FATIGUE MONITORING
Alertness for life
Fatigue monitoring in mining , both reactive and predictive , has moved well beyond a few trials and first adopters . It is now seen as an intrinsic part of most major mine health and safety plans and is helping instil a new culture of managing tiredness and drowsiness among operators , reports Paul Moore
In mining fleet fatigue monitoring , there are so-called predictive ( some technology providers prefer to call the more comprehensive versions proactive ) systems that warn operators of the increased likelihood of a fatigue related event such as those based on wearables monitoring sleep data , eye movements or even voice monitoring carried out pre-shift ; and reactive systems that monitor operators in real time in the equipment cab then react to a microsleep incident having occurred or about to occur – these are mainly based on cameras monitoring eye and head movements .
While in the past , operations tended to mainly look at reactive systems as immediate action to try to bring down fatigue related incidents , today , most operations are moving towards having a combination of both – with fatigue monitoring becoming much more part of the overall minesite health and safety plan and management approach – control of fatigue is increasingly seen as just as important as wearing PPE or testing for drugs and alcohol . This is reflected in the fact that most mining company sustainability reports now mention fatigue monitoring specifically .
The industry has also moved on from just conducting a few exploratory trials here and there , to choosing one set of technologies and rolling it out across the entire fleet . There remains some use of different technologies at different minesites within the same mining group – while others have opted to standardise across all their operations – Newmont using
Caterpillar ’ s Driver Safety System ( DSS ) worldwide being a good example .
These trends have also been reflected in technology provider activity ; with major players acquiring fatigue monitoring technology companies or at least deepening partnerships , so as to be able to offer mining clients a fatigue monitoring solution as part of a package that mayalso include collision avoidance systems , fleet management systems etc . Hexagon as an example acquired Guardvant and its leading OAS reactive system in 2018 , but in May 2021 also signed a partnership with Fatigue Science to offer its Readi platform for predictive fatigue management globally . Caterpillar owns the technology and IP for DSS in mining , part of its MineStar™ Detect portfolio of safety technologies and services but still works with the original developer Seeing Machines on R & D . It also uses Fatigue Science technology in its Smartband wearable predictive offering to complement its market leading DSS reactive system while Fatigue Science recently rolled out its ReadiWatch offering , replacing its ReadiBand . In May 2021 , Hitachi-owned Wenco acquired another industry leader , SmartCap , which uses electroencephalogram ( EEG ) monitoring to assess fatigue levels either in a cap / hard hat and / or wrist Lifeband as part of its overall Life fatigue management solution .
Finally , as the industry has evolved , the focus has moved from the heavy mining trucks to light and other vehicles on minesites – these fatigue monitoring systems tend to be simpler and with
Mechanical engineer Odilson Ribeiro wearing a fatigue monitoring SmartCap at Anglo American ' s Barro Alto nickel operation in Brazil
less hardware , but also cheaper , due to there being much larger numbers of vehicles involved . But they are based on the same technologies . In October 2020 , Caterpillar entered into an agreement with Seeing Machines to deliver and support light vehicle and on-highway driver fatigue and distraction monitoring technology through Cat ® dealers . Just like DSS , Seeing Machines ’ Guardian 2 system is an advanced , non-intrusive system that senses operator movements and analyses them for symptoms of fatigue or distraction in light vehicle applications . Seat vibration and audio alarms alert operators when a microsleep or distraction event is detected to effectively reduce dangerous and costly incidents . Hexagon offers its HxGN MineProtect Operator Alertness System for Light Vehicle or OAS-LV . Rollout of the light vehicle systems is still patchy , largely because the perceived need by mines is not as great given that unlike the mining trucks these vehicles are not being operated for 8 or 12 hour shifts , plus it is complicated by the fact that many of the these non-primary fleet vehicles are operated by contractors or other service providers . But the comprehensive use of fatigue monitoring across all vehicles in mining is inevitable as an important part of ensuring safety .
MUSA relies on Optalert
One of the fatigue monitoring technologies that has been in mining and other industries for the longest period , and which remains independent , is Australia ’ s Optalert – a technology commercially available since 2008 which grew out of the research and clinical trials of Dr Murray Johns , a world-renowned authority on sleep medicine . During his 40 years as a clinician , Dr Johns developed a special interest in the state of drowsiness and its associated dangers for people whose very lives depend on them remaining awake at the appropriate time . While in recent years its major focus has been on systems measuring drowsiness or wakefulness for pharmaceutical drug trials , mining is still a key market for the company .
Optalert ’ s drowsiness detection glasses work by measuring the velocity of the operator ’ s eyelid 500 times a second using a tiny invisible LED built into the frame of the glasses . “ Core to the success of our wearable technology are two key measurements tracking the amplitude velocity ratio - essentially measuring how fast and how far a person opens their eyelid after they close it .” These are translated into a score measured on the Johns Drowsiness Scale ( JDS ), which the operator sees displayed on their indicator or processor positioned in the cab .
JANUARY 2022 | International Mining 63