OENG1108: Introduction to Biomedical Engineering - Implants and Heart Valves

Introductory flashcards covering RMIT's OENG1108 course logistics, biomechanical stress/strain formulas, and the types/selection criteria for prosthetic heart valves.

What are the three main assessments for the OENG1108 course and their respective weightings?

Online Test 1 (20%), Lab Report (35%), and End of Year F2F Test (45%).

What activity is performed during the laboratories in weeks 3 through 6?

A 3D printed Hand Lab, where students build a 3D printed hand.

According to the lecture notes, define 'implant' as a verb.

To insert or fix tissue or an artificial object in a person's body, especially by surgery.

What is the formula for stress ($\sigma$), and what is the result if a rod is exposed to a tensile force of $20\,N$ with an area of $0.25\,m^2$?

The formula is $\sigma = F/A$. For the given values, $\sigma = 20\,N / 0.25\,m^2 = 80\,Pa$.

What is the formula for strain ($\varepsilon$), and how is it calculated for a $3\,m$ rod that elongates by $0.03\,m$?

The formula is $\varepsilon = \Delta L/L$. For the given values, $\varepsilon = 0.03\,m / 3\,m = 0.01$.

How is the modulus of elasticity ($E$) calculated using stress and strain?

It is calculated as $E = \sigma/\varepsilon$. For a stress of $80\,Pa$ and a strain of $0.01$, the modulus is $8000\,Pa$ or $8\,kPa$.

In an ECG, what does the P wave represent?

The atrial systole contraction pulse, which corresponds to the depolarization of the atria.

What does the QRS complex represent in an ECG signal?

The depolarization of the ventricles.

Identify the meanings of Q, R, and S within the QRS complex.

Q is the downward deflection preceding ventricular contraction; R is the peak of the ventricular contraction; S is the downward deflection immediately after the ventricular contraction.

What does the T wave represent in an ECG?

The recovery of the ventricles, also known as repolarisation.

During the systolic phase ($S_1$), which heart valves are closed?

The Mitral and Tricuspid valves.

During the diastolic phase ($S_2$), which heart valves are closed?

The Aortic and Pulmonary valves.

What are the primary characteristics of manufactured mechanical heart valves?

They are made of durable materials, are long-lasting (often the remainder of a patient's life), but require life-long blood-thinning medication to prevent clots.

Why is blood-thinning medication (warfarin) required for patients with mechanical heart valves?

To prevent clots from forming on valve flaps or hinges, which could cause malfunction or break off to form an embolism.

What are 'bioprosthetic' or tissue valves, and what is their typical lifespan?

They are created from animal donor valves or animal tissue; they typically last 10-20 years and usually do not require long-term medication.

What is the least common type of heart valve choice, typically lasting 10-20 years?

Human donor valve implantation.

What factors favor the selection of a mechanical prosthesis over a bioprosthesis?

The patient's desire, no contra-indication for warfarin therapy, already being on warfarin therapy, and being under age 65 with a long life expectancy.

What factors favor the selection of a bioprosthesis?

Age 65 or older, limited life expectancy, contra-indications for warfarin therapy, or being a woman of child-bearing age.