EP4646711A1

EP4646711A1 - A method and a computing device for assisting an assessment of head injury to a subject caused by a fall event

Info

Publication number: EP4646711A1
Application number: EP23836766.8A
Authority: EP
Inventors: Jia Long QIU; Ying Dong WEI; Gang Wang
Original assignee: Signify Holding BV
Current assignee: Signify Holding BV
Priority date: 2023-01-03
Filing date: 2023-12-20
Publication date: 2025-11-12
Also published as: JP2026505884A; WO2024146790A1; CN120457470A

Abstract

A method for assisting an assessment of head injury to a subject caused by a fall event occurred to the subject is disclosed. The method is performed by a processor and comprises the steps of obtaining measurement data of the fall event over a time period comprising the fall event, upon detection of the fall event; and generating indications for assisting the assessment of head injury, based on the measurement data. The indications comprises an animated fall trajectory, during the fall event and within a space where the fall happens, of the head of the subject, and speed data of the head of the subject during the fall event.

Description

A method and a computing device for assisting an assessment of head injury to a subject caused by a fall event

TECHNICAL FIELD

The present disclosure generally relates to the field of fall detection, more particularly, to a method and a computing device for assisting an assessment of head injury to a subject caused by a fall event occurred to the subject.

BACKGROUND

A major health risk in this modern society for vulnerable population including for example the elderly, infirmed, or disabled is injuries caused by an accidental fall, such as in the bathroom. Fall, which may be defined as an uncontrolled and sudden displacement of the body of a person to the ground or the floor, if left unnoticed, may cause serious health problem or even lead to death.

While physical injuries resulting from a fall, such as bruises or broken bones, can be noticed by the person or subject falling or a care giver, injuries or damages caused by a fall to the brain are sometimes not easy to detect. Delay in identifying such head injury may have severe result.

Various technologies have been developed by the healthcare industry to monitor fall events happening to different people groups and to raise an alarm. Automated fall detection based on various information collecting devices including wearable devices, cameras, and so on are currently available on the market.

Some camera-based elderly care solutions have gone beyond sending notification after a fall is detected. As an example, an available fall detection system offers an advanced injury assessment assisting feature. In the event of a fall, care staff has immediate access to a fall video of the fall detection system to help screen for injury, assess the seriousness of the incident, and determine if a trip to an Emergency Room is required.

One issue with camera based fall detection solutions is that a user may have concerns on privacy, especially for areas such as bathrooms or toilets. Furthermore, video playback based injury assessment or assessment assisting mainly depends on a subjective judgement of a person who watches the video, and therefore lacks objective information to support a better assessment. When it comes to head injury caused by a fall, it is even more difficult to be detected based on camera captured images or videos.

In consideration of the above, it is desirable that a fall detection solution can better assist the injury assessment, in particular of head injury, with privacy preserved and additional assessment supporting information considered.

SUMMARY

In a first aspect of the present disclosure, there is presented a method for assisting an assessment of head injury to a subject caused by a fall event occurred to the subject, the method performed by a processor and comprising the steps of: obtaining measurement data of the fall event over a time period comprising the fall event, upon detection of the fall event; generating indications for assisting the assessment of head injury, based on the measurement data, wherein the indications comprises: an animated fall trajectory, during the fall event and within a space where the fall happens, of the head of the subject, and speed data of the head of the subject during the fall event.

The present disclosure is based on the insight that better assistance to the assessment of head injury caused by a fall event happening to a subject may be provided by relying on indications for assisting the assessment of head injury. The indication includes an animated fall trajectory of the head of the subject in combination with speed data of the head of the subject during the fall. Both the animated fall trajectory and the speed data of the head of the subject during the fall are derived from measurement data of the fall event collected by for example a fall detection system.

When a fall event is detected, according to the method of the present disclosure, the measurement data of the fall event over a time period comprising the fall event, which is provided by the fall detection system detecting the fall event, is obtained and used to generate the animated fall trajectory as well as the speed of the head of the subject. The animated fall trajectory is depicted in a space where the fall event takes place. The animated fall trajectory of the head of the subject, together with the speed data of the head of the subject are then used to assist a personnel to evaluate or assess any possible head injury that occurs to the subject. The animated fall trajectory when being set in the space where the fall happens, makes it possible to identify sources of injury to the head of subject, such as the head hitting an object in the space.

The speed of the head of the subject during the fall, which is an objective parameter illustrative of factors such as a strength of a clash of the head to an object, is used as an objective factor or indication for accurately accessing the head injury.

Such indications of the present invention help to make the assessment of head injury more accurate as the method makes use of objective indicators derived from the measurement data of the fall event. The method further prevents any privacy issue that may occur as no images of the subject are used directly for detecting or assessing any injury that occurs to the subject.

In an example of the present disclosure, the measurement data of the fall event is obtained by a ranging sensor by measuring ranging data of different body parts of the subject over a number of instants in the time period comprising the fall event.

Instead of taking photos of a target, a ranging sensor monitors the target within its field of view by measuring distance between the ranging sensor and each point or part of a target. Such measurement data does not comprise any visual presentation of a body of the subject being monitored. Therefore there is no risk of violating privacy at all.

In this sense, there is even no image of the subject is generated. The ranging sensor based solution may also abstract a matchstick type skeleton of the subject from the ranging data, which is not a direct use of the image either.

In an example of the present disclosure, the ranging data at each instant of the time period comprises a plurality of positions of different body parts of the subject, the animated fall trajectory of the subject is generated by: arranging positions of the head of the subject sequentially from the earliest instant to the latest instant of the time period comprising the fall event to obtain a curve representing a movement trajectory of the head of the subject during the time period comprising the fall event; setting the curve against a pre-generated three-dimensional floor map comprising spatial location(s) and dimensions of at least one fixed object in the space where the fall happens.

Though the ranging sensor does not capture any direct visual representation of the subject that falls, the ranging sensor can measure distances to different body parts of the subject, that is, determining the positions of different body parts of the subject, for example relative to the ranging sensor. A range map allowing different body parts of the subject to be identified may be constructed from the ranging data.

Therefore the measurement data comprising positions to different body parts of the subject may be used to obtain a curve representing a movement trajectory of a specific body part, including the head, of the subject. The movement trajectory of each instant of the fall event when being animated over time, forms the animated fall trajectory of the subject.

The animated fall trajectory of the subject when being set against the floor map comprising spatially location(s) and dimensions of at least one fixed object in the space where the fall happens, allows a care giver or a medical staff to see in a straightforward manner whether the head of the subject goes through any action that would cause head injury.

In an example of the present disclosure, the step of generating indications for assisting the assessment of head injury based on the measurement data further comprises: generating distance data between the head of the subject and at least one fixed object in the space where the fall happens, during the fall event, based on the measurement data, based on the positions of the head of the subject and the spatially locations of the at least one fixed object.

With the distances of the head of the subject, of each instant during the fall event, which is available from the measurement data, and the floor map comprising one or more fixed objects in the space where the fall happens, the distance data between the head of the subject and at least one fixed object is generated by calculating distances between the head of the subject and each of the at least one fixed object for each time instance with reference to pre-generated floor map comprising the spatially location and dimension of the at least one fixed object.

This distance data between the head of the subject and one or more fixed objects in the space where the fall happens is also used together to assist the assessment of the severity of a head injury that is caused by the fall event. A much more reliable assessing result can be obtained as the different indicators combined allows the injury resulting from the fall event to be evaluated in an objective way.

In an example of the present disclosure, the pre-generated three-dimensional floor map is obtained by the ranging sensor by measuring ranging data of objects in the space where the fall happens.

The same ranging sensor used for acquiring the measurement data of the fall event may be used to measure the space being monitored for any potential fall, to generate a floor map beforehand. The floor map comprises fixed objects in the space, such as a basin or a toilet in a bathroom.

In an example of the present disclosure, the method further comprises the step of rendering the indications for assisting the assessment of head injury on a display device.

It can be contemplated by those skilled in the art the generated indications for assisting the assessment of head injury may be provided to a relevant person such as a medical staff or a care giver, allowing them to use the indications in a way that they like.

On the other hand, the method of the present disclosure may also have such indications for assisting the assessment of head injury rendered or displayed, on a display device, that is communicatively coupled or connected to the processor for performing the method of the present disclosure. It is very convenient especially when the processor and the display device are combined into a single device, which allows the indications to be displayed more efficiently, allowing the assessment of the head injury to be performed right away without any delay, after the relevant person becomes aware of the fall event.

In an example of the present disclosure, the method further comprises the steps of: finding one or more points on the animated fall trajectory, of the head of the subject, having smallest distance to each of the at least one fixed object, and highlighting a point on the animated fall trajectory having a smallest distance to one of the at least one fixed object when the smallest distance to the one of the at least one fixed objects is smaller than a threshold value.

It can be contemplated by those skilled in the art that the distance between the head of the subject and a part of a fixed object illustrates in a sense an objective criterion in determining if the head of the subject clashes against the object. It is not influenced by an subjective impression therefore is a clear indicator if the head is hit by something, which is a well-founded factor to be considered in assessing any possible head injury.

It is also possible that the head may hit an object and then bounce up and then hit the object again one or more times. Highlighting the point(s) of the animated fall trajectory with a distance between the head of the subject and the at least one fixed object which is smaller than a threshold value helps to draw the attention of the relevant person to such points and enable them to assess the head injury in a faster and more reliable way.

In an example of the present disclosure, the method further comprises the step of: highlighting the speed of the head of the subject at an instance corresponding to the highlighted point on the animated fall trajectory.

Further to considering the distance between the head of the subject and the fixed object in the space where the fall happens, the speed of the head may also be considered. Highlighting the speed of the head for the point(s) where the distance between the head of the subject and a fixed object is highlighted allows the assessment as to if the head indeed hits the object to be more accurate.

In an example of the present disclosure, the method further comprises the step of: highlighting the distance between the head of the subject and the fixed object at an instance corresponding to the highlighted point on the animated fall trajectory.

When the distance data between the head of the subject and the fixed object is also available, for those points highlighted on the animated fall trajectory, the distance between the head of the subject and the fixed object is also highlighted.

When the animated fall trajectory, the speed of the head of the subject and the distance of the head of the subject to the fixed object are considered together, the assessment of the severity of the head injury caused by the fall event is performed to a more precise extent.

In an example of the present disclosure, the ranging sensor is a Time of Flight, ToF, sensor.

A ToF sensor, especially a low resolution ToF sensor which is readily available from the market, is well suited for performing the measurement required in the present disclosure. This helps to keep the cost of the solution low.

A second aspect of the present disclosure presents a computing device comprising a processor, the processor arranged to perform the method for assisting an assessment of head injury to a subject caused by a fall event occurred to the subject according to any of the first aspect of the present disclosure.

In an example of the present disclosure, the computing device comprises a lighting device comprising an integrated ranging sensor and the processor, wherein: the ranging sensor is arranged to obtaining measurement data of the fall event over a time period comprising the fall event.

An example of the computing device may be an intelligent light device which is currently deployed in many households. The ranging sensor may be conveniently integrated into the light device, saving space while reducing cost. In an example of the present disclosure, the ranging sensor is further arranged to obtain measurement data for pre-generating a floor map comprising spatially location and dimension of at least one fixed object in the space where the fall happens.

The floor map is generated by a processor based on the measurement data obtained by the ranging sensor. The processor may be comprised in a device separate from the ranging sensor or the ranging sensor itself, depending on computational capacity of the device comprising the processor.

In a further example of the present disclosure, the ranging sensor is a Time of Flight, ToF, sensor.

A third aspect of the present disclosure provides a computer program product, comprising a computer readable storage medium storing instructions which, when executed on at least one processor, cause said at least one processor to carry out the method according to the first aspect of the present disclosure.

The above mentioned and other features and advantages of the disclosure will be best understood from the following description referring to the attached drawings. In the drawings, like reference numerals denote identical parts or parts performing an identical or comparable function or operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 schematically illustrates a fall detection system in accordance with an embodiment of the present disclosure.

Figs. 2(a) -2(c) respectively illustrate a picture of a bathroom, ranging data of the bath room, and a 3D floor map constructed from the ranging data.

Fig. 3 schematically illustrates, in a flow chart type diagram, an embodiment of a method of for assisting an assessment of head injury to a subject caused by a fall event occurred to the subject in accordance with the present disclosure.

Figs. 4(a) to 4(e) show several snapshots of a fallback animation in time sequence in accordance with the present disclosure.

Fig. 5 schematically illustrates exemplary moving speed of the head and distance of the head to the toilet during the fall procedure in accordance with the present disclosure.

DETAILED DESCRIPTION

Embodiments contemplated by the present disclosure will now be described in more detail with reference to the accompanying drawings. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein. Rather, the illustrated embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

Throughout the description, the terms “target”, “user”, “person” and “subject” are used interchangeably.

A method and a computing device, such as a backend server communicating with a fall detection device or a lighting device having a fall detection function, for assisting an assessment of head injury to a subject caused by a fall event occurred to the subject will be described in the following.

The method for assisting an assessment of head injury as proposed by the present disclosure is realized using a fall detection system based on a ranging sensor. The ranging sensor may be a Time of Flight sensor, in particular a low-resolution ToF sensor, which may help to keep the cost of the solution of the present disclosure low.

Figure 1 schematically illustrates a fall detection system 10 in accordance with an embodiment of the present disclosure. The fall detection system comprises two major parts or components: one or more ranging sensor 11 and a computing or processing device or a processor 12.

The ranging sensor 11 may be such as a low-resolution, for example 64 zone ToF sensor. The ToF sensor 11 may be deployed on a ceiling of a space to be monitored, such as in a washroom. The ToF sensor 11 is arranged to monitor a target in the space by capturing in real time ranging data of the target without capturing any privacy information. When the target is a person, such ranging data may indicate position and posture of the person. When the target is a fixed object, the ranging data may indicate spatial location and dimension of the object.

The computing or processing device or a processor 12 may be a backend server deployed remotely from the sensor 11. In this case, the processor 12 and each of the sensors 11 communicate 19 with each other via a network such as internet 18, in a wired or wireless manner.

The processor 12 is configured to receive date acquired or captured by the one or more sensors 11 and to store and optionally render such measurement data. The processor may further be arranged to determine whether a fall event is happening or has happened to the user, based on the data obtained from the sensor 11. The processor 12 may also configured to trigger an alarm device 13, by way of for example a trigger message transmitted 17 to the alarm device 13 when a fall event is detected.

The above describes the processor 12 as a device separate or independent from the sensor 11. However, as can be contemplated by those skilled in the art, the processor 12 and the sensor may be a single integrated device.

As an example, the sensor 11 may comprise a sensing part and further have a build-in processor that may process raw data captured by the sensing part of the sensor, to determine any possible event happening to the user.

It can also be the case that the sensor has a build in processor or a separate local processor for fall detection, another processor at the backend or a remote locations for generating indications for injury assessment assistant.

The processor 12 is described above as being deployed remotely from the sensor 11. In practice, the processor 12 may also be deployed locally and communicatively connected to the sensor 11.

An specific example of the fall detection system considered by the present disclosure may be a lighting device integrating a ranging sensor such as a ToF sensor and a processor. Such a lighting device, in addition to its lighting function, may also function as a fall detection device or system. The lighting device may perform the method of the present disclosure to be detailed in the following, when sufficient computing resources are available to the lighting device.

As an example, the ToF sensor may be based on indoor lighting fixtures readily available at each household, such as LED lights fixed to ceilings.

When the space with the ToF sensor 11 deployed is vacant, the sensor 11 is arranged to take measurement data of the space and send the measurements to the processor 12 for building up a three-dimensional, 3D, floor map of the space. Such a 3D floor map contains dimensions and positions of fixed objects in the space. As an example, when the space is a bathroom, fixed objects such as a toilet and a basin may be illustrated in the 3D floor map.

Figures 2(a) -2(c) respectively illustrate a picture of a bathroom, ranging data of the bathroom, and a 3D floor map of the bathroom constructed from the ranging data. The ranging data is obtained using for example a 64 (8x8) zone ToF ranging sensor.

Referring to Figure 2(b), such a ToF sensor can simultaneously output 64 (zonel~zone64) range measurements, that is, distances from any object in its detection range to the sensor, in one frame. A measuring frequency the ToF sensor can be from a few frames per seconds, FPS, to tens of FPS.

Specifically, Figure 2(a) is a photo 21 of one part of a vacant washroom which contains a basin 22 and a toilet 23.

Figure 2(b) is one frame output 24 of a 64 zone ToF sensor mounted on the ceiling of the washroom. The sensor’s field of view, FoV, covers the toilet 23 and part of the basin 22.

Figure 2(c) is a 3D floor map 25 generated by a computing device, such as a backend computing device, using the data of Figure 2(b) obtained by the ToF sensor. From the 3D floor map 25 the dimensions and positions of the fixed objects, that is, the toilet 23 and the basin 22, in the washroom are known. In practice it is not necessary to know what exactly an fixed object is.

The basin 22 and toilet 23 are both represented in Figure 2(b) and 2(c).

Figure 3 schematically illustrates, in a flow chart type diagram, an embodiment of a method 30 for assisting an assessment of head injury to a subject caused by a fall event occurred to the subject in accordance with the present disclosure.

A 3D floor map described above of the space where the fall event happens is pre-generated by a computing device performing the method for assisting assessment of head injury. Alternatively, such a 3D floor may be obtained from a further device which has generated the 3D floor map beforehand.

At step 31, when a fall event is detected by a fall detection system, the computing device or processor performing the method of the present disclosure obtains measurement data of the fall event happened to a subject or user of the fall detection system. The measurement data lasts over a time period comprising the fall event.

In practice, when a person is present in a space having the ToF sensor deployed, the ToF sensor starts to monitor motion and posture of the person. The sensor keeps recording measurement data over a pre-defined duration, such as for a period of the past 20 seconds.

Optionally, for the purpose of reducing a size of recorded data, the sensor may only record measurements of zones covering the person. The number of zones covering the person is not constant. When the person is standing or sitting, he or she may occupy up to 8 zones. When the person is falling or lying on the floor, he or she may occupy up to 12 zones. If the person falls, the fall detection system comprising the ToF sensor can detect the fall shortly after the person’s body is resting on the floor. Detection of the fall is beyond the scope of the present disclosure and will not be described herein.

At that moment when the fall is detected, the recorded data would contain measurement data covering the complete fall process experienced by the person. The ToF sensor can now stop recording the measurement data and send the recorded measurement data, optionally together with the fall alarm, to the computing device performing the method for assisting assessment of head injury such as a backend server.

As discussed above, for each time instant, the measurement data comprising ranging data of or distance (from the ToF sensor) to different body parts of the subject.

At step 32, indications for assisting assessment of head injury are generated based on the measurement data.

The indications for assisting assessment of head injury may be generated and provided to a user, allowing the user to display the indications in a manner that is appropriated. On the other hand, when the computing device comprising the processor for performing the method of the present disclosure is equipped or communicatively connected to a display device, the indications may be rendered or displayed, at step 33, on the display device directly.

As an example, an animated fall trajectory of the head of the subject during the fall procedure, together with a speed of the head of the subject and optionally a distance between the head of the subject and the one or more fixed object during the fall procedure, all of which will be described in the following, may be rendered on a display device, allowing a medical staff or a care giver to assess the severity of head injury in an objective and reliable manner.

The indications may comprise an animated fall trajectory, during the fall event and within a space where the fall happens, of the head of the subject, and speed data of the head of the subject during the fall event.

The animated fall trajectory of the head of the subject and the speed of the head of the subject may be generated in any order. It is not necessary to generated a specific one before the other.

For injury assessment, it is important to know whether the person who has fallen hits his or her head onto a fixed object, such as the toilet or the basin, on the way of falling down. And if so, how severe the head was hit. The animated fall trajectory and the speed of the head of the subject as generated by the present disclosure may be used to determine if such hitting exists, thereby assisting the assessment of the head injury to the subject.

Is an example, the backend server functioning as the computing device running the method of the present disclosure analyses the recorded measurement data to generate a playback animation of the fall process.

As can be contemplated by those skilled in the art, a plurality of distances to different body parts of the subject is recorded by the ToF sensor for each instant of the fall procedure. The distances of the head of the subject, when arranged sequentially from the earliest instant to the latest instant of the time period comprising the fall event, will form a curve representing a movement trajectory of the head of the subject during the time period comprising the fall event. When the curve obtained for different time instant of the fall procedure is played back in an animated way, against the 3D floor map of the space where the fall happens, the fall procedure is visualized.

The movement trajectory of the person’s head may be highlighted in the playback animation versus change of the person’s posture during the fall procedure. Figures 4(a) to 4(e) show several snapshots of a fall playback animation in time sequence.

Refer to Figure 4(a), a straight line segment 41 represents a standing person, with a small dot 42 on a top end of the straight line segment 41 representing the head of the person. A curve 43 formed by the small triangle 42 shown in each of Figures 4(b) to 4(e) illustrates a trajectory of the person’s head for the complete falling process.

The curve 43 is plotted against the 3D floor map representing the space where the fall event takes place, allowing possible sources of head injury such as the head hitting an object to be identified in a straightforward manner.

Figure 4(b) indicates the fall just started as the curve 43 shows that the head just started moving downwards. It is seen from the curve 43 of Figure 4(c) that the head is moving towards the toilet 23 and is about to hit against the toilet 43. Figure 4(d) shows a moment when the head touches the toilet 23. Figure 4(e) is the end of the fall when the person is lying on the floor.

To further confirm whether the person’s head hit the toilet as well as the severity of the hit, the backend calculates the moving speed of the person’s head, which is used as a further indication for assisting the assessment of head injury. Better assessment results may be obtained based on the animated fall trajectory, and the moving speed of the head of the falling person. A distance between the head of the person and a fixed object in the space where the fall event takes place, such as the top surface of the toilet, may also be obtained by using the measurement data. This is used as a further indication for assisting assessment of head injury.

It can be understood by those skilled in the art that the moving speed of the head of the subject is calculated by dividing a distance difference, as opposed to an object such as a toilet, between the instant and a previous instant of the head over a time difference between the instant and the previous instant.

As for the distance data to an object, it is determined by using the measured ranging data of the head of the subject and the ranging data of the object which is measured beforehand when generating the 3D floor map of the space where the fall happens.

Figure 5 schematically illustrates exemplary moving speed of the head and distance of the head to the toilet during the fall procedure.

In Figure 5, a horizonal axis is frame index which is connected to the time. As an example, when the FPS is 10, one frame is 0.1 second. A lower part of Figure 5 is the moving speed of the head in the vertical direction with a unit of meter per second, m/s; and an upper part of Figure 5 is the distance of the head to the top surface of the toilet with a unit of centimeter, cm.

Figure 5 covers the whole falling process and there are 6 dashed lines indicating several moments during the fall. The first line A of Figure 5 is the same moment of Figure 4(b) when the fall just started, which is reflected in Figure 5 as the speed of the head starting to increase and the distance between the head and the toilet 23 starting to reduce.

The second line B of Figure 5 is the same moment of Figure 4(c) when the person’s head is about to hit the toilet. At this moment, the speed of the head is at its maximal (~0.8 m/s) and right after the moment the speed of the head decreased dramatically that is, from about 0.8 m/s to 0.3 m/s within 0.1 second, which confirms that the head hit the toilet.

The speed of the head before hitting the toilet as well as the changing of speed when hitting the toilet are important information to assess the severity of the hit.

The third line C of Figure 5 is the same moment of Figure 4(d) when the person’s head is touching the toilet. After this moment the speed of the head increased for a very short period reflecting the head was bouncing off the surface of the toilet.

Then the speed and distance continued decreasing till a moment shown by the fourth line D of Figure 5, when the person’ head, and his/her upper body, is stably resting on the toilet till a moment shown by the fifth line E of Figure 5. From moment E, the person’s upper body started falling toward the floor and completely lay on the floor at the moment of the sixth line F, which is the same moment of Figure 4(e). During this period, the speed of the head increased again and then decreased, while the distance of the head further decreased to below zero indicating the head is lower than the top surface of the toilet.

Head injury is more likely to be caused by the head hitting an object. In the present disclosure, the head hitting an object can be indicated by several parameters or indicators that are obtained from the measurement data. Such parameters or indicators include the distance between the head and the object, the speed of the head when hitting the object and the speed change of the head before and after hitting the object.

Another factor to consider is when the head hits against an object and then bounces off and hits the object for a second or even a third time as a collective result of difference forces such as the gravity and an impact force between the head and the object.

In evaluating the head injury caused to the subject based on the animated fall trajectory, the speed of the head of the subject and the distance between the head of the subject and the one or more fixed objects, time instants with a minimum distance between the head of the subject and the one or more fixed objects and / or a significant speed change of the head of the subject are considered against each other. This allows the assessment of possible head injury to be performed more accurately.

Information which is of special interest to the medical staff or the care giver may be highlighted, so as to draw the attention of the medical staff or the care giver viewing the displayed indication for assisting the assessment of the head injury.

Therefore, at step 34, one or more of the rendered indications is highlighted.

As an example, one or more points on the animated fall trajectory of the head of the subject having smallest distance to each of the at least one fixed object may be decided. When a smallest distance to the one of the at least one fixed objects is smaller than a threshold value, such as for example 20cm, a point having such as distance of the animated fall trajectory is highlighted.

In addition, the head of the subject as well as the distance between the subject and the fixed object for a moment, or a time period comprising a moment, when the subject hits his or her head to an object may also be highlighted, as indicated by the grey area of Figure 5. This further helps the medical staff or care giver to make a fast and accurate assessment of the head injury to the subject. It can be contemplated by those skilled in the art that the assessment result may be rendered to a medical staff or a care giver together with the animated fall trajectory, the speed of the head of the subject and the distance between the head of the subject and the one or more fixed objects, allowing them to evaluate the whole situation based on professional experience.

The present disclosure is not limited to the examples as disclosed above, and can be modified and enhanced by those skilled in the art beyond the scope of the present disclosure as disclosed in the appended claims without having to apply inventive skills and for use in any data communication, data exchange and data processing environment, system or network.

Claims

CLAIMS:

1. A method (30) for assisting an assessment of head injury to a subject caused by a fall event occurred to the subject, the method (30) performed by a processor and comprising the steps of: obtaining (31) measurement data of the fall event over a time period comprising the fall event, upon detection of the fall event; generating (32) indications for assisting the assessment of head injury, based on the measurement data, wherein the indications comprises: an animated fall trajectory, during the fall event and within a space where the fall happens, of the head of the subject, and speed data of the head of the subject during the fall event. wherein the step of generating indications for assisting the assessment of head injury based on the measurement data further comprises: generating distance data between the head of the subject and at least one fixed object in the space where the fall happens, during the fall event, based on the measurement data, based on the positions of the head of the subject and the spatial location of the at least one fixed object.

2. The method (30) according to claim 1, wherein the measurement data of the fall event is obtained by a ranging sensor by measuring ranging data of different body parts of the subject over a number of instants in the time period comprising the fall event.

3. The method (30) according to claim 2, wherein the ranging data at each instant of the time period comprises a plurality of positions of different body parts of the subject, the animated fall trajectory of the subject is generated by: arranging positions of the head of the subject sequentially from the earliest instant to the latest instant of the time period comprising the fall event to obtain a curve representing a movement trajectory of the head of the subject during the time period comprising the fall event; setting the curve against a pre-generated three-dimensional floor map comprising spatial location(s) and dimensions of at least one fixed object in the space where the fall happens.

4. The method (30) according to claim 3, wherein the pre-generated three- dimensional floor map is obtained by the ranging sensor by measuring ranging data of objects in the space where the fall happens.

5. The method (30) according to any of the previous claims, further comprising the step of rendering the indications for assisting the assessment of head injury on a display device.

6. The method (30) according to claim 5, further comprising the steps of: finding one or more points on the animated fall trajectory, of the head of the subject, having smallest distance to each of the at least one fixed object, and highlighting (34) a point on the animated fall trajectory having a smallest distance to one of the at least one fixed object when the smallest distance to the one of the at least one fixed objects is smaller than a threshold value.

7. The method (30) according to claim 6, further comprising the step of: highlighting (34) the speed of the head of the subject at an instance corresponding to the highlighted point on the animated fall trajectory.

8. The method according to claim 6 or 7, further comprising the step of: highlighting (34) the distance between the head of the subject and the fixed object at an instance corresponding to the highlighted point on the animated fall trajectory.

9. The method according to any of the previous claims, wherein the ranging sensor is a Time of Flight, ToF, sensor.

10. A computing device comprising a processor, the processor arranged to perform the method for assisting an assessment of head injury to a subject caused by a fall event occurred to the subject according to any of the previous claims 1 to 9.

11. The computing device according to claim 10, comprising a lighting device comprising an integrated ranging sensor and the processor, wherein: the ranging sensor is arranged to obtaining measurement data of the fall event over a time period comprising the fall event.

12. The computing device according to claim 11, wherein the ranging sensor is further arranged to obtain measurement data for pre-generating a floor map comprising spatially location and dimension of at least one fixed object in the space where the fall happens.

13. The computing device according to claim 11 or 12, wherein the ranging sensor is a Time of Flight, ToF, sensor.

14. A computer program product, comprising a computer readable storage medium storing instructions which, when executed on at least one processor, cause said at least one processor to carry out the method according to any of the previous claims 1 to 9.