Understanding What You Can Monitor To Mitigate Risk
The health and safety of your team is one of the highest priorities in any environment. As an employer, it’s imperative to ensure that health and safety measures are effective to protect your team – especially in high-stress and potentially dangerous environments. Prevention is the best solution given that many incidents can be avoided when armed with the right information. Here we look at some signs and physiological parameters you can monitor to mitigate risk and improve productivity.
Section 1: Core Body Temperature
Core Body Temperature (CBT) is the temperature of the body’s internal organs, including the heart, liver, and brain. For normal function, a person’s CBT should be maintained between 36.5 – 37.5oC / 97.7 – 99.5oF. However, personnel that are exposed to high heat-intensive environments, whether from radiant heat generated by machinery in an industrial environment, or climatic heat emanating from the sun, or a combination of the two, are likely to exceed this normal range. The physiological strain put on the body by heat can negatively impact concentration, productivity and incident rates.
High CBT can lead to heat stress which can have damaging consequences on a person’s health. It can result in the impairment of multiple organs and, in severe cases, lead to death. Measuring CBT is a means of identifying when your team is experiencing heat stress so that early action can be taken.
“Team members that are exposed to extreme heat are at serious risk of short and long-term health complications. This risk is particularly high in settings where teams are wearing heavy clothing and PPE which prevents cooling, during labour-intensive work. The most common approach to assessing risk for heat-related incidents is to measure the external environment. However, the response to the same environment can be very different between individuals due to factors such as age, fluid intake, level of acclimatisation, pre-existing health conditions and medication. The Bodytrak CBT algorithm has been specifically designed for hot industrial environments so that we can monitor, identify, and help employers take preventative action when there’s a potentially dangerous rise in CBT for any team member. Through verification of our solution, we have demonstrated a mean absolute error of 0.18°C compared to gold-standard CBT measures such as an ingestible telemetric temperature pill. From this, we are confident that our non-invasive Bodytrak device and algorithm is a reliable, and cost-effective CBT measure.”James Davis, Senior Physiologist at Bodytrak
Section 2: Heart Rate
Heart Rate (HR) is the number of times that the heart beats per minute. HR adapts to meet the required blood supply of the working muscles, organs and skin so is an effective indicator of workload. Measuring HR regularly is vital for personnel in physically-demanding jobs as it allows the workload of the wearer to be observed and enables HR recovery to be monitored towards resting values.
“Heart rate is a valuable tool to monitor the workload of your team. There are lots of ways to measure heart rate such as using a strap-based sensor outside the torso or in a smartwatch. Alternatively, by using a strap-based sensor around the torso or in a smartwatch. However, accurate readings during strenuous work can be challenging due to signal noise caused by movement. Bodytrak uses a photoplethysmography (PPG) approach, which measures changes in blood flow through light absorption at the skin. The location of the heart rate sensor in the ear is ideal as it is less affected by movement and external light while being situated close to a lot of capillaries. This combination, along with the intelligent algorithm, allows for accurate heart rate readings to be obtained at rest and during strenuous activity.”James Davis, Senior Physiologist at Bodytrak
Section 3: Physiological Strain Index
Physiological strain index (PSI) is a metric calculated using HR and CBT to quantify heat strain during rest, heavy workloads, and recovery. It assesses the strain caused by meeting the demands of the working muscles and maintaining a normal resting CBT. This makes it a useful heat illness prevention tool as it can determine when your team may be experiencing high physiological strain, and as a result struggling to cope with challenging environmental conditions. PSI is a scale with a range of 0-10, where 0 indicates no strain and 10 indicates very strenuous physiological conditions.
“Physiological strain index, developed by Moran et al. (1998a), is used as a method to quantify heat strain, whether it is caused by a heavy workload, environmental conditions, clothing, or a combination. We calculate it in real-time, which means that quick action can be taken when team members are experiencing a raised physiological strain and are at increased risk of a heat-related illness. PSI is effective at both rest and during recovery so the individual’s return to a low physiological strain after heat stress can be monitored.”James Davis, Senior Physiologist at Bodytrak
Section 4: Fatigue
Measuring fatigue levels can help detect a lapse in energy, or an overwhelming need to sleep as a result of physical or mental exertion. At times this can be overlooked. However, fatigue which negatively impacts cognitive task performance, reaction times, concentration, memory and judgement often increase the likelihood of an occupational accident. Currently, there are no simple or common ways to measure fatigue and such, no gold standard. Detecting when personnel are fatigued ensures their health and safety and improves overall productivity. This data can also be used to identify and address the underlying causes of fatigue and help optimise work patterns and therefore productivity.
Bodytrak uses heart rate variability (HRV) which is a measure of the variation in time between each heartbeat. This variation is controlled by the autonomic nervous system which is divided into the sympathetic and parasympathetic nervous systems. During mental or physical fatigue, an increase in sympathetic nervous system activity and a decrease in parasympathetic nervous activity occurs, which is reflected in the HRV used by Bodytrak to determine fatigue level.
“Fatigue is a hazard in the workplace and should not be underestimated. It can reduce productivity, lead to ill-health and increase the risk of accidents with potentially serious consequences. Taking a proactive approach to identify fatigue early and take preventative action is vital. The Bodytrak fatigue algorithm identifies when team members are drowsy after prolonged, monotonous tasks or mentally fatigued due to exhausting, complex tasks or physically fatigued after strenuous physical activity. The physiological response to fatigue can differ between individuals, so we have developed our algorithm to automatically determine each user’s baseline. This means that we can accurately identify abnormal levels for each user based on their previously collected data.”James Davis, Senior Physiologist at Bodytrak
Section 5: Noise exposure
Working in busy and loud environments can lead to hearing-related health issues as well as physical and psychological stress and a reduction in productivity. It can also contribute to workplace accidents by restricting the ability to hear vital warning signals. Extensive research has shown that exposure to sounds above 85dB (approximately the volume of a hair dryer) for a typical 8-hour working day is considered unsafe. Louder and/or longer exposure can lead to tinnitus (ringing in the ears) as well as temporary or permanent hearing loss.
Accurately measuring the level and length of exposure is extremely important to ensure that the overall exposure is safe and that protective measures (such as earplugs) are suitable. Various instruments can be used, but the most common is a dosimeter which is a device worn by personnel to measure personal noise exposure levels. The Bodytrak solution allows continuous measurement from the proximity of the ear to provide accurate data even when the wearer is moving between different noise sources and whether or not they are wearing ear defenders.
“Hearing is an important sense for our safety and wellbeing, and cannot be repaired once damaged. It is essential to be proactive in monitoring noise and protecting hearing as it is almost always too late once the injury is recognised. By measuring noise exposure at the ear, and incorporating optional hearing protection into the device, Bodytrak makes collecting the valuable exposure data as convenient and discreet as possible so the team can focus on what they do best.”Jack Hallybone, Senior Audio Engineer at Bodytrak
To learn more about physiological parameters and how this can help mitigate risk in the workplace contact the Bodytrak team today.
Moran DS, Shitzer A, Pandolf KB. (a) A physiological strain index to evaluate heat stress. Am J Physiol Regul Integr Comp Physiol. 1998;275:R129–34.