CHBT Electrical Safety and Biomedical Engineering Principles 2

Question 1

When performing preventive maintenance on a hemodialysis machine, what electrical test measures the resistance between the equipment chassis and the ground pin of the power cord?

Accepted Answer

Ground continuity test

Answer

Insulation resistance test

Answer

Leakage current test

Answer

Dielectric strength test

Question 2

What is the function of a ground fault circuit interrupter (GFCI) in a hemodialysis clinical environment?

Accepted Answer

It interrupts power when current imbalance between hot and neutral exceeds ~5 mA

Answer

It regulates voltage to dialysis machines

Answer

It isolates patient circuits from building power

Answer

It monitors dialysate conductivity

Question 3

According to Ohm's Law, if a dialysis machine has a leakage current pathway with a resistance of 500,000 ohms and is connected to a 120V supply, what is the leakage current?

Accepted Answer

240 microamperes

Answer

24 milliamperes

Answer

24 microamperes

Answer

2.4 milliamperes

Question 4

Which NFPA standard specifically governs electrical safety requirements in health care facilities, including dialysis units?

Accepted Answer

NFPA 99

Answer

NFPA 70 (NEC)

Answer

NFPA 101

Answer

NFPA 13

Question 5

What is the primary biomedical engineering reason for using isolated power systems rather than standard grounded power in dialysis patient care areas?

Accepted Answer

To prevent a single ground fault from causing power interruption or patient electrocution

Answer

To provide higher voltage for dialysis machines

Answer

To reduce energy consumption of equipment

Answer

To allow use of three-phase electrical loads

Question 6

During biomedical equipment inspection, an insulation resistance test on a dialysis machine reads 0.5 megaohm. What does this indicate?

Accepted Answer

Degraded insulation that may pose a safety hazard

Answer

Excellent insulation integrity

Answer

Acceptable insulation within normal range

Answer

Normal reading for all dialysis machines

Question 7

Which type of electrical isolation transformer provides the safest power for patient-connected medical equipment in a dialysis unit?

Accepted Answer

Medical-grade isolation transformer

Answer

Autotransformer

Answer

Step-down transformer

Answer

Ferroresonant transformer