Method, apparatus and computer program product for operating a motor vehicle

Abstract

Procedure for operating a motor vehicle (1), - to which a position sensor (3) is assigned, the measurement signal (MS_Pos) of which includes spatial information of a given area of ​​a vehicle interior (5) of the motor vehicle (1), - to which at least one radiation source (7) is assigned that emits a specified radiation, and - to which at least one vital sensor (9) is assigned a detector that detects a portion of the radiation emitted by the radiation source (7) incident upon it, and whose measurement signal (MS_Vit) is representative of at least one vital parameter (VP) of a respective vehicle occupant, - in which, depending on the measurement signal (MS_Pos) of the position sensor (3), a position of at least one predefined reference body part (P_RKT) of the respective vehicle occupant is determined, and - in which, depending on the determined position of the specified reference body part (P_RKT) of the respective vehicle occupant, an orientation of the radiation source (7) is controlled, and in which - depending on the measurement signal (MS_Pos) of the position sensor (3) a characteristic value (K_BD) for a motion dynamic is determined and - depending on the characteristic value (K_BD) for the motion dynamics, the radiation source (7) is activated or deactivated.

Description

[0001] The invention relates to a method, a device and a computer program product for operating a motor vehicle in which a radiation source is controlled depending on a position sensor.

[0002] Motor vehicles are increasingly being equipped with cameras or sensors. These cameras or sensors can be used, for example, to monitor the health of a vehicle occupant. Monitoring the health of vehicle occupants can contribute to increased road safety.

[0003] US patent 2008 / 0069403A1 discloses an image recognition system for facial recognition of occupants of a motor vehicle.

[0004] Systems for recording biometric data of a motor vehicle driver are described in DE 10 2004 035 896 A1 and US 2012 / 0 150 387 A1.

[0005] The object underlying the invention is to create a method and a corresponding device that contributes to reliably recording the state of health of a vehicle occupant.

[0006] The problem is solved by the features of the independent patent claims. Advantageous embodiments are characterized in the dependent claims.

[0007] According to a first aspect, the invention is characterized by a method and a corresponding device for operating a motor vehicle. According to this first aspect, the motor vehicle is equipped with a position sensor whose measurement signal comprises spatial information about a predetermined area of ​​the vehicle's interior. Furthermore, the motor vehicle is equipped with at least one radiation source that emits a predetermined amount of radiation. Additionally, at least one vital sign sensor with a detector is arranged in the motor vehicle. The detector detects a portion of the radiation emitted by the radiation source that is incident upon the sensor. Depending on a raw measurement signal from the detector of the vital sign sensor, a measurement signal from the vital sign sensor can be generated. The measurement signal of the vital sign sensor is representative of at least one vital parameter of a respective vehicle occupant.Depending on the measurement signal from the position sensor, the position of at least one predefined reference body part of the respective vehicle occupant is determined. Based on the determined position of this reference body part, the radiation source is aligned. Furthermore, a characteristic value for a movement dynamic is determined based on the position sensor's measurement signal. Depending on this characteristic value, the radiation source is activated or deactivated.

[0008] In this way, the radiation source in the vehicle can be controlled simply and reliably. Thanks to the position sensor, the orientation of the radiation source can be adjusted to the movement of the respective vehicle occupant or at least to the movement of a predefined reference body part. This ensures that even when the vehicle occupant moves, a reflected portion of the radiation emitted by the radiation source reaches the vital signs sensor. The predefined reference body part of the respective vehicle occupant serves as a reference point to determine where the radiation from the source should be directed in order to determine at least one vital parameter. Furthermore, the movement-adapted orientation of the radiation source contributes to the safety of the respective vehicle occupant.

[0009] According to one embodiment of the first aspect, at least one vital parameter of the respective vehicle occupant is determined depending on the measurement signal of the vital sensor.

[0010] In this context, the radiation source is specifically directed at a particular area of ​​the vehicle occupant's skin, for example, the neck or face. The portion of the radiation reflected from this area of ​​skin can contain information about one or more vital parameters of the occupant, allowing for the contactless measurement of these parameters without restricting the occupant's movement. This eliminates the need to attach sensors directly to the occupant, which is perceived as comfortable. Furthermore, the occupant's clothing has no effect, as the face is typically not covered by clothing.

[0011] According to a further embodiment of the first aspect, at least one vital parameter of the respective vehicle occupant is determined based on vibrocardiography, depending on the measurement signal from the vital sensor. Vibrocardiography is a method in which radiation from a radiation source, for example, laser light, is directed onto the surface of an object under investigation, and a reflected portion of the laser light is analyzed. Due to the surface structure of the object, the laser light is reflected in such a way that an interference pattern can be observed at a corresponding distance from the object, which contains information about the surface properties and the object's movement.In this context, vibrocardiography can be used to determine vital parameters by directing the radiation from the source onto a specific area of ​​the vehicle occupant's skin. The reflected portion of this radiation is then detected by a vital sensor, and the sensor's measurement signal is subsequently processed. For example, a laser can be used as the radiation source, aimed at the area of ​​the carotid artery of the vehicle occupant. Due to the pulsating carotid artery, a periodic movement of the reflected interference pattern can be observed. Thus, a pulse or pulse waveform of the vehicle occupant can be determined as a vital parameter.

[0012] According to a further embodiment of the first aspect, at least one vital parameter of the respective vehicle occupant is determined based on photooximetry, depending on the measurement signal from the vital sensor. In this context, photooximetry refers to a method in which radiation from a radiation source, such as laser light, is directed at an object to be examined, and the reflected and / or transmitted portion of the laser light is analyzed. For example, the intensity of laser light reflected from a part of the skin of the respective vehicle occupant can be analyzed. In this way, for example, the oxygen content and / or blood glucose level of the blood can be determined non-invasively as vital parameters of the respective vehicle occupant.Both the oxygen content and the blood glucose level in the blood of each vehicle occupant affect the color of the blood, which is why, for example, blood with higher oxygen levels appears lighter than blood with lower oxygen levels. The different coloration of the blood beneath the skin of each vehicle occupant leads to varying intensities of the reflected laser light, allowing the vital parameters mentioned above to be determined by analyzing this reflected laser light.

[0013] According to a further embodiment of the first aspect, depending on the determined position of the reference body part of the respective vehicle occupant and the measurement signal of the vital sensor, the radiation source is controlled in the sense of aligning itself to at least one predetermined preferred position of the respective vehicle occupant.

[0014] This allows for a high correlation between the vital sign sensor's measurement signal and the respective vital parameter. A preferred location in this context could be the carotid artery or a temple area of ​​the vehicle occupant.

[0015] Another possibility is to target more than one predefined preferred position of the respective vehicle occupant, depending on the measurement signal from the vital sensor. For example, a good correlation between the measurement signal of the vital sensor and the respective vital parameter can be achieved for one vehicle occupant by directing the radiation source towards the carotid artery, and for another vehicle occupant by directing the radiation source towards the temple area. Furthermore, one of the preferred positions, such as a section of skin on the neck of the respective vehicle occupant, may be obscured by clothing, for example, a scarf. Therefore, another preferred position, such as the temple area, may be suitable for determining at least one vital parameter of the respective vehicle occupant.

[0016] The preferred position in which the measurement signal of the vital sensor has the highest correlation with the respective vital parameter to be determined for the respective vehicle occupant can be described as the optimal preferred position for that vehicle occupant.

[0017] Alternatively or additionally, it can be advantageous to optimize the alignment of the radiation source to achieve the highest possible correlation between the vital sign sensor's measurement signal and the respective vital parameter being measured. In this context, the radiation from the source is first directed towards a predetermined preferred position on the respective vehicle occupant, and the radiation is then varied within a defined area around this preferred position. By evaluating where the vital sign sensor's measurement signal exhibits the highest correlation with the respective vital parameter, a corresponding, optimized preferred position can be determined.

[0018] According to a further embodiment of the first aspect, the radiation intensity of the radiation source is controlled depending on the measurement signal of the vital sensor.

[0019] In this way, it is possible for the intensity of the reflected portion of the radiation to reach a predefined second threshold, thereby enabling the vital signs sensor to register a measurement signal. For example, a predefined signal-to-noise ratio can be achieved that allows the determination of at least one vital parameter of the respective vehicle occupant.

[0020] According to a further embodiment of the first aspect, the radiation source is activated or deactivated depending on the measurement signal from the position sensor. Among other things, this ensures the safety of the respective vehicle occupant by only activating the radiation source after the position of the respective vehicle occupant and / or the respective predefined reference body part has been detected.

[0021] Furthermore, this design includes non-contact measurement of at least one vital parameter of each vehicle occupant, for example, using multiple radiation sources located in the vehicle. For instance, one radiation source could be positioned in a headrest and directed at a specific area of ​​skin on the occupant's neck. Another radiation source could be located in the dashboard and directed at a specific area of ​​skin near the occupant's temple.

[0022] Furthermore, by activating or deactivating the radiation source, a measurement and determination of at least one vital parameter of the respective vehicle occupant can be carried out within a certain time interval and does not necessarily have to be carried out continuously within a driving cycle.

[0023] According to a further embodiment of the first aspect, a characteristic value for motion dynamics is determined depending on the measurement signal from the position sensor. Furthermore, the radiation source is activated or deactivated depending on this characteristic value for motion dynamics.

[0024] For example, a vehicle occupant might move rapidly depending on the situation, and the radiation source might not be able to follow this movement. If a characteristic value of the movement dynamics is detected that exceeds a predefined third threshold, the radiation source can be deactivated. In this way, the safety of the vehicle occupant is ensured even during sudden movements.

[0025] According to a further embodiment of the first aspect, the position sensor includes a camera. In this context, the camera can be a single camera or a stereo camera, thus providing spatial information about a predefined area of ​​the vehicle's interior. Cameras are often already installed in vehicles for other purposes, allowing, for example, the use of an existing resource.

[0026] According to a further embodiment of the first aspect, the position sensor includes an ultrasonic sensor. This is another way to acquire spatial information about a predefined area of ​​the vehicle's interior.

[0027] According to a further embodiment of the first aspect, the radiation source comprises a laser. Due to its radiation properties, the laser constitutes a preferred radiation source that emits coherent light with high brilliance. As a result, the laser light can be precisely directed onto a specific area of ​​the vehicle occupant's skin. By analyzing the portion of the laser radiation reflected from the skin, a vital parameter of the respective vehicle occupant can be determined, for example, using vibrocardiography or photooximetry.

[0028] According to a further embodiment of the first aspect, a person sensor is assigned to the vehicle, the measurement signal of which is representative of a personal identification characteristic of the respective vehicle occupant. Depending on the measurement signal of the person sensor, an identification is carried out, and thus an identified vehicle occupant is determined.

[0029] In this way, the measurement of the vital parameter(s) can be assigned to the identified vehicle occupant, making it possible, for example, to measure at least one vital parameter on a personal basis.

[0030] Furthermore, by identifying each vehicle occupant, it is possible to assign one or more predefined preferred positions to that occupant. For example, a data storage system can record which preferred position of the identified occupant proved optimal for determining vital parameters during a previous driving cycle, so that in a subsequent driving cycle, the radiation source will again select the optimal preferred position for that occupant.

[0031] Furthermore, the respective adapted preferred position for each identified vehicle occupant can also be stored. In this way, during a subsequent driving cycle and re-identification of the respective vehicle occupant, information about the optimal preferred position of the identified vehicle occupant and about a personalized, optimized orientation of the radiation source within the area of ​​the optimal preferred position is available.

[0032] According to a further development of the first aspect, the position sensor is also used as a person sensor. In this way, an existing sensor is used for an additional purpose, and additional sensors are not necessarily required.

[0033] According to a further refinement of the first aspect, each measurement signal from the vital signs sensor is assigned to the respective identified vehicle occupant. This makes it possible to directly assign the vital signs sensor's measurement signal to an identified vehicle occupant without further evaluation. Further processing of the measurement signal can, for example, take place externally to the vehicle and / or at a later time.

[0034] According to a second aspect, a system comprises the device for operating a motor vehicle, the position sensor, the radiation source, and the vital sensor with the detector.

[0035] According to a third aspect, the invention is characterized by a computer program product comprising executable program code, wherein the program code, when executed by a data processing device, performs the method for operating a motor vehicle according to the first aspect.

[0036] Exemplary embodiments of the invention are explained in more detail below with reference to the schematic drawings. These show: Fig. 1 a motor vehicle with a device for operating a motor vehicle, Fig. 2 a flowchart of a program that is executed in the device.

[0037] Elements of the same construction or function are marked with the same reference symbols across all figures.

[0038] A motor vehicle ( Fig. 1) A position sensor 3, a vital sensor 9 with a detector, and a radiation source 7 are assigned to the system. The radiation source emits a predefined radiation signal when activated. A measurement signal MS_Pos from the position sensor 3 comprises spatial information about a predefined area of ​​the vehicle interior 5 of the motor vehicle 1. A measurement signal MS_Vit from the vital sensor 9 comprises a reflected portion of the radiation emitted by the radiation source 7 and is representative of at least one vital parameter VP of a respective vehicle occupant.

[0039] Furthermore, a person sensor 11 and a control device 13 are arranged in the motor vehicle 1.

[0040] The control device 13 can, for example, include a data and program memory as well as a processing unit. It can be described as a device for operating a motor vehicle or as an on-board computer. The control device 13 is coupled to the position sensor 3, the vital sign sensor 9, and the radiation source 7 via signal transmission.

[0041] The person sensor 11 provides a measurement signal MS_Per that is representative of a personal identification characteristic of the respective vehicle occupant, so that the occupant is identified depending on the measurement signal MS_Per of the person sensor 11.

[0042] If the vehicle occupant is the driver of the vehicle 1, the position sensor 3 can be located, for example, in a front area of ​​the vehicle interior 5, such as in a corner near the windshield of the vehicle 1. The radiation source 7, the vital sign sensor 9, and the person sensor 11 can then be located, for example, in the dashboard of the vehicle 1. If the vehicle occupant is in a rear seat of the vehicle 1, the position sensor 3, the radiation source 7, the vital sign sensor 9, and the person sensor 11 can be integrated, for example, into a headrest of the front passenger and / or in the area of ​​an armrest of the vehicle 1. A flowchart ( Fig. 2) shows a program that is executed in the control device 13 of the motor vehicle 1.

[0043] In step S1, the program is started, in which variables are initialized, for example. The program can start, for instance, shortly after the engine of vehicle 1 is started.

[0044] In step S3, the measurement signal MS_Pos from position sensor 3 is read and temporarily stored.

[0045] In step S5, depending on the measurement signal MS_Pos from position sensor 3, it is checked whether a position P_RKT of at least one predefined reference body part of the respective vehicle occupant can be determined. If the position P_RKT of at least one predefined reference body part can be determined, the program continues in step S7. Otherwise, the program can continue again in step S3.

[0046] In step S7, the radiation source is activated and emits a predefined radiation. The position P_RKT of the predefined reference body part, determined in step S5, serves as the reference point for aligning the radiation source 7. The program can then continue in an optional step S8 or step S9.

[0047] In the optional step S8, the identity of each vehicle occupant can be determined using the person sensor 11. In this context, for example, an actual value of the person identification feature can be determined based on the MS_Per measurement signal from the person sensor 11. By comparing the actual value of the person identification feature with a predefined target value, which is stored, for example, in the data memory of the control device 13, a degree of agreement can be determined. The degree of agreement can be expressed as a percentage of the actual value and the target value, so that, relative to an initial threshold value specified in the program, the identification of the respective vehicle occupant is classified as successful or unsuccessful.If the identification of the respective vehicle occupant has been successfully carried out, a personal identifier ID is assigned to the identified vehicle occupant, which represents the respective identified vehicle occupant.

[0048] In a further step S9, the measurement signal MS_Vit from the vital sensor 9 is read and temporarily stored. In this context, the radiation from the radiation source 7 is directed to a predefined preferred position P_pr on the respective vehicle occupant. This could be, for example, a skin area on the neck or a temple area of ​​the respective vehicle occupant.

[0049] Furthermore, in step S9, it is determined whether the measurement signal MS_Vit from vital sensor 9 is such that it allows the determination of at least one vital parameter VP of the respective vehicle occupant. This can be checked, for example, by whether the measurement signal MS_Vit from vital sensor 9 exceeds a predefined second threshold value. This can be verified, for example, by a predefined signal-to-noise ratio. In this case, the amplitude value of the recorded measurement signal MS_Vit from vital sensor 9 is compared to the value of a constantly present background signal. If the value of this ratio exceeds the predefined second threshold value, the program continues in step S11. Otherwise, the program continues in step S10.

[0050] In step S10, the radiation source 7 is varied with regard to its orientation and / or radiation intensity in order to reach the specified second threshold value. This ensures that at least one vital parameter VP of the respective vehicle occupant can be determined from the recorded measurement signal MS_Vit of the vital sensor 9.

[0051] For example, depending on the measurement signal MS_Vit of the vital sensor 9 with respect to a given preferred position P_pr, the alignment of the radiation source 7 can be varied in such a way that the measurement signal MS_Vit of the vital sensor 9 is optimized with respect to its amplitude.

[0052] Another possibility is that several preferred positions P_pr are predefined, so that an optimal preferred position P_pr_opt is determined depending on the measurement signal MS_Vit of the vital sensor 9. In this context, the optimal preferred position P_pr_opt for each vehicle occupant is the preferred position P_pr at which the orientation of the radiation source 7 is optimized with regard to an optimal correlation between the measurement signal MS_Vit of the vital sensor 9 and the respective vital parameter VP of the respective vehicle occupant to be determined. For example, this could be the preferred position P_pr at which the measurement signal MS_Vit of the vital sensor 9 has the greatest amplitude or, in relation to the example above, at which the highest signal-to-noise ratio is given.

[0053] Alternatively or additionally, the signal-to-noise ratio can be varied by adjusting the radiation intensity of the radiation emitted by the radiation source 7. For example, if the radiation source 7 is aligned to a preferred position P_pr, the radiation intensity can be adjusted until the predefined second threshold of the signal-to-noise ratio of the measurement signal MS_Vit of the vital sensor 9 is reached.

[0054] Furthermore, the need for more than one predefined preferred position P_pr may arise if a preferred position, such as the skin on the neck of the respective vehicle occupant, is covered by an article of clothing, for example, a scarf. Therefore, another preferred position P_pr, such as a skin area in the temple region of the respective vehicle occupant, may be suitable for determining at least one vital parameter VP.

[0055] If an identified vehicle occupant was determined in the optional step S8, the radiation source 7 can be used, for example, to target the optimal preferred position P_pr_opt of the respective identified vehicle occupant, which may have already proven suitable for that occupant during a previous driving cycle FZK. For example, the carotid artery might be the optimal preferred position P_pr_opt for one identified vehicle occupant for the further course of the procedure, while the temple area might be the optimal position for another. This personal information can be stored, for example, in the data storage of the control device 13.

[0056] In a further step S11, depending on the measurement signal MS_Vit of the vital sensor 9, one or more vital parameters VP of the respective vehicle occupant are determined.

[0057] In an optional step S12, based on the determined person identifier ID in the optional step S8, the measurement signal MS_Vit from the vital sensor 9 and / or the vital parameter(s) VP of the identified vehicle occupant determined in step S11 can be combined into a data package DP. The data package DP is assigned to the respective identified vehicle occupant by the person identifier ID.

[0058] In a further step S13, a characteristic value K_BD is determined for the motion dynamics of the respective vehicle occupant, which is representative of the movement of that occupant. The determination of the characteristic value K_BD can, for example, be carried out within the control device 13 by evaluating the measurement signal MS_Pos from the position sensor 3, which monitors the position and movement of the respective vehicle occupant.

[0059] In step S15, the program checks whether the determined characteristic value K_BD of the motion dynamics exceeds a predefined third threshold, thus indicating a hazardous situation GS. This can occur, for example, if the orientation of the radiation source 7 cannot be adjusted quickly enough to the movement of the respective vehicle occupant. If the characteristic value K_BD is greater than the predefined third threshold, a hazardous situation GS exists, and the program continues in step S16. If the characteristic value K_BD is less than the predefined third threshold, no hazardous situation GS exists, and the program continues in step S17.

[0060] In step S16, radiation source 7 is deactivated for safety reasons to prevent it from endangering the vehicle occupant in the event of a sudden movement. For example, if a laser is used as radiation source 7, this prevents the laser light from propagating towards the occupant's eyes and thus dazzling or endangering their health. Subsequently, the position sensor 3 continues to monitor the movement dynamics of the vehicle occupant and determines the characteristic value K_BD of the movement dynamics until it falls below the predefined third threshold.

[0061] The program then continues at step S3 or S7.

[0062] In step S17, it is checked whether the respective driving cycle FZK has ended or not. If no hazard situation GS was detected starting from step S15 and the respective driving cycle FZK is considered incomplete, the program continues in step S9. The reading and temporary storage of the measurement signal MS_Vit from vital sensor 9 is then continued at the targeted preferred position P_pr. Otherwise, the respective driving cycle FZK is considered complete and the program continues in step S19.

[0063] The program terminates in step S19. Reference symbol list 1 motor vehicle 3 Position sensor 5 Vehicle interior 7 Radiation source 9 Vital signs 11 Person sensor 13 Control device MS_Pos measurement signal position sensor MS_Vit Measurement signal vital sensor MS_Per measuring signal personal sensor P_RKT Position Reference Body Part P_pr preferred position P_pr_opt optimal preferred position K_BD characteristic value of motion dynamics A_SQ Activation Radiation Source DA_SQ Deactivation of radiation source DP data packet VP Vital Parameters K_BD characteristic value of motion dynamics FZK driving cycle GS Dangerous situation Opt_MS_Vit Optimization of Measurement Signal Vital Sensor

Claims

[1] Method of operating a motor vehicle (1), - to which a position sensor (3) is assigned, the measurement signal (MS_Pos) of which includes spatial information of a given area of ​​a vehicle interior (5) of the motor vehicle (1), - to which at least one radiation source (7) is assigned that emits a specified radiation, and - to which at least one vital sensor (9) is assigned a detector that detects a portion of the radiation emitted by the radiation source (7) incident upon it, and whose measurement signal (MS_Vit) is representative of at least one vital parameter (VP) of a respective vehicle occupant, - in which, depending on the measurement signal (MS_Pos) of the position sensor (3), a position of at least one predefined reference body part (P_RKT) of the respective vehicle occupant is determined, and - in which, depending on the determined position of the specified reference body part (P_RKT) of the respective vehicle occupant, an orientation of the radiation source (7) is controlled, and in which - depending on the measurement signal (MS_Pos) of the position sensor (3) a characteristic value (K_BD) for a motion dynamic is determined and - depending on the characteristic value (K_BD) for the motion dynamics, the radiation source (7) is activated or deactivated. [2] The method of claim 1, wherein - depending on the measurement signal (MS_Vit) of the vital sensor (9) which determines at least one vital parameter (VP) of the respective vehicle occupant. [3] Method according to claim 1 or 2, wherein - at least one vital parameter (VP) of the respective vehicle occupant is determined based on vibrocardiography, depending on the measurement signal (MS_Vit) of the vital sensor (9). [4] Method according to any one of claims 1 to 3, wherein - at least one vital parameter (VP) of the respective vehicle occupant is determined based on photooxymetry, depending on the measurement signal (MS_Vit) of the vital sensor (9). [5] Method according to any one of claims 1 to 4, wherein - depending on the determined position (P_RKT) of the reference body part of the respective vehicle occupant and the measurement signal (MS_Vit) of the vital sensor (9), the radiation source (7) is controlled in the sense of aligning it to at least one predetermined preferred position (P_pr) on the respective vehicle occupant. [6] Method according to any one of claims 1 to 5, wherein - depending on the measurement signal (MS_Vit) of the vital sensor (9) a radiation intensity of the radiation source (7) is controlled. [7] Method according to any of the foregoing claims, wherein - depending on the measurement signal (MS_Pos) of the position sensor (3) the radiation source (7) is activated or deactivated. [8] Method according to any of the foregoing claims, wherein - the position sensor (3) includes a camera. [9] Method according to any one of claims 1 to 7, wherein - the position sensor (3) includes an ultrasonic sensor. [10] Method according to any of the preceding claims, wherein - the radiation source (7) comprises a laser. [11] Method according to one of the preceding claims, wherein a person sensor (11) is assigned to the motor vehicle (1), the measurement signal (MS_Per) of which is representative of a person identification feature of the respective vehicle occupant, - in which an identification is carried out depending on the measurement signal (MS_Per) of the person sensor (11), and thus an identified vehicle occupant is determined. [12] The method of claim 11, wherein - the position sensor (3) is also used as a person sensor (11). [13] Method according to claim 11 or 12, wherein - the respective course of the measurement signal (MS_Vit) of the vital sensor (9) is assigned to the respective identified vehicle occupant. [14] Device for operating a motor vehicle (1), - wherein the device is configured to perform a method according to any one of claims 1 to 13. [15] System with the device according to claim 14 and - a position sensor (3), a radiation source (7) and a vital sensor (9) with a detector. [16] computer program product - executable program code, wherein the program code executes a method according to any one of claims 1 to 13 by means of a data processing device.

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