Tag: Spring 2015

MSE and BME Seminar: Biomaterial design to interrupt pathological tissue remodeling processes

Tuesday, April 28, 2015
1:15 pm – 2:15 pm
Room U113, M&M Building

Biomaterial design to interrupt pathological tissue remodeling

John & Virginia Towers Distinguished Lecture Series

Prof. William R. Wagner
University of Pittsburgh

William Wagner Abstract April 28, 2015

Tissue remodeling occurs in disease and following trauma, often yielding results that are dysfunctional and which may ultimately progress towards tissue failure. In the case of mechanically active soft tissues, the mechanical environment in which the damaged tissue heals impacts the direction and outcome of the remodeling process. To develop biomaterial-based approaches to improve soft tissue repair we have created degradable supports that act as scaffolds for new tissue generation or as temporary load bearing elements during the remodeling process.

Efforts have been directed at the adverse ventricular remodeling process that occurs following myocardial infarction resulting in dilated ischemic cardiomyopathy, and the remodeling of veins used in arterial grafting and tissue engineered blood vessel development. Two general types of supporting biomaterials have been developed and tested in at least one of these settings. In the first approach thermoplastic elastomers, typified by poly(ester urethane)urea, have been synthesized and processed to form microporous elastic patches or wraps. Molecular design parameters can be selected to tune mechanical and degradation properties. In the processing steps, composites with natural materials, such as extracellular matrix digests and components, have been generated. A second approach has focused on the development of thermoresponsive, injectable copolymers that “set up” quickly in situ to provide mechanical support to tissues under load, but then degrade to become soluble over time. The application of these materials in vivo has been shown to alter remodeling patterns and to facilitate tissue generation with associated functional improvements.

Biography: Dr. William R. Wagner is the Director of the McGowan Institute for Regenerative Medicine and a Professor of Surgery, Bioengineering and Chemical Engineering at the University of Pittsburgh. He also serves as Scientific Director of the NSF Engineering Research Center on “Revolutionizing Metallic Biomaterials” and Chief Science Officer for the Armed Forces Institute of Regenerative Medicine. He holds a B.S. (Johns Hopkins Univ.) and Ph.D. (Univ. of Texas) in Chemical Engineering. Professor Wagner is the Founding Editor and Editor-in-Chief of one of the leading biomaterials journals, Acta Biomaterialia, and is a past-president of the American Society for Artificial Internal Organs (ASAIO). Currently he serves as Chairman for the Tissue Engineering and Regenerative Medicine International Society (TERMIS), Americas region. He is a fellow and former vice president of the American Institute for Medical and Biological Engineering and has also been elected a fellow of the Biomedical Engineering Society, the International Union of Societies for Biomaterials Science and Engineering, and the American Heart Association. In 2006 he was selected to the “Scientific American 50”, the magazine’s annual list recognizing leaders in science and technology from the research, business and policy fields. His research has generated numerous patents and patent filings that have resulted in licensing activity, the formation of a company that is currently engaged in clinical trials, and University of Pittsburgh Innovator Awards in 2007, 2008, 2009, 2010 and 2014. In recent years he has been awarded the Society for Biomaterials Clemson Award for Applied Research, the Chancellor’s Distinguished Research Award by the University of Pittsburgh, and the Senior Investigator Award by TERMIS-Americas. Dr. Wagner’s research interests are generally in the area of cardiovascular engineering with projects that address medical device biocompatibility and design, tissue engineering, and targeted imaging.

Biomedical Engineering Seminar: Capacitive Micro Machined Ultrasonic Transducers and Systems for Imaging and Surgery

Biomedical Engineering Seminar:
Jingkuang Chen, PhD, Principle Engineer, Johnson & Johnson
Thursday, February 12th, 11:00am, Fisher 132
“Capacitive Micro Machined Ultrasonic Transducers and Systems for Imaging and Surgery”
Sponsored by the Department of Biomedical Engineering

This talk will highlight the development of capacitive micromachined ultrasonic transducer (CMUT) arrays for clinical use that delivers diagnostic information, including anatomy images with a better contrast and resolution, as well as therapeutic and surgical functions not available from conventional piezoelectric tools. Examples of these devices include a tiny panoramic CMUT endoscope integrated with high-intensity focused ultrasound capability for arrhythmia diagnosis and surgery, a needle-shaped CMUT array that is smaller than a human hair for imaging, brain blood-flow-rate measurement, or hearing aids, and a CMUT photoacoustic imager. Using photon-induced acoustic waves for image reconstruction, photoacoustic imaging can capture images of blood and calcification cluster, and is exceptionally useful for identifying diseases/abnormalities related to blood, such as internal bleeding from pre-stroke or early-stage cancer. A novel architecture for photoacoustic imaging has been developed allowing light illumination through an infrared-transparent CMUT array, resulting in a compact portable modality suitable for ambulance and other field use. A broader spectrum on the clinical use of
CMUT technology will also be discussed, including the concept of wearable ultrasound patch for soft/hard tissue regeneration or wound healing.

Biomedical Engineering Seminar: Medical Devices and Technology

Biomedical Engineering Seminar: Smita Rao, PhD
Department of Electrical Engineering, University of Texas Arlington,
Sponsored by the Department of Biomedical Engineering
Thursday, February 5th, 3:00pm, Dillman 320

Title: “Medical Devices and Technology”

The recent advances in fabrication, design and simulation and ease of access to novel techniques have driven the advances in medical devices and technologies. There is a rise in the demand for wearable or minimally invasive interventions and therapies to improve the day-to-day life of a patient. Currently, several treatment modalities suffer from the need for bulky bedside equipment that limit mobility and hamper quality of life. The cost of such care is also significant. By reducing the size of the devices, making them battery operated or wireless improves the quality of life at a fraction of the cost. In many cases, the device can be implanted in a simple outpatient procedure lowering recovery times and risks associated with post-operation infections. New and innovative diagnostic methodologies, significantly smaller device footprints and lower cost of fabrication using existing techniques have yielded promising results. Implantable wireless, batteryless sensor for gastro-esophageal reflux disease, wirelessly powered gastrostimulators, miniature nanorod sensors for detecting neuro-transmitters such as dopamine have been demonstrated. Another aspect of these advances is in the field of lab-on-chip technologies for
diagnostic applications. Microfluidics has been in the forefront of this effort and continues to provide invaluable information. Microfluidic platforms to study biological phenomenon such as cell proliferation, migration and interaction promise to yield vital clues to the development and spread of diseases like cancer, study the interaction of drugs and explore the bio-mechanic aspects of tissues.

Biomedical Engineering Seminar: Applications of Coursework to Industrial Design and Clinical Practice: Biomedical Engineering/Science Applied to Cardiac Rhythm Disorders

Biomedical Engineering Seminar: Friday, January 30th: EERC 100, 3-4pm
D. Curt Deno, Senior Principle Scientist, St. Jude Medical Tech Center
“Applications of Coursework to Industrial Design and Clinical Practice: Biomedical Engineering/Science Applied to Cardiac Rhythm Disorders”
Sponsored by the Department of Biomedical Engineering

For the last roughly 100 years, technology has played crucial roles in advancing health care. Substantial contributions have come from academic and corporate R&D organizations–environments where learning and research have fostered the innovations that have shaped modern medicine. The speaker’s perspective includes training in both technical and biomedical disciplines. This talk intends to illustrate with examples how a good engineering or science background has repeatedly proven of value in advancing knowledge and developing products that benefit people with heart disease (form pediatric to the elderly). The speaker maintains that even despite occasional project related angst this is one of the most satisfying careers.

Biomedical Engineering seminar: Photoacoustic imaging and focusing in deep biological tissue

The Department of Biomedical Engineering Seminar;
Lidai Wang, Ph.D., Department of Biomedical Engineering, Washington University in St. Louis

Date: Thursday, January 29 – 1:00 pm, Room: 320 Dillman

Title: “Photoacoustic imaging and focusing in deep biological tissue”

Taking advantage of rich molecular contrasts and safe non-ionizing radiation, optical imaging has been playing increasingly important roles in biomedical applications. However, a fundamental limit of
optical imaging in biological tissue is light diffusion, which prohibits high-resolution imaging at depths beyond ~1mm. To break through this limit, we recently developed photoacoustic imaging and wavefront shaping technologies for in vivo functional imaging, early cancer detection, and focusing light into diffusive regimes. This presentation will first discuss the development of video-rate functional photoacoustic microscopy which, for the first time, enabled real-time quantitative imaging of oxygen release from single red blood cells in living tissue. Then I will introduce another functional photoacoustic imaging modality, ultrasonic-encoded photoacoustic flowgraphy, which can measure extremely slow blood flow in deep tissue with four times higher sensitivity than ultrasonic Doppler flowmetry. In addition, I will present a novel technique named nonlinear photoacoustic guided wavefront shaping (PAWS) that enables diffraction-limited optical focusing and imaging in highly scattering media such as deep biological tissue.

Biomedical Engineering Seminar: Molecular/Cellular Photoacoustic Imaging and High Sensitivity Non-Contact Optical Detection to Laser

Biomedical Engineering seminar Tuesday January 27, 2015, MEEM 111; 
Jinjun Xia, Ph.D.,
Title: Molecular/Cellular Photoacoustic Imaging and High Sensitivity

Non-Contact Optical Detection to Laser Photoacoustic (PA) imaging is based on the detection of acoustic signals induced by the distribution of specific optical heterogeneities in targeted objects when irradiated by short laser pulses. Contrast in PA images is primarily determined by optical absorption, while spatial resolution is the same as in ultrasound. The advantages of PA imaging including low cost, non-ionizing operation, and sub-mm spatial resolution at centimeters depth, make it a promising modality to probe nanoparticle-targeted abnormalities in real time at cellular and molecular levels. However, detecting rare cell types in a heterogeneous background with strong optical scattering and absorption remains a big challenge. For example, differentiating circulating tumor cells in vivo (typically fewer than 10 cells/mL for an active tumor) among billions of erythrocytes in the blood is nearly impossible. In this presentation, I will present two newly developed techniques, magneto-motive photoacoustic (mmPA) imaging and laser induced nonlinear ultrasonic/photoacoustic imaging, which can significantly increase the sensitivity and specificity of sensing targeted cells or molecular interactions. The primary advantage of these methods is suppression of background signals through magnetic enrichment/manipulation and laser induced bubbles with gold nanospheres coated emulsion beads with simultaneous PA detection of contrast agent targeted objects. The extension of these techniques and their applications in my future research will be presented. In the instrumentation aspect, the current integrated photoacoustic (PA)/Ultrasonic(US) imaging systems use bulky, low repetition rate lasers to provide sufficient pulse energies to image at depth within the body. However, integrating these lasers with real-time clinical ultrasound scanners is problematic due to their size and cost. In this presentation, I will present an integrated PA/US imaging system that can operate at frame rates >30Hz by employing a portable, low-cost, low-pulse energy, high repetition rate, 1053nm laser and a rotating galvo-mirror system enabling rapid laser beam scanning over the imaging area. This approach is demonstrated for potential applications requiring a few centimeters of penetration. The future improvement of this system will also be presented. Non-contact optical detection for laser generated ultrasound is very attractive for its flexibility.

Current non-contact systems have relatively low sensitivity compared to contact piezoelectric detection. They are difficult to adjust, very expensive, and strongly influenced by environmental noise. Here I will present a new type of a balanced fiber-optic Sagnac interferometer as part of an all-optical laser ultrasonics (LU) pump-probe system for non-destructive testing and evaluation of aircraft composites. This new system eliminates the most of current LU drawbacks by combining a new generation of compact, inexpensive fiber lasers with new developments on fiber telecommunication optics and an optimally designed balanced probe scheme. The performance of this LU system is demonstrated on a composite sample with known defects. A system noise figure of 12.3dB above the Nyquist thermal noise limit is achieved at a rough composite surface. Biomedical applications of this system and its modifications will be presented.