ANSI Z136.3 - Definitions Flashcards
Define
Ablation
Tissue removal (such as vaporization) by laser action.
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Accessible Emission Limit (AEL)
The maximum accessible emission level permitted within a particular laser hazard class.
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Accessible Laser Radiation
Laser radiation to which it is possible for the human eye or skin to be exposed in normal usage. This is also described as laser radiation emitted from a laser, including accessible radiant energy and power, that is compared with the AEL to determine its hazard class.
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Administrative Control Measure
Control measures incorporating administrative means (e.g., training, safety approvals, LSO designation, and policies and procedures) to mitigate the potential hazards associated with laser use.
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Average Power
The total energy imparted during exposure divided by the exposure duration.
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Aversion Response
Closure of the eyelid, eye movement, pupillary constriction, or movement of the head to avoid an exposure to a noxious or bright light stimulant.
In this standard, the aversion response to an exposure from a bright, visible, laser source is assumed to limit the exposure of a specific retinal area to 0.25 seconds or less.
Define
Beam Diameter
The distance between diametrically opposed points in that cross-section of a beam where the power or energy is 1/e (0.368) times that of the peak power or energy.
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Blink Reflex
The blink reflex is lid closure associated with the involuntary upward movement of the eye triggered by an external event such as an irritation of the cornea or conjunctiva, a bright flash, the rapid approach of an object, an auditory stimulus, or with facial movements. The ocular aversion response may include a blink reflex.
Define
Collateral Radiation
Any electromagnetic radiation, except laser radiation, emitted by a laser system. This does not include laser target interaction radiation.
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Collimated Beam
Effectively, a “parallel” beam of light with very low divergence or convergence.
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Continuous Wave (CW)
The output of a laser operated in a continuous rather than a pulsed mode.
In this standard, a laser operating with a continuous output for a period ≥ 0.25 seconds is considered a CW laser.
Define
Control Measure
A means to mitigate potential hazards associated with the use of a HCLS.
Control measures can be divided into three groups: engineering, procedural (administrative), and personal protective equipment (PPE).
Define
Deputy Laser Safety Officer (DLSO)
The person authorized and responsible for managing the laser safety program in the absence of the LSO.
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Diffraction
Deviation of part of a beam determined by the wave nature of radiation and occurring when the radiation passes the edge of an opaque obstacle.
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Diffuse Reflection
Change of the spatial distribution of a beam of radiation when reflected in multiple directions by non-specular reflections from various surfaces or mediums.
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Divergence
The increase in the diameter of the laser beam with propagation distances from the exit aperture.
Note - Sometimes referred to as beam spread.
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Embedded Laser
A laser with an assigned hazard classification higher than the classification of the laser system in which it is incorporated, where the system’s lower classification is the result of engineering features that limit the accessible emission levels.
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Energy
The capacity for doing work.
Energy content is commonly used to characterize the output from pulsed lasers, and is generally expressed in joules (J).
Define
Engineering Control Measure
Control measures designed or incorporated into the laser or laser system (e.g., interlocks, shutters, watch-dog timer circuits) or its application.
Define
Extended Source
A source of radiation that can be resolved by the eye into a geometrical image, in contrast to a point source of radiation that cannot be resolved into a geometrical image.
Define
Failsafe Interlock
An interlock where the failure of a single mechanical or electrical component of the interlock will cause the system to go into, or remain in, a safe mode.
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Fire Retardant
A material that does not support combustion without an external source of heat such as a laser.
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Focal Length
The distance from the secondary nodal point of a lens to the primary focal point.
In a thin lens, the focal length is the distance between the lens and the focal point.
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Focal Point
The point toward which radiation converges or from which radiation diverges or appears to diverge.
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Half-Power Point
The value on either the leading or trailing edge of a laser pulse at which the power is one-half of its maximum value.
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Healthcare Application
Use of a laser device on a patient (human or animal) by or under the supervision of a licensed practitioner, physician, dentist, or veterinarian, within their scope of practice for diagnostic, preventive, aesthetic, or therapeutic purposes, where bodily structure of function is altered or symptoms are relieved.
These include prescription use of the medical laser device and over-the-counter indications for use.
Define
Healthcare Facility
For the purpose of this standard, any location where a laser is applied for a healthcare application.
Define
Healthcare Laser System (HCLS)
A laser system used in healthcare applications.
The HCLS includes the laser or lasers, a delivery system to direct the output of the laser, a power supply with control and calibration functions, mechanical housing with interlocks, and associated liquids and gases required for the operation of the laser.
Define
Healthcare Personnel (HCP)
An individual directly involved in the use of a laser for healthcare applications.
Define
Hertz (Hz)
The unit which expresses the frequency of a periodic oscillation in cycles or pulses per second.
1 Hz = 1 cycle per second
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Infrared Radiation
Electromagnetic radiation with wavelengths that lie within the range of 700 nm to 1000 µm (1 mm).
Define
Installation
The procedure for supplying and connecting electrical power and other utilities to a HCLS.
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Intrabeam Viewing
The viewing condition whereby the eye is exposed to all or part of a laser beam.
Define
Ionizing Radiation
Electromagnetic radiation having sufficiently large photon energy to directly ionize atomic or molecular systems within a single quantum event.
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Irradiance
Radiant power incident per unit area upon a surface.
The SI unit of irradiance is watts-per-square-meter (W m^-2), or for convenience, watts-per-square-centimeter (W cm^-2)
Note - The terms power density and fluency rate are sometimes used as synonyms for irradiance, although these terms have slightly different technical meanings.
Define
Joule
A unit of energy.
1 joule = 1 watt second
Symbol: J
Define
Label
For the purposes of this standard, a display of written, printed, or graphic matter upon the protective housing of a laser product.
Define
Labeling
A term used in two senses in this standard.
First, Medical Device Regulations, 21CFR801, use “labeling” to indicate the intended and approved use of the HCLS.
Second, a term used to describe the physics label attached to the HCLS equipment.
Define
Laser
A device that produces an intense, coherent, directional beam of light by stimulating electronic or molecular transitions to lower energy levels.
An acronym for Light Amplification by Stimulated Emission of Radiation.
Define
Laser Generated Airborne Contaminants (LGAC)
Airborne contaminants generated when a laser beam interacts with target materials.
The materials may include, but are not limited to, plastics, metals, ceramics, glasses, wood, and tissue.
LGAC may be in the form of gases, vapors, organic or inorganic particulates, or aerosols, and often are a complex mixture of substances in all three states.
Define
Laser Operator
A person who handles the laser equipment and is responsible for setting up the laser prior to use or who operates the console to control the laser parameters under supervision of the user.
The laser operator may also be the laser user.
Define
Laser Protective Eyewear (LPE)
Equipment such as eyecups, face shields, goggles, eye shields, spectacles and visors, intended to protect the eyes from potentially harmful exposure to laser radiation, including blindness.
LPE does not include laser protective windows.
Define
Laser Radiation
Coherent optical (non-ionizing) radiation emitted by a laser.
Define
Laser Safety Officer (LSO)
The LSO is the person authorized by the administration and is responsible for the laser safety program.
This individual has the training and experience to administer a laser safety program and has responsibility for oversight and control of laser hazards (see 1.3).
Define
Laser Safety Site Contact (LSSC)
In diverse practice areas, such as large facilities or corporations, an LSSC serves under the supervision of the LSO.
The LSSC is responsible for all aspects of laser safety in each site where lasers are used and for which that individual has responsibility.
Define
Laser Safety Specialist (LSS)
The LSSC is referred to as the LSS in some facilities.
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Laser System
An assembly of electrical, mechanical, and optical components that includes a laser.
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Laser Target Interaction (LTIR)
Non-laser radiation, including ionizing radiation, emitted by a material as a result of that material’s exposure to laser radiation.
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Laser Treatment Controlled Area (LTCA)
The room within which the HCLS is used, and the occupancy and activity of those within this area are subject to supervision for the purpose of protection against all hazards associated with the use of HCLS.
In a large room, a limited LTCA can be designated if clearly marked and controlled.
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Laser User
A person who controls the application of the laser radiation at the working area and is applying the laser energy of the HCLS for its intended purpose within their scope of practice, license, training, and experience.
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Limiting Aperture
The diameter of a circle over which irradiance or radiant exposure is averaged for purposes of hazard evaluation.
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Limiting Exposure Duration
An exposure duration that is specifically limited by the design or intended use(s).
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Maintenance
Performance of those adjustments or procedures specified in user information provided by the manufacturer with the laser or laser system, which are to be performed by the user to ensure the intended performance of the product.
Maintenance does not include operation or service as defined in this section.
Define
Maximum Permissible Exposure (MPE)
The level of laser radiation to which a person, under normal circumstances, may be exposed without hazardous effects or adverse biological changes in the eye or skin.
The MPE criteria for the eye and skin are presented in ANSI Z136.1-2014.
Define
Medical Device Labeling
A term defined in the FDA Medical Device Regulations, 21CFR801, which includes all of the information required to appear in the device labeling including the intended use.
Labeling, for example in a user’s manual, is required to supply adequate directions for use, which is defined to mean directions under which the layman can use a device safely and for the purposes for which it is intended.
Exemptions from adequate directions for use may apply under specific circumstances for prescription devices.
Define
Nominal Hazard Zone (NHZ)
The space within which the level of the direct, reflected, or scattered radiation during normal operation exceeds the applicable MPE.
Note: Also referred to as the nominal ocular hazard area (NOHA)
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Nominal Ocular Hazard Distance (NOHD)
The distance along the axis of the unobstructed beam from the laser to the human eye beyond which the irradiance or radiant exposure during normal operation is not expected to exceed the applicable MPE.
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Non-Beam Hazard
All hazards arising from the operation of a laser system, excluding direct human exposure to direct or scattered laser radiation.
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Operation
The performance of the laser or laser system over the full range of its intended functions (normal operation).
It does not include maintenance or service as defined in this section.
Define
Optical Density
D(λ), OD
A value that defines the attenuation property of a filter and is equal to the logarithm to the base ten of the reciprocal of the transmittance at a particular wavelength.
D(λ) = log(1/τ(λ))
τ(λ)=transmittance at wavelength λ
Define
Patient
For purposes of this standard a patient is the recipient of the laser health care application.
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Perioperative
The period of time that extends from the setup to the completion of a surgical procedure, including the setup, testing, and use of the healthcare laser system.
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Personnel
Those persons who are engaged in laser use for healthcare applications.
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Personal Protective Equipment (PPE)
Personal safety protective devices used to mitigate hazards associated with laser use (e.g., laser eye protection, laser protective eyewear), and biological hazards for infection control (e.g., protective gowns, clothing, masks, and gloves).
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Plasma Radiation
Black-body radiation generated by luminescence of matter in a laser generated plume.
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Plume
Gases, vapors, and aerosol created by vaporization of tissue or other materials, which may contain viable bacteria, viruses, cellular debris, or noxious fumes.
Define
Point Source
For purposes of this standard, a source with an angular subtense at the cornea equal to or less than alpha-min (α-min), ≤ 1.5 mrad
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Policies and Procedures (P&Ps)
Written policies and procedures that list administrative and procedural control safety measures.
Define
Power
The rate at which energy is emitted, transferred, or received.
Power is expressed in watts (W).
1 W = 1 Joule per second
Symbol: W
Define
Pulse Repetition Frequency (PRF)
The number of pulses occurring per second, expressed in hertz
Symbol: F
Define
Procedural Control Measure
Methods or instructions that specify rules, work practices, or both.
Procedural control measures, which implement or supplement engineering controls, may specify the use of personal protectiv equipment (PPE).
Conflate: Administrative and procedural control measures. Thereby ensures immediate access to both and conformity in their representation.
Define
Protective Housing
An enclosure that surrounds a laser or laser system and prevents access to laser radiation above the applicable MPE.
The aperture through which the useful beam is emitted is not part of the protective housing.
The protective housing may enclose associated optics and a workstation, and limits access to other associated radiant energy emissions and to electrical hazards associated with components and terminals.
Define
Pulse Duration
The duration of a laser pulse; usually measured as the time interval between the half-power points on the leading and trailing edges of the pulse.
Define
Pulsed Laser
A laser that delivers its energy int he form of a single pulse or a train of pulses.
In this standard, the duration of a pulse is less than 0.25 seconds.
Define
Radian (rad)
A unit of angular measure equal to the angle subtended at the center of a circle by an arc whose length is equal to the radius of the circle.
1 radian ≈ 57.3 degrees
2π radians = 360 degrees
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Radiance
Radiant flux or power output per unit solid angle per unit area expressed in units of watts per steradian per meter squared (W sr^-1 m^-2)
Symbol: L
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Radiant Energy
Energy emitted, transferred, or received in the form of radiation expressed in the units of joules (J).
Symbol: Q
Define
Radiant Exposure
Surface density of the radiant energy received. The SI unit of radiant exposure is joules per meter squared (J m^-2), or for convenience joules per centimeter squared (J cm^-2).
Symbol: H
Note: The terms energy density and fluence are sometimes used as synonyms for radiant exposure, although these terms have slightly different technical meanings. The surface density of radiant energy received is synonymous with the radiant energy per unit area incident upon a surface.
Define
Radiant Flux
Power emitted, transferred, or received in the form of radiation expressed in units of watts (W).
Note: Also called radiant power.
Define
Radiant Intensity
(of a source in a given direction)
Quotient of the radiant flux leaving a source and propagated in an element of solid angle containing the given direction, and the element of solid angle expressed in units of watts per steradian (W sr^-1)
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Radiant Power
Power emitted, transferred, or received in the form of radiation.
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Reflectance
The ratio of total reflected radiant power to total incident power.
Also called reflectivity.
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Repetitive Pulse Laser
A laser with multiple pulses of radiant energy occurring in a sequence.
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Service
The performance of those procedures or adjustments described in the manufacturer’s service instructions that may affect any aspect of the performance of the laser or laser system.
These are usually performed by qualified technical personnel provided by the manufacturer or service companies.
It does not include maintenance or operation as defined in this section.
Define
Shall
The word “shall” is to be understood as mandatory.
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Should
The word “should” is to be understood as advisory.
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Specular Reflection
A mirror-like reflection.
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Transmission
Passage of radiation through a medium.
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Transmittance
The ratio of total transmitted radiant power to total incident radiant power.
Symbol: τ
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Ultraviolet (UV) Radiation
Electromagnetic radiation with wavelengths shorter than those of visible radiation; for the purpose of this standard wavelengths between 180 nm and 400 nm.
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Visible Radiation (light)
Electromagnetic radiation that can be detected by the human eye.
This term is commonly used to describe wavelengths that lie in the range of 400 nm to 700 nm.
Define
Watt
The unit of power or radiant flux.
1 watt = 1 J per second
Define
Wavelength
The distance between two successive points on a periodic wave that have the same phase.
Symbol: λ
