The threshold for laser-induced thermal retinal injury varies with the duration of the laser exposure and the MPEs as given in the laser safety guidelines are expected to define exposure levels not anticipated to result in retinal injury across the entire range of exposure durations. The form of the time dependence of the MPE for laser retinal exposures was established in 1972 based on the experimentally determined threshold data available at that time. More threshold data has accumulated since 1972. This paper compares the currently available time dependent threshold data to the MPE as defined in the most recent version of the laser safety guidelinesThe threshold for laser-induced thermal retinal injury varies with the duration of the laser exposure and the MPEs as given in the laser safety guidelines are expected to define exposure levels not anticipated to result in retinal injury across the entire range of exposure durations. The form of the time dependence of the MPE for laser retinal exposures was established in 1972 based on the experimentally determined threshold data available at that time. More threshold data has accumulated since 1972. This paper compares the currently available time dependent threshold data to the MPE as defined in the most recent version of the laser safety guidelines
{"title":"Time dependence of laser-induced retinal thermal injury","authors":"D. J. Lund","doi":"10.2351/1.5118563","DOIUrl":"https://doi.org/10.2351/1.5118563","url":null,"abstract":"The threshold for laser-induced thermal retinal injury varies with the duration of the laser exposure and the MPEs as given in the laser safety guidelines are expected to define exposure levels not anticipated to result in retinal injury across the entire range of exposure durations. The form of the time dependence of the MPE for laser retinal exposures was established in 1972 based on the experimentally determined threshold data available at that time. More threshold data has accumulated since 1972. This paper compares the currently available time dependent threshold data to the MPE as defined in the most recent version of the laser safety guidelinesThe threshold for laser-induced thermal retinal injury varies with the duration of the laser exposure and the MPEs as given in the laser safety guidelines are expected to define exposure levels not anticipated to result in retinal injury across the entire range of exposure durations. The form of the time dependence of the MPE for laser retinal exposures was established in 1972 based on the experimentally determined threshold data available at that time. More threshold data has accumulated since 1972. This paper compares the currently available time dependent threshold data to the MPE as defined in the most recent version of the laser safety guidelines","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121617370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Schulmeister, Mathieu Jean, D. J. Lund, B. Stuck
A computer model that predicts thresholds for laser induced corneal injury in the infrared wavelength range was used to systematically analyze wavelength, pulse duration and beam diameter dependencies. The thresholds were compared with the respective maximum permissible exposure (MPE) values promulgated by ANSI Z136.1-2014, ICNIRP 2013 and IEC 60825-1:2014, with an emphasis on the wavelength range of 1250 nm to 1400 nm, where a limit additional to the retinal limit is needed to protect the cornea. The ANSI standard features a dedicated limit to protect the cornea for wavelengths less than 1400 nm, ICNIRP recommends to use the skin MPEs, and IEC 60825-1:2014, for classification of laser products as Class 1, specifies Class 3B AELs as dual limit. Comparison with injury thresholds shows that the ANSI MPEs provide for an ample reduction factor for all wavelengths. Due to the 7 mm aperture stop defined in IEC 60825-1, levels permitted by the Class 3B limit exceed predicted injury thresholds for small beam diameters and wavelengths between about 1350 nm to 1400 nm even for short exposure durations so that in this case, the Class 3B AEL does not appear to be an appropriate limit. For beam diameters of about 4 mm and larger and wavelengths of less than about 1360 nm, the Class 3B limit affords sufficient protection. For the skin MPEs, the margin between corneal injury thresholds and MPEs decreases steadily for wavelength approaching 1400 nm. However, normal eye movements can be expected to reduce the effective exposure to remain below injury thresholds so that the skin MPEs can serve as adequate and simple dual limit to protect the cornea for wavelengths less than 1400 nm.A computer model that predicts thresholds for laser induced corneal injury in the infrared wavelength range was used to systematically analyze wavelength, pulse duration and beam diameter dependencies. The thresholds were compared with the respective maximum permissible exposure (MPE) values promulgated by ANSI Z136.1-2014, ICNIRP 2013 and IEC 60825-1:2014, with an emphasis on the wavelength range of 1250 nm to 1400 nm, where a limit additional to the retinal limit is needed to protect the cornea. The ANSI standard features a dedicated limit to protect the cornea for wavelengths less than 1400 nm, ICNIRP recommends to use the skin MPEs, and IEC 60825-1:2014, for classification of laser products as Class 1, specifies Class 3B AELs as dual limit. Comparison with injury thresholds shows that the ANSI MPEs provide for an ample reduction factor for all wavelengths. Due to the 7 mm aperture stop defined in IEC 60825-1, levels permitted by the Class 3B limit exceed predicted injury thresholds for small beam diam...
{"title":"Comparison of corneal injury thresholds with laser safety limits","authors":"K. Schulmeister, Mathieu Jean, D. J. Lund, B. Stuck","doi":"10.2351/1.5118573","DOIUrl":"https://doi.org/10.2351/1.5118573","url":null,"abstract":"A computer model that predicts thresholds for laser induced corneal injury in the infrared wavelength range was used to systematically analyze wavelength, pulse duration and beam diameter dependencies. The thresholds were compared with the respective maximum permissible exposure (MPE) values promulgated by ANSI Z136.1-2014, ICNIRP 2013 and IEC 60825-1:2014, with an emphasis on the wavelength range of 1250 nm to 1400 nm, where a limit additional to the retinal limit is needed to protect the cornea. The ANSI standard features a dedicated limit to protect the cornea for wavelengths less than 1400 nm, ICNIRP recommends to use the skin MPEs, and IEC 60825-1:2014, for classification of laser products as Class 1, specifies Class 3B AELs as dual limit. Comparison with injury thresholds shows that the ANSI MPEs provide for an ample reduction factor for all wavelengths. Due to the 7 mm aperture stop defined in IEC 60825-1, levels permitted by the Class 3B limit exceed predicted injury thresholds for small beam diameters and wavelengths between about 1350 nm to 1400 nm even for short exposure durations so that in this case, the Class 3B AEL does not appear to be an appropriate limit. For beam diameters of about 4 mm and larger and wavelengths of less than about 1360 nm, the Class 3B limit affords sufficient protection. For the skin MPEs, the margin between corneal injury thresholds and MPEs decreases steadily for wavelength approaching 1400 nm. However, normal eye movements can be expected to reduce the effective exposure to remain below injury thresholds so that the skin MPEs can serve as adequate and simple dual limit to protect the cornea for wavelengths less than 1400 nm.A computer model that predicts thresholds for laser induced corneal injury in the infrared wavelength range was used to systematically analyze wavelength, pulse duration and beam diameter dependencies. The thresholds were compared with the respective maximum permissible exposure (MPE) values promulgated by ANSI Z136.1-2014, ICNIRP 2013 and IEC 60825-1:2014, with an emphasis on the wavelength range of 1250 nm to 1400 nm, where a limit additional to the retinal limit is needed to protect the cornea. The ANSI standard features a dedicated limit to protect the cornea for wavelengths less than 1400 nm, ICNIRP recommends to use the skin MPEs, and IEC 60825-1:2014, for classification of laser products as Class 1, specifies Class 3B AELs as dual limit. Comparison with injury thresholds shows that the ANSI MPEs provide for an ample reduction factor for all wavelengths. Due to the 7 mm aperture stop defined in IEC 60825-1, levels permitted by the Class 3B limit exceed predicted injury thresholds for small beam diam...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126288963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CoLaSE (Common Laser Safety Environment) is a hardware and software solution to understand and manage real-time laser safety risk, as driven by the source.CoLaSE (Common Laser Safety Environment) is a hardware and software solution to understand and manage real-time laser safety risk, as driven by the source.
{"title":"CoLaSE (common laser safety environment)","authors":"Scott Wohlstein","doi":"10.2351/1.5118541","DOIUrl":"https://doi.org/10.2351/1.5118541","url":null,"abstract":"CoLaSE (Common Laser Safety Environment) is a hardware and software solution to understand and manage real-time laser safety risk, as driven by the source.CoLaSE (Common Laser Safety Environment) is a hardware and software solution to understand and manage real-time laser safety risk, as driven by the source.","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129812053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background Laser irradiation of implants has been used in conjunction with mechanical debridement for treatment of peri-implantitis. The heat transferred to the peri-implant bone can cause iatrogenic damage to the patient. The aim of this study was to assess the influence of intra-bony defect morphology on temperature change (ΔT) of irradiated implants using a CO2−laser and to use this data to establish a safe protocol for laser decontamination. Materials and Methods Five separate defects (circumferential, one-walled, two-walled, three-walled or horizontal defect) were created around dental implants that were placed into a synthetic (bovine) bone analogue that mimics type II quality bone. Each implant surface and the surrounding bone were irradiated by a non-contact CO2−laser (2W power in continuous and pulsed mode, defocused beam) for 30 and 60 seconds. Results The most substantial pulse setting-induced temperature differences (30s) of the apical thermocouple were observed in the 2- and 3- wall defect. This was also seen at the 60s mark. Similar temperature changes were not observed at the apical thermocouple of circumferential, one-wall and horizontal defects using the pulse setting. ΔT at the coronal part of the implant during pulsed laser irradiation recorded less than 10°C. In contrast, the continuous mode was associated with ΔT over 10°C for circumferential, 3-walled and 2-walled defects during 30sec irradiation and over the critical threshold within 60sec of irradiation. In the apical area, the continuous mode created ΔT over 10°C in 3-wall or circumferential defects. Conclusions According to the results of this study, the morphology of the peri-implant defect appears to affect the resultant heat dissemination on an implant. The architecture of the peri-implant defect should influence the protocol with the CO2-laser treatment modality. Pulsed mode setting is ideal for all laser assisted peri-implant decontamination. It is important to consider that circumferential, two-and three-walled defects may have a greater risk for heat-induced implant failure and therefore irradiation should be kept within 30 second-bursts. Background Laser irradiation of implants has been used in conjunction with mechanical debridement for treatment of peri-implantitis. The heat transferred to the peri-implant bone can cause iatrogenic damage to the patient. The aim of this study was to assess the influence of intra-bony defect morphology on temperature change (ΔT) of irradiated implants using a CO2−laser and to use this data to establish a safe protocol for laser decontamination. Materials and Methods Five separate defects (circumferential, one-walled, two-walled, three-walled or horizontal defect) were created around dental implants that were placed into a synthetic (bovine) bone analogue that mimics type II quality bone. Each implant surface and the surrounding bone were irradiated by a non-contact CO2−laser (2W power in continuous and pulsed mode, defocused bea
{"title":"The safety implications of peri-implant defect morphology on temperature changes during CO2-Laser decontamination","authors":"G. Romanos, Edmond Rexha","doi":"10.2351/1.5118630","DOIUrl":"https://doi.org/10.2351/1.5118630","url":null,"abstract":"Background Laser irradiation of implants has been used in conjunction with mechanical debridement for treatment of peri-implantitis. The heat transferred to the peri-implant bone can cause iatrogenic damage to the patient. The aim of this study was to assess the influence of intra-bony defect morphology on temperature change (ΔT) of irradiated implants using a CO2−laser and to use this data to establish a safe protocol for laser decontamination. Materials and Methods Five separate defects (circumferential, one-walled, two-walled, three-walled or horizontal defect) were created around dental implants that were placed into a synthetic (bovine) bone analogue that mimics type II quality bone. Each implant surface and the surrounding bone were irradiated by a non-contact CO2−laser (2W power in continuous and pulsed mode, defocused beam) for 30 and 60 seconds. Results The most substantial pulse setting-induced temperature differences (30s) of the apical thermocouple were observed in the 2- and 3- wall defect. This was also seen at the 60s mark. Similar temperature changes were not observed at the apical thermocouple of circumferential, one-wall and horizontal defects using the pulse setting. ΔT at the coronal part of the implant during pulsed laser irradiation recorded less than 10°C. In contrast, the continuous mode was associated with ΔT over 10°C for circumferential, 3-walled and 2-walled defects during 30sec irradiation and over the critical threshold within 60sec of irradiation. In the apical area, the continuous mode created ΔT over 10°C in 3-wall or circumferential defects. Conclusions According to the results of this study, the morphology of the peri-implant defect appears to affect the resultant heat dissemination on an implant. The architecture of the peri-implant defect should influence the protocol with the CO2-laser treatment modality. Pulsed mode setting is ideal for all laser assisted peri-implant decontamination. It is important to consider that circumferential, two-and three-walled defects may have a greater risk for heat-induced implant failure and therefore irradiation should be kept within 30 second-bursts. Background Laser irradiation of implants has been used in conjunction with mechanical debridement for treatment of peri-implantitis. The heat transferred to the peri-implant bone can cause iatrogenic damage to the patient. The aim of this study was to assess the influence of intra-bony defect morphology on temperature change (ΔT) of irradiated implants using a CO2−laser and to use this data to establish a safe protocol for laser decontamination. Materials and Methods Five separate defects (circumferential, one-walled, two-walled, three-walled or horizontal defect) were created around dental implants that were placed into a synthetic (bovine) bone analogue that mimics type II quality bone. Each implant surface and the surrounding bone were irradiated by a non-contact CO2−laser (2W power in continuous and pulsed mode, defocused bea","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123132803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Responding to accidents is an important element of any organization’s safety program. Robust emergency response plans are developed for accident scenarios involving fire, natural disasters, chemical spills or radiological contamination. Yet few institutions can point to a comparable plan for incidents resulting in a laser-related injury. Laser-related incidents are happening at a frequency that warrants the development of an institutional process for responding to laser accidents. Is the Laser Safety Officer (LSO) prepared to take that call and respond to an injury? Laser-related accidents often require a medical diagnosis. Have medical staff capable of providing diagnosis and effective care been identified?The Lawrence Berkeley National Lab (LBNL) has adopted a structured approach to provide guidance for initial response, conducting investigations, and implementation (and verification) of corrective actions. This process may also be used for investigating near misses, management concerns, or notable events. It was developed using the basic principles of incident response involving an injured or contaminated individual; resulting in a process familiar to industrial hygienists, health physicists, or other safety-trained personnel. The approach allows for a graded, flexible plan that can be adapted to serve any institution.Responding to accidents is an important element of any organization’s safety program. Robust emergency response plans are developed for accident scenarios involving fire, natural disasters, chemical spills or radiological contamination. Yet few institutions can point to a comparable plan for incidents resulting in a laser-related injury. Laser-related incidents are happening at a frequency that warrants the development of an institutional process for responding to laser accidents. Is the Laser Safety Officer (LSO) prepared to take that call and respond to an injury? Laser-related accidents often require a medical diagnosis. Have medical staff capable of providing diagnosis and effective care been identified?The Lawrence Berkeley National Lab (LBNL) has adopted a structured approach to provide guidance for initial response, conducting investigations, and implementation (and verification) of corrective actions. This process may also be used for investigating near misses, management concerns, or notable even...
{"title":"You just had a laser accident, what do you do now?","authors":"Rock Neveau, G. Toncheva, Robert FairchildIII","doi":"10.2351/1.5118658","DOIUrl":"https://doi.org/10.2351/1.5118658","url":null,"abstract":"Responding to accidents is an important element of any organization’s safety program. Robust emergency response plans are developed for accident scenarios involving fire, natural disasters, chemical spills or radiological contamination. Yet few institutions can point to a comparable plan for incidents resulting in a laser-related injury. Laser-related incidents are happening at a frequency that warrants the development of an institutional process for responding to laser accidents. Is the Laser Safety Officer (LSO) prepared to take that call and respond to an injury? Laser-related accidents often require a medical diagnosis. Have medical staff capable of providing diagnosis and effective care been identified?The Lawrence Berkeley National Lab (LBNL) has adopted a structured approach to provide guidance for initial response, conducting investigations, and implementation (and verification) of corrective actions. This process may also be used for investigating near misses, management concerns, or notable events. It was developed using the basic principles of incident response involving an injured or contaminated individual; resulting in a process familiar to industrial hygienists, health physicists, or other safety-trained personnel. The approach allows for a graded, flexible plan that can be adapted to serve any institution.Responding to accidents is an important element of any organization’s safety program. Robust emergency response plans are developed for accident scenarios involving fire, natural disasters, chemical spills or radiological contamination. Yet few institutions can point to a comparable plan for incidents resulting in a laser-related injury. Laser-related incidents are happening at a frequency that warrants the development of an institutional process for responding to laser accidents. Is the Laser Safety Officer (LSO) prepared to take that call and respond to an injury? Laser-related accidents often require a medical diagnosis. Have medical staff capable of providing diagnosis and effective care been identified?The Lawrence Berkeley National Lab (LBNL) has adopted a structured approach to provide guidance for initial response, conducting investigations, and implementation (and verification) of corrective actions. This process may also be used for investigating near misses, management concerns, or notable even...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125659771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When discussing controls for your typical Class 4 laser, one can usually rely on commercially available products to fill the need. However, in the realm of very high-output lasers (Class 5?) things get complicated. This is especially true with today’s graphical user interface (GUI) controlled lasers. GUIs can be complicated and designed without safety in mind. Component failure is a very real thing, especially in the world of research and development (R&D). A risk assessment (RA) or failure modes and effects analysis (FMEA) is a definite requirement now.Neither the American National Standards Institute (ANSI) Z136.1-2014 nor ANSI Z136.8-2012 offer real guidance for very high-output lasers, except for calling out the use of a Danger sign. With the price per watt/Joule decreasing at a rapid pace, high average power and high intensity lasers are fast becoming common place. This paper will discuss these lasers that are truly dangerous to life and health and the controls that are needed to operate them safety.When discussing controls for your typical Class 4 laser, one can usually rely on commercially available products to fill the need. However, in the realm of very high-output lasers (Class 5?) things get complicated. This is especially true with today’s graphical user interface (GUI) controlled lasers. GUIs can be complicated and designed without safety in mind. Component failure is a very real thing, especially in the world of research and development (R&D). A risk assessment (RA) or failure modes and effects analysis (FMEA) is a definite requirement now.Neither the American National Standards Institute (ANSI) Z136.1-2014 nor ANSI Z136.8-2012 offer real guidance for very high-output lasers, except for calling out the use of a Danger sign. With the price per watt/Joule decreasing at a rapid pace, high average power and high intensity lasers are fast becoming common place. This paper will discuss these lasers that are truly dangerous to life and health and the controls that are needed to operate them safety.
{"title":"Beyond class 4, laser safety controls for very high-power lasers","authors":"Jamie J. KingCLSO","doi":"10.2351/1.5118664","DOIUrl":"https://doi.org/10.2351/1.5118664","url":null,"abstract":"When discussing controls for your typical Class 4 laser, one can usually rely on commercially available products to fill the need. However, in the realm of very high-output lasers (Class 5?) things get complicated. This is especially true with today’s graphical user interface (GUI) controlled lasers. GUIs can be complicated and designed without safety in mind. Component failure is a very real thing, especially in the world of research and development (R&D). A risk assessment (RA) or failure modes and effects analysis (FMEA) is a definite requirement now.Neither the American National Standards Institute (ANSI) Z136.1-2014 nor ANSI Z136.8-2012 offer real guidance for very high-output lasers, except for calling out the use of a Danger sign. With the price per watt/Joule decreasing at a rapid pace, high average power and high intensity lasers are fast becoming common place. This paper will discuss these lasers that are truly dangerous to life and health and the controls that are needed to operate them safety.When discussing controls for your typical Class 4 laser, one can usually rely on commercially available products to fill the need. However, in the realm of very high-output lasers (Class 5?) things get complicated. This is especially true with today’s graphical user interface (GUI) controlled lasers. GUIs can be complicated and designed without safety in mind. Component failure is a very real thing, especially in the world of research and development (R&D). A risk assessment (RA) or failure modes and effects analysis (FMEA) is a definite requirement now.Neither the American National Standards Institute (ANSI) Z136.1-2014 nor ANSI Z136.8-2012 offer real guidance for very high-output lasers, except for calling out the use of a Danger sign. With the price per watt/Joule decreasing at a rapid pace, high average power and high intensity lasers are fast becoming common place. This paper will discuss these lasers that are truly dangerous to life and health and the controls that are needed to operate them safety.","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"59 12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134056917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laser Safety assessments of systems and the consequential control methods are mostly dominated by the direct optical radiation hazard. The general work place safety environment now has an all hazards culture which looks at all equipment including laser systems as completely self-contained and inherently safe. A mismatch of hazard perception and safety solutions gives rise to typical families of laser process associated hazards which is the region where fatalities and major injuries occur. This can, for example, be highlighted with a ‘Fortress Approach’ to laser safety, in which containment of the radiation dominates the control engineering and fails to deal with a range of other process generated hazards and the fortress now contains as well as concentrates these hazards often leading to serious long term injury and death.The perception of Laser Safety has not really changed in the last 40 years, neither have the attitudes to tackling Laser Safety issues, consequently the protection strategy is dominated with the requirement of user goggles. This approach is generally produced as a consequence of subject specific specialists not appreciating the wider safety problems. This has little influence on improving the overall safety culture in this sector. In contrast general safety culture has in the last 15 years harnessed a more progressive hazard and risk based approach. Laser radiation safety remains fixed around the Maximum Permissible Exposure concept (MPE)Perceptions prompt behaviour, and repeated behaviours become habits and take on attitudinal labels. Traditional measurement tools used for behavioural safety have a major limitation. That is, they focus on behaviours that are relevant only to those people who have problems doing them regularly, e.g. working with laser safety goggles on.A lack of relevance, increases the chances of people perceiving low value in the process, and can decrease participation in it.Safety culture improvement can be better understood by using a model to represent the process. Loughborough University in conjunction with public health England have identified a process which seeks to identify the hazards associated with; the laser, the beam delivery, the laser process, the environment and finally all people involved.It is usually the process with which the laser is involved/initiating, which determines the complete hazard family associated with the laser process. The laser is normally used within a process to monitor target activity, control the environment or process or induce some material/energy interaction. An alternative way of categorising the process is to examine the material/energy interaction. Thus a low level of interaction means the process is really determined by the detector limits, a median level is where energy absorption is beginning to interact with the material and a high level of absorption is where phase changes in the material (such as heating, melting, evaporation and plasma) take place. The proces
{"title":"Laser safety fortresses can be dangerous","authors":"J. Tyrer","doi":"10.2351/1.5118600","DOIUrl":"https://doi.org/10.2351/1.5118600","url":null,"abstract":"Laser Safety assessments of systems and the consequential control methods are mostly dominated by the direct optical radiation hazard. The general work place safety environment now has an all hazards culture which looks at all equipment including laser systems as completely self-contained and inherently safe. A mismatch of hazard perception and safety solutions gives rise to typical families of laser process associated hazards which is the region where fatalities and major injuries occur. This can, for example, be highlighted with a ‘Fortress Approach’ to laser safety, in which containment of the radiation dominates the control engineering and fails to deal with a range of other process generated hazards and the fortress now contains as well as concentrates these hazards often leading to serious long term injury and death.The perception of Laser Safety has not really changed in the last 40 years, neither have the attitudes to tackling Laser Safety issues, consequently the protection strategy is dominated with the requirement of user goggles. This approach is generally produced as a consequence of subject specific specialists not appreciating the wider safety problems. This has little influence on improving the overall safety culture in this sector. In contrast general safety culture has in the last 15 years harnessed a more progressive hazard and risk based approach. Laser radiation safety remains fixed around the Maximum Permissible Exposure concept (MPE)Perceptions prompt behaviour, and repeated behaviours become habits and take on attitudinal labels. Traditional measurement tools used for behavioural safety have a major limitation. That is, they focus on behaviours that are relevant only to those people who have problems doing them regularly, e.g. working with laser safety goggles on.A lack of relevance, increases the chances of people perceiving low value in the process, and can decrease participation in it.Safety culture improvement can be better understood by using a model to represent the process. Loughborough University in conjunction with public health England have identified a process which seeks to identify the hazards associated with; the laser, the beam delivery, the laser process, the environment and finally all people involved.It is usually the process with which the laser is involved/initiating, which determines the complete hazard family associated with the laser process. The laser is normally used within a process to monitor target activity, control the environment or process or induce some material/energy interaction. An alternative way of categorising the process is to examine the material/energy interaction. Thus a low level of interaction means the process is really determined by the detector limits, a median level is where energy absorption is beginning to interact with the material and a high level of absorption is where phase changes in the material (such as heating, melting, evaporation and plasma) take place. The proces","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114550221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laser Technology and Safety, the First Half-Century, or so …Lasers were ‘invented’, when a (not-without-a-progenitor-controversy) group of scientists working in the late 1950’s and early 1960’s demonstrated the first devices producing light amplification by stimulated emission of radiation.This, of course, was hailed as a leap for technological advancement, but for some time thereafter, lasers were affectionately regarded as “a brilliant solution, looking for a problem” as uses for the new optical radiation technology slowly evolved out of the laboratories, to the application labs, and finally blossomed onto the wide-ranging scope of commercial and scientific uses.Unlike prior “ages”, since the dawn of industrialization in 1750, the Laser Age was blessed with sufficiently conscientious people who almost simultaneously engaged in major safety efforts, to ensure the technology was implemented without the death and destruction that had followed much of the earlier breakthroughs (mine deaths, train disasters, nuclear and other ionizing radiation exposures, etc.)As we walk forward through the history of developments in the laser industry, and its ancillary technologies in computer tech, vision systems, metrology, robotics, 3D, AI, medicine, displays, moving platforms….and so on, its interesting to note the simultaneous or anticipatory projection of organized safety concern both governmental and non-governmentLaser Technology and Safety, the First Half-Century, or so …Lasers were ‘invented’, when a (not-without-a-progenitor-controversy) group of scientists working in the late 1950’s and early 1960’s demonstrated the first devices producing light amplification by stimulated emission of radiation.This, of course, was hailed as a leap for technological advancement, but for some time thereafter, lasers were affectionately regarded as “a brilliant solution, looking for a problem” as uses for the new optical radiation technology slowly evolved out of the laboratories, to the application labs, and finally blossomed onto the wide-ranging scope of commercial and scientific uses.Unlike prior “ages”, since the dawn of industrialization in 1750, the Laser Age was blessed with sufficiently conscientious people who almost simultaneously engaged in major safety efforts, to ensure the technology was implemented without the death and destruction that had followed much of the earlier breakthroughs (mine deaths, train disasters,...
{"title":"Laser technology and safety, the first half-century, or so…","authors":"T. Lieb","doi":"10.2351/1.5118602","DOIUrl":"https://doi.org/10.2351/1.5118602","url":null,"abstract":"Laser Technology and Safety, the First Half-Century, or so …Lasers were ‘invented’, when a (not-without-a-progenitor-controversy) group of scientists working in the late 1950’s and early 1960’s demonstrated the first devices producing light amplification by stimulated emission of radiation.This, of course, was hailed as a leap for technological advancement, but for some time thereafter, lasers were affectionately regarded as “a brilliant solution, looking for a problem” as uses for the new optical radiation technology slowly evolved out of the laboratories, to the application labs, and finally blossomed onto the wide-ranging scope of commercial and scientific uses.Unlike prior “ages”, since the dawn of industrialization in 1750, the Laser Age was blessed with sufficiently conscientious people who almost simultaneously engaged in major safety efforts, to ensure the technology was implemented without the death and destruction that had followed much of the earlier breakthroughs (mine deaths, train disasters, nuclear and other ionizing radiation exposures, etc.)As we walk forward through the history of developments in the laser industry, and its ancillary technologies in computer tech, vision systems, metrology, robotics, 3D, AI, medicine, displays, moving platforms….and so on, its interesting to note the simultaneous or anticipatory projection of organized safety concern both governmental and non-governmentLaser Technology and Safety, the First Half-Century, or so …Lasers were ‘invented’, when a (not-without-a-progenitor-controversy) group of scientists working in the late 1950’s and early 1960’s demonstrated the first devices producing light amplification by stimulated emission of radiation.This, of course, was hailed as a leap for technological advancement, but for some time thereafter, lasers were affectionately regarded as “a brilliant solution, looking for a problem” as uses for the new optical radiation technology slowly evolved out of the laboratories, to the application labs, and finally blossomed onto the wide-ranging scope of commercial and scientific uses.Unlike prior “ages”, since the dawn of industrialization in 1750, the Laser Age was blessed with sufficiently conscientious people who almost simultaneously engaged in major safety efforts, to ensure the technology was implemented without the death and destruction that had followed much of the earlier breakthroughs (mine deaths, train disasters,...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122607278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Tyrer, Lewis C. R. Jones, J. Edwards, A. Beswick, D. Bard, J. Britton
The use of laser processes for surgical, medical and cosmetic procedures has been increasing with five hundred thousand workers exposed to laser surgical smoke per year. The use of lasers introduces direct beam hazards into the environment but also generates unique hazards such as material ejected from the laser process. Within this material can be potentially harmful particulate when inhaled by humans, accompanying this particulate is a foul unwanted odour. Along with the generation of these particles it is extremely possible for viable biological organisms to be generated with the particulate. Airborne particulate matter or bio-aerosols are not just a hazard to the patient, but also to other people in the environment around the laser process.The aim of this paper is to investigate and quantify the aerosol danger to both patients and operators when utilising lasers within surgical procedures, while suggesting a suitable initial solution. The tailored research for this aim will focus on whether a suitable extraction system can be developed and the effects that different types of lasers have on the size and visuals of any particulate generated. To determine whether there is a risk of infection and to ascertain the level of infection control, the possibility of viable bio-aerosols being detected after a laser process should be considered. The experiments are split into 3 sections; section 1 is the testing of the extraction system using a smoke generation system to ascertain visual proof of a functioning extraction system, section 2 is the testing of the effect of laser irradiance on the tissue simulant to determine the effect of varying laser types on the particulate generated and section 3 is the generation and measurement of bio-aerosols with the use of bio markers to test for survival of laser processing and transmission.The use of laser processes for surgical, medical and cosmetic procedures has been increasing with five hundred thousand workers exposed to laser surgical smoke per year. The use of lasers introduces direct beam hazards into the environment but also generates unique hazards such as material ejected from the laser process. Within this material can be potentially harmful particulate when inhaled by humans, accompanying this particulate is a foul unwanted odour. Along with the generation of these particles it is extremely possible for viable biological organisms to be generated with the particulate. Airborne particulate matter or bio-aerosols are not just a hazard to the patient, but also to other people in the environment around the laser process.The aim of this paper is to investigate and quantify the aerosol danger to both patients and operators when utilising lasers within surgical procedures, while suggesting a suitable initial solution. The tailored research for this aim will focus on whether a suitable...
{"title":"Viable pathogen aerosols produced during laser dermatology surgery – A quantified analysis","authors":"J. Tyrer, Lewis C. R. Jones, J. Edwards, A. Beswick, D. Bard, J. Britton","doi":"10.2351/1.5118631","DOIUrl":"https://doi.org/10.2351/1.5118631","url":null,"abstract":"The use of laser processes for surgical, medical and cosmetic procedures has been increasing with five hundred thousand workers exposed to laser surgical smoke per year. The use of lasers introduces direct beam hazards into the environment but also generates unique hazards such as material ejected from the laser process. Within this material can be potentially harmful particulate when inhaled by humans, accompanying this particulate is a foul unwanted odour. Along with the generation of these particles it is extremely possible for viable biological organisms to be generated with the particulate. Airborne particulate matter or bio-aerosols are not just a hazard to the patient, but also to other people in the environment around the laser process.The aim of this paper is to investigate and quantify the aerosol danger to both patients and operators when utilising lasers within surgical procedures, while suggesting a suitable initial solution. The tailored research for this aim will focus on whether a suitable extraction system can be developed and the effects that different types of lasers have on the size and visuals of any particulate generated. To determine whether there is a risk of infection and to ascertain the level of infection control, the possibility of viable bio-aerosols being detected after a laser process should be considered. The experiments are split into 3 sections; section 1 is the testing of the extraction system using a smoke generation system to ascertain visual proof of a functioning extraction system, section 2 is the testing of the effect of laser irradiance on the tissue simulant to determine the effect of varying laser types on the particulate generated and section 3 is the generation and measurement of bio-aerosols with the use of bio markers to test for survival of laser processing and transmission.The use of laser processes for surgical, medical and cosmetic procedures has been increasing with five hundred thousand workers exposed to laser surgical smoke per year. The use of lasers introduces direct beam hazards into the environment but also generates unique hazards such as material ejected from the laser process. Within this material can be potentially harmful particulate when inhaled by humans, accompanying this particulate is a foul unwanted odour. Along with the generation of these particles it is extremely possible for viable biological organisms to be generated with the particulate. Airborne particulate matter or bio-aerosols are not just a hazard to the patient, but also to other people in the environment around the laser process.The aim of this paper is to investigate and quantify the aerosol danger to both patients and operators when utilising lasers within surgical procedures, while suggesting a suitable initial solution. The tailored research for this aim will focus on whether a suitable...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127510152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elharith M. Ahmed, E. Early, P. Kennedy, R. Thomas
Probabilistic risk assessment is an acceptable technique for laser hazard analysis in uncontrolled environments. Risk is a combination of probability of exposure and probability of an injury resulting from that exposure. A dose-response model quantifies the probability of injury. In the present study, we developed a human dose-response model for laser induced retinal injuries. It consists of two sub-models, one for the mean and the other for the standard deviation of the dose-response probability distribution. The model for the mean fits experimental data to a simple three-parameter expression as a function of wavelength, exposure duration, and retinal tissue type. A scaling factor converts the fit to be appropriate for exposure of humans. A new human vulnerability model, based on the diversity of relevant physical characteristics within the human population, determines the standard deviation. Since the dose-response model is specific to retinal injuries, the variables are refractive error, ocular transmittance, and retinal absorptance. A Monte Carlo simulation with probability distributions for these variables, based on age, determines the standard deviation as a function of wavelength. We present details of the dose-response model along with their application to common human populations.Probabilistic risk assessment is an acceptable technique for laser hazard analysis in uncontrolled environments. Risk is a combination of probability of exposure and probability of an injury resulting from that exposure. A dose-response model quantifies the probability of injury. In the present study, we developed a human dose-response model for laser induced retinal injuries. It consists of two sub-models, one for the mean and the other for the standard deviation of the dose-response probability distribution. The model for the mean fits experimental data to a simple three-parameter expression as a function of wavelength, exposure duration, and retinal tissue type. A scaling factor converts the fit to be appropriate for exposure of humans. A new human vulnerability model, based on the diversity of relevant physical characteristics within the human population, determines the standard deviation. Since the dose-response model is specific to retinal injuries, the variables are refractive error, ocular transmi...
{"title":"Human laser retinal dose-response model","authors":"Elharith M. Ahmed, E. Early, P. Kennedy, R. Thomas","doi":"10.2351/1.5118527","DOIUrl":"https://doi.org/10.2351/1.5118527","url":null,"abstract":"Probabilistic risk assessment is an acceptable technique for laser hazard analysis in uncontrolled environments. Risk is a combination of probability of exposure and probability of an injury resulting from that exposure. A dose-response model quantifies the probability of injury. In the present study, we developed a human dose-response model for laser induced retinal injuries. It consists of two sub-models, one for the mean and the other for the standard deviation of the dose-response probability distribution. The model for the mean fits experimental data to a simple three-parameter expression as a function of wavelength, exposure duration, and retinal tissue type. A scaling factor converts the fit to be appropriate for exposure of humans. A new human vulnerability model, based on the diversity of relevant physical characteristics within the human population, determines the standard deviation. Since the dose-response model is specific to retinal injuries, the variables are refractive error, ocular transmittance, and retinal absorptance. A Monte Carlo simulation with probability distributions for these variables, based on age, determines the standard deviation as a function of wavelength. We present details of the dose-response model along with their application to common human populations.Probabilistic risk assessment is an acceptable technique for laser hazard analysis in uncontrolled environments. Risk is a combination of probability of exposure and probability of an injury resulting from that exposure. A dose-response model quantifies the probability of injury. In the present study, we developed a human dose-response model for laser induced retinal injuries. It consists of two sub-models, one for the mean and the other for the standard deviation of the dose-response probability distribution. The model for the mean fits experimental data to a simple three-parameter expression as a function of wavelength, exposure duration, and retinal tissue type. A scaling factor converts the fit to be appropriate for exposure of humans. A new human vulnerability model, based on the diversity of relevant physical characteristics within the human population, determines the standard deviation. Since the dose-response model is specific to retinal injuries, the variables are refractive error, ocular transmi...","PeriodicalId":118257,"journal":{"name":"International Laser Safety Conference","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128397895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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