VIRTUAL REALITY SYSTEM

There is provided a virtual reality headset system. The virtual reality headset system comprises a display device, a headband coupled to the display device, and a sensor configured to measure an indication of at least one biomarker in the sweat of a user associated with a stress level of the user when the user is wearing the virtual reality headset system.

This application claims priority from European patent application No. 22170717.7, filed on Apr. 29, 2022, the contents of which are hereby incorporated herein in their entirety by this reference.

TECHNICAL FIELD

The embodiments described herein relate to a virtual reality headset system and an associated computer-implemented method for monitoring at least one biomarker in the sweat of a user during using of the virtual reality headset system.

BACKGROUND

With the rise of Ed Tech (Technologies in Digital Education), digital fatigue has emerged in the educational domain, with significant physical and psychological impacts on both teachers and students. A device or a process that would reduce and/or mitigate these impacts would be welcomed by consumers.

Digital fatigue is directly correlated with stress; recent studies have shown that there is a 10% increase in stress levels at younger ages in the period between 2013 to 2019. On the other hand, multiple studies have shown that stress can also aid in the learning process as the hormones released during a stressful event can enhance memory formation, thus leading to robust memories. However, this effect is active up to a certain threshold, which when exceeded can undermine the learning process.

Virtual Reality (VR) has been in the forefront of technological developments with multiple companies developing complete product solutions. Consumer awareness of the technology is increasing, and this is reflected by the fact that VR headset sales are expected to grow by more than double by2024. This increase in sales has also triggered research in Human Machine Interfaces (HMI) for the VR platform. Many products that track users' finger and wrist motions are available and can be used for VR applications. Most recently, engineers and researchers from ETH Zurich have developed a handwriting digitization device for VR applications (including drawing), that is essentially mimicking a physical writing instrument. The user is holding a physical pen, that is then brought inside the virtual world. Such a device can improve the drawing experience in a VR environment, given that today is limited due to the use of entire VR controllers as an input system.

A substantial amount of research has also been focused on the effects of VR on its users. Recent studies have indicated that VR can both distract users from pain, while also reducing their stress levels significantly. Moreover, PwC has reported that VR in education can contribute to the user's learning abilities since VR learners were found to absorb information four times faster than their counterparts in a real classroom.

Recently, research has increasingly focused on the development of biosensors to measure stress, which is not necessarily based solely on measuring heartbeat or an increase in body temperature. For this purpose, hormones that are present in sweat may be used.

A suitable indicator for stress is cortisol. Cortisol is a steroid hormone that historically has been difficult to measure without a blood sample. A research team from Caltech has managed to develop a nonintrusive method for measuring cortisol levels in human sweat. This ultrathin graphene sensor can accurately determine the stress levels of a user—given that cortisol is directly correlated to stress in humans. A very thin graphene structure is doped with cortisol antibodies, that trap the cortisol found in the user's sweat, which then can be detected electrochemically.

Further, a recent study has shown users can significantly reduce their cortisol (stress) levels, after following an art-making session, irrespective of their prior experience and type of artmaking.

The preceding findings lead to the situation that VR headsets can be further developed in terms of monitoring the stress of the user and thus be made suitable for a number of applications.

SUMMARY

According to a first aspect, there is provided a virtual reality headset system. The virtual reality headset system comprises a display device, a headband coupled to the display device, and a sensor configured to measure an indication of at least one biomarker in the sweat of a user associated with a stress level of the user when the user is wearing the virtual reality headset system.

According to a second aspect, there is provided a computer-implemented method for monitoring at least one biomarker in the sweat of a user during using a virtual reality headset system. The computer-implemented method comprises providing a first virtual reality content to the user through a virtual reality headset system, measuring the concentration level of the at least one biomarker in the sweat of a user through a sensor coupled to the virtual reality headset, interrupting the providing of the first virtual reality content to the user, when the concentration level of the at least one biomarker exceeds a predetermined first threshold concentration level, and returning to providing the first virtual reality content to the user, when the concentration level reaches a level below a predetermined second threshold concentration level.

An effect of the technique of the present specification is to provide a virtual reality headset system that is configured to measure an indication of at least one biomarker in the sweat of a user associated with a stress level and thus may open a wide range of applications, for example, to reduce stress level of students in a digital education environment. This may make the latest findings on good learning situations applicable in practice. The proposed headset allows digital education environments that are more customized to a student's individual needs or cognitive abilities than conventional forms of teaching. A possible minimizing of potential physical and psychological impacts on both teachers and students due to elevated stress levels may allow a more efficient learning and may enhance memory formation.

The proposed virtual reality headset system may improve the learning abilities of students by allowing them to maintain an optimal level of stress, which can be achieved not least by interrupting learning sessions when measured biomarkers indicate excessive stress.

The suggested interruptions of a learning session can build further skills of the student. For example, one effect may be to improve the student's artmaking skills by using interruptions for digital art teaching content. Progressive monitoring of a stress-indicating biomarker even during the interruption may provide the ability to return to an educational environment when the stress level of the user has normalized.

DETAILED DESCRIPTION

FIG.1schematically illustrates an example of a virtual reality headset system10. According to the first aspect, the virtual reality headset system10comprises a display device11, a headband12coupled to the display device11, and a sensor13configured to measure an indication of at least one biomarker in the sweat of a user associated with the stress level of the user, when the user is wearing the virtual reality headset system10. A “virtual reality” may be a simulated experience via the display device11that can be similar to or completely different from the real world. Applications of virtual reality may include entertainment (particularly video games), education (such as medical or military training), and business (such as virtual meetings). Other distinct types of VR-style technology may include augmented reality and mixed reality, sometimes referred to as extended reality or XR. The display device11may be configured to display (virtual reality) content to the user wearing the virtual reality headset system10.

In an embodiment, the at least one biomarker is a stress hormone. In an example, the at least one biomarker is cortisol. Cortisol is a steroid hormone that is produced by the adrenal glands and is released by the human body in the presence of a stressful event. Thereby, cortisol is present in sweat in a similar concentration as in blood. The stress level experienced by a person is directly correlated with the cortisol level.

In an embodiment, the sensor13may be configured to measure a concentration level of the at least one biomarker and to output a signal corresponding to the concentration level. In an example, a higher voltage or current may be generated at the output of the sensor13when the concentration level of the biomarker in the sweat of the user increases, or for example, a lower voltage or current may be generated at the output when the concentration level of the biomarker in sweat decreases, or vice versa. In an example, the sensor13comprises a graphene layer, for example, a single layer carbon structure, with cortisol antibodies configured to bound the cortisol in the sweat of the user allowing to output a signal corresponding to the cortisol concentration level. In an example, a higher voltage or current may be generated at the output of the sensor13when the concentration level of cortisol in the sweat of the user becomes higher or for example, a lower voltage or current may be generated at the output when the concentration level of cortisol in sweat decreases, or vice versa.

In an example, the virtual reality headset system10may comprise a power supply (not shown) configured to provide electrical power. The sensor13and/or the display device11may be configured to receive electrical power from the power supply. The power supply may comprise an energy storage device, such as a lithium-ion battery, or any other suitable form of energy storage device. Further, the power supply may comprise a charging system configured to charge the energy storage device, or any kind of a power supply circuit configured to provide electrical power directly to the components, such as sensor13and/or display device11, of the virtual reality headset system10. The charging system and/or the power supply circuit may comprise an AC-DC converter, for example.

In an example, the sensor13may be attached to a location at the body of the user where sensor13may contact the skin of the user, such as head, arms, hands, legs, feet, or torso. For example, the sensor13may be part of a self-adhesive pad that may be attached to a suitable location, preferably, in the locations where the human body secretes more sweat than in other locations.

In an embodiment, the sensor13may be attached to the headband12or to the display device11at a location where the sensor13may contact the skin of the user, such as the forehead, neck, back of the head, temples, chin area, nose, area around the eyes, end or the upper head area. The possible design of the virtual reality headset system10and wearing it on the head of the user may cause the user to start sweating during use. Particularly at the points where the virtual reality headset system10rests or rests on the user's head, it may be suitable to place the sensor13.

In an embodiment, the display device11may be one of, but not limited to, a liquid crystal display (LCD), an organic light emitting diode display (OLED), or a light emitting diode display (LED). The display device11may be configured to use a (variable) refresh rate of for example 60 Hz, 72 Hz, 90 Hz, 120 Hz, 240 Hz, 360 Hz. The display device11may be part of a mobile device that may be inserted into the virtual reality headset10by the user before using the headset.

In an embodiment, the virtual reality headset10may comprise a computer system14configured to operate the virtual reality headset and to receive a signal corresponding to the indication of the at least one biomarker. In an example, the sensor13may be electrically connected to an interface of the computer system to provide the signal corresponding to the concentration level of the at least one biomarker to the computer system14. In an example, the sensor13may be electrically connected to a sensor communication interface, such as a near field communication chip, being placed close to the sensor13or mechanically coupled to the sensor13and configured to transmit the signal corresponding to the concentration level to the computer system14. The computer system14may comprise at least one of a central processing unit (CPU), a random access memory (RAM), or a read only memory (ROM). In an example, the computer system14may comprise a storage medium configured to store software, firmware and/or data required to operate the virtual reality headset system10. Encompassed in the definition of a storage medium, but not limited to, is long-term storage such as flash storage or a hard disc drive capable of storing the firmware, and software required for the computer system14to store, read, and process digital data. The computer system14may comprise software such as the operating system (OS) that is configured to manage the hardware and software resources and provides common services for application specific algorithms. The computer system14may be configured to process the signal corresponding to the concentration level of the at least one biomarker. The computer system14may further be configured to provide driving data to the display device11, for example through a display interface encompassing the electronics for converting the output of the central processing unit to a video signal suitable for visual representation by the display device11such that the user may experience the virtual environment or the virtual content when using the virtual reality headset system10.

FIG.2schematically illustrates an example of a virtual reality input interface15.

In an embodiment, the virtual reality headset system10may comprise a virtual reality input interface15configured to track movements of the user and to output a signal corresponding to the movements. The virtual reality input interface15may be electrically coupled to another interface of the computer system14to transmit signals to other components of the computer system14, such as the CPU, by wiring, or may be configured to communicate by wireless connection, for example using Bluetooth or Wireless Fidelity (Wi-Fi) as a communication protocol. The computer system14may be configured to process the output signal corresponding to the movements from the virtual reality input interface15and may be configured to coordinate the hardware of the headset10such that the user requests (input) are recognized and executed appropriately. The computer system14may comprise hardware and software to allow displaying content to the user and to interact with the virtual environment and/or virtual reality applications provided through the display device11to the user via the virtual reality input interface15. The interface15may be configured to track movements of the user such as hand movements, arm movements, entire body movements, and/or eye movements, and may be configured to translate the physical movements into data that may be utilized by the computer system14as an input and may be further processed. The virtual reality input interface15may comprise motion trackers, such as Microsoft Kinect, Joysticks, HTC Vive Controllers, Oculus Rift Controllers, Generic VR controllers.

FIG.3schematically illustrates an example of a virtual reality input interface15with an exemplary communication interface16.

In an embodiment, the computer system14may comprise a communication interface16configured to allow the computer system14to communicate with a computer and/or a mobile device. The communication interface16may be configured to establish the wireless connection between the virtual reality headset system10and other devices (such as a computer and/or a mobile device). The communication protocol operated by the communication interface16may be, for example, a Bluetooth or Wireless Fidelity (Wi-Fi) interface, as but two examples. The communication interface16may be configured to communicate with the virtual reality input interface15to receive the signals corresponding to the movements of the user and/or may be configured to communicate with the sensor13using wireless communication through a sensor communication interface.

In an example, sensor13may be further configured to measure the heart rate of the user associated with the stress level of the user, when the user is wearing the virtual reality headset system10and the sensor13is contacting the skin. The sensor13may be configured to provide a signal corresponding to the heart rate to the computer system14. The computer system14may be configured to process the data corresponding to the heart rate of the user in an equal manner as the data corresponding to the concentration level of the at least biomarker. In an example, the sensor13configured to measure the heart rate of the user may be one of an optical heart rate sensor utilizing photoplethysmography or an electrical heart rate sensor utilizing electrocardiography.

In an example, the sensor13may be further configured to measure the body temperature of the user associated with the stress level of the user, when the user is wearing the virtual reality headset system10. The sensor13may be configured to measure the body temperature directly on the skin of the user and/or may be configured to measure the temperature of the sweat of the user indicating the body temperature. The sensor13may be configured to provide a signal corresponding to the body temperature to the computer system14. The computer system14may be configured to process the data corresponding to the body temperature of the user in an equal manner as the data corresponding to the concentration level of the at least biomarker. In an example, the at least biomarker may be a body temperature.

FIG.4schematically illustrates an example of a computer-implemented method100for monitoring at least one biomarker in the sweat of a user.

According to the second aspect, there is provided a computer-implemented method100for monitoring at least one biomarker in the sweat of the user during using a virtual reality headset system10. The computer-implemented method comprises providing110a first virtual reality content to the user through a virtual reality headset system10, measuring120the concentration level of the at least one biomarker in the sweat of the user through a sensor13coupled to the virtual reality headset system10, interrupting130the providing110of the first virtual reality content to the user, when the concentration level of the at least one biomarker exceeds a predetermined first threshold concentration level, and returning140to providing the first virtual reality content to the user when the concentration level reaches a level below a predetermined second threshold concentration level. The first virtual reality content may be a virtual educational content, preferably in an asynchronous virtual educational environment, where each student can work at their own pace, or in addition to an educational environment in the physical world. The virtual educational environment may be a digital classroom or other kinds of auditoriums or workshop environments. The environment may also be an examination environment. In an example, the concentration level of the at least one biomarker exceeds a predetermined first threshold concentration level because of a situation and/or an event experienced by the user triggering a stress level of the user being higher than a stress level before the situation and/or event. In an educational environment, as the course progresses, the user might have some questions or may have not completely comprehended the thought material. This can potentially lead to a rising stress level of the user, for example, as the user might think that the user is “left behind”. The increased stress causes the body of the user to release specific biomarkers indicating stress, such as cortisol, in the bloodstream of the user, which is then reflected to the sweat of the user. When the concentration level of the at least biomarker exceeds a predetermined first threshold concentration level the user may be notified by the system to pause the learning and the providing110of the first virtual reality content is interrupted. Once a period of time has passed and the concentration level has moved below a predetermined second threshold concentration level, the system returns140to provide the first virtual reality content.

In an embodiment, the computer-implemented method100may comprise providing150a second virtual reality content to the user configured to reduce the concentration level of the at least one biomarker in the sweat of the user, when providing the first virtual reality content to the user is interrupted. While interrupting the providing110of the first virtual reality content the system may provide a second virtual reality content to the user which is suitable for reducing the concentration level of the at least one biomarker associated with the stress level of the user. Such a virtual reality content may comprise instructions on how to draw predefined shapes/sketches/drawings or any other kind of artmaking task. The artmaking task may comprise drawing on a digital canvas, a virtual reality sculpting session, a virtual reality pottery session, or a painting tutorial. The artmaking task may be tailored to the experience of each user and preferred artmaking type. The second virtual content is based on the age of the user and/or skills of the user. The second virtual reality content may comprise relaxing virtual environments such as environments known from holidays or virtual landscapes that appeal to the user. Any kind of virtual reality content may be used that is suitable for lowering the concentration level of the at least biomarker associated with the stress level of the user.

In an embodiment, the computer-implemented method may comprise adjusting160the second virtual reality content, when the concentration level may be not reduced at a predetermined rate. The adjusting160may comprise simplifying a task to be solved by the user, improving the comprehensibility of the second virtual reality content, and/or temporal extending of the virtual reality content. During the second virtual reality content configured to reduce the concentration level of the at least one biomarker the concentration level may be constantly monitored by the system. If the concentration level of the at least one biomarker maintains over the second threshold concentration level for a predetermined time range and/or does not reduce at a predetermined rate, the artmaking task, for example, may be changed and/or simplified to ensure that the concentration level of the at least one biomarker, such as cortisol, associated with a stress level of the user is being reduced to allow to return140to providing110the first virtual reality content.

FIG.5schematically illustrates an example of an exemplary calibrating step before providing110the first virtual reality content to the user.

In an embodiment, the computer-implemented method100may comprise calibrating200before providing the first virtual reality content to the user. The calibrating200may comprise providing210a plurality of virtual situations to the user, measuring220the concentration level of at least one biomarker in the sweat of the user corresponding to each virtual situation of the plurality of virtual situations by the sensor13, receiving230, via an input interface15, from a user an estimation of the stress level felt by the user corresponding to each virtual situation of the plurality of virtual situations, matching240the estimation of a stress level felt by the user with the concentration level measured by the sensor13corresponding to each virtual situation of the plurality of virtual situations, determining250a third threshold concentration level corresponding to a stress level above which the user has experienced a stress level in a smaller number of virtual situations that is greater than a stress level experienced by the user in a greater number of other virtual situations of the plurality of virtual situations and/or determining260a fourth threshold concentration level corresponding to a stress level below which the user has experienced a stress level in a smaller number of virtual situations that is smaller than a stress level experienced by the user in a greater number of other virtual situations of the plurality of virtual situations, storing270the matching, the third threshold concentration level and/or the fourth threshold concentration level in the storage medium. Given that each user might have different cortisol responses to a similar stressful event, the calibrating200may be required to relate the stress level experienced by the user to the measured concentration level of the at least one biomarker. For example, a series of stressful tasks can be given to the user while constantly monitoring the cortisol level. At the end of each task, the user may be asked to grade the task in terms of the stress the user felt. This grading may be used by the system to create an appropriate relationship between the concentration level of the at least one biomarker and the subjectively perceived stress level. In an example, the calibrating200is enabled in predefined time intervals or based on a quality criterion derivable from the results of measuring the concentration level of the at least one biomarker. In an example, while using the virtual reality headset system10, the frequency of interrupting130in a given time period may be recorded. For example, a quality criterion can be derived from the fact interrupting110occurs more frequently in a certain time period than in previous time periods, which indicates that calibrating200may be necessary. For example, calibrating200may be performed every hour, several times an hour or day, or randomly. For example, calibrating may be performed whenever a new first virtual reality content may be provided. In an example, the first virtual reality content may comprise a plurality of various educational content. For example, calibrating200may be performed between a first virtual educational content and a second virtual educational content.

In an embodiment, the first threshold concentration level may equal the third threshold concentration level, or may be below the third threshold concentration level, or may be above the third threshold concentration level. Calibrating200may be used to determine the threshold above which a user may perceive a task or virtual situation to be more stressful than another virtual situation, which may be determined using a concentration level of the biomarker that may be greater than a concentration level corresponding to a greater number of other virtual situations of the plurality of virtual situations. For example, the intake of the user of the first virtual content, such as educational content, may be hindered by a perceived stress level. The third threshold concentration level, which may be determined during calibrating200, may result in the first threshold concentration level above which the providing110of the first virtual content is interrupted, but it can also only represent a rough order of magnitude in which, for example, the first threshold concentration level may be arranged.

In an embodiment, the second threshold concentration level may equal the fourth threshold concentration level, or may be below the fourth threshold concentration level, or may be above the fourth threshold concentration level. Calibrating200may be used to determine the threshold concentration level below which a user may perceive a task or virtual situation to be less stressful than another virtual situation, which may be determined using a concentration level of the biomarker that may be smaller than a concentration level corresponding to a greater number of other virtual situations of the plurality of virtual situations. For example, while interrupting130the providing110of the first virtual reality content, the concentration level of the at least one biomarker falls below a second threshold concentration level. The fourth threshold concentration level, which may be determined during calibrating200, may result in the second threshold concentration level below returning140to providing110the first virtual reality content is executed, but it can also only represent a rough order of magnitude in which, for example, the second threshold concentration level may be arranged. In an example, the first threshold concentration level and the second threshold concentration level are approximately the same. For example, when the first threshold concentration level is exceeded, the providing110may be interrupted and when the concentration level falls again below the first threshold concentration level returning140to providing110may be executed.

In an example, the range between a third threshold concentration level and the fourth threshold concentration level forms a range being suitable for a user for learning purposes. For example, each user may have a range between two concentration levels of the at least one biomarker being expressive of the stress level felt by the user that favors a higher receptivity than when the stress level is higher or lower, this may be the case for example in the context of an educational content.

References throughout the preceding specification to “one embodiment”, “an embodiment”, “one example” or “an example”, “one aspect” or “an aspect” means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, “one example” or “an example”, “one aspect” or “an aspect” in various places throughout this specification are not necessarily all referring to the same embodiment or example.

Furthermore, the particular features, structures, or characteristics can be combined in any suitable combinations and/or sub-combinations in one or more embodiments or examples.

Embodiments