CHBT Electrical Safety and Biomedical Engineering Principles 3

Question 1

What is the primary purpose of equipotential bonding in a hemodialysis patient care area?

Accepted Answer

To ensure all conductive surfaces are at the same electrical potential, eliminating current flow between them

Answer

To increase electrical power capacity for multiple machines

Answer

To provide a return path for dialysate current

Answer

To ground the blood pump separately from the dialysis machine

Question 2

A biomedical technician measures 150 microamperes of chassis leakage current on a hemodialysis machine. What is the appropriate action?

Accepted Answer

Remove the machine from service immediately and tag it out of service

Answer

Document the reading and continue normal operation

Answer

Reduce the voltage supply to lower leakage

Answer

Install an additional ground wire and return to service

Question 3

In biomedical engineering terms, what does 'applied part' mean in the context of IEC 60601-1 for dialysis equipment?

Accepted Answer

The part of equipment that comes into physiological contact with the patient

Answer

Any mechanical component attached to the machine frame

Answer

The electrical power supply module

Answer

Software-controlled treatment parameters

Question 4

Which protection classification under IEC 60601-1 designates equipment with a floating (isolated) patient connection suitable for cardiac applications?

Accepted Answer

Type CF

Answer

Type B

Answer

Type BF

Answer

Type AP

Question 5

What is the correct method for testing ground wire integrity on hemodialysis equipment using a biomedical safety analyzer?

Accepted Answer

Pass at least 25 amperes DC through the ground conductor and measure resistance

Answer

Apply 120V AC between the chassis and ground pin

Answer

Measure resistance using a standard digital multimeter on ohms setting

Answer

Use a megohmmeter at 500V to test ground resistance

Question 6

During a power failure in a dialysis unit, which component of the electrical system is designed to provide immediate backup power to hemodialysis machines without interruption?

Accepted Answer

Uninterruptible power supply (UPS)

Answer

Generator transfer switch

Answer

Isolation transformer

Answer

Line isolation monitor

Question 7

According to AAMI TIR No. 12, what is the recommended maximum resistance for the protective earth (ground) conductor in patient-connected medical equipment?

Accepted Answer

0.1 ohm

Answer

0.01 ohm

Answer

0.5 ohm

Answer

1.0 ohm