General Practice Flashcards

A biomedical technician is troubleshooting an infusion pump that delivers inconsistent flow rates. Which component is MOST likely responsible?

Answer: Peristaltic pump mechanism

The peristaltic pump mechanism directly controls fluid delivery, and wear or misalignment causes inconsistent flow rates.

According to NFPA 99, the maximum allowable ground resistance for a receptacle in a patient care area is:

Answer: 0.1 ohms

NFPA 99 requires receptacle ground resistance to not exceed 0.1 ohms in patient care areas to ensure electrical safety.

Which type of fire extinguisher is appropriate for electrical equipment fires in a biomedical equipment area?

Answer: Class C (CO2 or dry chemical)

Class C extinguishers use non-conductive agents like CO2 or dry chemical, making them safe for energized electrical equipment fires.

A patient monitor displays an artifact that disappears when the patient's lead wires are disconnected. This MOST likely indicates:

Answer: EMI from external sources coupling through the leads

When artifact disappears upon lead disconnection, the leads are acting as antennas picking up electromagnetic interference from external sources.

The term 'microshock' refers to hazardous current delivered:

Answer: Directly to the heart via an intracardiac catheter at levels as low as 10 µA

Microshock occurs when current bypasses skin resistance and reaches the heart directly, where as little as 10 µA can induce ventricular fibrillation.

During preventive maintenance on a ventilator, the BIOMED finds the exhalation valve is slow to close. The MOST immediate patient safety concern is:

Answer: Inadequate tidal volume delivery due to gas leakage

A slow-closing exhalation valve allows delivered gas to escape before full tidal volume is delivered to the patient's lungs.

Which standard specifically governs the safety requirements for medical electrical equipment in the United States?

Answer: ANSI/AAMI ES60601-1

ANSI/AAMI ES60601-1 is the US adoption of IEC 60601-1 and governs general safety requirements for medical electrical equipment.

A hospital's isolated power system (IPS) is designed primarily to protect against:

Answer: Macroshock from single-fault ground currents in wet locations

An IPS isolates the patient care circuit from ground so a single fault does not create a complete circuit for dangerous ground currents (macroshock).

When testing a line isolation monitor (LIM), the alarm should activate when the hazard current exceeds:

Answer: 5 mA

NFPA 99 requires the LIM alarm to activate when total hazard current reaches 5 mA, indicating the IPS isolation has degraded to a dangerous level.

A technician notices the hospital's oxygen wall outlet delivers flow but at a lower pressure than specification. The MOST likely cause is:

Answer: Excessive demand from too many simultaneous users on that zone

Excessive simultaneous demand on a piped medical gas zone creates a pressure drop due to flow resistance in the supply piping.

In a digital-to-analog converter (DAC) used in medical equipment, increasing the bit resolution from 8-bit to 12-bit:

Answer: Increases the number of discrete output levels from 256 to 4,096

An 8-bit DAC produces 2^8 = 256 levels while a 12-bit DAC produces 2^12 = 4,096 levels, providing finer output resolution.

A technician is performing annual PM on a hospital bed. Which safety check is MOST critical for patient fall prevention?

Answer: Testing siderail locking mechanisms for secure engagement

Siderail locking mechanism failure is directly linked to patient falls, making it the highest-priority safety check during hospital bed PM.

The International System of Units (SI) base unit for electric current is the:

Answer: Ampere

The ampere (A) is the SI base unit for electric current, defined as the flow of electric charge past a point per unit time.

A biomedical technician must ensure an ECG machine's patient lead leakage current does not exceed which limit for a CF-type device per IEC 60601-1?

Answer: 10 µA under normal conditions

For CF (cardiac floating) applied parts, IEC 60601-1 limits patient leakage current to 10 µA under normal conditions due to direct cardiac risk.

When using a multimeter to measure AC voltage on a 120V circuit, the technician should set the range to:

Answer: A range equal to or above 120V to prevent meter damage

Always select a range at or above the expected voltage to prevent damage to the meter and ensure safe, accurate measurement.

A hospital laboratory centrifuge vibrates excessively during operation. The MOST likely cause is:

Answer: An unbalanced load due to improperly paired or misplaced samples

Centrifuges must have balanced loads; unequal or improperly positioned samples create centrifugal force imbalance causing severe vibration.

Which type of radiation is MOST effectively stopped by a thin sheet of aluminum foil?

Answer: Beta particles

Beta particles (electrons) have moderate penetration and are effectively shielded by a few millimeters of aluminum, unlike alpha (paper stops it) or gamma (requires dense shielding).

A technician completing a work order should document which of the following to satisfy Joint Commission traceability requirements?

Answer: Device identification, service performed, test results, technician ID, and date

Joint Commission requires complete service records including device ID, work performed, test results, technician identification, and the service date for full traceability.

The output impedance of a device should ideally be low because:

Answer: It minimizes signal voltage drop when driving a load

Low output impedance ensures minimal voltage drop across the source impedance when current flows, maintaining signal integrity to the load.

Which sterilization method is MOST appropriate for heat-sensitive flexible endoscopes?

Answer: Ethylene oxide (EtO) gas sterilization

Ethylene oxide gas sterilizes at low temperatures (37–63°C), making it suitable for heat-sensitive devices like flexible endoscopes that would be damaged by steam or dry heat.