Method, calculation unit and computer program for calculating cardiac activity characteristic value of vehicle occupant

Abstract

The invention relates to a method for calculating a cardiac activity characteristic value of one or more vehicle occupants (30), a calculation unit (500) for carrying out the method, and a computer program. The method comprises: determining a cardiac activity signal (100) of one or more vehicle occupants (30) using a camera (20); determining a respiratory activity signal (100) of the one or more vehicle occupants (30) using a radar sensor (20); adapting the determined cardiac activity signal (100) of the one or more vehicle occupants (30) as a function of the determined respiratory activity signal (200); and determining cardiac activity characteristic values of the one or more vehicle occupants (30) from the adapted cardiac activity signals (300).

Description

TECHNICAL FIELD

[0001] The present application relates to a method for calculating a value of a heart activity characteristic of a vehicle occupant, a computing unit for carrying out the method and a computer program. BACKGROUND

[0002] Monitoring the health and general physical condition of a vehicle occupant, in particular the driver, can contribute to improving safety in road traffic.

[0003] For example, information about the health of the driver in a driver assistance system can be used in order to activate an emergency stop function of the vehicle, for example in an emergency situation. Thereby, both the vehicle occupant and potential accident victims can be protected and serious accidents can be avoided.

[0004] Against this background, WO 2023 / 031339 A1 describes a method for determining the vital functions of a vehicle occupant, wherein electrocardiogram signals are determined using magnetic field sensors integrated in the vehicle seat, by means of which vital functions can be calculated. However, in this case, an additional sensor, i.e. a magnetic field sensor integrated in the seat, has to be installed in the vehicle interior. In contrast thereto, it would be advantageous if the vital functions (heart activity and respiratory activity) of the vehicle occupant could be determined in a sufficiently precise manner using already existing sensors, for example in order to be able to draw conclusions about the physical condition of the driver.

[0005] Existing sensors are, for example, interior space cameras, which are usually used for object recognition and for the recognition of persons in the vehicle interior / surroundings. Furthermore, radar sensors can also be installed in the vehicle interior, for example on the roof lining, which can be used, for example, for the recognition of persons or animals enclosed in a parked vehicle (e.g. Child-Presence-Detection - CPD).

[0006] The heart activity of a vehicle occupant can be captured using an interior space camera, for example by photoplethysmography (PPG). In the photoplethysmography (PPG), light is usually shot into the tissue and at the same time the light intensity shot out of the tissue again is measured using a photoelectric sensor. The basic principle of the photoplethysmography is based on the dependence of the reflection and transmission properties of the tissue on the blood volume, which in turn changes with the heartbeat. In the systole phase, the light transmission through the tissue decreases, while in the diastole phase, the transmission increases.

[0007] The method of using a video camera as a photoelectric sensor to record a PPG signal is referred to as "remote photoplethysmography (rPPG)" or "imaging photoplethysmography (iPGG)" and enables, for example, obtaining information about the heart activity of a subject by capturing blood volume changes in the facial region of the subject due to the heartbeat (perfusion rhythmicity).

[0008] If such information from a vehicle occupant is captured, it can be used to implement or improve new or existing vehicle functions (e.g. classification of a vehicle occupant, identification of a critical (health) condition of a vehicle occupant, etc.). SUMMARY

[0009] A method for calculating a heart activity characteristic value of a vehicle occupant is proposed according to the present application, as well as a computing unit and a computer program for carrying out the method. Advantageous embodiments are the subject matter of the dependent claims and the following description.

[0010] The present application enables determining a heart activity characteristic value of a vehicle occupant with increased accuracy from a camera-based heart activity signal. For this purpose, interference signals, for example resulting from the respiratory activity of a vehicle occupant, are identified by a radar sensor and removed from the camera-based heart activity signal before determining the heart activity characteristic value.

[0011] Heart activity signal here refers to any signal from which the heart activity of a person can be inferred. Suitably, signals recording the activity of the blood circulation system of a person (e.g. the characteristics of a pulse wave resulting from heart activity / heartbeat) should also be included in the term "heart activity signal".

[0012] In the method according to the present application, a camera is used to determine a heart activity signal of a vehicle occupant. The camera can in particular be an interior space camera of the vehicle. For example, the interior space camera can be a color camera, e.g. an RGB camera. Near-infrared (NIR) cameras as well as combined color-infrared (RGB-IR) cameras are also feasible. Any other camera type suitable for capturing a heart activity signal of a vehicle occupant can also be used. For example, the camera can be mounted on or in the region of a rearview mirror in the interior space of the vehicle (e.g. above / below it). Any other position suitable for capturing a heart activity signal of a vehicle occupant is also feasible.

[0013] The heart activity signal determined by the camera can in particular be a photoplethysmography signal (PPG signal) which can be determined in a known manner, for example from recordings of one or more facial regions (regions of interest - ROIs) of the vehicle occupant. Suitable ROIs can for example be regions of the forehead and the cheeks of the vehicle occupant. Other skin regions of the vehicle occupant, for example the palm of the hand and / or the neck region, can also be determined as ROIs.

[0014] For example, in order to determine a PPG signal, an interior space camera can record a video sequence containing a certain number of images of the vehicle occupant and identify the ROIs in each image. The perfusion rhythm can then be determined in a spatially resolved manner from the image pixels of the ROIs, wherein an average value of the pixel values within the ROIs is formed in order to improve the signal-to-noise ratio of the PPG signal. When using an RGB camera, its red, blue and green color channels can be evaluated separately and spatially averaged. In particular, the green color channel can be used to determine the PPG signal, since the oxygenated and deoxygenated hemoglobin of the blood components have a high absorption coefficient at its wavelength, so that the resulting PPG signal has a higher amplitude than the other color channels.

[0015] If a NIR camera is used, the recorded luminance values can thus be evaluated and a PPG signal derived therefrom.

[0016] The determination of the PPG signal as a heart activity signal can for example be carried out in a computing unit of the interior space camera. This computing unit can be a separate computing unit or a computing unit integrated into the vehicle control device. For example, the vehicle control device can contain one or more functional blocks which are set up to determine one or more regions of interest (ROIs) from video sequences received from the interior space camera and to extract a PPG signal therefrom. Suitably, the heart activity signal of the vehicle occupant can be determined continuously. It can also be determined over a certain period of time and / or depending on the environmental conditions of the vehicle / vehicle occupant.

[0017] It has been shown, however, that PPG signals recorded by interior space cameras can be influenced to different degrees by different breathing activities of the vehicle occupant. Here, rhythmic movements in the ROIs are triggered by breathing, which can lead to fluctuations in the detected light intensity which are not attributable to heart activity. In particular, the breathing frequency (fundamental frequency of the periodic breathing activity signal) and its harmonics can produce interference frequencies which can negatively influence the acquisition of the heart activity.

[0018] Because this could lead to misinterpretations of cardiac activity in vehicle occupants, radar sensors, which can also be deployed within the vehicle's interior, can now be used to determine respiratory activity signals in addition to cardiac activity signals. These radar sensors can be, for example, frequency-modulated continuous wave radar (FMCW) or ultra-wideband radar (UWB). The radar sensor can, for example, acquire chest movements of the vehicle occupant and determine respiratory activity signals accordingly. For example, respiratory rate / frequency and depth can be inferred based on the frequency and amplitude of chest movements. When using a UWB sensor, chest movements can be determined, for example, using the impulse response of the transmitted signal, while an FMCW sensor can use, for example, Doppler frequencies. Respiratory activity signals can be determined in a similar manner to cardiac activity signals of vehicle occupants. In other words, if cardiac activity signals are also determined so that they can be appropriately adapted / corrected, then respiratory activity signals can always be determined as well.

[0019] The determination of the respiratory activity signal can, for example, be performed within the computing unit of the radar sensor. This computing unit can be a standalone unit or integrated into the vehicle control system. For instance, the vehicle control system may include one or more functional blocks configured to determine the respiratory activity signal based on the received radar signal.

[0020] Before one or more cardiac activity characteristic values ​​are determined based on the adapted cardiac activity signal, the determined cardiac activity signal, particularly the PPG signal, is adapted based on the determined respiratory activity signal. In particular, by comparing the respiratory activity signal with the cardiac activity signal, respiratory-based interfering oscillations on the latter can be identified and removed or at least attenuated.

[0021] According to one implementation, the heart rate (heartbeat rate) of a vehicle occupant can be determined as a cardiac activity characteristic value. For this purpose, for example, an FFT analysis can be performed on an adapted PPG signal. Another cardiac activity characteristic value could be, for example, the heart rate variability of the vehicle occupant (…). (Heart Rate Variability) is used to assess the interval between consecutive regular heartbeats. The interval between two consecutive heartbeats can be determined based on two consecutive amplitudes of a time-based PPG signal. Furthermore, the blood oxygen saturation and / or blood pressure of a vehicle occupant can be determined from the PPG signal using known methods as characteristics of cardiac activity.

[0022] The heart activity characteristic values determined in this way can be transmitted, for example, to control device functions in the vehicle control device, which deduce therefrom, for example, the health status of the vehicle occupants, in particular the driver, and further process it or intervene in critical cases. These control device functions can include, for example, driver assistance functions.

[0023] According to an embodiment, the determined heart activity signal can be adapted by filtering in such a way that the fundamental frequency of the respiratory activity signal and / or its harmonics are removed therefrom. For example, a parameterizable filter can be used to adapt the heart activity signal, by means of which disturbing oscillations superimposed on the heart activity signal are suppressed.

[0024] According to an embodiment, a band-stop filter or a comb filter can be used for this, which makes it possible to suppress disturbing spectral components of the respiratory activity. A band-stop filter can block frequencies between its two cutoff frequencies (Grenzfrequenz) and pass frequencies on both sides of this range. It is thus possible to use a band-stop filter to suppress signals in a specific frequency range selectively. A comb filter is characterized by a plurality of filter frequencies with the same spacing and can thus be used for frequency selection and harmonic removal.

[0025] According to an embodiment, one or more parameters of the band-stop filter and / or the comb filter can be determined depending on the specific respiratory activity signal. For example, the cutoff frequencies of the band-stop filter and / or the filter frequencies of the comb filter can be determined / set depending on the respiratory activity signal. Alternatively or additionally, the attenuation and / or the edge slope of the filter can also be adjusted depending on the respiratory activity signal.

[0026] According to an embodiment, a power density spectrum of the respiratory activity signal can be determined in order to set the filter parameters. For this purpose, for example, an FFT (English: fast Fourier transform) analysis can be carried out on the respiratory activity signal. The power density spectrum can in particular be determined continuously (for example, at a predetermined update frequency). The determination of the power density spectrum can be carried out, for example, in a computing unit of the radar sensor and / or in the vehicle control device.

[0027] According to one embodiment, one or more respiration activity signal characteristic values can be determined from the power density spectrum of the respiration activity signal, on the basis of which the parameters of the band-stop filter or comb filter are determined / set. This can also take place, for example, in the computing unit of the radar sensor and / or in the vehicle control device. In particular, the amplitude of the fundamental frequency of the respiration activity signal and / or the amplitude of the harmonics of the fundamental frequency can be used as the one or more respiration activity signal characteristic values. In this way, for example, the attenuation of the band-stop filter can be adapted to the depth of the breath of the vehicle occupant in the respective frequency range, which is characterized by the respective amplitudes. For this purpose, the amplitude of the fundamental frequency of the respiration activity signal and / or the amplitude of the harmonics thereof can be transmitted from the computing unit of the radar sensor to the computing unit of the built-in camera, which determines the filter parameters for adapting the cardiac activity signal on the basis thereof. Alternatively, the respiration activity signal characteristic values can be determined in the vehicle control device and the filter parameters are adapted.

[0028] In this way, the respiration-related interfering oscillations on the camera-based cardiac activity signal can be effectively removed or at least reduced, so that one or more cardiac activity characteristic values, such as the heart rate, can be determined correctly and with high accuracy.

[0029] The computing unit according to the application, for example the control device of a motor vehicle, can preferably be a central computer or vehicle computer, which is in particular set up in a programmed manner to carry out the method according to the application as described above.

[0030] It is likewise advantageous for the method according to the application to be implemented in the form of a computer program or computer program product having program code for carrying out all the method steps, since this leads to particularly low costs, in particular in the case where the control device carrying out the implementation is also used for other tasks and is therefore always present. Finally, a machine-readable storage medium is provided, on which the computer program as described above is stored. Suitable storage media or data carriers for providing the computer program are in particular magnetic, optical and electronic memories, such as hard disks, flash memories, EEPROMs, DVDs, etc. The program can also be downloaded via a computer network (internet, intranet, etc.). Such a download can take place in a wired / cabled or wireless manner (for example, via a WLAN network, a 3G, 4G, 5G or 6G connection, etc.).

[0031] A vehicle having a vehicle interior, a camera, a radar sensor and a computing unit is also proposed.

[0032] Further advantages and embodiments of the application result from the description of the attached drawings.

[0033] The application is illustrated schematically by the embodiments in the drawings and described hereinafter with reference to the drawings. Identical elements are designated by the same reference numerals here and are not described again unless necessary. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The functional blocks of a computing unit for carrying out the method according to an embodiment of the application are illustrated schematically and exemplarily.

[0035] Figure 2a and 2b The respiratory activity signal and the heart activity signal of a vehicle occupant are each illustrated schematically, as well as the adaptation of the heart activity signal on the basis of a respiratory activity signal characteristic value of the respiratory activity signal according to an embodiment of the application.

[0036] Figure 3a and 3b The respiratory activity signal and the heart activity signal of a vehicle occupant are each illustrated schematically, as well as the adaptation of the heart activity signal on the basis of a further respiratory activity signal characteristic value of the respiratory activity signal according to a further embodiment of the application. DETAILED DESCRIPTION

[0037] Figure 1 The functional blocks 50 to 55 of a computing unit 500 for carrying out the method according to an embodiment of the application are illustrated schematically and exemplarily. In particular, the computing unit 500 is used to determine an accurate heart activity signal of any vehicle occupant, for example the driver 30, from which suitable heart activity characteristic values can be determined / estimated, on the basis of which the condition of the vehicle occupant can be inferred. These heart activity characteristic values serve as input variables for a control device function in the form of a driver assistance function 55 in the computing unit 500 in order to intervene in the event of a critical condition of the vehicle occupant. The term "control device function" is to be understood here as encompassing all functions which further process the determined heart activity or characteristic values thereof. For example, information systems, warning systems, intervention systems, extended eCall, etc.

[0038] The illustrated computing unit 500, in particular, can be a vehicle control device or a vehicle computer 500, in the present case comprising a camera control unit 50 with an evaluation unit 51 with an adaptation unit 52. The evaluation unit 51 is connected to one or more cameras 10 via a signal line 11, which can be a cable-based or radio-based signal line 11. In the present case, the camera 10 is an interior space camera 10, which is installed in the vehicle interior space, not shown in detail, and records a plurality of facial recordings 10a (indicated by the solid arrows between the driver 30 and the camera 10) of the driver 30, who is here, for example, located behind the steering wheel 31, as a vehicle occupant. The camera 10 can be, for example, an infrared camera and / or a color camera, in particular an RGB camera, an NIR camera or a combined RGB and infrared camera.

[0039] For example, the plurality of facial recordings 10a can be, for example, a video sequence comprising a certain number of facial recordings 10a of the driver 30. This video sequence can be transmitted via the signal line 11 to the evaluation unit 51 of the camera control unit 50, which can determine / identify one or more facial regions (region of interest - ROI) of the driver 30 from each facial recording 10a, for example. Suitable ROIs can be, for example, the regions of the forehead and the cheeks of the driver 30.

[0040] The perfusion rhythm of the driver 30 can then be determined as a photoplethysmographic (PPG) signal as a cardiac activity signal in a spatially resolved manner from the image pixels of the ROIs by the evaluation unit 51. The PPG signal of the driver 30 can be determined continuously, as appropriate. It can also be determined over a certain period of time and / or depending on the environmental conditions of the vehicle and the driver 30.

[0041] In order to improve the signal-to-noise ratio of the PPG signal, an average of the pixel values within the ROIs can be formed here. In particular, the evaluation unit 51 can evaluate the red, blue and green color channels of the RGB camera 10 separately and spatially average them. The green color channel can be used in the evaluation unit 51 to determine the PPG signal, as appropriate, since the oxygenated hemoglobin and the deoxygenated hemoglobin of the blood composition have a high absorption coefficient at their wavelength, so that the resulting PPG signal has a higher amplitude than the other color channels.

[0042] If an infrared camera is used, the recorded luminance values can be evaluated and the PPG signal can be derived therefrom. However, due to the respiratory activity of the driver 30, light reflections within the ROIs can produce oscillations in / on the PPG signal which are not due to the perfusion rhythm. In particular, the fundamental frequency of the respiratory activity and its harmonics can be superimposed on the PPG signal in an interfering manner.

[0043] Since these can lead to misinterpretations in the heart activity of the driver 30, in addition to the PPG signal, a respiration activity signal of the driver 30 can also be determined in the computing unit 500. For this purpose, the illustrated computing unit 500 comprises a radar control unit 54, which is connected via a further signal line 21 to a radar sensor 20, which is also arranged within the vehicle interior. Said signal line 21 can also be a cable-based or radio-based signal line 21. The radar sensor can be, for example, a frequency modulated continuous wave radar (FMCW) or an ultra wideband radar (UWB).

[0044] In this case, the radar sensor 20 acquires the thoracic movements of the driver 30 (indicated by three differently diametrical circles in the chest region of the driver 30 and two dashed arrows between the driver 30 and the radar sensor 20) in order to infer its respiration activity or to determine a respiration activity signal of the driver 30. The radar sensor 20 can, for example, acquire the frequency and the amplitude of the thoracic movements, from which the radar control unit 54 can calculate the respiration frequency / respiration rate and the respiration depth. When using a UWB sensor, for example, the impulse response of the emitted signal can be used to determine the thoracic movements of the driver 30, while a FMCW sensor can, for example, use the Doppler frequency to determine the thoracic movements. The radar control unit 54 determines the respiration activity signal in parallel to the PPG signal of the driver determined by the camera control unit 51 and sends it to the adaptation unit 52 of the camera control unit 51. This adaptation unit 52 compares the two signals and corrects the PPG signal on the basis of the respiration activity signal. For example, a parameterizable filter (such as a comb filter and / or a band-stop filter) can be used in the adaptation unit 51 to correct the PPG signal. For this purpose, for example, the power density spectrum of the respiration activity signal can be determined, on the basis of which the fundamental frequency of the respiration activity and its harmonics and the respective amplitudes are determined. This can be carried out, for example, either in the radar control unit 54 or in the adaptation unit 51. On the basis of these variables, the cut-off frequency of the band-stop filter and its edge slope and attenuation can be adjusted in the adaptation unit 51, for example. In this way, the oscillations based on the respiration activity can be removed from the PPG signal, as is shown in the following Figures 2a to 3b .

[0045] The calibrated / adapted PPG signal is then sent from the camera control unit 51 to the arithmetic unit 53 of the computing unit 500, which thereby determines cardiac activity characteristics, such as heart rate, heart rate variability, blood oxygen saturation, and / or blood pressure. In this case, the arithmetic unit 53 outputs the cardiac activity characteristics to the control device functions of the computing unit 500, such as driver assistance function 55, which can then intervene in the driving activities of the driver 30 based on the acquired cardiac activity characteristics.

[0046] Contrary to the illustrations shown, the described functional blocks 50-55 can also be contained in multiple separate computing units / control devices.

[0047] Figure 2a and 2b The power density spectrum of the respiratory activity signal (AT) 200 of a vehicle occupant, such as driver 30, at frequency f and the power density spectrum of the PPG signal as cardiac activity signal 100 are schematically shown respectively, as well as the adaptation of cardiac activity signal 100 based on at least one respiratory activity signal characteristic value 201 of respiratory activity signal 200 according to an embodiment of the present invention.

[0048] in particular, Figure 2a The spectrum of the respiratory activity signal 200 of the driver 30, determined by the radar control unit 54 using the radar sensor 20, is shown, in which the fundamental frequency f1 of the respiratory activity and its harmonics f2 and f3 can be identified (see...). Figure 2a (Above). Furthermore, Figure 2a The spectrum of the PPG signal 100, as determined by the camera control unit 51, before adaptation / calibration by the adaptation unit 52 is also shown (see [reference]). Figure 2a (Below).

[0049] Clearly, the PPG signal 100 has high amplitudes at frequencies f1, f2, and f3, which should be attributed to the respiratory activity of the driver 30. If these amplitudes are not removed from the PPG signal 100, the cardiac activity characteristics of the driver 30 (e.g., his heart rate) may be calculated incorrectly.

[0050] Therefore, according to Figure 2b In this embodiment, the respiratory activity signal characteristic value 201 of the respiratory activity signal 200 is determined, and the amplitude 201 of the fundamental frequency f1 is determined accordingly as the respiratory activity signal characteristic value 201 (see [reference]). Figure 2b (Above). Based on the amplitude 201 of the respiratory activity signal 200 at the fundamental frequency f1, the attenuation, edge slope, and cutoff frequency of the band-stop filter can be set / determined, for example, and can be used to filter the PPG signal 100.

[0051] The thus adapted / corrected PPG signal 300 is generated in which the amplitudes at the frequencies f1 no longer occur (see Figure 2b below). Thereby, the heart activity characteristic value of the driver 30, for example its heart rate, can be determined with a higher accuracy.

[0052] Figure 3a and 3b The power density spectrum of the respiratory activity signal 2000 of the vehicle occupant, for example the driver 30, and the power density spectrum of the PPG signal 100 at the frequency f, and the adaptation of the PPG signal 100 based on the further respiratory activity signal characteristic value 201 of the respiratory activity signal 200 according to a further embodiment of the application are schematically shown.

[0053] In Figure 3b , the further respiratory activity signal characteristic value 201 of the respiratory activity signal 200 is determined, in particular differently from Figure 2b The amplitudes 201 of the harmonics f2 and f3 are additionally determined as respiratory activity signal characteristic values 201 (see Figure 3b above). In this case, for example, a comb filter can be used to eliminate the disturbing oscillations in the PPG signal 100 and to determine / adjust their damping, frequency and harmonic ratio based on the respiratory activity signal characteristic values 201.

[0054] The thus adapted / corrected PPG signal 300 is generated as a heart activity signal in which the amplitudes at the frequencies f1, f2 and f3 no longer occur (see Figure 3b Figure 3b below). Thereby, the heart activity characteristic value of the driver 30, for example its heart rate, can be determined with an even higher accuracy.

Claims

1. A method for determining cardiac activity characteristics of at least one vehicle occupant (30) in the interior space of a vehicle using a camera (10) and radar sensor (20), particularly of a vehicle, comprising the steps of: - Use the camera (20) to determine the cardiac activity signal (100) of at least one vehicle occupant (30); - The radar sensor (20) is used to determine the respiratory activity signal (200) of the vehicle occupant (30); - Adapt the determined cardiac activity signal (100) of the vehicle occupant (30) to the determined respiratory activity signal (200); as well as - Determine at least one cardiac activity characteristic value of the vehicle occupant (30) based on the adapted cardiac activity signal (300).

2. The method according to claim 1, wherein, The fundamental frequency (f1) and / or its harmonics (f2, f3) of the respiratory activity signal (200) are determined in order to adapt to the determined cardiac activity signal (100).

3. The method according to claim 2, wherein, In order to adapt to the determined cardiac activity signal (100), the cardiac activity signal (100) is filtered such that the fundamental frequency (f1) and / or its harmonics (f2, f3) of the respiratory activity signal (200) are removed from the cardiac activity signal (100).

4. The method according to any one of the preceding claims, wherein, Band-stop filters and / or comb filters are used to adapt to the determined cardiac activity signals (100).

5. The method of claim 4, wherein one or more parameters of the band-stop filter and / or the comb filter are determined based on the determined respiratory activity signal (200).

6. The method according to any one of the preceding claims, wherein the power density spectrum of the respiratory activity signal (200) is determined.

7. The method according to claims 5 and 6, wherein the parameters of the band-stop filter and / or the comb filter are determined based on one or more respiratory activity signal characteristic values ​​(201) of the power density spectrum of the respiratory activity signal (200).

8. The method according to claim 7, wherein, The amplitude (201) of the fundamental frequency (f1) of the respiratory activity signal (200) and / or the amplitude of the harmonics (f2, f3) of the fundamental frequency (f1) are determined as one or more respiratory activity signal characteristic values ​​(201).

9. The method according to any one of the preceding claims, wherein, The at least one cardiac activity characteristic value is selected from the heart rate, heart rate variability, blood oxygen saturation, and blood pressure of the vehicle occupant (30).

10. A computing unit (500) configured to perform all method steps of the method according to any one of the preceding claims.

11. A computer program, when executed on a computing unit (500), causes the computing unit (500) to perform all the method steps of the method according to any one of claims 1 to 9.

12. A machine-readable storage medium having a computer program as claimed in claim 11 stored thereon.

13. A vehicle having an interior space, a camera, a radar sensor, and a computing unit according to claim 10.

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