SENSOR DEVICE

Abstract

A sensor device comprises a first light emitter for emitting light having a wavelength from a first spectral range, a second light emitter for emitting light having a wavelength from a second spectral range, a first light detector configured to detect light having a wavelength from the first spectral range but not responding to light having a wavelength from the second spectral range, and a second light detector configured to detect light having a wavelength from the first spectral range and light having a wavelength from the second spectral range. A distance between the first light emitter and the first light detector is smaller than a distance between the second light emitter and the second light detector.

Description

[0001] The present invention relates to a sensor device.

[0002] Sensor devices for capturing health and fitness-related data of a human user are known in the art. Such sensor devices can, for example, determine heart rate and / or arterial oxygen saturation. Methods are known for optically capturing such parameters by measuring light absorption when the user's skin is illuminated.

[0003] DE 10 2014 117 879 A1 describes a pulse oximetry device having a light emission device configured to emit light having a wavelength from a first wavelength interval and light having a wavelength from a second wavelength interval, a first light detector configured to detect light having a wavelength from the first wavelength interval but not responding to light having a wavelength from the second wavelength interval, and a second light detector configured to detect light having a wavelength from the first wavelength interval and light having a wavelength from the second wavelength interval.

[0004] WO 2015 / 109 005 A1 describes a device for combining near-infrared spectroscopy and diffuse correlation spectroscopy.

[0005] US 2013 / 0030267 A1 describes a sensor system for monitoring physiological parameters.

[0006] One object of the present invention is to provide a sensor device. This object is achieved by a sensor device having the features of claim 1. Various further developments are specified in the dependent claims.

[0007] A sensor device comprises a first light emitter for emitting light with a wavelength from a first spectral range, a second light emitter for emitting light with a wavelength from a second spectral range, a first light detector configured to detect light with a wavelength from the first spectral range but not to respond to light with a wavelength from the second spectral range, and a second light detector configured to detect light with a wavelength from the first spectral range and light with a wavelength from the second spectral range. A distance between the first light emitter and the first light detector is smaller than a distance between the second light emitter and the second light detector.

[0008] The light emitted by the light emitters of this sensor device can be irradiated into the upper layers of the skin of a user of this sensor device. Light reflected from or in the user's skin can be detected by the light detectors of this sensor device. The first light detector detects only light from the first light emitter, while the second light detector can detect light from both the first light emitter and the second light emitter.

[0009] Advantageously, the distance between the second light emitter and the associated second light detector in this sensor device is greater than the distance between the first light emitter and the associated first light detector. As a result, the light emitted by the second light emitter travels a longer distance in the skin of the user of the sensor device before being detected by the second light detector than the light emitted by the first light emitter before being detected by the first light detector. This allows differences in the reflection and absorption levels of the light in the user's skin, which depend on the wavelength of the emitted light, to be taken into account. This can advantageously result in increased measurement accuracy of the sensor device.

[0010] Because the first light detector is configured to respond only to light with a wavelength from the first spectral range, but not to light with a wavelength from the second spectral range, the first light detector can be enabled to detect light with a wavelength from the first spectral range with particularly high accuracy. For this purpose, the first light detector can, for example, have a filter that filters out light with a wavelength from the second spectral range while allowing light with a wavelength from the first spectral range to pass through.

[0011] In one embodiment of the sensor device, it has a third light emitter for emitting light with a wavelength from a third spectral range. The first light detector is designed not to respond to light with a wavelength from the third spectral range. The second light detector is designed to detect light with a wavelength from the third spectral range. In this sensor device, light emitted by the third light emitter that is reflected on or in the skin of a user of the sensor device is thus detected by the second light detector, but not by the first light detector. The light emitted by the third light emitter can be used to implement an additional measuring functionality of the sensor device, but can also, for example, support the measurement carried out using the light emitted by the second light emitter.The distance between the third light emitter and the second light detector can also be greater than the distance between the first light emitter and the first light detector. Because the first light detector does not respond to light with a wavelength from the third spectral range, the first light detector can be configured to detect light with a wavelength from the first spectral range with particularly high accuracy.

[0012] In one embodiment of the sensor device, the third spectral range is the infrared spectral range. As a result, light emitted by the third light emitter can be suitable, for example, for determining an arterial oxygen saturation in the blood of a user of the sensor device using the sensor device.

[0013] In one embodiment of the sensor device, the first spectral range is the wavelength range from 520 nm to 570 nm. As a result, light emitted by the first light emitter with a wavelength from the first spectral range can be suitable, for example, for determining a heart rate of a user of the sensor device.

[0014] In one embodiment of the sensor device, the second spectral range is the red spectral range. As a result, light emitted by the second light emitter with a wavelength from the second spectral range can be suitable, for example, for determining arterial oxygen saturation in the blood of a user of the sensor device.

[0015] In one embodiment of the sensor device, the first light detector is arranged between the first light emitter and the second light detector. This advantageously ensures that the distance between the first light emitter and the first light detector is smaller than the distance between the second light emitter and the second light detector. This results in a space-saving arrangement of the components of the sensor device, which makes it possible to design the sensor device in a compact manner.

[0016] In one embodiment of the sensor device, the first light detector is arranged between the second light emitter and the second light detector. This also advantageously achieves a distance between the first light emitter and the first light detector being smaller than the distance between the second light emitter and the second light detector. This results in a space-saving arrangement of the components of the sensor device, which allows for a compact design of the sensor device.

[0017] In one embodiment of the sensor device, it has a fourth light emitter for emitting light with a wavelength from the first spectral range. The fourth light emitter can, for example, be designed like the first light emitter. Advantageously, this can increase the overall brightness of the light emitted by the sensor device with a wavelength from the first spectral range. Furthermore, the first light emitter and the fourth light emitter can be arranged such that the portions of the light emitted by the first light emitter and the fourth light emitter with a wavelength from the first spectral range strike the skin of a user of the sensor device from different spatial directions, thereby enabling a particularly reliable and accurate measurement.

[0018] In one embodiment of the sensor device, the first light detector is arranged between the first light emitter and the fourth light emitter. Advantageously, portions of the light emitted by the first light emitter and the fourth light emitter, having a wavelength from the first spectral range, pass through different sections of the skin of a user of the sensor device before being detected by the first light detector, thereby enabling the measurement performed by the sensor device to be particularly reliable and accurate.

[0019] In one embodiment of the sensor device, the first light detector has a filter configured to filter out light having a wavelength from the second spectral range. This advantageously enables the first light detector to detect light having a wavelength from the first spectral range with particularly high accuracy, without light having a wavelength from the second spectral range impinging on the first light detector potentially leading to interference with the measurement signal.

[0020] In one embodiment of the sensor device, the first light emitter is embodied as a light-emitting diode chip. Alternatively or additionally, the second light emitter can be embodied as a light-emitting diode chip. This advantageously enables a cost-effective and compact design of the light emitters of the sensor device. Furthermore, light emitters embodied as light-emitting diode chips can be configured to emit light with a very precisely defined wavelength.

[0021] In one embodiment of the sensor device, the first light detector is designed as a photodetector, in particular as a photodiode. Alternatively or additionally, the second light detector can be designed as a photodetector, in particular as a photodiode. Advantageously, the light detectors of the sensor device can thus be compact, be available cost-effectively, and enable high-accuracy light detection.

[0022] In one embodiment of the sensor device, it is designed to measure a heart rate using the reflective photoplethysmography method. Advantageously, the sensor device thus enables optical measurement of the heart rate without requiring a user of the sensor device to attach additional electrodes or the like.

[0023] In one embodiment of the sensor device, it is designed to measure oxygen saturation in a patient's blood. Advantageously, the sensor device enables optical and non-invasive measurement of oxygen saturation.

[0024] The above-described properties, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments, which are explained in more detail in connection with the drawings. In each case, in a schematic representation Fig. 1 a plan view of a first sensor device; and Fig. 2 a plan view of a second sensor device.

[0025] Fig. 1 shows a top view of a schematically illustrated sensor device 10 according to a first embodiment. The sensor device 10 is intended to determine health- or fitness-relevant data of a user of the sensor device 10. The sensor device 10 can, for example, be intended to measure an arterial oxygen saturation in the blood of a user of the sensor device 10. In addition, the sensor device 10 can be intended to determine a heart rate (pulse rate) of a user of the sensor device 10 using the reflective photoplethysmography method. The measurements performed by the sensor device 10 are carried out using optical methods.

[0026] The sensor device 10 has a housing 400 which is Fig. 1 is only shown schematically. Fig. 1 shows a top view of the housing 400. The housing 400 can have a Fig. 1. If such a cover is present, it is at least partially transparent to the light emitted by the sensor device 10. The sensor device 10 can, for example, be integrated into a portable device, in particular, for example, into a wristwatch.

[0027] To perform measurements, the housing 400 of the sensor device 10 must be arranged on the skin of a user of the sensor device 10 such that the top side of the housing 400 faces the user's skin.

[0028] The sensor device 10 has a first light emitter 110. The first light emitter 110 is configured to emit light with a wavelength from a first spectral range. The first spectral range can, for example, be the wavelength range from 520 nm to 570 nm. In this case, the light emitted by the first light emitter 110 is green.

[0029] Furthermore, the sensor device 10 has a second light emitter 120. The second light emitter 120 is configured to emit light with a wavelength from a second spectral range. The second spectral range can be, for example, the red spectral range. The light emitted by the second light emitter 120 can, for example, have a wavelength of 660 nm.

[0030] Additionally, the sensor device 10 has a third light emitter 130. The third light emitter 130 is configured to emit light with a wavelength from a third spectral range. The third spectral range can be, for example, the infrared spectral range. The light emitted by the third light emitter 130 can, for example, have a wavelength of 940 nm.

[0031] The sensor device 10 further includes a fourth light emitter 140. The fourth light emitter 140 is configured to emit light with a wavelength from the first spectral range. The fourth light emitter 140 can be configured to emit light with the same or a similar wavelength as the first light emitter 110.

[0032] The first light emitter 110, the second light emitter 120, the third light emitter 130 and the fourth light emitter 140 may each be formed as light-emitting diode (LED) chips.

[0033] The sensor device 10 further comprises a first light detector 210. The first light detector 210 is designed to detect light incident on the first light detector 210 having a wavelength from the first spectral range. Furthermore, the first light detector 210 is designed not to respond to light incident on the first light detector 210 having a wavelength from the second spectral range. The first light detector 210 also does not respond to light incident on the first light detector 210 having a wavelength from the third spectral range. For this purpose, the first light detector 210 can have a first filter 215, which is designed to filter out light having a wavelength from the second spectral range and light having a wavelength from the third spectral range, but to allow light having a wavelength from the first spectral range to pass through.The first filter 215 can be designed, for example, as an interference filter, in particular, for example, as a Bragg mirror.

[0034] In addition to the first light detector 210, the sensor device 10 includes a second light detector 220. The second light detector 220 is configured to detect light with a wavelength from the first spectral range, light with a wavelength from the second spectral range, and light with a wavelength from the third spectral range. For example, the second light detector 220 can be configured to detect light with any wavelength from a broad wavelength range that includes the first spectral range, the second spectral range, and the third spectral range.

[0035] The first light detector 210 and the second light detector 220 of the sensor device 10 can be designed, for example, as photodetectors, in particular, for example, as photodiodes.

[0036] The first light emitter 110, the fourth light emitter 140, and the first light detector 210 can be used to optically determine a heart rate of a user of the sensor device 10 using the reflective photoplethysmography method. For this purpose, the light emitted by the first light emitter 110 and the fourth light emitter 140, with a wavelength from the first spectral range, is radiated into the upper layers of the skin of a user of the sensor device 10. In the user's skin, the light with the wavelength from the first spectral range is partially absorbed and partially reflected. Light reflected from or in the user's skin with a wavelength from the first spectral range can reach the first light detector 210 and is detected by the first light detector 210. In the skin of the user of the sensor device 10, hemoglobin contained in the blood forms a strong absorber.Due to a heartbeat-dependent change in the volume of the blood vessels in the user's skin, the amount of light with a wavelength from the first spectral range reflected in the user's skin to the first light detector 210 also changes in a heartbeat-dependent manner. This is detected by the first light detector 210 to determine the heart rate of the user of the sensor device 10.

[0037] The light emitted by the first light emitter 110 with a wavelength from the first spectral range and the light emitted by the fourth light emitter 140 with a wavelength from the first spectral range strikes the skin of a user of the sensor device 10 from different spatial directions and passes through different sections of the skin on its way to the first light detector 210. As a result, the measurement performed by the sensor device 10 can be carried out with particularly high accuracy and with particularly low susceptibility to interference. It is expedient here if the first light detector 210 is arranged between the first light emitter 110 and the fourth light emitter 140, as shown in Fig. 1. In a simplified embodiment, however, either the first light emitter 110 or the fourth light emitter 140 can be omitted.

[0038] The detection by the first light detector 210 of the light emitted by the first light emitter 110 and by the fourth light emitter 140 having a wavelength from the first spectral range, which has been reflected on or in the skin of a user of the sensor device 10, is advantageously not disturbed by light emitted by the second light emitter 120 having a wavelength from the second spectral range or by light emitted by the third light emitter 130 having a wavelength from the third spectral range, since such light having a wavelength from the second spectral range or from the third spectral range is filtered out by the first filter 215 of the first light detector 210.

[0039] The second light emitter 120, the third light emitter 130, and the second light detector 220 of the sensor device 10 can be used to measure the arterial oxygen saturation of a user of the sensor device 10. For this purpose, light emitted by the second light emitter 120 with a wavelength from the second spectral range and light emitted by the third light emitter 130 with a wavelength from the third spectral range are irradiated into the upper layers of the skin of a user of the sensor device 10, where they are absorbed and reflected depending on the wavelength. Part of the light with a wavelength from the second spectral range and part of the light with a wavelength from the third spectral range return to the sensor device 10 and strike the second light detector 220, where it is detected.From the amount of light reaching the second light detector 220 with a wavelength from the second spectral range and the amount of light reaching the second light detector 220 with a wavelength from the third spectral range, the arterial oxygen saturation in the blood of the user of the sensor device 10 can be inferred.

[0040] Since the scattering and absorption of light with a wavelength from the second spectral range and of light with a wavelength from the third spectral range in human skin can be lower than the scattering and absorption of light with a wavelength from the first spectral range, it is expedient to achieve good measurement results if the light emitted by the first light emitter 110 and the fourth light emitter 140 with a wavelength from the first spectral range travels a shorter distance in the skin of a user of the sensor device 10 than the light emitted by the second light emitter 120 with a wavelength from the second spectral range and the light emitted by the third light emitter 130 with a wavelength from the third spectral range.This is achieved in the sensor device 10 in that a first distance 310 between the first light emitter 110 and the first light detector 210 is smaller than a second distance 320 between the second light emitter 120 and the second light detector 220. A distance between the fourth light emitter 140 and the first light detector 210 substantially corresponds to the first distance 310 between the first light emitter 110 and the first light detector 210. Accordingly, a distance between the third light emitter 130 and the second light detector 220 substantially corresponds to the second distance 320 between the second light emitter 120 and the second light detector 220.

[0041] In order to achieve the desired distances 310, 320 between the light emitters 110, 120, 130, 140 and the light detectors 210, 220 while arranging the components of the sensor device 10 in a space-saving manner, the first light detector 210 is arranged between the first light emitter 110 and the second light detector 220. The first light detector 210 is also arranged between the second light emitter 120 and the second light detector 220.

[0042] The housing 400 of the sensor device 10 is divided into a first chamber 410, a second chamber 420, and a third chamber 430. The second chamber 420 is arranged between the first chamber 410 and the third chamber 430. The chambers 410, 420, and 430 are separated from each other by opaque walls.

[0043] The first light emitter 110, the second light emitter 120, and the third light emitter 130 are arranged in the first chamber 410 of the housing 400. The first light detector 210 is arranged in the second chamber 420 of the housing 400. The fourth light emitter 140 and the second light detector 220 are arranged in the third chamber 430 of the housing 400. The arrangement of the light emitters 110, 120, 130, 140 and the light detectors 210, 220 in separate and light-tight chambers 410, 420, 430 of the housing 400 of the sensor device 10 prevents light emitted by the light emitters 110, 120, 130, 140 from reaching the light detectors 210, 220 directly, without prior reflection on or in the skin of a user of the sensor device 10. However, the division of the housing 400 into separate chambers 410, 420, 430 can also be omitted.

[0044] Fig. Figure 2 shows a top view of a sensor device 20 according to a second embodiment. The sensor device 20 has great similarities with the sensor device 10. Components of the sensor device 20 that correspond to components present in the sensor device 10 are shown in Fig. 2 are provided with the same reference numerals as in Fig. 1. In the following, only the differences between the sensor device 20 and the sensor device 10 are described. Otherwise, the above description of the sensor device 10 of the Fig. 1 also for the sensor device 20 of the Fig. 2.

[0045] The sensor device 20 has only the first light emitter 110 for emitting light with a wavelength from the first spectral range. The fourth light emitter 140 is missing.

[0046] For this purpose, the sensor device 20 has a third light detector 230 in addition to the first light detector 210 and the second light detector 220. The third light detector 230 is designed to detect light with a wavelength from the first spectral range, but not to respond to light with a wavelength from the second spectral range or to light with a wavelength from the third spectral range. For this purpose, the third light detector 230 can have a further filter 235 designed to filter out light with a wavelength from the second spectral range and light with a wavelength from the third spectral range, but to allow light with a wavelength from the first spectral range to pass through. The third light detector 230 can be designed like the first light detector 210. The further filter 235 of the third light detector 230 can be designed like the first filter 215 of the first light detector 210.

[0047] The first light emitter 110, the first light detector 210, and the third light detector 230 of the sensor device 20 can be used to measure the heart rate of a user of the sensor device 10. For this purpose, both the first light detector 210 and the third light detector 230 detect light emitted by the first light emitter 110 with a wavelength from the first spectral range, which has been reflected on or in the skin of a user of the sensor device 10. Light with a wavelength from the first spectral range detected by the first light detector 210 passes through different sections of the skin of the user of the sensor device 10 than light with a wavelength from the first spectral range detected by the third light detector 230.The light detected by the first light detector 210 also strikes the skin of the user of the sensor device in a different spatial direction than the light detected by the third light detector 230 with a wavelength from the first spectral range. This allows the heart rate to be measured with high accuracy and low susceptibility to interference, even with the sensor device 20.

[0048] It is expedient if the first light emitter 110 is arranged between the first light detector 210 and the third light detector 230, as shown in Fig. 2. A space-saving arrangement of the components of the sensor device 20 is also achieved if the first light emitter 110 is arranged between the first light detector 210 and the second light detector 220 and the first light emitter 110 is also arranged between the second light emitter 120 and the second light detector 220, as shown in Fig.2. This can be achieved by arranging the first light emitter 110 in the second chamber 420 of the housing 400, the second light emitter 120, the third light emitter 130, and the first light detector 210 in the first chamber 410 of the housing 400, and the second light detector 220 and the third light detector 230 in the third chamber 430 of the housing 400.

[0049] This arrangement also ensures that the first distance 310 between the first light emitter 110 and the first light detector 210 is smaller than the second distance 320 between the second light emitter 120 and the second light detector 220 in the sensor device 20. The distance between the third light emitter 130 and the second light detector 220 again corresponds approximately to the second distance 320 between the second light emitter 120 and the second light detector 220. The distance between the first light emitter 110 and the third light detector 230 corresponds approximately to the first distance 310 between the first light emitter 110 and the first light detector 210.

[0050] The invention has been illustrated and described in detail using the preferred embodiments. However, the invention is not limited to the disclosed examples. Rather, other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. LIST OF REFERENCE SYMBOLS 10 Sensor device 20 Sensor device 110 first light emitter 120 second light emitter 130 third light emitter 140 fourth light emitter 210 first light detector 215 first filter 220 second light detector 230 third light detector 235 additional filters 310 first distance 320 second distance 400 housings 410 first chamber 420 second chamber 430 third chamber

Claims

[1] Sensor device (10) with a housing (400) which is divided into a first chamber (410), a second chamber (420) and a third chamber (430), wherein the second chamber (420) is arranged between the first chamber (410) and the third chamber (430), wherein the first chamber (410), the second chamber (420) and the third chamber (430) are separated from one another by opaque walls, a first light emitter (110) for emitting light having a wavelength from a first spectral range, a second light emitter (120) for emitting light having a wavelength from a second spectral range, a first light detector (210) which is designed to detect light having a wavelength from the first spectral range, but not to respond to light having a wavelength from the second spectral range, and a second light detector (220) which is designed to detect light having a wavelength from the first spectral range and light having a wavelength from the second spectral range, wherein the first light emitter (110) and the second light emitter (120) are arranged in the first chamber (410), the first light detector (210) is arranged in the second chamber (420) and the second light detector (220) is arranged in the third chamber (430) of the housing (400), wherein a distance (310) between the first light emitter (110) and the first light detector (210) is less than a distance (320) between the second light emitter (120) and the second light detector (220). [2] Sensor device (10) according to claim 1, wherein the sensor device (10) has a third light emitter (130) for emitting light having a wavelength from a third spectral range, wherein the first light detector (210) is designed not to respond to light having a wavelength from the third spectral range, wherein the second light detector (220) is configured to detect light having a wavelength from the third spectral range. [3] Sensor device (10) according to claim 2, wherein the third spectral range is the infrared spectral range. [4] Sensor device (10) according to one of the preceding claims, wherein the first spectral range is the wavelength range from 520 nm to 570 nm. [5] Sensor device (10) according to one of the preceding claims, wherein the second spectral range is the red spectral range. [6] Sensor device (10) according to one of the preceding claims, wherein the first light detector (210) is arranged between the first light emitter (110) and the second light detector (220). [7] Sensor device (10) according to one of the preceding claims, wherein the first light detector (210) is arranged between the second light emitter (120) and the second light detector (220). [8] Sensor device (10) according to one of the preceding claims, wherein the sensor device (10) has a fourth light emitter (140) for emitting light having a wavelength from the first spectral range. [9] Sensor device (10) according to claim 8, wherein the first light detector (210) is arranged between the first light emitter (110) and the fourth light emitter (140). [10] Sensor device (10) according to one of the preceding claims, wherein the first light detector (210) has a filter (215) configured to filter out light having a wavelength from the second spectral range. [11] Sensor device (10) according to one of the preceding claims, wherein the first light emitter (110) is designed as a light-emitting diode chip and / or the second light emitter (120) is designed as a light-emitting diode chip. [12] Sensor device (10) according to one of the preceding claims, wherein the first light detector (210) is designed as a photodetector, in particular as a photodiode, and / or the second light detector (220) is designed as a photodetector, in particular as a photodiode. [13] Sensor device (10) according to one of the preceding claims, wherein the sensor device (10) is designed to measure a heart rate according to the method of reflective photoplethysmography. [14] Sensor device (10) according to one of the preceding claims, wherein the sensor device (10) is designed to measure an oxygen saturation in the blood of a patient.

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