WO2016124415A1

WO2016124415A1 - Safety system, workflow management system, safety method and computer program product

Info

Publication number: WO2016124415A1
Application number: PCT/EP2016/051281
Authority: WO
Inventors: Paul Anthony Shrubsole; Luca TIBERI; Ralf Gertruda Hubertus VONCKEN; Maurice Herman Johan Draaijer
Original assignee: Koninklijke Philips N.V.
Priority date: 2015-02-05
Filing date: 2016-01-22
Publication date: 2016-08-11

Abstract

A safety system (100) is disclosed that includes a first sensor arrangement (110, 210) for monitoring a physical activity of a person (10) and generating first sensor signals indicative of the monitored physical activity, a further sensor arrangement (120, 220) for monitoring a concentration level of said person during said physical activity and generating further sensor signals indicative of the monitored concentration level as well as a processor arrangement arranged to receive the first sensor signals and the further sensor signals and adapted to determine a relationship between the first sensor signals and the further sensor signals; and produce an alert signal upon determining a loss of said relationship during the physical activity. A workflow management system including such safety systems, a method for operating such a safety system and a computer program product for executing the method on such a safety system are also disclosed.

Description

Safety system, workflow management system, safety method and computer program product

FIELD OF THE INVENTION

The present invention relates to a safety system for monitoring a concentration level of a person engaged in a physical activity.

The present invention further relates to a workflow management system including such safety systems.

The present invention yet further relates to a method for maintaining the safety of a person performing a physical activity.

The present invention yet further relates to a computer program product for implementing this method when executed on a processor arrangement of a safety system.

BACKGROUND OF THE INVENTION

People are routinely involved in physical activities that require a certain level of concentration to ensure that the person performing the physical activity and/or the environment of this person is kept safe. Examples of such physical activities include but are not limited to the operation of power tools, vehicles and so on, assembly-line work, performing tasks in hazardous locations such as at heights, and so on. For example, when operating a vehicle, a loss of concentration, e.g. due to fatigue, may cause an accident, which may injure the occupants of the vehicle or people otherwise involved in the accident.

Similarly, when operating a power tool, in particular a heavy duty power tool or a cutting or sawing tool, or when performing a task in a potentially hazardous position, such loss of concentration can lead to serious injury.

It is therefore desirable to provide safety systems that can monitor the loss of concentration of a person performing a physical task such that the person can be warned when a loss of concentration is detected, thereby reducing the risk of accidents and injuries caused by the loss of concentration during the performance of such a physical activity.

Several examples of concentration monitoring systems are already known. For example, US 2009/0171232 Al discloses a drowsiness detection system in which an EEG detection circuit detects brain waves of a human brain for getting an EEG signal. The EEG signal is sent to a micro-controller circuit to generate a control signal. In accordance with the control signal, a processing circuit processes the EEG signal so as to learn the drowsiness state of the user in time. The system further includes an alarm unit coupled to the micro-control circuit for generating a warning signal upon detection of the human being fatigued.

US 2014/0023999 Al discloses a neurosensing and feedback device to detect mental states and alert the wearer, such as in real-time. Neural activity is detected by sensors that measure frequency, amplitude, synchrony, sequence and site of brain activity. These measurements can be compared to neural signatures and patterns shown to be correlated to neuropsychological conditions and disorders. When these measurements indicate an undesirable state the wearer is alerted via visual, audible or tactile means designed to be highly effective at alerting the wearer and allowing them to adjust their brain activity. The device is designed to be used during primary activities, e.g. reading and listening, and to not require third party intervention during primary use

WO 2014/001928 Al discloses a system and method for enhancing alertness and performance, in particular for recovering or enhancing alertness of vehicle drivers. The system comprises a drowsiness detector for detecting a first signal indicative of a

physiological state of a subject and a trigger controller for initiating a recovery procedure under consideration of the first signal. The recovery procedure comprises a sleep onset stage, a resting stage and an alertness enhancement stage, and uses a recovery sensor for detecting a second signal attributable to a recovery-related physiological state of the subject, a recovery stimulator device for selectively influencing the recovery-related physiological state of the subject, comprising at least one light source for selectively administering light to the subject and a recovery controller configured to control the recovery stimulator device under consideration of the detected second signal, at least while executing the recovery procedure.

These prior art concentration monitoring solutions have in common that they rely on a predefined model defining sufficient alertness or concentration levels and intervene if the measured alertness or concentration deviates by a predetermined amount from the predefined model. However, such a globalised approach may not be accurate enough in certain circumstances, e.g. where different individuals cause the generation of different signals for the same level of alertness or concentration, or where different physical activities require different levels (types) of concentration. Therefore, there remains a need for a safety system that can be tailored to and individual and/or physical activity.

SUMMARY OF THE INVENTION The present invention seeks to provide a safety system capable of more accurately monitoring loss of concentration during a physical activity of a particular individual.

The present invention seeks to provide a workflow management system including such safety system for generating a workflow plan based on data collected by the safety systems.

The present invention yet further seeks to provide a method for operating such a safety system in order to more accurately maintaining the safety of a person performing a physical activity.

The present invention yet further seeks to provide a computer program product that can implement such a method when executed on a processor arrangement of a safety system.

According to an aspect, there is provided a safety system including a first sensor arrangement for monitoring a physical activity of a person and generating first sensor signals indicative of the monitored physical activity; a further sensor arrangement for monitoring a concentration level of said person during said physical activity and generating further sensor signals indicative of the monitored concentration level;

a processor arrangement arranged to receive the first sensor signals and the further sensor signals and adapted to determine a relationship between the first sensor signals and the further sensor signals; and produce an alert signal upon determining a loss of said relationship during the physical activity.

The present invention is based on the realization that by providing a safety systems that can monitor the physical activity simultaneously with the concentration level of the person engaged in the physical activity, a relationship such as a correlation between the first sensor signals of the first sensor arrangement monitoring the physical activity and the further sensor signals of the further sensor arrangement monitoring the concentration levels can be determined on the fly, for instance when a pattern of physical movements corresponds to a certain level of concentration, e.g. when both the first sensor signals and the further sensor signals have a common frequency. This relationship may be different for different individuals because the exact nature of the relationship is not particularly relevant as the processor arrangement is configured to merely determine the existence of any relationship between the different sensor signals, such that the safety system provides a concentration level monitoring approach that is tailored to each individual using the safety system. The processor arrangement is further arranged to detect the loss of the relationship during the physical activity, e.g. a change in the further sensor signals, which is used to generate an alert signal, which alert signal may be used to activate an alert generator to alert the individual that his or her concentration levels are dropping, thereby enabling their individual to take appropriate actions to avoid accidents or injuries, such as taking a rest or refocusing on the task at hand.

In an embodiment, the first sensor arrangement comprises at least one wearable sensor for wearing on a body part engaged in said physical activity. This is for instance particularly advantageous when the safety system preferably is wearable.

Alternatively or additionally, the first sensor arrangement may comprise at least one image sensor for capturing the physical activity. This is for instance particularly advantageous when the safety system is in a fixed location, such as integrated in a vehicle such as a car, train, aeroplane or the like, in which case the at least one image sensor may monitor the fixed position of the operator of the vehicle.

In an embodiment, the further sensor arrangement comprises a head- mountable brain activity sensor. Such a brain activity sensor is particularly suitable for monitoring the concentration level of the person engaged in the physical activity as changes in the concentration of a person typically corresponds to a change in brain activity, e.g.

brainwave frequency, in which case the processor arrangement may be adapted to determine the loss of said relationship from a change in frequency of the brain waves detected by said brain activity sensor.

The processor arrangement may be further adapted to monitor the frequency of the brain waves during a disruption of said physical activity, for instance when the person is taking a break from the physical activity in order to determine if the person has rested enough for the person to safely resume the physical activity. To this end, the processor arrangement may be adapted to detect a change in the frequency of the brain waves during said disruption that is indicative of the person being ready to resume the physical activity; and generate an indication signal upon detecting said change.

Alternatively or additionally, the further sensor arrangement comprises a head- mountable device including an inward facing camera for monitoring gaze and/or viewing direction of said person. Loss of concentration may also be detected by a change in the gaze of the person engaged with physical activity, e.g. pupillary dilation changes, changes in the rate of blinking, and so on, or by a change in the gazing or viewing direction, which may be indicative of the person no longer watching an area of relevance to the physical activity, such as a work area when operating a power tool, road when operating a vehicle, and so on. In this embodiment, the processor arrangement may be adapted to determine the loss of said relationship from a change in said gaze and/or viewing direction.

The safety system may further comprise an alert generator responsive to said alert signal for providing the person engaged in the physical activity with an alert signal, e.g. a warning signal, indicating that the person is likely to suffer from a loss of concentration, which may increase the risk of an accident or injury to that person or his or her environment.

The alert generator may take any suitable form; for instance, the alert generator may comprise at least one of a lighting device, an audio device, a display device and a tactile stimulus generating device.

In a particularly advantageous embodiment, the alert generator is integrated in a powered device in use during the physical activity, wherein the alert generator is arranged to alter the operation of said device in response to said alert signal, e.g. cut the power to the device. This even further reduces the risk of accidents and/or injuries because the operation of the powered device can be altered, e.g. the device can be (partially) disabled when detecting the loss of the relationship, i.e. the loss of concentration, during the physical activity.

According to another aspect, there is provided a workflow management system comprising a plurality of safety systems according to any of the above embodiments, wherein each of the safety systems is associated with a different person, the workflow management system including a database for storing time-stamped relationship data obtained from each of said safety systems and a further processor adapted to process said time- stamped relationship data and derive a workflow schedule for said different persons from said relationship data. By keeping track of the relationship between the first and further sensor signals over time, the ability of different individuals to maintain concentration levels, e.g. when performing physical tasks in the line of duty, and their recovery times, can be determined, which information may be used to generate work schedules for these different individuals that optimises the safe utilization of the resources provided by these individuals. This may therefore improve efficiency of a workflow provided by these individuals, as each individual may be utilized for as long as the individual is capable of concentrating on the job in hand, whilst at the same time reducing the risk of accidents or injuries.

According to yet another aspect, there is provided a method for maintaining the safety of a person performing a physical activity, the method comprising receiving first sensor signals from a first sensor arrangement monitoring said physical activity; receiving further sensor signals from a further sensor arrangement monitoring a level of concentration of said person during said physical activity; determining a relationship between the first sensor signals and the further signals; and generating an alert upon determining a loss of said relationship during the physical activity. By determining and monitoring a relationship, e.g. a correlation, between the first and further sensor signals, an individualized method for maintaining the safety of a person performing such a physical activity is provided that does not rely on predefined models for determining a loss of alertness or concentration.

According to yet another aspect, there is provided a computer program product comprising a computer-readable medium carrying computer-readable program instructions for, when executed on a processor arrangement of the safety system according to any of the above embodiments, implementing the aforementioned method.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described in more detail and by way of non- limiting examples with reference to the accompanying drawings, wherein

Fig. 1 schematically depicts a safety system according to an example embodiment;

Fig. 2 schematically depicts a safety system according to another example embodiment;

Fig. 3 schematically depicts a safety system according to yet another example embodiment;

Fig. 4 schematically depicts a safety system according to yet another example embodiment;

Fig. 5 schematically depicts a workflow management system according to an example embodiment; and

Fig. 6 depicts a flow chart of a method according to an example embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

At least some aspects of the present invention are concerned with providing a safety system for monitoring concentration levels of a person engaged in a physical activity such as operating machinery. The safety system according to these aspects comprises three main components. The first component comprises a first sensor arrangement for monitoring a physical activity of a person and generating first sensor signals indicative of the monitored physical activity. To this end, the first sensor arrangement may monitor a motion of the person associated with the physical activity, such as the movement of a body part such as a limb, torso and/or head of the person engaged in the physical activity. Suitable sensors for the first sensor arrangement include but are not limited to wearable sensors such as wearable motion sensors, e.g. gyroscopes, accelerometers and so on, which may be worn on one or more body parts engaged in the physical activity, optical sensors such as image sensors or cameras to capture a sequence of images of the person engaged in the physical activity, which sequence may be processed to derive the motion from said sequence. The sequence of images may be a sequence of still images, a video stream, and so on. In some embodiments, the first sensor arrangement may comprise one or more sensor of a single type, e.g. motion sensors only or image sensors only. In some alternative embodiments, the first sensor arrangement may comprise sensors of different types, e.g. a combination of one or more motion sensors and image sensors.

The second component comprises a further sensor arrangement for monitoring a concentration level of said person during said physical activity and generating further sensor signals indicative of the monitored concentration level. An example of a suitable sensor type for the further sensor arrangement is a brainwave sensor, which may be worn on the head in any suitable form, such as integrated a strap, headwear such as a hat or cap, a head-mountable device such as (smart) glasses, and so on. As is well-known per se, brainwaves are indicative of a level of concentration and the monitoring of such brainwaves is therefore particularly suitable for monitoring a level of concentration of a person engaged in a physical activity.

Another example of a suitable sensor type for the further sensor arrangement is an optical sensor for monitoring gaze and/or eye movement of the person involved in the physical activity, such as an image sensor or camera. In an embodiment, such an optical sensor may be integrated in a head-mountable device, e.g. smart headgear such as eyeglasses, goggles, a helmet, a hat, a visor, a headband, or any other device that can be supported on or from the wearer's head. A change in gaze, frequency of eye movement, direction of vision, and so on can also be indicative of a loss of concentration and is therefore also suitable to monitor the concentration levels of a person engaged in a physical activity. In an

embodiment, such an optical sensor integrated in a head-mountable device comprises an inward facing optical sensor, e.g. camera. A pair of such optical sensors may be provided for each eye of the person involved in the physical activity.

In some embodiments, the further sensor arrangement may comprise one or more sensor of a single type, e.g. brainwave sensors only or optical sensors only. In some alternative embodiments, the further sensor arrangement may comprise sensors of different types, e.g. a combination of one or more brainwave sensors and optical sensors.

At this point, it is reiterated that the above examples of sensors for the first and further sensor arrangements should not be construed as limiting the scope of the present invention; it should be understood that any suitable sensor for each of these arrangements may be contemplated.

The third component comprises a processor arrangement, e.g. a single (micro)processor or a plurality of (micro)processors arranged in a co-operating fashion, which processor arrangement is arranged to receive the first sensor signals and the further sensor signals and is adapted to determine a relationship between the first sensor signals and the further sensor signals. Such a relationship may be a correlation between the first sensor signals and the further sensor signals that exists when the person is concentrated on performing the physical task. For example, where the physical task involves a repetition of motion, a repetition frequency may correlate with a frequency of brainwaves or eye movements. The respective frequencies may be extracted from the first and further sensor signals by the processor arrangement, which for instance may monitor these frequencies over a period of time to establish the existence of a relationship between the motions of the person as observed by the first sensor arrangement and the brainwaves or eye movements as observed by the further sensor arrangement. For instance, where the correlation between these respective sensor signals remains more or less constant, i.e. within a predefined threshold, over the period of time, the processor arrangement may decide that such a relationship exists.

In some embodiments, the processor arrangement may be adapted to detect that a person is involved in a particular physical activity by determining a degree of repetitiveness according to a profile of the activity, e.g. through auto-correlation. Such motion profiles can be inferred from historical data captured by the first sensor arrangement, or may be derived from a pre-determined motion profile that corresponds to an expected physical activity of the person, such as a motion profile of a task or operation associated with a particular profession. At this point, it is noted that the aforementioned relationship does not necessarily relate to correlating frequencies; it is for instance equally feasible that a level of concentration is derived from a different characteristic of the further sensor signals, such as a gaze fixed on a particular focal point, e.g. a work area in case of the person engaged in a work task, the route ahead in case of the person operating a vehicle, a change in a fixed gaze direction and so on. Similarly, even though the safety system is particularly suited for monitoring repetitive physical activity, i.e. activities that involve a repetitive motion, it should be understood that in some embodiments, the safety system may be adapted to detect that the person engaged in a physical activity is in a potentially dangerous situation, for instance performing the physical activity at a height, in which case the safety system may further comprise one or more sensors for detecting environmental conditions, e.g. one or more height sensors, image sensors for detecting density of people or traffic in the environment, and so on.

Once the processor arrangement has determined the existence of such a relationship, the processor arrangement may continue to monitor the first sensor signals and the further sensor signals to determine a change in the relationship, i.e. a loss of said relationship during the person being engaged in the physical activity. For example, the processor arrangement may detect a change in the characteristics of the further sensor signals indicative of the level of concentration of the person whilst the first sensor signals do not exhibit a change in characteristics, which is therefore indicative of the person still being engaged in the physical activity but losing concentration. Upon the detection of such a change in the relationship between the first and further sensor signals, e.g. a loss of correlation between the signals, the processor arrangement will generate an alert signal, which may be provided to an alert generator for warning the person engaged in the physical activity that there may be an increased risk of accident or injury due to a loss of concentration by the person.

As will be explained in more detail below, the alert generator may form part of the safety system in some embodiments, whereas in some other embodiments, the alert generator may be separate to the safety system, in which case the safety system may be adapted to communicate the alert signal to the external alert generator.

In some embodiments, the safety system may be a wearable system in which case the first sensor arrangement, the further sensor arrangement and the processor arrangement are all wearable components. For instance, the processor arrangement may form part of a wearable device further including the first sensor arrangement and/or the further sensor arrangement, or may form part of a discrete wearable device, with the further sensor arrangement and the further sensor arrangement forming part of separate wearable devices. For example, the processor arrangement may form part of a head-mountable computing device, e.g. smart glasses or the like, or may be worn of a different part of the body.

In some embodiments, the processor arrangement 130 may be integrated in a portable device such as a mobile phone, tablet, personal digital assistant or the like, in which case an app may be provided on the portable device that allows the processor arrangement 130 to perform the evaluation of the first sensor signals and the further sensor signals and generate the alert signal accordingly. In such an embodiment, the processor arrangement 130 may be the general purpose processor(s) of the portable device.

In some embodiments, at least some parts of the safety system may be affixed to a support structure such that these paths are in a more or less permanent location. This is for instance advantageous in embodiments where the person engaged in the physical activity remains in a fixed location, for instance when operating a vehicle, working on an assembly line, and so on. For example, where the person is operating a vehicle, at least some of the sensors of the first and further sensor arrangement and/or the processor arrangement may be integrated in the vehicle in any suitable location.

FIG. 1 schematically depicts a safety system 100 according to an example embodiment. In this embodiment, the safety system 100 comprises the first sensor arrangement in the form of a set of wearable motion sensors 110, e.g. one or more motion sensors such as accelerometers, gyroscopes or the like, which may be worn by the person 10 engaged in a physical activity such as operating machinery 20 on part of the body engaged in the physical activity. The safety system 100 further comprises the further sensor arrangement in the form of a brainwave sensor arrangement, i.e. one or more brainwave sensors 120 integrated in a head-wearable device as previously explained.

The one or more motion sensors 110 and brainwave sensors 120 are communicatively coupled to the processor arrangement 130 for providing the first sensor signals and the further sensor signals to the processor arrangement 130 over said

communication link. Such a communication link may be realized in any suitable fashion, e.g. may be a wired link or a wireless link. Any suitable wireless communication protocol may be used for any of the wireless communication between the first sensor arrangement 110 and/or the further sensor arrangement 120 on the one hand and the processor arrangement 130 on the other hand, e.g., an infrared link, Zigbee, Bluetooth, a wireless local area network protocol such as in accordance with the IEEE 802.11 standards, a 2G, 3G or 4G telecommunication protocol, and so on.

Although not explicitly shown, in case of such a wireless communication link, the first sensor arrangement 110 and/or the further sensor arrangement 120 and the processor arrangement 130 may each comprise a suitable wireless communication interface for facilitating such wireless communication. As such wireless communication interfaces are well-known per se, this will not be explained in further detail for the sake of brevity only. It suffices to say that any suitable wireless communication interface may be used for this purpose.

The one or more motion sensors 110, brainwave sensors 120 and the processor arrangement 130 are shown as separate components by way of non-limiting example only. As previously explained, it is equally feasible that at least some of these components are integrated in a single device, e.g. a wearable device such as a wearable computing device in case the processor arrangement 130 is present in the device.

The processor arrangement 130 is adapted to determine the relationship between the first sensor signals and the further sensor signals as previously explained and to monitor the maintenance of this relationship during the performance of the physical activity by the person 10. In particular, the processor arrangement 130 is adapted to detect a change in the brain activity captured in the further sensor signals, which change may be indicative of a loss of concentration by the person 10 during the performance of the physical activity as indicated by the first sensor signals.

In an embodiment, the detection of such brain activity comprises the detection of brain wave patterns. As is well-known per se, the human brain produces brain waves at different frequencies, with brain waves in a particular frequency band being indicative of a state of awareness or consciousness of that person. Gamma waves appear in a frequency range of about 40-100 Hz and are associated with higher processing tasks as well as cognitive functioning. Gamma waves are important for learning, memory and information processing. Beta waves appear in a frequency range of about 12-40 Hz and are known as high frequency low amplitude brain waves that are commonly observed in people that are awake. These waves are involved in conscious thought, logical thinking, and tend to have a stimulating effect. Having the right amount of beta waves allows people to focus and complete school or work-based tasks more effectively. Alpha waves appear in a frequency range of about 8-12 Hz. These waves bridge the gap between conscious thinking and the subconscious mind and can be indicative of a state of relaxation or an inability to focus. Theta waves appear in a frequency range of about 4-8 Hz and typically appear during daydreaming and sleep. Finally, delta waves appear in a frequency range of about 0-4 Hz and are most often found in infants as well as in young children and are associated with deepest levels of relaxation and restorative, healing sleep.

Consequently, changes in the frequency composition of the monitored brain waves are indicative of a change in levels of concentration as they for instance indicate changes in focus or alertness. For example, on an assembly line, when the repetitive motion profile of the person 10 is fast and fluid as detected with the first sensor arrangement, but sufficient alpha and/or beta-level frequency in brain activity is inferred as detected with the second sensor arrangement, no intervention would be necessary as it is reasonable to assume that the person 10 is focused on the physical at hand.

However, when the motion profile remains repetitive but the EEG signals obtained by the one or more brainwave sensors 120 transition to the theta-type frequency range, e.g. an increase in theta-type brainwaves is detected by the processor arrangement 130, this may be an indication of the person 10 losing focus on the physical activity at hand, in which case the processor arrangement 130 generates an alert signal for alerting the person 10 that he or she is losing concentration, e.g. is getting fatigued.

For example, the processor arrangement 130 may monitor a threshold of the amount or ratio of a particular frequency (band) of brainwaves being present in the overall spectrum of brainwaves captured by the one or more brainwave sensors 120 and may generate the alert signal upon this threshold being crossed. This is not limited to detection of theta waves; it is for instance equally feasible to monitor changes in the ratio of different types of brainwaves present in the brainwave spectrum, e.g. the ratio of alpha and beta waves, as for instance disclosed in US 6,167,298.

Other suitable of trigger thresholds for generating the alert signal may be used in combination with or instead of the aforementioned brainwave composition threshold; for instance a loss of the aforementioned relationship may further be detected when the motion profile as derived from the first sensor signals becomes more erratic or slower repetitions, i.e. a reduction in the frequency of the repetitive motions as derived from the first sensor signals, occur in conjunction with the recorded changes in the brain activity profile.

Additionally or alternatively, the detection of the brain activity by the further sensor arrangement 120 may involve the detection of electrical activity in the brain that correlates with the motion detected by the sensor arrangement 110 or changes in the detected activity, which may be detected by brain activity sensors attached or otherwise in communicative contact with corresponding regions of the scalp of the person being monitored, e.g. EEG sensor electrodes. The detection of such brain activity may for instance involve the detection of electrical activity in specific regions or areas of the brain, where the reduction or loss of correlated electrical activity, e.g. the reduction or loss of electrical activity in a particular region of the brain, may be indicative of the person losing

concentration on the monitored physical activity, which indication may be used to trigger the generation of the alert signal as previously explained.

In an embodiment, the various thresholds that may be applied by the processor arrangement 130 may be stored in a look-up table or another suitable data storage medium, which look-up table for instance may comprise an appropriate alert signal generation for each threshold. For example, the safety system 100 may provide different alert signals for different types of threshold being exceeded, such that different alert generators may be activated by these different alert signals.

In an embodiment, the safety system 100 may further monitor the response of the person 10 to the generation of an alert, in order to determine if an applied threshold is appropriate. For example, where a person 10 ignores the alert, this is an indication of the applied threshold being too severe, e.g. low, such that this response may be used to adjust, e.g. increased, the applied threshold. In this manner, the safety system 100 may learn over time from the corrective actions applied by the person 10 and adjust the applied threshold levels accordingly. This for instance may involve updating the aforementioned look-up table.

The processor arrangement 130 may be communicatively coupled to an alert generator 140 in a wired or wireless fashion as previously explained for providing the alert generator 140 with the alert signal. In response to receiving the alert signal, the alert generator 140 generates an alert for alerting the person 10 that his or her concentration levels are dropping, such that person 10 can take a break from the physical activity, e.g. to take a rest before resuming the physical activity.

Any suitable type of alert generator 140 may be used for this purpose. For instance, the alert generator 140 may be a lighting device or system that generates a light effect, e.g. flashing lights or the like, switching on one or more lights, and so on, in response to the alert signal. The alert generator 140 may be a sound generating device such as a loudspeaker or the like to generate a sound upon receiving the alert signal. The alert generator 140 may be a display device displaying a warning message to the person 10 upon receiving the alert signal. The alert generator 140 may be a tactile stimulus generating device worn by the person 10 that generates a tactile stimulus, e.g. a vibration or the like, in response to receiving the alert signal. Other suitable examples of such an alert generator 140 will be immediately apparent to the skilled person. It should furthermore be understood that more than one alert generator 140, e.g. any combination of the aforementioned alert generators, may be used to alert the person 10.

The alert generator 140 may form part of the safety system 100 or may be external thereto; for instance, the alert generator may be an external lighting system that can be communicatively coupled to the safety system 100, e.g. through a suitable wired or wireless link.

The alert generator 140 may be integrated into a wearable or portable device further comprising at least some of the components of the safety system 100. For example, the alert generator 140 may be integrated in a head-mountable computing device, e.g. a loudspeaker, tactile stimulus generator or display integrated in the head-mountable computing device. For example, the alert generator 140 may form part of a portable device such as a mobile phone or tablet, wherein the mobile phone or tablet may be configured to generate the alert, e.g. by displaying a message on the display of such a device, by generating a sound alert or a vibration, and so on. Other suitable embodiments of the alert generator 140 will be immediately apparent to the skilled person.

In an embodiment, the safety system 100 may be adapted to continue monitoring the brainwaves of the person 10 upon terminating the physical activity following an alert, as this can provide insights into when the person 10 may be ready to resume the physical activity. For example, the person 10 may take a rest from the physical activity, during which monitoring of the brainwaves of the person 10 may indicate when the person 10 is rested enough to resume the physical activity, for instance because the amount of theta waves, the ratio of alpha and beta waves, and so on indicates that the concentration levels of the person 10 are sufficient to ensure safe resumption of the physical activity. As will be explained in further detail below, the relationship data, i.e. the first and further sensor signals and the relationship therebetween, and such brainwave data during a break may be used to optimize the utilization of the person 10 in a workflow process, as the active and resting periods of the person 10 may be optimized in accordance with the collected data.

FIG. 2 schematically depicts another example embodiment of the safety system 100, in which the safety system 100 as schematically depicted in FIG. 1 and described in detail above is extended with a further alert generator 140' integrated in the machinery 20. The safety system 100 may utilize the further alert generator 140' in combination with or instead of the alert generator 140. In this embodiment, the machinery 20 may be powered by an electrical power supply, e.g. a mains supply or battery, or a fuel supply. The machinery 20 for instance may be an electrical power tool such as a power drill, cutting or sawing device, a fuel-powered device such as a chainsaw, and so on. The further alert generator 140' is adapted to alter the operation of the machinery 20 upon receiving the alert signal from the processor arrangement 130 via any suitable communication link such as a wireless communication link as previously described.

The further alert generator 140' for instance may be arranged to reduce the power or a fuel supplied to the machinery 20 such that the machinery 20 is forced to operate in a safe mode, e.g. a reduced power mode. The further alert generator 140' alternatively may be arranged to completely cut the supply of power or fuel to the machinery 20 in response to receiving the alert signal from the processor arrangement 130 in order to prevent accidents or injuries as a result of the operation of the machinery 20 without the required levels of concentration.

As previously explained, the safety system 100 may use different types of sensors for the first and further sensor arrangements. FIG. 3 schematically depicts an example embodiment of the safety system 100 in which the first sensor arrangement comprises one or more image sensors 210, e.g. cameras or the like, for monitoring the motions of the person 10 during the physical activity. In this embodiment, such motions may be derived from a sequence of images generated by the one or more image sensors 210 and provided in the first sensor signals to the processor arrangement 130. The processor arrangement 130 may employ image processing algorithms to derive the (frequency of) motion of (part of the body of) the person 10 from the first sensor signals. As it is well- known per se to estimate motion from a sequence of images, this will not be explained in further detail for the sake of brevity only.

As mentioned before, the use of one or more image sensors 210 is for instance particularly advantageous if the person 10 performs the physical activity in a fixed location, e.g. being seated when operating a vehicle or performing tasks on an assembly line, in which case the one or more image sensors 210 may be fixed in a location from which the fixed location in which the person 10 performs the physical activity can be monitored. For example, in case of a person 10 operating a vehicle, the one or more image sensors 210 may be integrated vehicle.

FIG. 4 schematically depicts an example embodiment of the safety system 100 in which the further sensor arrangement is integrated in a head-mountable device and comprises one or more inward-facing optical sensors 220, e.g. cameras or the like, to monitor the visual attention of the person 10 whilst performing the physical activity, which may be a visually oriented task. The one or more inward- facing optical sensors 220 may be arranged to capture gaze, eye movement, blinking and so on and provide the processor arrangement 130 with a further sensor signals indicative of the captured eye data. In this embodiment, the processor arrangement 130 may derive the concentration levels of the person 10 from the captured eye data, e.g. by determining changes in the gaze and/or direction of view of the person 10. For instance, if the safety system 100 detects that the direction of view maintained by the person 10 or the gaze characteristics of the person 10 no longer correlates with the motion detected in the first sensor signals, the processor arrangement 130 may generate the alert signal accordingly. In this embodiment, the alert may be generated on the head- mountable device in order to provide a particularly compact safety system 100. This further has the advantage that the alert generated by the alert generator 140 may be kept private to the person 10.

As mentioned above, the data generated by a safety system 100 may be used to schedule a workflow involving a plurality of persons 10, e.g. a plurality of employees performing physical activities. FIG. 5 schematically depicts a workflow management system 300 according to an example embodiment. The workflow management system 300 comprises a plurality of safety systems 100 each associated with a different person 10, which safety systems 100 monitor the concentration of the different persons 10 on the physical activities they are involved in as explained above. Each of the safety systems 100 communicatively coupled to a database 310 in which the relationship data generated by the respective processor arrangements 130 is stored. Each of the safety systems 100 may be

communicatively coupled to the database 310 in any suitable manner, e.g. using any suitable wireless communication link as previously explained.

The relationship data, i.e. the monitored first and further sensor signals over time and the relationship and potential loss thereof between the first and further sensor signals during the performance of the physical activity by the person 10 associated with the safety system 100 is stored in the database 310. In an embodiment, the relationship data may further comprise recovery data for the person 10 associated with the safety system 100 as previously explained, e.g. data indicative of the restoration of the ability of the person 10 to concentrate during a break from the physical activity of the person 10. The relationship data is typically time-stamped, i.e. stored in combination with information about the (date and) time of capturing the relationship data by the safety system 100, as such time information may provide valuable insights about the ability of the person 10 to concentrate on a physical activity during different parts of the day.

The workflow management system 300 further comprises a further processor arrangement 320 arranged to process the time-stamped relationship data stored in the database 310 and derive a work schedule for the different persons 10 monitored by the respective safety systems 100 from the collected relationship data. This for instance may be used to generate a work schedule based on the length of time a person 10 can remain focused on a physical activity, and the amount of time required by such a person 10 to recover during a break from the physical activity, such that a work schedule is generated in which the human resources for performing physical tasks in a concentrated manner are maximized, thereby maximizing the safe production of goods or services as the risk of accidents or injuries during the performance of these physical tasks is reduced or even minimized.

In an embodiment, the person 10 associated with a safety system 100 may have control over whether the safety system 100 is allowed to communicate with the database 310. For example, the person 10 may not want his or her employer to learn that the person 10 has lost concentration during the performance of a physical activity, in which case the person 10 may not want the safety system 100 to communicate with the database 310. In such an embodiment, this communication function may be configurable, i.e. must be enabled by the person 10 for the safety system 100 being allowed to communicate with the database 310.

Alternatively, the relationship data may be communicated to the database 310 but may only be accessible by authorized persons, e.g. the person 10 only, e.g. upon provision of a password or the like to provide access to the relationship data. Such authorized persons may be able to configure the access rights to the relationship data in the database 310, e.g. by defining the appropriate access privileges in a user interface (not shown) to the database 310. Such access rights for instance may be set such that the further processor arrangement 320 may be given or prohibited from getting access to that particular instance of the relationship data.

FIG. 6 depicts a flowchart of a method 400 for maintaining the safety of a person 10 performing a physical activity, which method 400 may be executed on the processor arrangement 130 of the safety system 100. The method starts in step 410, for instance by powering up the safety system 100, placement of the first and further sensor arrangements, and so on. The method 400 then proceeds to step 420 in which the processor arrangement 130 receives the first and further sensor signals from the first and further sensor arrangements as explained in more detail above. In step 430, the processor arrangement 130 evaluates the received first and further sensor signals to determine if the person 10 is engaged in a recognizable physical activity and if a relationship such as a correlation is present between the first and further sensor signals as determined in step 435. If no such a

relationship can be detected the method 400 may terminate or revert back to step 420.

If on the other hand a relationship such as a correlation between the first and further sensor signals has been determined, the method may proceed to step 440 in which the maintenance of this relationship in subsequently received first and further sensor signals is monitored in order to determine if the person 10 remains focused on the physical activity. If it is determined in step 445 that the concentration levels of the person 10 performing the physical activity are maintained, no loss of the relationship between the first and further sensor signals is detected, the method will revert back to step 440 in which the first and further sensor signals are further monitored to establish the maintenance of the

aforementioned relationship between the signals. If on the other hand it is determined in step 445 that there is a loss of the relationship during the physical activity indicating a loss of concentration of the person 10 performing the physical activity, e.g. by detecting changes in the composition of the monitored brainwave spectrum of the person 10 and/or changes in gaze and/or eye direction of the person 10 as previously explained, the method 400 proceeds to step 450 in which an alert signal is generated by the processor arrangement 130. This step may further include the generation of the alert by an alert generator 140 and/or a further alert generator 140' in response to receiving the alert signal as previously explained. Although not shown in FIG. 6, the method may further comprise the optional step of monitoring the recovery of the person 10 during a break from the physical activity following the generation of the alert signal in step 450 as previously explained before the method 400 terminates in step 460. Alternatively, following the generation of the alert signal in step 450 and the optional monitoring of the recovery of the person 10, the method may revert back to step 420, for instance if the person 10 is to resume the physical activity after a break therefrom. In such a scenario, the method 400 typically terminates in step 460 upon the person 10 completing the physical task and/or disabling the safety system 100.

Aspects of the present invention may be embodied as a safety system 100, a workflow management system 300 or a method 400 for maintaining the safety of a person performing a physical activity. Aspects of the present invention may take the form of a computer program product embodied in one or more computer-readable medium(s) having computer readable program code embodied thereon. The code typically embodies computer- readable program instructions for, when executed on a processor arrangement 130 of such a safety system 100, implementing the method 200.

Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Such a system, apparatus or device may be accessible over any suitable network connection; for instance, the system, apparatus or device may be accessible over a network for retrieval of the computer readable program code over the network. Such a network may for instance be the Internet, a mobile communications network or the like. More specific examples (a non- exhaustive list) of the computer readable storage medium may include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of the present application, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for carrying out the methods of the present invention by execution on the processor arrangement 130 may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the processor arrangement 130 as a stand-alone software package, e.g. an app, or may be executed partly on the processor arrangement 130 and partly on a remote server. In the latter scenario, the remote server may be connected to the system 100 through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer, e.g. through the Internet using an Internet Service Provider.

Aspects of the present invention are described above with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions to be executed in whole or in part on the processor arrangement 130 of the safety system 100, such that the instructions create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer-readable medium that can direct the safety system 100 to function in a particular manner.

The computer program instructions may be loaded onto the processor arrangement 130 to cause a series of operational steps to be performed on the processor arrangement 130, to produce a computer-implemented process such that the instructions which execute on the processor arrangement 130 provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. The computer program product may form part of the safety system 100, e.g. may be installed on the safety system 100.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several distinct elements. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

CLAIMS:

1. A safety system (100) including :

a first sensor arrangement (110, 210) for monitoring a physical activity of a person (10) and generating first sensor signals indicative of the monitored physical activity;

a further sensor arrangement (120, 220) for monitoring a concentration level of said person during said physical activity and generating further sensor signals indicative of the monitored concentration level;

a processor arrangement (130) arranged to receive the first sensor signals and the further sensor signals and adapted to:

determine a relationship between the first sensor signals and the further sensor signals; and produce an alert signal upon determining a loss of said relationship during the physical activity.

2. The safety system (100) of claim 1, wherein the physical activity comprises repetitive motion by the person and wherein the processor arrangement (130) is adapted to determine a frequency of said repetitive motion and to determine said relationship based on said determined frequency.

3. The safety system (100) of claim 1 or 2, wherein the first sensor arrangement (110) comprises at least one wearable sensor for wearing on a body part engaged in said physical activity and/or at least one image sensor for capturing the physical activity.

4. The safety system (100) of any of claims 1-3, wherein the further sensor arrangement (120) comprises a head-mountable brain activity sensor.

5. The safety system (100) of claim 4, wherein the processor arrangement (130) is adapted to determine the loss of said relationship from a change in frequency of the brain waves detected by said brain activity sensor.

6. The safety system (100) of claim 4 or 5, wherein the processor arrangement

(130) is further adapted to monitor the frequency of the brain waves during a disruption of said physical activity.

7. The safety system (100) of claim 6, wherein the processor arrangement (130) is adapted to:

detect a change in the frequency of the brain waves during said disruption that is indicative of the person (10) being ready to resume the physical activity; and

generate an indication signal upon detecting said change.

8. The safety system (100) of any of claims 1-5, wherein the further sensor arrangement (220) comprises a head-mountable device including an inward facing camera for monitoring gaze and/or viewing direction of said person.

9. The safety system (100) of claim 8, wherein the processor arrangement (130) is adapted to determine the loss of said relationship from a change in said gaze and/or viewing direction.

10. The safety system (100) of any of claims 1-9, further comprising an alert generator (140, 140') responsive to said alert signal.

11. The safety system (100) of claim 10, wherein the alert generator (140') is integrated in a powered device (20) and arranged to alter the operation of said device in response to said alert signal.

12. The safety system (100) of claim 10 or 11, wherein the alert generator (140) comprises at least one of a lighting device, an audio device, a display device and a tactile stimulus generating device.

13. A workflow management system (300) comprising a plurality of safety systems (100) according to any of claim 1-12, wherein each of the safety systems is associated with a different person, the workflow management system including a database (310) for storing time-stamped relationship data obtained from each of said safety systems and a further processor (320) adapted to process said time-stamped relationship data and derive a workflow schedule for said different persons from said relationship data.

14. A method (400) for maintaining the safety of a person performing a physical activity, the method comprising:

receiving (420) first sensor signals from a first sensor arrangement monitoring said physical activity;

receiving (420) further sensor signals from a further sensor arrangement monitoring a level of concentration of said person during said physical activity;

determining (430, 435) a relationship between the first sensor signals and the further signals; and

generating (450) an alert upon determining a loss of said relationship during the physical activity.

15. A computer program product comprising a computer-readable medium carrying computer-readable program instructions for, when executed on a processor arrangement of the safety system according to any of claims 1-12, implementing the method (400) of claim 14.