Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
16 Cards in this Set
- Front
- Back
|
Provide a comprehensive definition of the term “Biomaterial”. |
Any material, natural or synthetic, that comes in contact with human tissue, blood or bodily fluids, and is intended for use in medicine. |
|
|
What are the general applications areas of biomaterials? |
- Storage of bodily fluids and tissues; - Diagnosis and monitoring ; - Surgery; - Wound healing; - Biomedical devices and implants. |
|
|
Understand what is meant by the term “Biocompatibility”. |
Key concept: Definition: The ability of a biomedical device to perform with an appropriate host response in a specific application. |
|
|
Explain how biocompatibility can be conditional. |
Core concept: Biocompatibility testing is device and application specific. It is the assessment of the risk benefit ratio that requires, by definition, a functioning device. Core concept: Biocompatibility can be conditional or time dependent. The term is “often” misused and confused with the terms “Tissue Response” “Biosafety” and “non-toxic”. |
|
|
Describe how biomaterials have evolved since the 1950’s. |
1950-1975: off the shelf materials that were inert or nontoxic Ex: 1954 at Houston Veterans Administration Hospital, Michael E DeBakey, MD, used Dacron underwear to make the first vascular graft that worked successfully. 1975-2000: Newer materials that degrade or have engineered properties Ex: 2000-present: Materials designed to stimulate specific responses Ex: Biologically - inspired bone cements |
|
|
Explain how medical devices are classified? In your answer provide examples of each classification and describe how the general classification scheme differs from one class to another. |
- Class I devices: crutches, bedpans, tongue depressors, adhesive bandages etc. –minimal invasiveness, do not contact the user internally. - Class II devices: hearing aids, blood pumps, catheters, contact lens, electrodes etc. –higher degree of invasiveness and risk, but relatively short duration. - Class III devices: cardiac pacemakers, intrauterine devices, intraocular lenses, heart valves, orthopedic implants, etc. -considerably more invasive and can pose immense risk to the user-implants. |
|
|
What are the different classes of biomaterials? |
Two Primary Classification Schemes Scheme 1 • Metals • Ceramics • Polymers • Composites Scheme 2 • Synthetic Materials • Natural Materials All materials fall into a category from scheme 1 and scheme 2 (i.e. they are not exclusive) |
|
|
Describe the different levels of organization of a biomaterial. |
- Atomic or Elemental Composition - Structure - Molecular (Ultrastructure, Nanostructure) - Microscale -Macroscale |
|
|
Describe how the atomic makeup and microstructure of a biomaterial influences design decisions of engineers in the biomedical device industry. |
A |
|
|
Explain what a metal is and how its structure is related to its properties. |
A |
|
|
Explain what a ceramic is and provide an example of how they are used clinically. |
A |
|
|
List two properties and at least 6 general requirements of a biomaterial incorporated in a biomedical device |
-Mechanical Properties -Electrical -Magnetic -Optical -Thermal Be non-pyrogeneic Non-carcinogenic Non-toxic Sterilizable Manufacturible / producible Packageable Storable Cost effective |
|
|
Draw a stress strain curve, label its axes, and explain what relevant mechanical characteristics can be determined from a materials stress-strain curve |
Also - Ultimate tensile strength: Maximum stress on plot. (Units: Mpa )- Total Strain: Maximum strain or elongation at failure. (Units: % )- Toughness: Area under the curve. (Units: MPa) |
|
|
Draw an idealized representative stress strain curve for a metal, ceramic and a polymer |
A |
|
|
Define the working principle, probe depth (surface sensitivity) and information provided by AFM and optical profilometry |
Optical Profilometry - High-precision, optical method to measure surface topography, roughness and height - Non-contact, non-destructive method - Capable of nm vertical resolution across large fields-of- view - Limited in horizontal resolution because it uses visible light |
|
|
Differentiate between the concepts of inertness and bioactivity with regard to a surface coating |
Ahij |
