Category: Seminars

Seminar: Instrumenting the Human Body

sep22Seminar presentation jointly sponsored by Michigan Technological University’s College of Engineering and the Departments of Biomedical Engineering and Electrical and Computer Engineering
Date: Monday, September 22, 2014; Time: 4:00-5:00 p.m.; Location: M&M U115
Title: Instrumenting the Human Body
Richard B. Brown, Ph.D., Dean of Engineering, University of Utah, Salt Lake City

Abstract: Advances in semiconductor technology are enabling research into, and treatment of, many human diseases. Prof. Brown will present a highly‐integrated, low‐power, wireless, mixed-signal microprocessor that was designed for implantable biomedical applications, and braincomputer interfaces that enable researchers to monitor electrical firing of individual neurons, local field potentials, and chemical signaling in the brain.

Biography: Prof. Brown earned the degrees BS and MS in Electrical Engineering from Brigham Young University. After working in industry for six years, he returned to school at the University of Utah and received the degree PhD in EE in 1985, developing one of the first “smart sensors,” an array of liquid chemical sensors with integrated electronics. Upon graduation, he joined the faculty of the University of Michigan, where he developed their VLSI program and conducted research on circuits (high‐speed, low‐power, high‐temperature, and radiation hard), microprocessors (high‐performance, low‐power, and mixed‐signal), sensors (for ions, heavy metals, and neurotransmitters), and brain‐machine interfaces. At Michigan he held an Arthur F. Thurnau Endowed Professorship. In 2004, he was appointed Dean of the College of Engineering at the University of Utah, where he has continued to do research on circuits, mixed-signal microcontrollers and neural interfaces. Prof. Brown has been a founder with his students of Mobius Microsystems (all‐silicon clock generators), i‐SENS (glucose sensors), Sensicore (water chemistry sensors), and e‐SENS (chemical sensors). He holds 17 patents, has authored more than 225 peer‐reviewed publications, and graduated 30 PhD students.

Richard B. Brown, Ph.D., Dean of Engineering, University of Utah, Salt Lake City presented a seminar at Michigan  Title: Instrumenting the Human Body; Shown here 2nd from left with Michigan Tech faculty, Paul Bergstrom, ECE Chair Daniel Fuhrmann and Saeid Nooshabadi
Richard B. Brown, Ph.D., Dean of Engineering, University of Utah, Salt Lake City presented a seminar at Michigan Title: Instrumenting the Human Body; Shown here 2nd from left with Michigan Tech faculty, Paul Bergstrom, ECE Chair Daniel Fuhrmann and Saeid Nooshabadi

Seminar: Vascularized Bone Grafts for Craniofacial Regeneration

sep5Biomedical Engineering Graduate Seminar: Warren Grayson, Ph.D. Assistant Professor, Biomedical Engineering, Johns Hopkins University; Friday, September 5 – 138 Fisher at 10:00 a.m.

Title: Vascularized Bone Grafts for Craniofacial Regeneration

The treatment of large bone loss due to congenital defects, trauma or cancer resection remains a huge clini-cal challenge. There are approximately one million fractures requiring bone transplantation annually in the US and it is predicted that within the next 10 years this number will significantly increase, particularly in per-sons over 50 years of age. Tissue engineering provides a viable means of obtaining ‘autologous’ bone grafts for the treatment of large bone defects. Successful application of tissue-engineered grafts however requires that we can couple the formation of de novo vasculature in tandem with new bone growth. Our lab has investigated methods for cultivating anatomically-shaped bone grafts in bioreactors and pre-vascularizing these grafts via co-culture techniques. More recent studies have examined the use of adipose-derived stem cells (ASCs) to engineer vascularized bone grafts that can be used to repair craniofacial de-fects. We have found that heterotypic interaction among endothelial and non-endothelial sub-populations mediate by growth factor effects can choreograph the formation of complex tissue grafts. These findings suggest the tremendous potential for using ASCs in concert with engineering techniques to provide clinically relevant vascularized bone grafts for the repair and regeneration of craniofacial bone loss.

This seminar is partially funded by the Visiting Women & Minority Lecturer/Scholar Series which is funded by the President’s Office and a grant to the Office of Institutional equity from the State of Michigan’s King-Chavez-Parks Initiative

Biomedical Engineering Graduate Seminar

Biomedical Engineering Graduate Seminar: Dr. Monica Hinds, Associate Professor, Department of Biomedical Engineering, Oregon Health & Science University; Friday, 4/18 at 3:00 in U113 M&M

Title: Endothelialization of Vascular Biomaterials

In developing blood-contacting vascular biomaterials, a confluent endothelial cell (EC) monolayer may be required to avoid adverse blood reactions. In vitro, the hemostatic properties (“thrombogenicity”) of ECs have typically been char-acterized using anticoagulated blood, static or non-physiologic flow conditions, and short blood exposure times. Con-sequently, the relevance of these findings for in vivo applications remains uncertain. Moreover, there have been few studies of the reactivity of EC constructs in vivo, and no studies have been reported that systematically relate the in vitro properties of endothelialized surfaces with their responses in vivo. Accordingly, it is now recognized within the tissue engineering community that a key impediment to further progress towards applications in man is the lack of predictive animal models that will enable the rational design of cellular constructs. We are characterizing the in vitro and ex vivo pro-hemostatic and anti-hemostatic properties of ECs (that can affect platelets and coagulation), and im-portant in vivo responses of thrombosis and vascular healing in a physically relevant primate model. Endothelial out-growth cells (EOCs), isolated from the circulating endothelial progenitor cells of baboons, have been seeded on pro-tein-coated ePTFE vascular grafts. We have studied the role of extracellular matrix coatings and hemodynamic pre-conditioning on the EOC phenotype, particularly related to coagulation and inflammation. Subsequently, in an ex vivo baboon shunt model, platelet and fibrin accumulation were measured under conditions of controlled, native blood flow. Finally, the endothelialized vascular grafts were implanted as aorto-iliac interposition grafts for 28 days. After a thorough evaluation of potential correlations, a linear regression model using in vitro data was established to predict platelet accumulation. This regression correlated significantly and strongly to both ex vivo platelet and in vivo intimal hyperplasia data. This is the first work of this type—attempting to determine predictors for vascular graft performance from in vitro endothelial markers, and while future work should examine the scope of the model by applying it to other endothelialized grafts, we are encouraged by these results, which may aid in improving translation of small diameter vascular grafts into clinical improvements.

This seminar is partially funded by the Visiting Women & Minority Lecturer/Scholar Series which is funded by the President’s Office and a grant to the Office of Institutional equity from the State of Michigan’s King-Chavez-Parks Initiative

Biomedical Engineering Graduate Seminar: Magnesium-Neodymium Alloys for Biomedical Applications

Biomedical Engineering Graduate Seminar:
Dr. Jan-Marten Seitz, Institut für Werkstoffkunde, Leibniz Universität Hannover, Garbsen, Germany
Friday, April 4 at 3:00 in U113 M&M

Title: “Development and Characterization of Magnesium-Neodymium Alloys for Biomedical Applications”
The aim of the presented study is to investigate and demonstrate the potential of neodymium additions as a substitute for rare earth (RE) misch-metal in magnesium alloys for biomedical applications. Here, the alloys LAE442, LANd442, ZEK100, ZNdK100, and Nd2 were manufactured and processed to evaluate their material characteristics in different states and to investigate the effects of Nd additions. To determine the mechanical characteristics of these alloys, tensile tests were initially carried out in the hot extruded state. Subsequent T5- and T6-heat treatments were con-ducted to reveal their effect on the alloys’ strength and elongation values. The general degradation behavior of the alloys in a 0.9% NaCl solution was investigated by means of polarization curves and hydrogen evolution. In addition, by using various in-vivo-parameters, a corrosion environ-ment was established to determine the alloys’ degradation in vitro. Comparing LAE442 and LANd442, a lack of corrosive stability could be ob-served while the mechanical strength remained constant in the latter alloy’s Nd substitution for the RE mischmetal. A contrary effect was deter-mined for the alloy ZEK100 compared with ZNdK100. In both substitutional approaches, heat treatment procedures could not align the substi-tutes’ material properties with the educts’ material properties. However, in the case of Nd2, which was initially chosen as relevant alloy to deter-mine the effects of Nd on Mg in a simple binary composition, excellent ductility and corrosion properties could be observed. This makes the alloy a promising candidate for use as resorbable implant material, especially in the field of stenting applications. Here, the enormous increase of duc-tility, promoted by an advantageous microstructural behavior under loadings, could be attributed to additions of Nd.

Biography: Within the past 5 years, Dr. Seitz has worked as a PhD Student and Scientist at Leibniz Universität in Hannover, Germany, with a focus on lightweight materials research and biomedical engineering applications. He developed process chains for resorbable Mg-implant applications such as stents, intramedullary nails, and sutures. This work included basic processes such as casting, hot-extrusion, heat treatment, drawing and coating procedures, as well as many analytical processes. The impact of different alloying elements on the mechanical and corrosive behavior of Mg in different conditions was one of the biggest challenges in this context. Besides the development of promising biodegradable Mg alloys, he also worked on the manufacture of thin wires from magnesium by means of extrusion and drawing processes. During an overseas stay at The University of Auckland, he developed polymer and ceramic based coatings for medical applications with magnesium and analyzed their structural behavior in a corrosive environment.

Biomedical Engineering Seminar: Slow Potentials of the Sensorimotor Cortex During Rhythmic Movements of the Ankle

Biomedical Engineering Seminar:
Name: Ryan J. McKindles, doctoral candidate in Biomedical Engineering from Marquette University; Date: Friday, October 25 at 3:00 in U113 M&M
Title: “Slow Potentials of the Sensorimotor Cortex During Rhythmic Movements of the Ankle”

The objective of this research was to more fully understand the role of the human brain in the production of lower ex-tremity rhythmic movements. Throughout the last century, evidence from animal models has demonstrated that spinal reflexes and networks alone are sufficient to propagate ambulation. However, observations after neural trauma, such as a spinal cord injury, demonstrate that humans require supraspinal drive to facilitate locomotion. To investigate the unique nature of lower extremity rhythmic movements, electroencephalography was used to record neural signals from the sensorimotor cortex during three cyclic ankle movement experiments. First, we characterized the differences in slow movement-related cortical potentials during rhythmic and discrete movements. During the experiment, motion analysis and electromyography were used characterize lower leg kinematics and muscle activation patterns. Second, a custom robotic device was built to assist in passive and active ankle movements. These movement conditions were used to examine the sensory and motor cortical contributions to rhythmic ankle movement. Lastly, we explored the differences in sensory and motor contributions to bilateral, rhythmic ankle movements. Experimental results from all three studies suggest that the brain is continuously involved in rhythmic movements of the lower extremities. We ob-served temporal characteristics of the cortical slow potentials that were time-locked to the movement. The amplitude of these potentials, localized over the sensorimotor cortex, revealed a reduction in neural activity during rhythmic movements when compared to discrete movements. Moreover, unilateral ankle movements produced unique sensory potentials that tracked the position of the movement and motor potentials that were only present during active dorsi-flexion. In addition, the spatiotemporal patterns of slow potentials during bilateral ankle movements suggest similar cortical mechanisms for both unilateral and bilateral movement. Lastly, beta frequency modulations were correlated to the movement-related slow potentials within medial sensorimotor cortex, which may indicate they are of similar cortical origin. From these results, we concluded that the brain is continuously involved in the production of lower extremity rhythmic movements, and that the sensory and motor cortices provide unique contributions to both unilateral and bilat-eral movement.

Ryan McKindles is a 2006 Biomedical Engineering graduate from Michigan Tech.

Biomedical Engineering Seminar: Histotripsy for non-invasive liver cancer ablation

The Department of Biomedical Engineering presents Eli Vlaisavljevich, NSF Fellow in Biomedical Engineering, University of Michigan; Monday, October 21 – 4:00 pm in 129 Fisher;

Title: Histotripsy for non-invasive liver cancer ablation
and Students Perspective on Graduate School and Research

Abstract: Hepatocellular carcinoma (HCC) or liver cancer is one of the fastest growing cancers in the United States. Liver transplantation and surgical resection of liver tumors are proven treatment options but are associated with high rates of morbidity and mortality. Further, surgical resection or transplantation is not possible in many cases such as patients with decompensated cirrhosis. Current liver ablation methods are primarily thermal-based and share limitations due to the heat sink effect from blood flow through the highly vascular liver such as ineffective abla-tion near major vessels and unrealistic treatment times for larger tumors. We are developing histotripsy for the non-invasive treatment of liver cancer. Histotripsy is a non-thermal ultrasonic ablation method that fractionates tissue through the precise control of acoustic cavitation. Since histotripsy is non-thermal, it is not affected by the heat sink effect from blood vessels and does not share the limitations associated with thermal ablation methods. We are cur-rently working to develop histotripsy as a non-invasive liver cancer ablation technique capable of selectively ablating liver tumors while preserving the healthy tissue and major hepatic vessels surrounding the tumors.

Biography: Eli Vlaisavljevich graduated from Michigan Tech University in 2010 with a B.S. in Biomedical Engineering and is a currently pursuing his Ph.D in Biomedical Engineering at the University of Michigan. In addition to his research presentation, Eli will also give a brief overview of his experience in Ann Arbor and provide some information about graduate opportunities at the University of Michigan.

Biomedical Engineering Graduate Seminar: Optical Coherence Tomography

The Department of Biomedical Engineering presents Xuan Liu, PhD, Assistant Professor, Department of Biomedical Engineering, Michigan Technological University; Friday, October 11 – 3:00 pm in U113 M&M Building

Title: Smarter Optical Coherence Tomography for Biomedical Applications

Optical coherence tomography (OCT) is a three-dimensional, high speed, high resolution imaging modality with a broad range of biomedical applications. For example, OCT has become a standard diagnostic device in clinical ophthalmology. Besides diagnosis, OCT also has great potential in surgical guidance. A miniature OCT probe based on fiber-optic components can be integrated with a conventional surgical instrument for hand-held scanning. Such small, light-weight OCT probe can offer surgeon with freedom to access imaging sites of interest with large field of view in limited space and thus provide real-time intraoperative imaging and sensing capability to enhance surgical outcome. In the past few years, my research focus has been the development of a hand-held OCT system for intraoperative applications. In this presentation, I will show a few examples of our research efforts for the development of intraoperative hand-held OCT. With my extensive experience in using OCT to interrogate various properties (physical/chemical) of specimen and processing the obtained information with sophisticated algorithm at a high speed, I plan to develop smarter OCT systems for biomedical applications here at Michigan Tech.

Biography: Dr. Liu received her B.S. and M.S. degrees from Tsinghua University, Beijing, China. She started to study in the Johns Hopkins University since 2007 and received her Ph.D degree in 2011. Before joining the faculty of Michigan Tech, Dr. Liu worked as post-doctoral fellow in the Johns Hopkins University.

BME Graduate Seminar: Biomechanical Behaviour

BME Graduate Seminar; Dr. Ray Vanderby, Department of Orthopedics and Rehabilitation, University of Wisconsin School of Medicine
Time: 3:00, Friday, September 27 in U113 M&M

Title: A Method to Quantify Biomechanical Behaviour in Soft TIssues

Computational and in vitro studies of softs tissues provide insight into functional behavior and demonstrate the intrinsic value of mechanical metrics. Methodological limitations, however, make in vivo data more challenging to gather and hence, rarely used clinically. Acoustoelastic (AE) analysis of ultrasound data has shown promise for providing in vivo mechanical data. AE studies analyze the changing ultrasound echoes in a loaded tissue and compute tissue stiffness from the AE equations. Using tendons as an example, this seminar will discuss how this concept can be implemented with standard ultrasound systems to characterize local tissue pathologies and mechanical compromise. Results provide localized tissue stress, strain, and stiffness from ultrasound echo intensities. We demonstrate our method on tendinopathy regions in human Achilles tendons and other examples under current investigation. Comparative local stiffnesses (normal versus tendinopathic) indicate the degree of mechanical compromise in the pathological region. Within limits of resolution and modeling assumptions, these data can quantify structural compromise and monitor functional healing in pathological tendons.

Lecture: New Frontiers in the Pharmaceutical and Medical Sciences

College of Engineering Distinguished Speakers Series: “New Frontiers in the Pharmaceutical and Medical Sciences: Advanced Intelligent Hydrogels for Treatment of Diabetes, Cancer and Multiple Sclerosis” Nicholas A. Peppas, Sc.D.
Fletcher Stuckey Pratt Chair in Engineering, Professor of Biomedical Engineering, Chemical Engineering and Pharmacy, Chairman, Biomedical Engineering Department, Director of Center on Biomaterials, Drug Delivery, and Bionanotechnology, The University of Texas at Austin; Thursday, March 7 at 4 pm—Great Lakes Research Center Room 202
More details

Video of Nicholas A. Peppas Lecture “New Frontiers in the Pharmaceutical and Medical Sciences” on Michigan Tech Engineering Channel on Vimeo