CABT Certified Associate in Biomedical Technology Exam — Questions and Answers

Question 1: In anatomical position, which directional term refers to a structure closer to the point of attachment of a limb?

Distal
Proximal (Correct answer)
Inferior
Lateral

Correct answer: Proximal

Proximal describes a position closer to the point of origin or attachment of a limb, while distal refers to farther away.

Question 2: Which interference source is most likely to cause an artifact that mimics ventricular fibrillation on an ECG monitor?

60 Hz AC interference from a faulty electrode or lead wire (Correct answer)
Patient talking or coughing
Low battery in the wireless transmitter
Use of a non-standard electrode gel

Correct answer: 60 Hz AC interference from a faulty electrode or lead wire

Severe 60 Hz AC interference can produce a coarse, irregular waveform on the ECG that visually resembles ventricular fibrillation, requiring electrode and lead wire inspection.

Question 3: Which type of epithelium lines the urinary bladder and is capable of stretching?

Stratified squamous epithelium
Transitional epithelium (urothelium) (Correct answer)
Pseudostratified columnar epithelium
Simple squamous epithelium

Correct answer: Transitional epithelium (urothelium)

Transitional epithelium (urothelium) lines the urinary bladder and ureters, uniquely able to stretch as the bladder fills.

Question 4: A Class I recall is initiated when a device has a reasonable probability of causing:

Serious adverse health consequences or death (Correct answer)
Minor adverse health consequences
Only property damage with no human health risk
No health consequences but violates FDA labeling regulations

Correct answer: Serious adverse health consequences or death

A Class I recall indicates the most serious situation where use of or exposure to the device will cause serious adverse health consequences or death.

Question 5: The 'dead volume' in a syringe pump infusion system is clinically significant because it:

Increases the risk of air embolism in the IV line
Delays actual drug delivery when a new syringe is loaded or rate is changed (Correct answer)
Causes the pump motor to draw excess current
Prevents accurate weight-based dosing calculations

Correct answer: Delays actual drug delivery when a new syringe is loaded or rate is changed

Dead volume in the syringe plunger and tubing means the pump must compress or expand that volume before drug flow reaches the patient, creating a clinically important delivery lag.

Question 6: Which physiological effect occurs when 60 Hz AC current in the range of 10–20 mA passes through the thorax?

Tingling sensation only
Ventricular fibrillation
'Let-go' threshold exceeded, causing inability to release the conductor (Correct answer)
Respiratory arrest without cardiac involvement

Correct answer: 'Let-go' threshold exceeded, causing inability to release the conductor

At 10–20 mA, sustained muscle tetany prevents voluntary release of the energized conductor, defining the 'let-go' threshold.

Question 7: In the context of biomedical equipment used during surgery, which nerve plexus supplies the brachial region and is a landmark for regional anesthesia?

Cervical plexus
Sacral plexus
Lumbar plexus
Brachial plexus (Correct answer)

Correct answer: Brachial plexus

The brachial plexus (C5–T1) innervates the upper extremity and is the target for brachial plexus nerve blocks used in upper limb surgeries.

Question 8: A pulse oximeter measures oxygen saturation using light absorption. Which property of hemoglobin makes this possible?

Hemoglobin fluoresces under UV light when oxygenated
Oxyhemoglobin and deoxyhemoglobin absorb red and infrared light differently (Correct answer)
Hemoglobin changes molecular weight when bound to oxygen
Oxygen binding increases hemoglobin's electrical conductivity

Correct answer: Oxyhemoglobin and deoxyhemoglobin absorb red and infrared light differently

Pulse oximeters exploit the different light absorption spectra of oxyhemoglobin (red light) and deoxyhemoglobin (infrared light) to calculate SpO2.

Question 9: During installation of a patient monitoring system, the technician discovers the network port assignment conflicts with an existing device on the LAN. Who should be contacted to resolve this?

The nursing supervisor
The Joint Commission surveyor
The equipment manufacturer only
The hospital's IT/biomedical informatics department (Correct answer)

Correct answer: The hospital's IT/biomedical informatics department

Network IP address and port conflicts must be resolved by the hospital IT or biomedical informatics team who manage the clinical network infrastructure.

Question 10: What is the medical term for high blood pressure?

Hyperglycemia
Hypertension (Correct answer)
Hypotension
Hypoglycemia

Correct answer: Hypertension

Hypertension is the medical term for high blood pressure, a condition where the force of blood against the artery walls is consistently too high. It is a significant risk factor for heart disease, stroke, and kidney disease. Regular monitoring and management are crucial for individuals diagnosed with hypertension.

Question 11: A biomedical technician services a patient warming system. Which physiological mechanism does this device support by maintaining core body temperature?

Osmoregulation
Thermoregulation (Correct answer)
Glucoregulation
Hematopoiesis

Correct answer: Thermoregulation

Thermoregulation maintains core body temperature within narrow limits (36.5–37.5°C) to ensure optimal enzymatic function and cellular processes.

Question 12: Which parameter most directly controls image noise in a CT acquisition?

Reconstruction filter (kernel)
Detector collimation width
Tube current-time product (mAs) (Correct answer)
Gantry rotation speed

Correct answer: Tube current-time product (mAs)

mAs (milliampere-seconds) determines the number of X-ray photons reaching the detector; higher mAs reduces quantum noise while increasing patient dose.

Question 13: Which regulatory body oversees the accreditation of healthcare organizations in the United States and evaluates compliance with safety standards?

OSHA
The Joint Commission (TJC) (Correct answer)
FDA
CMS

Correct answer: The Joint Commission (TJC)

The Joint Commission accredits and certifies healthcare organizations, evaluating compliance with performance standards to improve patient care quality and safety.

Question 14: Which of the following best describes 'risk priority number' (RPN) used in Failure Mode and Effects Analysis (FMEA)?

The total cost of potential failures over device lifetime
A regulatory classification assigned by the FDA
The product of severity, occurrence, and detectability ratings for a failure mode (Correct answer)
The number of reported adverse events divided by total devices in service

Correct answer: The product of severity, occurrence, and detectability ratings for a failure mode

RPN is calculated by multiplying severity × occurrence × detectability scores, helping prioritize which failure modes require the most urgent corrective action.

Question 15: A coagulation analyzer displays a 'clot detect error' on a patient sample. The MOST likely cause is:

Insufficient sample volume or presence of a fibrin clot in the sample (Correct answer)
Wrong reagent lot number loaded
Expired control material
Low ambient temperature in the lab

Correct answer: Insufficient sample volume or presence of a fibrin clot in the sample

Clot detect errors are most commonly caused by insufficient sample volume or fibrin strands/microclots in the specimen that interfere with the optical or mechanical clot detection system.

Question 16: A hospital becomes aware that a patient's death may have been the result of a malfunction in a medical device. Under the requirements of the Safe Medical Devices Act (SMDA), the user facility must report the incident to:

The Food and Drug Administration (FDA) only, within 24 hours.
The hospital's legal department and insurance carrier only.
The device manufacturer only, within 30 days.
Both the manufacturer and the FDA, within 10 working days. (Correct answer)

Correct answer: Both the manufacturer and the FDA, within 10 working days.

The Safe Medical Devices Act (SMDA) of 1990 mandates that user facilities (e.g., hospitals) report device-related deaths to both the manufacturer and the FDA. The report must be submitted within 10 working days of the facility becoming aware of the event. This dual reporting ensures that both the regulatory body and the company responsible for the device are aware of potentially serious issues.

Question 17: Which of the following electronic components is a semiconductor device that allows current to flow in only one direction and is often used for rectification in power supplies for medical equipment?

Inductor
Capacitor
Resistor
Diode (Correct answer)

Correct answer: Diode

A diode is a semiconductor device with two terminals that essentially acts as a one-way switch for current. It allows current to flow easily in one direction (forward bias) but severely restricts current from flowing in the opposite direction (reverse bias). This property is fundamental for converting alternating current (AC) to direct current (DC), a process called rectification, which is crucial for powering most electronic medical devices.

Question 18: A transcutaneous electrical nerve stimulator (TENS) unit produces a burning sensation for the patient during use. After ruling out technique error, the technician should:

Switch to a higher-frequency mode
Replace the electrodes with larger ones immediately
Test output waveform and current amplitude against manufacturer specifications (Correct answer)
Increase the pulse width to distribute current

Correct answer: Test output waveform and current amplitude against manufacturer specifications

A burning sensation may indicate output parameters outside of specifications; testing the actual output waveform and amplitude against manufacturer specs is the proper diagnostic step.

Question 19: During a survey, The Joint Commission (TJC) is evaluating a hospital's Medical Equipment Management Plan. Which of the following is a critical performance metric TJC will review to ensure equipment safety and reliability?

The average cost of repairs for each device category.
The brand of test equipment used for preventive maintenance procedures.
The number of new medical devices acquired in the last fiscal year.
The on-time completion percentage for scheduled equipment maintenance. (Correct answer)

Correct answer: The on-time completion percentage for scheduled equipment maintenance.

The Joint Commission emphasizes proactive risk management. A key indicator of a healthy Medical Equipment Management Plan is a high completion rate for scheduled preventive maintenance (PM). This demonstrates the hospital is actively maintaining its equipment to ensure it is safe and functions as intended, which directly impacts patient safety.

Question 20: In the context of electrical safety, 'macroshock' is defined as current entering the body:

Via inductive coupling only
Through the intact skin surface (Correct answer)
Through a broken ground conductor
Directly into the heart via a catheter

Correct answer: Through the intact skin surface

Macroshock refers to electric current entering and exiting through the skin surface, requiring higher currents (mA range) to cause fibrillation.

Question 21: Which gas is used as the primary pneumatic drive gas in most hospital ventilators and why?

Air or oxygen at 50 psi, because it provides consistent driving pressure for bellows or pistons (Correct answer)
Oxygen, because it enriches the delivered FiO2
Helium, because of its low density and reduced work of breathing
Nitrogen, because it is inert and low-cost

Correct answer: Air or oxygen at 50 psi, because it provides consistent driving pressure for bellows or pistons

Hospital ventilators use 50 psi compressed air or oxygen as a pneumatic drive source because this pressure reliably actuates pneumatic valves and drives bellows or pistons.

Question 22: Which type of amplifier configuration provides both voltage gain and current gain but with a 180° phase shift?

Common collector
Common gate
Common base
Common emitter (Correct answer)

Correct answer: Common emitter

The common emitter configuration inverts the output signal (180° phase shift) and provides both voltage and current gain.

Question 23: What is the primary consideration when implementing changes to imaging systems?

Vendor preference
Impact assessment and change management (Correct answer)
Speed of implementation
Personal convenience

Correct answer: Impact assessment and change management

Impact assessment and proper change management ensure that modifications do not introduce unexpected problems or service disruptions.

Question 24: What is the function of a low-pass filter in biomedical signal processing?

Passes low frequencies and attenuates high frequencies (Correct answer)
Attenuates all frequencies equally
Passes a specific band of frequencies
Passes high frequencies and attenuates low frequencies

Correct answer: Passes low frequencies and attenuates high frequencies

A low-pass filter allows signals below its cutoff frequency to pass while attenuating higher frequency components.

Question 25: Which condition would cause a falsely elevated SpO2 reading on a standard two-wavelength pulse oximeter?

Carboxyhemoglobin (COHb) poisoning (Correct answer)
Methemoglobinemia
Hypothermia
Severe anemia

Correct answer: Carboxyhemoglobin (COHb) poisoning

Standard pulse oximeters cannot distinguish carboxyhemoglobin from oxyhemoglobin at 660 nm, causing COHb to be misread as oxygenated hemoglobin and falsely elevating SpO2.

Question 26: What is the primary safety function of an isolation transformer in the power supply of medical equipment used in an operating room?

To increase the line voltage for high-power devices.
To act as the primary circuit breaker for the device.
To create an ungrounded secondary circuit, reducing macroshock risk. (Correct answer)
To convert the incoming AC power to DC power.

Correct answer: To create an ungrounded secondary circuit, reducing macroshock risk.

An isolation transformer's primary purpose in medical systems is safety. It creates a secondary power source that is electrically isolated from the grounded primary. This means that a person touching one live conductor and ground will not complete a circuit, drastically reducing the risk of a dangerous macroshock, which is especially important in critical care areas like operating rooms.

Question 27: Which factor MOST significantly affects the quality of technical outcomes in CABT practice?

The brand of equipment being used
The practitioner's training, preparation, and attention to detail (Correct answer)
The time of day the procedure is performed
The speed at which procedures are completed

Correct answer: The practitioner's training, preparation, and attention to detail

The quality of technical outcomes depends primarily on the practitioner's level of training, thorough preparation, and careful attention to detail. While equipment matters, the professional's competence is the most significant factor.

Question 28: An op-amp in an inverting configuration has Rf = 100 kΩ and Rin = 10 kΩ. What is the voltage gain?

-0.1
+10
+0.1
-10 (Correct answer)

Correct answer: -10

Inverting amplifier gain = -Rf/Rin = -100kΩ/10kΩ = -10, where the negative sign indicates phase inversion.

Question 29: During a surgical procedure using a monopolar electrosurgical unit (ESU), the active electrode delivers the cutting current. What is the essential function of the large patient return electrode (dispersive pad)?

To provide a low-resistance path for the electrical current to safely exit the body and return to the generator. (Correct answer)
To monitor the patient's heart rate and rhythm during the procedure.
To cool the patient's skin directly under the active electrode.
To deliver a secondary, lower-power coagulating current.

Correct answer: To provide a low-resistance path for the electrical current to safely exit the body and return to the generator.

In monopolar electrosurgery, the electrical circuit flows from the ESU generator, through the active electrode, into the patient's tissue, and then must return to the generator. The patient return electrode has a large surface area to safely disperse the current as it exits the body, preventing burns at the exit site. Without this complete and safe path, the current could seek alternative routes and cause significant injury.

Question 30: What is the first step in troubleshooting a non-functional medical device?

Replace the battery
Check power and connections (Correct answer)
Disassemble the unit
Call the manufacturer

Correct answer: Check power and connections

When troubleshooting a non-functional medical device, the first and most fundamental step is to check its power source and all connections. Many device malfunctions stem from simple issues like being unplugged, a tripped circuit breaker, a dead battery, or loose cables. Verifying these basic elements can quickly resolve common problems before moving on to more complex diagnostic steps.

Question 31: The term 'patient environment' or 'patient care vicinity' as defined by NFPA 99 refers to a space extending:

10 feet in all directions from the patient
The entire patient room floor area
3 feet horizontally and 5 feet vertically from the patient's head
6 feet horizontally and 7.5 feet vertically from the patient bed edge (Correct answer)

Correct answer: 6 feet horizontally and 7.5 feet vertically from the patient bed edge

NFPA 99 defines the patient care vicinity as a zone 6 feet horizontally from the bed edge and up to 7.5 feet above the floor.

Question 32: A bispectral index (BIS) monitor primarily measures which physiological parameter?

Cardiac output via echocardiography
Cerebral perfusion pressure
Depth of anesthesia or sedation via processed EEG (Correct answer)
Degree of neuromuscular blockade

Correct answer: Depth of anesthesia or sedation via processed EEG

The BIS monitor uses a processed EEG algorithm to generate a numeric index (0–100) that reflects the patient's level of consciousness or depth of anesthesia.

Question 33: What is the main function of a dialysis machine?

Deliver anesthesia
Filter blood (Correct answer)
Monitor brain activity
Inject insulin

Correct answer: Filter blood

The main function of a dialysis machine is to filter and purify the blood when a patient's kidneys are no longer able to perform this vital function adequately. It removes waste products, excess salts, and water from the blood, mimicking the natural role of healthy kidneys. This process is crucial for patients with kidney failure to maintain fluid and electrolyte balance.

Question 34: What is the primary function of a laminar flow hood in a clinical laboratory?

To maintain specimen temperature during processing
To sterilize instruments with UV light
To provide negative pressure containment for hazardous pathogens
To provide a sterile work environment by directing HEPA-filtered air over the work surface (Correct answer)

Correct answer: To provide a sterile work environment by directing HEPA-filtered air over the work surface

Laminar flow hoods direct HEPA-filtered air in a unidirectional flow over the work surface to protect samples and cultures from contamination.

Question 35: The term 'slew rate' in an operational amplifier refers to:

Gain-bandwidth product
Maximum rate of change of output voltage (Correct answer)
Input offset voltage drift
Maximum output voltage swing

Correct answer: Maximum rate of change of output voltage

Slew rate is the maximum rate at which the op-amp output voltage can change, typically expressed in V/µs, limiting high-frequency large-signal performance.

Question 36: During preventive maintenance, a technician measures 0.15 Ω between two metal IV poles in the same patient room. Per NFPA 99, this finding indicates:

An unsafe condition exceeding the 0.1 Ω limit (Correct answer)
A safe result within the 0.5 Ω limit
No action required since IV poles are not patient-connected
A marginal result; both poles should be rebonded to the ground bus

Correct answer: An unsafe condition exceeding the 0.1 Ω limit

NFPA 99 requires that resistance between any two exposed conductive surfaces in a patient care vicinity not exceed 0.1 Ω; 0.15 Ω exceeds this limit.

Question 37: Which of the following best describes the purpose of a 'load test' on an uninterruptible power supply (UPS)?

Checks the battery charger input current
Tests the surge suppression circuitry
Verifies input voltage regulation under steady-state conditions
Confirms the UPS can deliver rated output power for a specified duration (Correct answer)

Correct answer: Confirms the UPS can deliver rated output power for a specified duration

A load test applies rated or specified load to the UPS to verify it sustains output power for the required backup duration.

Question 38: What is the recommended action when an automated analyzer's QC result exceeds the 3-SD (3 standard deviation) Westgard rule?

Reject the run, investigate the cause, and do not report patient results until resolved (Correct answer)
Repeat QC once and report if within 2 SD on the second run
Report patient results with a flag and continue
Adjust calibration to bring QC within range

Correct answer: Reject the run, investigate the cause, and do not report patient results until resolved

A 3-SD violation (1₃s rule) indicates random error and requires run rejection, root cause investigation, and re-running QC before releasing patient results.

Question 39: Which organization publishes ANSI/AAMI ST79, the comprehensive guideline for steam sterilization and sterility assurance in health care facilities?

Centers for Disease Control and Prevention (CDC)
The Joint Commission (TJC)
Association for the Advancement of Medical Instrumentation (AAMI) (Correct answer)
Occupational Safety and Health Administration (OSHA)

Correct answer: Association for the Advancement of Medical Instrumentation (AAMI)

AAMI (Association for the Advancement of Medical Instrumentation) publishes ANSI/AAMI ST79, the primary U.S. guideline for steam sterilization practices in healthcare facilities.

Question 40: What is the term for the double-layered membrane surrounding the heart?

Perichondrium
Pericardium (Correct answer)
Peritoneum
Pleura

Correct answer: Pericardium

The pericardium is the fibrous sac enclosing the heart, consisting of two layers that reduce friction.

Question 41: A surgical electrosurgical unit (ESU) causes burns at the dispersive electrode site. Which is the most likely cause?

Excessive generator output setting
Inadequate contact area or poor adhesion of the dispersive electrode (Correct answer)
Broken active electrode pencil
Incorrect frequency setting

Correct answer: Inadequate contact area or poor adhesion of the dispersive electrode

Burns at the dispersive (return) electrode site are most commonly caused by inadequate skin contact area or poor adhesion, increasing current density at that site.

Question 42: Which of the following best describes 'design validation' in medical device development under 21 CFR Part 820?

Verifying that software code is free of errors
Ensuring manufacturing processes are documented
Confirming the device meets user needs and intended use through testing (Correct answer)
Confirming that device design outputs meet design inputs

Correct answer: Confirming the device meets user needs and intended use through testing

Design validation confirms that the device conforms to defined user needs and intended uses, typically through real-world or simulated use testing.

Question 43: In an EEG amplifier, why is a notch filter at 60 Hz commonly used?

To eliminate power line interference from the signal (Correct answer)
To prevent electrode polarization
To increase signal-to-noise ratio across all frequencies
To amplify brain wave frequencies

Correct answer: To eliminate power line interference from the signal

A 60 Hz notch filter selectively attenuates power line frequency interference while passing the EEG signal frequencies (0.5–100 Hz).

Question 44: A biomedical technician is calibrating a spirometer. The primary performance verification standard for volume accuracy requires the device to be within what tolerance?

±10 mL absolute
±3.5% of reading or 65 mL (whichever is greater) (Correct answer)
±5% of reading
±1% of reading

Correct answer: ±3.5% of reading or 65 mL (whichever is greater)

ATS/ERS standards require spirometer volume accuracy within ±3.5% of reading or ±65 mL, whichever is greater.

Question 45: What is the time constant (τ) of an RC circuit with R = 10 kΩ and C = 100 µF?

100 seconds
0.1 seconds
10 seconds
1 second (Correct answer)

Correct answer: 1 second

τ = RC = 10,000 Ω × 0.0001 F = 1 second.

Question 46: Stray capacitance in medical equipment can cause:

Unwanted leakage current flow through non-conductive paths (Correct answer)
Reduced electromagnetic emissions
Increased device gain
Higher ground-fault impedance

Correct answer: Unwanted leakage current flow through non-conductive paths

Stray capacitance between energized conductors and the chassis creates a capacitive path for leakage current even through nominally non-conductive materials.

Question 47: A biomedical technician notices a pH meter gives inconsistent readings. The FIRST corrective step should be:

Replace the electrode
Increase the temperature compensation setting
Replace the meter entirely
Recalibrate with fresh buffer solutions (Correct answer)

Correct answer: Recalibrate with fresh buffer solutions

Recalibration with fresh, properly prepared buffer solutions is always the first step when troubleshooting inconsistent pH meter readings.

Question 48: How should failed parts be managed during repair?

Returned to user
Reused
Thrown away
Documented and disposed properly (Correct answer)

Correct answer: Documented and disposed properly

Failed parts in medical equipment must be documented and disposed of properly to ensure accountability, track potential recurring issues, and comply with environmental and safety regulations. Improper disposal could lead to hazardous waste contamination or unauthorized reuse, posing risks to public health and the environment. Documentation also aids in inventory management and future repair planning.

Question 49: Which of the following accurately describes the function of the blood-brain barrier (BBB)?

It prevents all nutrients from entering the brain
It is formed by neurons in the cerebral cortex
It regulates the flow of cerebrospinal fluid between ventricles
It selectively restricts the passage of substances between blood and brain tissue (Correct answer)

Correct answer: It selectively restricts the passage of substances between blood and brain tissue

The BBB, formed by tight junctions between brain capillary endothelial cells and supported by astrocyte endfeet, selectively controls what enters brain tissue.

Question 50: Which class of chemical indicator provides the most reliable evidence that all critical parameters of a sterilization cycle were met?

Class 4 multi-variable indicators
Class 5 integrating indicators (Correct answer)
Class 1 process (exposure) indicators
Class 2 Bowie-Dick test indicators

Correct answer: Class 5 integrating indicators

Class 5 integrating indicators respond to all critical sterilization parameters (time, temperature, and sterilant) and provide the highest chemical indicator assurance level.

Question 51: A ventilator's flow sensor reads consistently 15% higher than the reference standard during calibration. This is an example of:

Hysteresis
Systematic bias (offset error) (Correct answer)
Random error
Noise artifact

Correct answer: Systematic bias (offset error)

A consistent, predictable deviation in one direction from the true value is called systematic bias or offset error, which can often be corrected through calibration adjustment.

Question 52: What does the abbreviation 'BP' stand for in medicine?

Brain Potential
Body Pulse
Blood Profile
Blood Pressure (Correct answer)

Correct answer: Blood Pressure

In medicine, 'BP' is a widely recognized abbreviation for Blood Pressure. It refers to the force exerted by circulating blood against the walls of the body's arteries. Monitoring BP is a routine part of medical examinations and is crucial for diagnosing and managing conditions like hypertension or hypotension.

Question 53: During a surgical procedure requiring laparotomy, the surgeon identifies the retroperitoneal organs. Which of the following is a retroperitoneal organ?

Spleen
Transverse colon
Kidneys (Correct answer)
Stomach

Correct answer: Kidneys

The kidneys are retroperitoneal, lying behind the peritoneum against the posterior abdominal wall, unlike most abdominal organs covered by peritoneum.

Question 54: Which class of electrical equipment relies solely on basic insulation for protection and has no grounding conductor?

Class III
Class II
Class I
Class 0 (Correct answer)

Correct answer: Class 0

Class 0 equipment relies only on basic insulation with no additional safety measure such as grounding or protective extra-low voltage.

Question 55: Which blood vessel directly supplies oxygenated blood to the myocardium?

Pulmonary artery
Coronary arteries (Correct answer)
Aortic arch branches
Superior vena cava

Correct answer: Coronary arteries

The left and right coronary arteries arise from the aortic root and supply oxygenated blood directly to the myocardium.

Question 56: In a pulse oximeter, which two wavelengths of light are used to differentiate oxyhemoglobin from deoxyhemoglobin?

550 nm and 850 nm
780 nm and 1000 nm
660 nm and 940 nm (Correct answer)
450 nm and 580 nm

Correct answer: 660 nm and 940 nm

Pulse oximeters use red light (~660 nm) and infrared light (~940 nm) because oxyhemoglobin and deoxyhemoglobin absorb these wavelengths at different ratios.

Question 57: In medical electronics, what is the maximum allowable patient leakage current for a Type CF (cardiac floating) applied part under normal conditions per IEC 60601-1?

500 µA
100 µA
1000 µA
10 µA (Correct answer)

Correct answer: 10 µA

IEC 60601-1 limits patient leakage current for Type CF (cardiac floating) applied parts to 10 µA under normal conditions to protect against microshock hazards.

Question 58: Which organization accredits hospitals and evaluates biomedical equipment management programs in the United States?

The Joint Commission (TJC) (Correct answer)
IEEE
FDA
AAMI

Correct answer: The Joint Commission (TJC)

The Joint Commission accredits healthcare organizations and evaluates their environment of care standards, which include biomedical equipment management programs.

Question 59: Under the FDA's Quality System Regulation (21 CFR Part 820), which record documents the complete history of the manufacture of a finished device lot?

Corrective Action Report (CAR)
Device History Record (DHR) (Correct answer)
Device Master Record (DMR)
Design History File (DHF)

Correct answer: Device History Record (DHR)

The Device History Record (DHR) contains the production records demonstrating that the device was manufactured in accordance with the DMR.

Question 60: A technician is troubleshooting a patient monitoring system where a very weak physiological signal (like an ECG) is not being displayed correctly. The issue is likely in the amplification stage. Which component is specifically designed to amplify such weak signals with high precision in medical instruments?

A fuse
A relay
An operational amplifier (Op-Amp) (Correct answer)
A transformer

Correct answer: An operational amplifier (Op-Amp)

Operational amplifiers (Op-Amps) are essential components in medical instrumentation for amplifying weak biological signals, such as those from an ECG or EEG. They provide the high gain, high input impedance, and low output impedance necessary to accurately boost these signals for processing and display without significant distortion or loss.

Question 61: Which of the following is the most significant danger associated with microshock?

Induction of ventricular fibrillation from a very low current. (Correct answer)
Severe skin burns at the point of contact.
Overheating of internal electronic components.
Involuntary muscle contraction causing patient injury.

Correct answer: Induction of ventricular fibrillation from a very low current.

Microshock is hazardous because it involves a very small current applied directly to or near the heart, bypassing the skin's high resistance. Currents as low as 10 to 20 microamperes can be sufficient to induce ventricular fibrillation, a life-threatening cardiac arrhythmia. Macroshock, in contrast, involves larger currents passing through the skin.

Question 62: In digital-to-analog conversion, the term 'settling time' refers to:

Propagation delay through digital logic
Time constant of the output filter
Time for the ADC to complete one conversion
Time for the DAC output to reach and stay within a specified accuracy band after a code change (Correct answer)

Correct answer: Time for the DAC output to reach and stay within a specified accuracy band after a code change

Settling time is the time required for the DAC output to settle within a defined error band (e.g., ±½ LSB) after the digital input changes.

Question 63: A Wheatstone bridge is balanced when:

R1 + R2 = R3 + R4
R1 × R2 = R3 × R4
R1 - R2 = R3 - R4
R1/R2 = R3/R4 (Correct answer)

Correct answer: R1/R2 = R3/R4

The Wheatstone bridge is balanced (zero galvanometer current) when the ratio of resistances in each arm are equal: R1/R2 = R3/R4.

Question 64: The maximum allowable chassis leakage current for a patient-connected device in a general care area per NFPA 99 is:

100 µA (Correct answer)
1 mA
10 µA
500 µA

Correct answer: 100 µA

NFPA 99 allows a maximum chassis leakage current of 100 µA for patient-connected devices in general care (Category 2) areas.

Question 65: Which connective tissue structure connects muscle to bone?

Tendon (Correct answer)
Cartilage
Ligament
Fascia

Correct answer: Tendon

Tendons are dense regular connective tissue structures that attach skeletal muscles to bones, transmitting contractile force.

Question 66: The 'source leakage current' measured during medical device safety testing represents current flowing:

From the patient leads to the neutral wire
Through the signal output connector only
Between two pieces of equipment connected in series
From the power source through the chassis to ground without any external patient load (Correct answer)

Correct answer: From the power source through the chassis to ground without any external patient load

Source leakage current (also called chassis or enclosure leakage) flows from the power-line conductors through insulation to the chassis and then to ground.

Question 67: What is the role of the sinoatrial (SA) node in cardiac physiology?

It supplies blood to the conduction system
It controls valve opening and closing
It initiates the electrical impulse that sets the heart rate (Correct answer)
It delays conduction between atria and ventricles

Correct answer: It initiates the electrical impulse that sets the heart rate

The SA node, located in the right atrium, spontaneously depolarizes at 60–100 bpm, acting as the natural pacemaker of the heart.

Question 68: What minimum PPE combination is required when manually decontaminating soiled surgical instruments in a central sterile department?

N95 respirator and sterile draping over all work surfaces
Examination gloves and a standard laboratory coat
Sterile gloves only, to protect instruments from recontamination during handling
Utility gloves, fluid-resistant gown, surgical mask, and eye protection (Correct answer)

Correct answer: Utility gloves, fluid-resistant gown, surgical mask, and eye protection

Manual decontamination requires utility gloves, a fluid-resistant gown, a mask, and eye protection to protect workers from bloodborne pathogen exposure and chemical splashes.

Question 69: An anesthesia machine's low-pressure system includes all of the following EXCEPT:

Breathing circuit
Flowmeters
Vaporizer
Pressure-reducing regulators (Correct answer)

Correct answer: Pressure-reducing regulators

Pressure-reducing regulators are part of the intermediate-pressure system; the low-pressure system begins after the flowmeters and includes the vaporizer and breathing circuit.

Question 70: Which semiconductor device is most suitable for controlling large currents in medical power supplies using a low-power control signal?

Junction diode
MOSFET (Correct answer)
Zener diode
Bipolar junction transistor

Correct answer: MOSFET

MOSFETs are voltage-controlled devices with very high input impedance, capable of switching large currents with minimal gate drive power, making them ideal for power supply control.

Question 71: When comparing biphasic and monophasic defibrillators, which of the following is a key operational advantage of biphasic technology?

They require significantly less energy to achieve the same or higher efficacy, reducing potential cardiac damage. (Correct answer)
Biphasic waveforms are less effective but have a longer battery life.
Monophasic technology is newer and provides more detailed post-shock ECG analysis.
Biphasic defibrillators always deliver a higher maximum energy shock (e.g., 360 Joules).

Correct answer: They require significantly less energy to achieve the same or higher efficacy, reducing potential cardiac damage.

Biphasic defibrillators send the current in two directions, which allows them to terminate arrhythmias with significantly lower energy levels (e.g., 120-200J) compared to monophasic devices (which may go up to 360J). This lower energy reduces the risk of skin burns and damage to the heart muscle. Biphasic technology is the current standard and has largely replaced the older monophasic technology.

Question 72: A central venous pressure (CVP) waveform shows an elevated 'a' wave. This finding is most associated with:

Tricuspid stenosis or right ventricular non-compliance (Correct answer)
Mitral stenosis
Tricuspid regurgitation
Pulmonary hypertension

Correct answer: Tricuspid stenosis or right ventricular non-compliance

An elevated 'a' wave in the CVP tracing reflects increased atrial contraction force against a non-compliant or obstructed right ventricle, as seen in tricuspid stenosis.

Question 73: After replacing a fuse in a biomedical device, the new fuse blows immediately upon power-up. The technician should:

Replace the fuse again and monitor for recurrence
Use a wire jumper temporarily until parts arrive
Install a higher-rated fuse to handle the load
Investigate for a short circuit or overload condition before replacing the fuse again (Correct answer)

Correct answer: Investigate for a short circuit or overload condition before replacing the fuse again

An immediately blown replacement fuse indicates an underlying short circuit or overload condition that must be diagnosed and corrected before installing another fuse.

Question 74: Which reflex arc component converts a stimulus into an electrical nerve impulse?

Receptor (Correct answer)
Motor neuron
Effector
Interneuron

Correct answer: Receptor

Receptors are specialized sensory structures that detect stimuli and transduce them into electrical signals (action potentials) that travel along afferent neurons.

Question 75: Which law in the United States regulates the sale and use of radiation-emitting electronic products including medical X-ray equipment?

The Radiation Control for Health and Safety Act (RCHSA) (Correct answer)
The Safe Medical Devices Act (SMDA)
The Medical Device Amendments Act of 1976
The Occupational Safety and Health Act (OSHA)

Correct answer: The Radiation Control for Health and Safety Act (RCHSA)

The Radiation Control for Health and Safety Act (RCHSA) authorizes the FDA to set and enforce performance standards for radiation-emitting electronic products, including X-ray equipment.

Question 76: A near-infrared spectroscopy (NIRS) oximeter placed on the forehead primarily monitors:

Regional cerebral oxygen saturation (rSO2) (Correct answer)
Tissue CO2 partial pressure
Systemic arterial oxygen saturation
Mixed venous oxygen saturation

Correct answer: Regional cerebral oxygen saturation (rSO2)

NIRS cerebral oximeters use near-infrared light to measure the regional oxygen saturation of the underlying brain tissue in a non-pulsatile manner.

Question 77: What tool is commonly used to test electrical safety in devices?

Safety analyzer
Clamp meter
Oscilloscope (Correct answer)
Multimeter

Correct answer: Oscilloscope

An oscilloscope is primarily used to visualize and analyze electrical waveforms and signals within a device's circuitry. While dedicated safety analyzers perform specific electrical safety tests, an oscilloscope can be instrumental in diagnosing underlying electrical issues, such as ground faults, signal noise, or power supply irregularities, that could compromise a device's overall electrical safety. By observing these internal electrical characteristics, technicians can identify potential hazards.

Question 78: In a biomedical instrumentation amplifier, the primary purpose of the input stage with matched resistors is to:

Provide high voltage gain
Achieve very high CMRR and input impedance (Correct answer)
Filter high-frequency artifacts
Reduce output offset voltage

Correct answer: Achieve very high CMRR and input impedance

The matched-resistor input stage of an instrumentation amplifier maximizes CMRR and provides high input impedance to avoid loading the signal source.

Question 79: The combining form 'cardi/o' refers to which organ?

Kidney
Lung
Liver
Heart (Correct answer)

Correct answer: Heart

'Cardi/o' refers to the heart and is used in terms like cardiogram and cardiology.

Question 80: In a biomedical device, a zener diode is used primarily to:

Regulate voltage (Correct answer)
Store electrical charge
Rectify AC to DC
Amplify small signals

Correct answer: Regulate voltage

Zener diodes operate in reverse breakdown to maintain a stable reference voltage, making them ideal for voltage regulation.

Question 81: What does the suffix '-plasty' indicate in medical terminology?

Inflammation of
Disease of
Surgical repair or reconstruction (Correct answer)
Incision into

Correct answer: Surgical repair or reconstruction

'-Plasty' indicates a surgical procedure involving repair, reconstruction, or reshaping of a structure.

Question 82: What does 'CV%' (coefficient of variation) measure when validating laboratory equipment precision?

The percentage of random variability relative to the mean across repeated measurements (Correct answer)
The difference between measured and true values
The percentage of samples that passed quality control
The number of measurements within acceptable range

Correct answer: The percentage of random variability relative to the mean across repeated measurements

CV% = (standard deviation / mean) × 100, expressing random variability as a percentage of the mean to assess instrument precision.

Question 83: In an automated immunoassay analyzer, what is the function of the 'wash buffer' step?

To denature the antigen before detection
To calibrate the optical system
To remove unbound antibodies or conjugates, reducing background signal (Correct answer)
To dilute the patient sample before incubation

Correct answer: To remove unbound antibodies or conjugates, reducing background signal

Wash buffer steps remove unbound reactants between incubation phases, which is essential for minimizing background and achieving specific, accurate immunoassay results.

Question 84: Electromagnetic interference (EMI) from a nearby electrosurgical unit most commonly affects which monitoring device by inducing artifact that mimics the signal of interest?

End-tidal CO2 waveform
Non-invasive blood pressure reading
ECG rhythm display (Correct answer)
Pulse oximeter plethysmographic waveform

Correct answer: ECG rhythm display

ESU RF energy couples into ECG lead wires, which act as antennas, producing artifact that obscures the cardiac signal during electrosurgical activation.

Question 85: During pulmonary artery catheter insertion, the characteristic waveform that confirms the catheter tip is in the right ventricle is:

Low phasic waveform with prominent 'a' and 'v' waves
High systolic and diastolic pressure with dicrotic notch
Continuous low-pressure waveform
High systolic pressure with low diastolic pressure and no dicrotic notch (Correct answer)

Correct answer: High systolic pressure with low diastolic pressure and no dicrotic notch

The right ventricular waveform shows high systolic pressure, near-zero diastolic pressure, and a distinct upstroke without a dicrotic notch, differentiating it from the pulmonary artery.

Question 86: During a nuclear medicine gamma camera quality control test, a 'uniformity flood' is performed to check:

Count rate linearity at high activity levels
Spatial resolution of the collimator
Homogeneous sensitivity response across the detector face (Correct answer)
Energy resolution of the photomultiplier tubes

Correct answer: Homogeneous sensitivity response across the detector face

A uniformity flood test exposes the entire detector to a uniform source; non-uniform response (hot or cold spots) indicates PMT or crystal problems requiring service.

Question 87: In MRI, which parameter is adjusted to change T1 contrast between tissues?

Bandwidth
Repetition time (TR) (Correct answer)
Echo time (TE)
Flip angle in gradient echo sequences only

Correct answer: Repetition time (TR)

Repetition time (TR) controls how much T1 relaxation occurs between pulses; a short TR emphasizes T1 differences between tissues, producing T1-weighted contrast.

Question 88: Which standard covers requirements for medical device software lifecycle processes?

ISO 14971
IEC 60601-1
IEC 62304 (Correct answer)
ISO 9001

Correct answer: IEC 62304

IEC 62304 specifies life cycle requirements for medical device software development, maintenance, and risk management processes.

Question 89: During cardiopulmonary resuscitation (CPR), compressions are performed on the sternum. Which anatomical landmark guides correct hand placement?

Sternal angle (angle of Louis)
Manubrium
Xiphoid process
Lower half of the sternum (Correct answer)

Correct answer: Lower half of the sternum

CPR guidelines direct compressions to the lower half of the sternum to compress the heart between the sternum and vertebral column.

Question 90: ISO 13485 is a quality management standard specifically designed for:

Clinical laboratory operations
Hospital infection control programs
Organizations in the medical device supply chain (Correct answer)
General manufacturing industries

Correct answer: Organizations in the medical device supply chain

ISO 13485 specifies requirements for a quality management system where an organization needs to demonstrate its ability to provide medical devices and related services.

Question 91: In CABT certification, what does redundancy in system design primarily provide?

Simplified maintenance
Increased complexity
Fault tolerance and high availability (Correct answer)
Lower initial cost

Correct answer: Fault tolerance and high availability

Redundancy provides fault tolerance by ensuring that if one component fails, backup components maintain system availability.

Question 92: How frequently should ongoing assessments be conducted in Certified Associate in Biomedical Technology practice?

Only when problems are reported
Only when required by external auditors
Once annually regardless of circumstances
At regular intervals based on established protocols and as conditions change (Correct answer)

Correct answer: At regular intervals based on established protocols and as conditions change

Ongoing assessments should follow established protocols for regular intervals and also be conducted when conditions change. This balanced approach ensures continuous monitoring while remaining responsive to new developments.

Question 93: Glutaraldehyde (2%) used as a high-level disinfectant requires a minimum immersion contact time of approximately:

5 minutes at room temperature
3 hours for complete inactivation of all pathogens
20–45 minutes for high-level disinfection (Correct answer)
10 hours to achieve full sterilization of immersed instruments

Correct answer: 20–45 minutes for high-level disinfection

2% glutaraldehyde requires approximately 20–45 minutes of immersion contact time to achieve high-level disinfection and inactivate all non-spore microorganisms.

Question 94: Which type of muscle tissue is involuntary, striated, and found only in the heart?

Smooth muscle
Skeletal muscle
Cardiac muscle (Correct answer)
Visceral muscle

Correct answer: Cardiac muscle

Cardiac muscle is uniquely involuntary and striated, with intercalated discs that allow electrical coupling between cells for coordinated contraction.

Question 95: What is the purpose of 'PEEP' in mechanical ventilation?

To trigger a breath when the patient makes an inspiratory effort
To limit the maximum airway pressure during inspiration
To maintain positive pressure in the airway at end-expiration and prevent alveolar collapse (Correct answer)
To increase inspiratory flow rate

Correct answer: To maintain positive pressure in the airway at end-expiration and prevent alveolar collapse

Positive End-Expiratory Pressure (PEEP) keeps a baseline positive pressure in the airways at the end of exhalation, preventing alveolar collapse and improving oxygenation.

Question 96: A biomedical technologist notices that an ultrasound image shows a bright echo directly behind a highly reflective structure. This is best described as:

Reverberation artifact (Correct answer)
Posterior acoustic enhancement
Mirror image artifact
Acoustic shadowing

Correct answer: Reverberation artifact

Reverberation artifact appears as multiple equally spaced bright lines behind a strongly reflective interface due to sound bouncing back and forth.

Question 97: Which hormone is produced by the adrenal medulla and plays a key role in the 'fight-or-flight' response?

Aldosterone
Cortisol
Insulin
Epinephrine (Correct answer)

Correct answer: Epinephrine

The adrenal medulla secretes epinephrine (adrenaline) and norepinephrine in response to sympathetic nervous system activation during stress.

Question 98: What type of feedback is used in most biomedical amplifier designs to stabilize gain and improve linearity?

No feedback
Positive feedback
Negative feedback (Correct answer)
Regenerative feedback

Correct answer: Negative feedback

Negative feedback reduces gain but improves stability, linearity, bandwidth, and reduces distortion — essential characteristics for accurate biomedical signal amplification.

Question 99: Which test instrument is used to measure the insulation resistance of medical electrical equipment to detect degraded insulation?

Digital multimeter set to AC volts
Clamp meter
Megohmmeter (megger) (Correct answer)
Oscilloscope

Correct answer: Megohmmeter (megger)

A megohmmeter applies a high DC test voltage (typically 500 V) and measures the resulting resistance to assess insulation integrity.

Question 100: Which anatomical term describes the movement of a limb away from the midline of the body?

Adduction
Inversion
Abduction (Correct answer)
Circumduction

Correct answer: Abduction

Abduction is the movement of a body part away from the midline, while adduction moves it toward the midline.

Question 101: Which part of the brain controls balance and coordination?

Cerebrum
Cerebellum (Correct answer)
Thalamus
Brainstem

Correct answer: Cerebellum

The cerebellum, located at the back of the brain below the cerebrum, plays a critical role in motor control, coordination, and balance. It helps refine movements, maintain posture, and learn new motor skills. Damage to the cerebellum can result in problems with coordination and equilibrium.

Question 102: The modulation transfer function (MTF) of an imaging system describes:

How spatial frequencies (detail) are preserved from object to image (Correct answer)
How patient dose varies with image noise
The relationship between kVp and image contrast
The uniformity of detector response across its area

Correct answer: How spatial frequencies (detail) are preserved from object to image

The MTF quantifies what fraction of the true contrast is preserved for each spatial frequency, characterizing the system's spatial resolution performance.

Question 103: Which device helps patients with respiratory issues?

Ventilator (Correct answer)
Infusion pump
ECG machine
Defibrillator

Correct answer: Ventilator

A ventilator is a medical device that provides mechanical ventilation by moving breathable air into and out of the lungs. It is essential for patients who are unable to breathe adequately on their own due to various respiratory issues, such as severe pneumonia, acute respiratory distress syndrome, or during surgery. The ventilator supports lung function, ensuring proper oxygenation and carbon dioxide removal.

Question 104: In a hemodialysis machine, the conductivity monitor of the dialysate circuit is critical because it detects:

Blood leak into the dialysate
Incorrect electrolyte concentration that could cause patient harm (Correct answer)
Transmembrane pressure exceeding safe limits
Air bubbles in the blood circuit

Correct answer: Incorrect electrolyte concentration that could cause patient harm

Conductivity correlates directly with dissolved electrolyte (sodium) concentration; a conductivity alarm stops dialysate delivery to prevent hypo- or hypernatremia.

Question 105: In a full-wave bridge rectifier, how many diodes are required?

2
1
6
4 (Correct answer)

Correct answer: 4

A full-wave bridge rectifier uses 4 diodes arranged so that current flows through the load in the same direction for both AC half-cycles.

Question 106: A biomedical technician is servicing a defibrillator and notices the time it takes to deliver a shock is significantly delayed. This issue is most likely related to a failing component responsible for storing electrical charge. Which of the following electronic components is the most probable cause?

Transistor
Diode
Resistor
Capacitor (Correct answer)

Correct answer: Capacitor

Capacitors are fundamental electronic components that store electrical energy in an electric field. In a defibrillator, a large capacitor is charged to a high voltage and then rapidly discharged to deliver the therapeutic shock. A failing capacitor would struggle to store the necessary charge or discharge it effectively, leading to performance issues like a delayed shock.

Question 107: What does the term 'duty cycle' refer to in electrosurgical units (ESU)?

The number of surgeries performed between servicing
The ratio of on-time to total period of the RF waveform (Correct answer)
The frequency of the cutting waveform
The maximum wattage output the unit can sustain

Correct answer: The ratio of on-time to total period of the RF waveform

Duty cycle is the ratio of active (on) time to total cycle time in the RF waveform, which determines whether the ESU operates in cut or coagulation mode.

Question 108: Under the Safe Medical Devices Act (SMDA), which facilities are required to report device-related adverse events to the FDA?

Manufacturers and importers only
Only device manufacturers
Only outpatient clinics and ambulatory surgery centers
User facilities such as hospitals and nursing homes (Correct answer)

Correct answer: User facilities such as hospitals and nursing homes

The SMDA requires user facilities, including hospitals and nursing homes, to report device-related deaths and serious injuries to the FDA and/or manufacturer.

Question 109: An IFU (Instructions for Use) for a medical device must be provided in which language for devices sold in the United States?

English, with translations required if the device is sold in multilingual markets
English and Spanish
English and any language spoken by more than 5% of the local population
English only (Correct answer)

Correct answer: English only

FDA requires that IFUs for devices marketed in the US be in English, though manufacturers may include additional languages.

Question 110: Which biomedical device delivers medications over time?

Syringe
Infusion pump (Correct answer)
Thermometer
Stethoscope

Correct answer: Infusion pump

An infusion pump is a medical device that delivers fluids, such as nutrients, medications, or blood, into a patient's body in controlled amounts. These pumps are designed to administer precise volumes at specific rates over an extended period, ensuring accurate and consistent delivery of therapeutic substances. This controlled delivery is vital for patient safety and treatment efficacy.

Question 111: Which part of the brain controls balance and coordination?

Cerebrum
Medulla oblongata
Cerebellum (Correct answer)
Thalamus

Correct answer: Cerebellum

The cerebellum coordinates voluntary movements, balance, and fine motor control.

Question 112: A technician is preparing an autoclave for a standard sterilization cycle for wrapped surgical instruments. Which combination of temperature, pressure, and time is a widely recognized minimum for effective steam sterilization in a gravity displacement sterilizer?

121°C (250°F) at 15 psi for 30 minutes (Correct answer)
100°C (212°F) at 0 psi for 60 minutes
110°C (230°F) at 10 psi for 45 minutes
134°C (273°F) at 30 psi for 4 minutes

Correct answer: 121°C (250°F) at 15 psi for 30 minutes

The standard and widely accepted parameters for steam sterilization of wrapped goods in a gravity displacement autoclave are 121°C (250°F) at a pressure of at least 15 psi for a minimum of 30 minutes. These specific conditions of steam, temperature, pressure, and time are required to effectively kill all microorganisms, including spores. The other options represent incorrect combinations of these critical parameters.

Question 113: A surgical electrosurgical unit (ESU) causes interference on the patient monitor in the same OR. The first corrective step is to:

Install a notch filter on the monitor
Inspect and improve the ESU's return electrode contact (Correct answer)
Replace the patient monitor
Relocate the patient monitor to another room

Correct answer: Inspect and improve the ESU's return electrode contact

Poor return-electrode contact forces stray ESU current through alternative paths, increasing electromagnetic interference; improving the pad contact is the first step.

Question 114: What potential hazard is associated with using a cellular phone near certain implanted cardiac devices?

Thermal burns from RF energy absorption
Ultrasonic damage to the device housing
Accidental activation of remote device programming
Electromagnetic interference (EMI) potentially inhibiting pacemaker output (Correct answer)

Correct answer: Electromagnetic interference (EMI) potentially inhibiting pacemaker output

Although modern pacemakers have improved shielding, cellular phone RF signals can potentially cause electromagnetic interference that inhibits pacemaker output in some susceptible devices.

Question 115: What does the term 'dead volume' refer to in the context of automated liquid handling systems?

Maximum volume the system can dispense
Volume lost to evaporation during runs
Volume of waste fluid produced per cycle
Volume remaining in a well that cannot be aspirated (Correct answer)

Correct answer: Volume remaining in a well that cannot be aspirated

Dead volume is the residual liquid that cannot be aspirated from a vessel due to the geometry of the tip and container, and must be accounted for in assay planning.

Question 116: Which lubricant is generally recommended for O-rings in medical gas equipment?

Petroleum jelly (Vaseline)
Lithium grease
Petroleum-based grease
Silicone-based lubricant (Correct answer)

Correct answer: Silicone-based lubricant

Silicone-based lubricants are oxygen-compatible and are recommended for O-rings in medical gas systems; petroleum-based products are fire hazards with oxygen.

Question 117: A defibrillator capacitor stores 360 joules at 5000 V. What is the capacitance value?

14.4 µF
144 µF
72 µF
28.8 µF (Correct answer)

Correct answer: 28.8 µF

Energy E = ½CV², so C = 2E/V² = 2×360/(5000²) = 28.8 µF.

Question 118: During preventive maintenance on a patient-controlled analgesia (PCA) pump, the technician discovers the drug library is outdated. What is the correct action?

Return the pump to service and notify IT later
Continue PM without updating the library
Delete the library and allow nurses to enter values manually
Update the drug library per facility protocol and pharmacy approval before returning to service (Correct answer)

Correct answer: Update the drug library per facility protocol and pharmacy approval before returning to service

An outdated drug library is a patient safety risk; it must be updated per facility protocol with pharmacy approval before the PCA pump is returned to clinical use.

Question 119: Which cellular organelle is the primary site of ATP production through oxidative phosphorylation?

Endoplasmic reticulum
Golgi apparatus
Mitochondria (Correct answer)
Lysosome

Correct answer: Mitochondria

Mitochondria contain the electron transport chain and ATP synthase complexes responsible for producing the majority of cellular ATP.

Question 120: A new biomedical technician is looking for a comprehensive, consensus-based standard on recommended practices for electrical safety testing and medical equipment management in a healthcare facility. Which organization would be the primary source for this type of guidance?

The National Fire Protection Association (NFPA).
The Occupational Safety and Health Administration (OSHA).
The Association for the Advancement of Medical Instrumentation (AAMI). (Correct answer)
The Joint Commission (TJC).

Correct answer: The Association for the Advancement of Medical Instrumentation (AAMI).

While NFPA (specifically NFPA 99) and TJC are critical for regulations and accreditation, AAMI is the primary organization that develops detailed, consensus-based standards (like ANSI/AAMI EQ56) and technical information reports (TIRs) specifically for the testing, maintenance, and management of medical instrumentation.

CABT Certified Associate in Biomedical Technology Exam

The CABT Certified Associate in Biomedical Technology Exam validates foundational competencies in biomedical equipment technology, including installation, maintenance, troubleshooting, anatomy, electronics, patient safety, and healthcare regulations.

120

Questions

120 min

Time Limit

70%

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