, especially immunochemical methodolgies. He is involved in the isolation of specific cell types (e.g. fetal cells in the maternal circulation) for diagnostic purposes. He is coordinating a new program in "genomic engineering" at Columbia University.


Expert has expertise in sorption phenomena, which includes the use of materials in vivo and in vitro to remove toxins or rebalance the composition of biological media. He can assist with evaluation of sorption capacity and specificity, biocompatibility, modification of sorbents with membranous coatings, and design of physical containers to control flow, pressure changes, thrombosis, and to minimize mass transfer resistances external to the sorbent. His experience includes both the use of biospecific and generic ligands.

Expert has extensive experience in the engineering, design, and development of blood-wetted devices including conduits (catheters, cannulae, vascular prostheses), implants (recently, in particular, stents), and active devices, especially those involved in the extraction from or release of materials into blood. His experience includes early, laboratory development and in vitro experiments, animal evaluations, and participation in design and evaluation of clinical trials.

Expert's principal experience (please also see his paragraph on "biological engineering") is with blood-wetted devices, both in vivo and ex vivo. His experience includes design, regulatory issues, some aspects of manufacture (including sterilization), and evaluation of experimental results from in vitro, animal, and clinical trials.

Expert has experience in ethylene oxide sterilization which is particularly related to evaluation of ethylene oxide removal after sterilization. He has familiarity with immunological issues associated with inadequate removal of ethylene oxide.

Expert has familiarity with gas transport in blood-gas exchangers, both carbon dioxide and oxygen. He has a strong technical background in mass transfer in blood and through both semipermeable and microporous membranes. He is familiar with oxygenator acoutrements: filters, reservoirs, cannuale, and aspirators. He is able to advise on biomaterial issues. He has conducted research on the deterioration of membrane performance during use due to water intrusion into membrane pores. He has also analyzed flow and shear rate distribution in commercial gas exchangers.

Expert regularly teaches mathematical approaches to predicting and analyzing both spatial and temporal distributions of materials in organisms, organs, and other tissues. He is familar with various controlled-release technologies and tests that establish their efficacy. He is especially strong in relating basic material properties of releasing implants to their performance.

Expert is familiar with both chemically- and biochemically- (immunospecific and other) based sorptive phenomena that either accidentally or intentionally alter the composition of biological fluids. He has extensive experience with spatial and temporal distributions of protein absorption (including the 'Vroman effect') and evaluations of the importance of these phenomena in blood-wetted devices. He has substantial research experience in interaction of cells (especially T lymphocytes) with biological molecules adsorbed on synthetic substrates and artificial lipid layers. (Please also see Expert's pargraph on "absorption.")

Expert has worked with numerous artificial materials exposed to blood. He is familar with (and critical of) in vitro methods for evaluating thromboresistance. He notes that he is not an advocate of a particular type of thromboresistant material. He can evaluate the effects of flow, geometry, and anastomoses on thromboresistance of implants.

Expert notes that his experience is limited to cardiovascular implants, and particularly to issues associated with flow and geometry that define the graft environment, and issues of diffusion into and out of the graft. He is capable of participating the the evaluation of grafts that carry transfected genes, either to alter their performance or to have a systemic effect, although his expertise falls far short of dealing with all issues that these systems raise.

Expert has life-long experience in evaluating the convective and diffusive transport of molecules in biological systems. He is currently writing a textbook for biomedical engineers titled, "Transport and Rate Phenomena in Biological Systems". He is experienced in evaluating transport problems at the organismic, organ, and cellular level.