CBET key terms

A rapid, self-propagating change in the electrical voltage across a cell membrane caused by ion movement. In nerve and muscle tissue it triggers contraction or signal transmission and is the source of signals recorded by ECG, EEG, and pacemakers.

The shift of a cell's membrane voltage toward a less negative, more positive value as ions cross the membrane. In cardiac muscle it precedes contraction and produces the waveforms that an ECG records.

The volume of blood the heart pumps each minute, calculated as heart rate multiplied by stroke volume. It indicates whether circulation is adequate and is estimated or measured by several monitoring devices.

The portion of the cardiac cycle in which the ventricles contract and push blood into the arteries. It corresponds roughly to the QRS complex on an ECG and to the upper number of a blood pressure reading.

An estimate of the percentage of hemoglobin in arterial blood that is carrying oxygen. A pulse oximeter derives it noninvasively by comparing how red and infrared light are absorbed by pulsating tissue.

The body's tendency to keep internal conditions such as temperature, pH, blood glucose, and blood pressure within narrow limits using feedback mechanisms. It explains why monitored physiologic values normally stay within a predictable range.

The relationship stating that voltage equals current multiplied by resistance (V = I x R). Technicians use it to predict current flow, check circuit behavior, and reason about patient-connected circuits.

The total opposition a circuit presents to alternating current, combining resistance with reactance, and it changes with frequency. It matters for ECG leads, defibrillation pads, and electrosurgical return electrodes.

The ability of two conductors separated by an insulator to store electric charge, measured in farads. In medical equipment it explains coupling between circuits, filter behavior, and stored-energy hazards after power is removed.

The property of a conductor that opposes changes in current by storing energy in a magnetic field, measured in henries. It is central to how transformers, motors, and relay coils behave in device power circuits.

Small unintended current that flows through a chassis, protective ground, or patient connection instead of the intended circuit path. It must be limited and measured because it can contribute to electric shock.

A transformer that transfers AC power magnetically without a direct conductive path between primary and secondary windings. It limits shock hazard and is used in patient-care equipment and ungrounded power systems in critical care areas.

A very small current, on the order of microamperes, delivered directly to heart tissue through catheters or intracardiac leads. It can trigger ventricular fibrillation, so devices connected to the heart have especially strict leakage limits.

Current that passes through intact skin and the body, generally perceptible at about one milliampere and dangerous at tens of milliamperes. Grounding, insulation, and isolation are used to prevent it.

A messaging standard that defines the structure and content of clinical and administrative data exchanged between healthcare software systems. It is commonly used for admissions, orders, and results interfaces.

A standard for storing, transmitting, and displaying medical images and related information. It defines the file format and network services that let imaging devices, archives, and viewing workstations work together.

A picture archiving and communication system that stores, retrieves, and distributes medical images across a facility. Its performance depends on DICOM conformance, network capacity, and correctly calibrated displays.

Software that receives, translates, routes, and queues messages between otherwise incompatible systems. It maps data fields, handles errors, and keeps clinical data flowing between devices and record systems.

An electronic record of a patient's health information and care across encounters. It exchanges data with laboratory, imaging, and monitoring systems and is governed by privacy and security requirements.

A logical grouping of network ports or devices that behaves like a separate local network regardless of physical location. It is used to isolate medical device traffic from general traffic and to reduce broadcast congestion.

Practices and controls that protect devices, networks, and data from unauthorized access, tampering, or loss. In healthcare it includes patching, access control, network segmentation, monitoring, and incident response planning.

A device that delivers fluids or medications into a patient at a controlled rate. Periodic testing verifies flow accuracy, occlusion and air-in-line alarms, and battery performance.

A machine that supports or controls breathing by delivering gas at set volumes, pressures, and rates. Verified parameters typically include tidal volume, inspiratory pressure, PEEP, and oxygen concentration.

A device that delivers a controlled electrical shock through paddles or pads to restore an organized heart rhythm. Testing verifies delivered energy, charge time, and synchronized cardioversion timing.

Equipment that cuts or coagulates tissue using high-frequency electrical current. Its testing covers output power accuracy, return-electrode monitoring, and leakage current.

Apparatus that delivers oxygen and anesthetic gases while supporting the patient's breathing. Service includes vaporizer calibration, breathing-circuit leak testing, and verification of gas monitoring and scavenging.

A device that continuously displays and alarms on physiologic parameters such as ECG, SpO2, blood pressure, and temperature. Maintenance confirms sensor accuracy, alarm limits, and audible alarm function.

An imaging system that uses a strong magnetic field and radio waves to produce detailed images without ionizing radiation. Its hazards include the projectile effect and radiofrequency heating, requiring strict access zoning and patient screening.

A structured investigation that identifies the underlying system and process failures behind an incident instead of assigning blame. It is performed after serious device-related events to prevent repetition.

Scheduled inspection, cleaning, calibration, and performance testing intended to keep equipment safe and reliable. Intervals are commonly based on manufacturer recommendations, use, and the device's risk category.

Adjusting an instrument so its measurement or output agrees with a known reference standard within allowed tolerance. The adjustment and the before-and-after readings are documented for traceability.

A computerized maintenance management system that tracks equipment inventory, work orders, scheduled maintenance, parts, and repair history. It serves as the department's primary record of service activity.

A documented request or authorization describing maintenance or repair work to be performed, including the equipment, the problem, the actions taken, and the person completing the task.

A test instrument that measures leakage current, protective-ground resistance, and insulation on medical devices. Technicians use it during acceptance testing, preventive maintenance, and after repairs.

A procedure for isolating hazardous energy before servicing equipment so it cannot be started unexpectedly. It requires locks, tags, and verification that the equipment is truly de-energized.

The health care facilities code that addresses electrical systems, medical gases, vacuum, and environmental hazards in care settings. It defines risk categories that determine how strictly equipment and systems must be designed and maintained.

A radiation protection principle meaning doses are kept as low as reasonably achievable. It is applied through shielding, distance from the source, limited exposure time, and proper technique.

Personal protective equipment such as gloves, gowns, masks, and eye protection worn to reduce exposure to bloodborne pathogens, chemicals, and other workplace hazards. Selection is based on the task's expected exposure risk.