NCSSM BME Midterm

Subspecialties, Engineering Design Proess, FDA Regulatory Process, Biomaterials, Bone Repair, & Gait Analysis

Biomedical Electronics

BMEs advise and assist the hospital staff with the safe operation of the technical equipment.

involves working closely with nurses, technicians, physicians and other hospital staff who use the wide range of electronic devices in modern medical practice.

Biomechatronics

is an applied interdisciplinary science aiming to integrate mechanical elements, electronics and parts of biological organisms. 

Bioinstrumentation

is the application of electronics and measurement techniques to develop devices used in diagnosis and treatment of disease.

Biomaterials

include both living tissue and artificial materials used for implantation. 

Biomechanics

applies classical mechanics (statics, dynamics, fluids, solids, thermodynamics, and continuum mechanics) to biological or medical problems. It includes the study of motion, material deformation, flow within the body and in devices, and transport of chemical constituents across biological and synthetic media and membranes

Bionics

is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology.

Cellular, Tissue, and Genetic Engineering

involves the study of biomedical problems at the microscopic level. 

Clinical Engineering

the application of technology to health care in hospitals.

Medical Imaging

combines knowledge of a unique physical phenomenon (sound, radiation, magnetism, etc.) with high speed electronic data processing, analysis and display to generate an image.

Orthopedic Bioengineering

is the specialty methods of engineering and computational mechanics are applied to understanding the function of bones, joints and muscles, and for the design of artificial joint replacements 

Rehabilitation Engineering

enhance the capabilities and improve the quality of life for individuals with physical and cognitive impairments

Systems Physiology

describes the aspect of biomedical engineering in which engineering strategies, techniques and tools are used to gain a comprehensive and integrated understanding of the function of living organisms ranging from bacteria to humans. Computer modeling is used in the analysis of experimental data and in formulating mathematical descriptions of physiological events. 

Bionanotechnology

 indicates the merger of biological research with various fields of nanotechnology. Concepts enhanced through nanobiology include: nanodevices, nanoparticles, and nanoscale phenomena occurring within the discipline of nanotechnology. This technical approach to biology allows scientists to imagine and create systems used for biological research.

Neural Engineering

uses engineering techniques to understand, repair, replace, enhance, or the properties of neural systems.

Engineering Design process

1. Identify the need

2. Research the Problem

3. Brainstorm possible solutions

4. Select the most promising solution

5. Build a prototype

6. Test and evaluate the prototype

7. Redesign

Class 1 Devices

medical devices that pose minimal risks to patients. These devices are subject to the least regulatory control and typically are exempt from the premarket notification process (510(k)), meaning they do not require FDA clearance before marketing.

Class 2 Devices

typically require premarket notification, known as a 510(k), demonstrating that they are substantially equivalent to a legally marketed device.

must adhere to specific performance standards and post-market surveillance requirements.

Class 3 Devices

highest risk to patients and typically require the most stringent regulatory controls. These devices are critical to sustaining human life, preventing health impairment, or treating a disease, and they generally require premarket approval (PMA) to demonstrate safety and efficacy through extensive clinical trials and scientific data

Investigation Device Exemption

Allows an investigation device to be used in a clinical study to collect safety and effectiveness data for the next step in the process

Premarket Notification (510 K)

Application process for products that are very similar to products that are already on the market

Premarket Approval (PMA)

Scientific and regulatory approval process for new devices and Class III devices

Hooke’s Law (Modulus of Elasticity)

measures a materials resistance to elastic deformation under stress

Elastic (Linear) Region

A material will return to its original size and shape after a force is removed

Plastic Region

A material will not return to its original size and shape after a force is removed

Ductility

A measure of the degree of plastic deformation that has been sustained under tensile stress. 

Brittle

A material that experiences very little or no plastic deformation upon fracture

Proportional (Elastic) Limit

Beyond this point on the stress-strain curve the material begins to deform plastically

Yield Point

Point near the beginning of the plastic region where the material elongates suddenly even though the load remains the same or drops

Ultimate Stress Point

the point at which the maximum load for a sample is achieved.  Beyond this point, elongation of the sample continues but the force being exerted decreases. 

Modulus of Resilience

Area under the linear portion of the stress-strain curve; measures the capacity of a material to absorb energy when it is deformed elastically

Modulus of Toughness

Area under the entire stress-strain curve; measures the ability of a material to absorb energy up to fracture.

Breaking/Rupture Point

The maximum amount of stress that can be applied before rupture occurs.   

Compressive Forces

shortens and widens a structure

Tensile Loading

produces an elongation and narrowing of a structure

Shear Forces

act parallel to the surface and tend to deform a structure in an angular manner.

Torsional Loading

a geometric variation of shear and acts to twist a structure about an axis

Bending

results in the generation of maximum tensile forces on the convex surface of the member and maximum compressive forces on the concave side.

Transverse

A fracture at a right angle to the bone’s long axis. A fracture straight across the bone, usually the result of sharp, direct blows or stress fractures caused by prolonged running.

Oblique

A fracture that is diagonal to the bone’s long axis, often with a has a curved or sloped angle.

Torsion (Spiral)

A fracture in which part of the bone has been twisted.  Often caused by a twisting motion or force, such as planting your foot while the rest of your leg keeps twisting.

Comminuted

A fracture in which the bone is broken into several pieces.

Avulsion

A fracture in which part of the bone is separated from its main part

Impacted

A fracture in which bone fragments have been driven into each other

Fissure

An incomplete fracture in which the crack is only in the outer bone layer

Greenstick

A fracture in which only one side of the bone is broken. The bone usually has a bend to it and the fracture is located at the outside of the bend. Considered an incomplete fracture in which the bone is bent; occurs most often in children because their bones are not yet as hard as adult bones

Stages of bone healing

1. Hematoma

2. Fibrocartilaginous callous

3. bony callus

4. remodeling

Hematoma

Blood clot at the injure site

Fibrocartilaginous callus

tissue that holds the bone in place while new blood vessels form

Bony callus

new bone matrix that forms as the osteoblasts have time to secrete new minerals that harden into bone

remodeling

callus dissolves until the bone resembles its original form

External Fixation

Install temporary repair supports outside of the skin to stabilize and align bone while the body heals

Internal Fixation

Temporary or permanent fixtures directly attached to the bone under the skin, for alignment and support

Gait Analysis

Systematic study of human motion using visual observations and movement measurements

Gait Cycle

Begins when one foot hits the ground and ends when that foot hits the ground again.  These events are heel strike (HS) and toe-off (TO); since we have two limbs, there are a total of four events

Stance Phase

From HS to TO-percentage of the gait cycle when the foot is in contact with the ground (60% of cycle)

Swing Phase

From TO to HS-percentage of the gait cycle when the foot is in the air (40% of cycle)

Stance Time

The amount of time that passes during the stance phase of one extremity in a gait cycle.  It includes single and double support

Swing Time

The amount of time that passes during the swing phase of one extremity in a gait cycle.

Single Support

only one foot in contact with the floor

Double Support

both feet in contact with the floor- two periods approximately 24% of cycle

Stride Length

distance between the heel strike (HS) of one foot and the subsequent heel strike (HS) of that same foot

Step Length

distance between the same point of different feet (usually heel to heel)

• RHS – LHS = right

• LHS – RHS = left

Cadence

number of steps in a standard time frame (steps/min)

Walking Speed

Distance covered by the body in unit time