BIOMEDICAL DEVICES A MULTI/INTER-DISCIPLINARY SUBJECT Effective treatments of patient health problems are often limited by devices, technologies and medications currently available. Breakthroughs are needed! Biology, chemistry and physics inform both medicine and engineering. Engineering applies controlled experimentation and physical-mathematical modeling to conceptualize, design, fabricate and lab-test prototype devices. Collaborations with industry lead to the development, fabrication and clinical testing of ‘final’ human- compatible biomedical devices. The work requires multi/interdisciplinary teams of specialists working collaboratively to generate (i) devices that cure disease and save lives and, possibly, (ii) valuable intellectual property.
Blood Flow By-Pass CatheterHumphrey and Gillies in collaboration with Drs. L. Gimple and M. Ragosta
Schematic shows two renderings of a double-lumen bypass device designed to divert the flow of blood (red) approaching a thrombus or other lesion (purple) while dispensing a stream with medication (blue) to a thrombus (or other lesion) at controlled flow rates independently of the flow of blood.
Applications:
(i) thrombi (PVD)
(ii) restenosis (iii) plaque passivation (iv) improved imaging
Blood Flow By-Pass CatheterHumphrey and Gillies in collaboration with Drs. L. Gimple and M. Ragosta
Ultimate objective is the ‘on-the-spot’ fabrication of catheters using a research methodology that combines:
(i) geometrically- and dynamically-scaled experiments
(ii) computational fluid dynamics, heat and mass transfer
(iii) genetic algorithms for randomly-guided optimization
(iv) micro-fabrication techniques
to evolve optimal, patient-specific devices
Novel Access Device for Femoral Artery CatheterizationMichael Ragosta, M.D. – Concept and Clinical NeedScott Lim, M.D. – Design GuidanceSrijoy Mahapatra, M.D. – Design OversightGeorge T. Gillies, Ph.D. – Prototype Development
Problem: Percutaneous puncture of femoral artery is inexact and may result in access of a side branch potentially leading to a complication.
Potential solution: Need a method to allow an injection of contrast while maintaining a method to introduce a guide wire and the system should be small enough so that repositioning the needle will be easy and not cause bleeding
Concept to prototype time: 6 weeks!
Device fabricated using onlyFDA-approved components.
SOM-Cardiology/SEAS-MAE
Counter-Current Fluid-Fluid Flows Mixer C2F3MHumphrey (in collaboration with Landers’ lab, Chemistry)
On demand mixing: Two counter-flowing streams meet in the open space between a pair of separation plates where they split in the presence of pressure and shear forces that induce good mixing. This mix-and-split feature of the single unit has been built into a multi-unit prototype mixer. Applications range from small (sub-mm) to large (dm) devices.
Counter-Current Fluid-Fluid Flows Mixer C2F3MHumphrey (in collaboration with Landers, Chemistry)
Virginia Prostate Exam Simulatorwith Dr. Marcus Martin, Emergency Medicine & Reba Moyer Childress, Nursing
Our central premise is that simulators, to be useful, must monitor and provide feedback on trainees’ technique, facilitate the training experience via augmented feedback, and utilize a range of graded practice scenarios that accurately reflect disease progression.
SimulatorNormal
ProstateProstatitis BPH Carcinoma
Nasco (with torso)
One CaseNormal state
No Cases No Cases Three Cases, 3 ScenariosUnder skin tumorSmall tumor on the outside of skinEntire prostate is cancerous
Nasco (without torso)
One CaseNormal state
No Cases Two CasesBPH onlyBPH with early cancer nodule
Three Cases, 3 ScenariosEarly cancer in normal prostateEarly cancer in hyperplastic prostateLate invasive cancer
Virginia Prostate ExaminationSimulator (VPES)
One CaseNormal state
Four CasesLeft lobe only inflamedRight lobe only inflamedLeft lobe and center inflamedRight lobe and center inflamedProstatitis with cancer (34 scenarios)
Four CasesLeft and right lobes inflamed with sulcus intact, no tumorsMild inflammation with sulcus mostly obliterated, no tumorsLeft and right lobes inflamed with sulcus mostly obliterated, no tumorsBPH with cancer (17 scenarios)
Three Cases, 96 ScenariosSingle tumor cases of 4 different sizesMultiple tumors of different sizesEntire prostate is cancerous62 different cancer scenarios
No tumors on the outside of skin, this is not necessary to replicate
Simulators with Corresponding Disease State Representations
Design Requirement
Basic Elements ofPhysiologicallyAccurate Anatomy
Posterior section
Rectal Wall
Accurate ProstateSize/Stiffness
Entire Range of Disease States
Scenarios
Multiple
Reconfigurable
Graded
FeedbackTechnique
Performance
Simulation Framework for Training Chest Tube Insertion Using Virtual Reality and Force Feedback
• Simulation of the chest tube insertion procedure– Utilizes force feedback– Teaches cognitive tasks and
info management– 18 procedural steps broken
into 6 major tasks – Status / Navigation Aids
Post perform-ance report
with Dr. Marcus Martin, Emergency Medicine & Reba Moyer Childress, Nursing
Secure Mobile Computing Using BiotelemetricsBen Calhoun (ECE), Travis Blalock (ECE), and
Alfred Weaver (CS)
• Goal: develop a low-power integrated circuit with a biometric sensor, microcontroller, and radio
• Chip attaches to body like a Band-Aid• Collects biometric data, performs some local
processing, and transmits data over a wireless channel to a mobile device, e.g., PDA or laptop
• Initially we are using a heart rate sensor, Bluetooth, and an HP iPAQ PDA
• Ultimately the chip will be powered using energy-scavenging from the body, and will support additional sensors
• We will be able to export the biometric signal over the Internet—securely—to anywhere in the world
• Prototype using discrete logic is currently operational
