Sensor arrangement

Abstract

The invention relates to a sensor arrangement (1a) for attachment to a user's arm. The sensor arrangement (1a) comprises at least one laser feedback interferometer sensor (25), a support structure (21), and a processing unit (20). The support structure (21) is configured to support the at least one laser feedback interferometer sensor (25) on the user's arm such that the at least one laser feedback interferometer sensor (25) emits at least one laser beam (28, 37, 38) in an expanded emission area (24) towards the back of the hand (35) and / or towards the palm (39) of the user. The processing unit (20) serves to determine the position of at least one of the user's fingers based on a detected first power signal from the laser feedback interferometer sensor (25).

Description

[0001] The invention relates to a sensor arrangement for attachment to the arm, in particular the forearm, of a user. Furthermore, the invention relates to a method for determining the position of at least one finger of a user by means of a sensor arrangement arranged on the arm, in particular the forearm, of the user. State of the art

[0002] Document US 11,409,365 B2 describes a sensor assembly for attachment to a user's finger. The sensor assembly incorporates SMI sensors, also known as laser feedback interferometer sensors. These SMI sensors can detect the user's finger gestures.

[0003] Based on this, it is an object of the present invention to develop a sensor arrangement which determines the position of at least one finger of the user in a simpler way. Disclosure of the invention

[0004] To solve the problem, a sensor arrangement for attachment to an arm, in particular a forearm, of a user is proposed according to claim 1. Furthermore, a method for determining the position of at least one finger of a user is proposed according to claim 13, using a sensor arrangement arranged on an arm, in particular a forearm, of the user.

[0005] The sensor arrangement for attachment to a user's arm, particularly the forearm, comprises at least one laser feedback interferometer sensor, a support structure, and a processing unit. The support structure is configured to support or attach the at least one laser feedback interferometer sensor to the user's arm, particularly the forearm, such that the at least one laser feedback interferometer sensor emits at least one laser beam in an expanded emission area towards the back of the user's hand and / or towards the palm of the user's hand. The expanded emission area is, in particular, conical in shape. The processing unit is configured to determine, based on a detected first power signal from the laser feedback interferometer sensor, the position, in particular the current position, of at least one of the user's fingers.The initial power signal detected is, in particular, the first voltage signal from the laser feedback interferometer sensor. This utilizes the so-called self-mixing effect, in which the reflected first laser beam interferes with a light wave located in a laser cavity of the laser feedback interferometer sensor. This interference can be detected from the initial power signal and provides information about the distance of the reflected object.

[0006] Preferably, the processing unit is configured to determine a first position of at least one of the user's fingers based on a first power signal detected at a first time point, and a second position of the at least one finger based on a second power signal detected at a second time point following the first. Furthermore, the processing unit is configured to determine the movement of the at least one of the user's fingers based on the determined first and second positions. Preferably, the processing unit is configured to modulate the optical power of the at least one laser feedback interferometer sensor. In particular, the processing unit is configured to modulate the operating current of the at least one laser feedback interferometer sensor.The processing unit is additionally configured to determine the speed of the detected movement of at least one finger, depending on the detected, in particular modulated, first and second power signals. Preferably, the processing unit is configured to determine user activity, in particular of the hand, depending on the detected movement of the user's at least one finger.

[0007] Preferably, the at least one laser feedback interferometer sensor is configured to emit the at least one laser beam in a first direction along a user's finger that is extended straight forward and in a second direction that intersects the extended finger. Thus, the emitted laser beam is reflected by the at least one finger as soon as the finger moves up or down. This can occur either through a movement of the finger itself or through a movement of the hand up or down.

[0008] Preferably, the sensor arrangement additionally comprises a diffractive optical element. The diffractive optical element is, in particular, a holographic optical element. Alternatively, the diffractive optical element is a meta-optic. The diffractive optical element is configured to diffract the at least one emitted laser beam such that the expanded, in particular conical, emission area is generated. Alternatively, the sensor arrangement additionally comprises a lens. The lens is, in particular, configured as a cylindrical lens. The lens is configured to refract the emitted laser beam such that the expanded, in particular conical, emission area is generated.

[0009] Preferably, the sensor arrangement comprises a plurality of laser feedback interferometer sensors. Each laser feedback interferometer sensor is configured to emit a laser beam associated with that sensor. The support structure is designed to carry the laser feedback interferometer sensors on the user's arm, particularly the forearm, in such a way that all the laser feedback interferometer sensors together generate a widened, particularly conical, emission area. This allows for even more precise determination of finger positions and movements. Preferably, at least one laser feedback interferometer sensor is assigned to each finger of the user's hand.

[0010] Preferably, the support structure is designed to carry, and in particular attach, the laser feedback interferometer sensors to the user's arm, especially the forearm, such that at least one emitted first laser beam is directed towards the back of the hand and at least one emitted second laser beam is directed towards the palm of the hand. In this context, the support structure is preferably designed to carry, and in particular attach, at least two laser feedback interferometer sensors to the user's arm, especially the forearm, such that one of the two laser feedback interferometer sensors emits the first laser beam towards the back of the hand and the other laser feedback interferometer sensor emits the second laser beam towards the palm of the user. Thus, both upward and downward finger movements can be detected.

[0011] Preferably, the support structure is designed as a wristband. It is particularly advantageous for the laser feedback interferometer sensor to be integrated on the outer surface of the wristband. The outer surface of the wristband refers specifically to the side of the wristband facing away from the user's skin. This elevated positioning of the laser feedback interferometer sensor relative to the user's arm prevents the first laser beam emitted by the sensor from potentially being reflected by the user's arm hair. Preferably, the sensor arrangement also includes a deflection unit integrated into the wristband, particularly a static one, which is designed to redirect the laser beam emitted by the laser feedback interferometer sensor towards the back of the user's hand or forearm.The deflection unit is, in particular, a static mirror arranged in a cavity of the first laser feedback interferometer sensor. In this context, the wristband preferably also features an optical window for extracting the laser beam generated by the laser feedback interferometer sensor. Preferably, the wristband is designed as a fitness tracker. In this context, the sensor arrangement can, for example, be used to detect finger movements during sports exercises. This allows, for instance, the determination of whether the user is holding a dumbbell correctly during weight training.

[0012] Preferably, the sensor arrangement additionally includes a transmission unit. The transmission unit is configured to transmit the user's at least one finger position, determined by the processing unit, to an optical system. This optical system is configured to display content, particularly images, of a virtual or augmented reality to the user of the sensor arrangement. This makes it possible to use the user's detected finger movements to control virtual image content displayed by the optical system. Preferably, the optical system is designed as glasses, in particular smart glasses or virtual reality glasses. For example, the detected finger position or movement can be used to control an avatar, particularly a virtual one, which then virtually executes the detected finger position or movement.

[0013] A further object of the present invention is a method for determining the position of at least one finger of a user by means of a sensor arrangement arranged on the user's arm, in particular the forearm. This is in particular the sensor arrangement described above. Here, at least one laser beam is first emitted in an expanded, in particular conical, emission area in the direction of the back of the hand and / or in the direction of the palm of the user by means of at least one laser feedback interferometer sensor of the sensor arrangement. In a further method step, a first power signal, in particular a voltage signal, from the laser feedback interferometer sensor is detected by means of a processing unit of the sensor arrangement. Subsequently, the position, in particular the current position, of the at least one finger of the user is determined by means of the processing unit as a function of the detected first power signal.

[0014] Preferably, a first position of at least one of the user's fingers is determined by the processing unit based on the first power signal, in particular the first voltage signal, of the at least one laser feedback interferometer sensor detected at a first time point. Furthermore, a second position of the at least one finger is determined by the processing unit based on a second power signal, in particular the second voltage signal, of the at least one laser feedback interferometer sensor detected at a second time point following the first. The movement of the at least one of the user's fingers is also determined by the processing unit based on the determined first and second positions of the at least one finger. Preferably, an optical power, in particular an operating current, of the at least one laser feedback interferometer sensor is also modulated by the processing unit.Furthermore, the speed of the detected movement of at least one finger is determined as a function of the detected, in particular modulated, first and second power signal by means of the computing unit. Description of the drawings Fig. 1a and Fig. Figure 1b shows a first embodiment of a sensor arrangement for attachment to an arm. Fig. Figure 2 shows a second embodiment of a sensor arrangement for mounting on an arm. Fig. Figure 3 shows a third embodiment of a sensor arrangement for mounting on an arm. Fig. Figure 4a shows exemplary horizontal and vertical measurement planes for determining the finger position. Fig. 4b and Fig. 4c show the Fig. 4a associated measurement diagrams. Fig. Figure 5 shows a method for determining the position of at least one finger of a user by means of a sensor arrangement arranged on an arm, in particular forearm, of the user. Description of the exemplary implementations

[0015] The Fig. 1a and Fig. Figure 1b shows a first embodiment of a sensor arrangement 1a for attachment to the arm, in particular the forearm, of a user. The sensor arrangement comprises a laser feedback interferometer sensor 25, a support structure 21 in the form of a wristband, and a processing unit 20. The support structure 21 is configured to support the laser feedback interferometer sensor 25 on the forearm 31 of the user, in particular to attach it such that the laser feedback interferometer sensor 25 emits at least one laser beam 28 in an expanded, in particular conical, emission area 24 in the direction of the back of the hand 35 of the user. The processing unit 20 is configured to determine, as a function of a detected first power signal, in particular a first voltage signal, from the laser feedback interferometer sensor 25, the position, in particular the current position, of at least one finger 34a to 34e of the user. Laser beams 22 and 23 on Fig. 1a designates the outermost laser beams emitted in a horizontal direction and laser beams 37 and 38 on Fig. 1b denotes the outermost laser beams emitted in a vertical direction.

[0016] Optionally, the computing unit 20 is further configured to determine a first position of at least one finger 34a to 34e of the user as a function of a first power signal detected at a first time point, and a second position of the at least one finger 34a to 34e as a function of a second power signal detected at a second time point following the first. The computing unit 20 also serves to determine a movement of the at least one finger 34a to 34e of the user as a function of the determined first and second positions of the at least one finger 34a to 34e. Furthermore, the computing unit 20 is optionally configured to modulate an optical power, in particular an operating current, of the laser feedback interferometer sensor 25.The processing unit 20 further serves to determine the speed of the detected movement of at least one finger 34a to 34e, depending on the detected, in particular modulated, first and second power signals. Optionally, the processing unit 20 is also configured to determine user activity, in particular of the hand, depending on the detected movement of the user's at least one finger. This user activity could be, for example, typing on a computer keyboard.

[0017] The first embodiment of the sensor arrangement 1a further comprises a diffractive optical element 33, which is configured as a holographic optical element. The diffractive optical element 33 is designed to diffract the emitted laser beam 28 such that the expanded, in particular conical, emission area 24 is generated. Thus, all fingers 34a to 34e of one of the user's hands can be reached in the direction of the back of the hand 35 using only one laser feedback interferometer sensor 25. Optionally, another laser feedback interferometer sensor, not shown here for the sake of simplicity, is attached to the underside of the wristband 21 or the forearm 31 such that the additional laser feedback interferometer sensor emits at least one further laser beam in another expanded, in particular conical, emission area in the direction of the palm of the user's hand.This allows finger positions or finger movements upwards or downwards to be determined.

[0018] Optionally, the sensor arrangement 1a also includes a transmission unit 27, which is configured to transmit at least one finger position of the user, determined by the processing unit 20, to an optical system 36. The optical system 36, in turn, is configured to display content, in particular image content, of a virtual or augmented reality to the user of the sensor arrangement 1a. Optionally, the optical system 36 is configured as glasses, in particular as smart glasses or virtual reality glasses.

[0019] Fig. Figure 2 shows a top view of a second embodiment of a sensor arrangement 1b for mounting on an arm. In contrast to the first embodiment, the sensor arrangement 1b has a plurality of laser feedback interferometer sensors 30a to 30c. For the sake of simplicity, not all laser feedback interferometer sensors 30a to 30c are shown here. Each laser feedback interferometer sensor 30a to 30c emits a laser beam 45a to 45c, which is assigned to the respective laser feedback interferometer sensor 30a to 30c. The support structure 21 is again designed to support the laser feedback interferometer sensors 30a to 30c on the user's arm, in particular the forearm, in such a way that an expanded outer emission area 46 is generated by all laser feedback interferometer sensors 30a to 30c together.

[0020] Optionally, at least one laser feedback interferometer sensor 30a to 30c is assigned to each finger of the user's hand.

[0021] In this context, the sensor arrangement 1b optionally includes a lens 32, which is configured as a cylindrical lens. The lens 32 is designed to refract the emitted laser beam 45a to 45c in such a way as to generate the expanded outward emission area 46.

[0022] Fig. Figure 3 shows a third embodiment of a sensor arrangement 1c for mounting on an arm. Here too, the sensor arrangement 1c comprises a plurality of laser feedback interferometer sensors 40a to 40c. In contrast to the embodiment shown in Figure 3, the sensor arrangement 1c is further divided into three parts. Fig. 2 In this process, each laser feedback interferometer sensor 40a to 40c generates an expanded outgoing transmission range 43a to 43c, which partially overlap.

[0023] In this context, the sensor arrangement 1c optionally also includes a lens 42, which is configured as a cylindrical lens. The lens 42 is designed to refract the laser beams emitted by the respective laser feedback interferometer sensors 40a to 40c in such a way that the emission ranges 43a to 43c associated with the respective laser feedback interferometer sensors 40a to 40c are generated.

[0024] Fig. Figure 4a shows a top view of a plurality of laser beams emitted by means of at least one laser feedback interferometer sensor (not shown here), which span a widened, net-like emission area 54. The laser beams are emitted in a plurality of first directions 52a to 52d along a finger 50 of the user that is extended straight forward, and in a plurality of second directions 51a to 51d that cross the finger 50 that is extended straight forward. Fig. Figure 4b shows the measurement data of the at least one laser feedback interferometer sensor for the laser beams emitted in the second directions 51a to 51d. The distance is plotted on the x-axis 55b and the intensity of the signal, in particular the power signal, on the y-axis 55a. The measurement signal, in particular the power signal, 56d is assigned to the laser beam in the second direction 51d, the measurement signal 56c is assigned to the laser beam in the second direction 51c, the measurement signal 56b is assigned to the laser beam in the second direction 51b, and the measurement signal 56a is assigned to the laser beam in the second direction 56a. It can therefore be determined that measurement signals with the same intensity can be measured at different distances relative to the at least one laser feedback interferometer. This means that a finger 50 is straight.The direction in which this finger 50 is extended is determined by the measurement data of the at least one laser feedback interferometer sensor on the laser beams emitted in the first directions 52a to 52d. Fig. Question 4c is answered. Here too, the distance is plotted on the X-axis (60b) and the signal intensity on the Y-axis (60a). The measurement signal 61a is assigned to the laser beam in the first direction (52a), the measurement signal 61b to the laser beam in the second direction (52b), the measurement signal 61c to the laser beam in the second direction (52c), and the measurement signal 61d to the laser beam in the second direction (52d). As can be seen from the measurement diagram, only the measurement signal 61b and especially the measurement signal 61c show an increased intensity. This indicates that the finger 50 is extended straight forward along the first direction (52c) and is positioned tangent to the second first direction (52c).

[0025] Fig.Figure 5 illustrates, using a flowchart, a method for determining the position of at least one finger of a user by means of a sensor arrangement mounted on the user's arm, in particular the forearm. The sensor arrangement is, in particular, one of the previously described sensor arrangements. In a process step 70, at least one laser beam is emitted in an expanded, in particular conical, emission area towards the back of the hand and / or towards the palm of the user by means of at least one laser feedback interferometer sensor of the sensor arrangement. In a further process step 80, a first power signal, in particular a first voltage signal, from the laser feedback interferometer sensor is acquired by means of a processing unit of the sensor arrangement.In a further process step 90, the processing unit determines the current position of at least one of the user's fingers, based on the initial power signal. The process then terminates.

[0026] In an optional process step 100 following process step 90, the first position of at least one of the user's fingers is determined by the processing unit based on the first power signal, in particular the first voltage signal, of the at least one laser feedback interferometer sensor, acquired at a first time point. In a further optional process step 110 following process step 100, a second position of the at least one finger is determined by the processing unit based on a second power signal, in particular the second voltage signal, of the at least one laser feedback interferometer sensor, acquired at a second time point following the first time point. In a further process step 120, a movement of the at least one of the user's fingers is determined by the processing unit based on the determined first and second positions of the at least one finger.

[0027] Optionally, in a process step 130, an optical power, in particular an operating current, of the at least one laser feedback interferometer sensor is modulated by the processing unit. In a subsequent process step 140, a velocity of the detected movement of the at least one finger is determined as a function of the detected, in particular modulated, first and second power signals by the processing unit.

[0028] Optionally, in a process step 150, depending on the determined movement of at least one finger of the user, a user activity, in particular of the hand, is determined by means of the computing unit.

[0029] Optionally, in process step 160, at least one finger position of the user, determined by the processing unit, is transmitted to an optical system via a transmission unit. In a subsequent process step 170, content, in particular image content, of a virtual or augmented reality is displayed to the user of the sensor arrangement. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 11,409,365 B2

[0002]

Claims

[1] Sensor arrangement (1a, 1b, 1c) for attachment to an arm, in particular forearm, of a user, comprising at least - a laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c), - a support structure (21), and - a computing unit (20), wherein the support structure (21) is configured to carry, and in particular attach, the at least one laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c) to the arm, in particular the forearm (31), of the user in such a way that the at least one laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c) emits at least one laser beam (22, 23, 28, 37, 38, 45a, 45b, 45c) in an expanded, in particular conical, emission area (24, 43a, 43b, 43c, 46) in the direction of the back of the hand (35) and / or in the direction of the palm (39) of the user, wherein the computing unit (20) is configured to determine, as a function of a detected first power signal, in particular a first voltage signal, of the laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c), a, in particular current, position of at least one finger (34a, 34b, 34c, 34d, 34e, 50) of the user. [2] Sensor arrangement (1a, 1b, 1c) according to claim 1, characterized by , that the computing unit (20) is configured to determine a first position of at least one finger (34a, 34b, 34c, 34d, 34e, 50) of the user as a function of the first power signal detected at a first time point, and a second position of the at least one finger (34a, 34b, 34c, 34d, 34e, 50) as a function of a second power signal detected at a second time point following the first time point, wherein the computing unit (20) is configured to determine a movement of the at least one finger (34a, 34b, 34c, 34d, 34e, 50) of the user as a function of the determined first and second position of the at least one finger (34a, 34b, 34c, 34d, 34e, 50). [3] Sensor arrangement (1a, 1b, 1c) according to claim 2, characterized by, that the computing unit (20) is configured to modulate an optical power, in particular an operating current, of the at least one laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c), wherein the computing unit (20) is additionally configured to determine a speed of the determined movement of the at least one finger (34a, 34b, 34c, 34d, 34e, 50) as a function of the detected, in particular modulated, first and second power signal. [4] Sensor arrangement (1a, 1b, 1c) according to one of claims 2 or 3, characterized by , that the computing unit (20) is designed to determine a user activity, in particular of the hand, depending on the determined movement of at least one finger (34a, 34b, 34c, 34d, 34e, 50) of the user. [5] Sensor arrangement (1a, 1b, 1c) according to any one of claims 1 to 4, characterized by, that the at least one laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c) is configured to emit the at least one laser beam (22, 23, 28, 37, 38, 45a, 45b, 45c) in a first direction (52a, 52b, 52c, 52d, 52e) along a finger (34a, 34b, 34c, 34d, 34e, 50) of the user which is extended straight forward and along a second direction (51a, 51b, 51c, 51d, 51e) which crosses the finger (34a, 34b, 34c, 34d, 34e, 50) which is extended straight forward. [6] Sensor arrangement (1a, 1b, 1c) according to any one of claims 1 to 5, characterized by, that the sensor arrangement (1a, 1b, 1c) additionally comprises a diffractive optical element (33), in particular a holographic optical element, wherein the diffractive optical element (33) is configured to diffract the at least one emitted laser beam (22, 23, 28, 37, 38, 45a, 45b, 45c) in such a way that the expanded, in particular conical, emission area (24, 43a, 43b, 43c, 46) is generated. [7] Sensor arrangement (1a, 1b, 1c) according to any one of claims 1 to 5, characterized by , that the sensor arrangement additionally comprises a lens (32, 42) in particular a cylindrical lens, wherein the lens (32, 42) is configured to refract the emitted laser beam (22, 23, 28, 37, 38, 45a, 45b, 45c) in such a way that the expanded, in particular conical, emission area (24, 43a, 43b, 43c, 46) is generated. [8] Sensor arrangement (1a, 1b, 1c) according to any one of claims 1 to 7, characterized by, that the sensor arrangement (1a, 1b, 1c) comprises a plurality of laser feedback interferometer sensors (25, 30a, 30b, 30c, 40a, 40b, 40c), wherein each laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c) emits a laser beam (22, 23, 28, 37, 38, 45a, 45b, 45c) associated with the respective laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c), wherein the support structure (21) is configured to support the laser feedback interferometer sensors (25, 30a, 30b, 30c, 40a, 40b, 40c) to be worn on the arm, in particular the forearm (31), of the user, in particular to be attached in such a way that all laser feedback interferometer sensors (25, 30a, 30b, 30c, 40a, 40b, 40c) together generate an expanded, in particular conical, outward emission area (24, 43a, 43b, 43c, 46). [9] Sensor arrangement (1a, 1b, 1c) according to claim 8, characterized by, that at least one finger (34a, 34b, 34c, 34d, 34e, 50) of the user's hand is assigned at least one laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c). [10] Sensor arrangement (1a, 1b, 1c) according to one of claims 8 or 9, characterized by , that the support structure (21) is designed to carry, and in particular attach, the laser feedback interferometer sensors (25, 30a, 30b, 30c, 40a, 40b, 40c) to the arm, in particular the forearm (31), of the user in such a way that at least one emitted first laser beam (22, 23, 28, 37, 38, 45a, 45b, 45c) is emitted in the direction of the back of the hand (35) and at least one emitted second laser beam (22, 23, 28, 37, 38, 45a, 45b, 45c) is emitted in the direction of the palm of the hand (39). [11] Sensor arrangement (1a, 1b, 1c) according to any one of claims 1 to 10, characterized by , that the support structure (21) is designed as a bracelet. [12] Sensor arrangement (1a, 1b, 1c) according to any one of claims 1 to 11, characterized by , that the sensor arrangement (1a, 1b, 1c) additionally has a transmission unit (27), wherein the transmission unit (27) is configured to transmit the at least one finger position of the user determined by means of the computing unit (20) to an optical system (36), which is configured to display content, in particular image content, of a virtual or augmented reality to the user of the sensor arrangement. [13] Method for determining the position of at least one finger (34a, 34b, 34c, 34d, 34e, 50) of a user by means of a sensor arrangement (1a, 1b, 1c) arranged on an arm, in particular forearm (31), of the user, in particular a sensor arrangement (1a, 1b, 1c) according to one of claims 1 to 12, wherein the method comprises the following method steps: - Emitting (70) at least one laser beam (22, 23, 28, 37, 38, 45a, 45b, 45c) in an expanded, in particular conical, emission area (24, 43a, 43b, 43c, 46) in the direction of the back of a hand (35) and / or in the direction of a palm (39) of the user by means of at least one laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c) of the sensor arrangement (1a, 1b, 1c), and - Acquisition (80) of a first power signal, in particular a voltage signal, of the laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c) by means of a computing unit (20) of the sensor arrangement (1a, 1b, 1c), - Determining (90) the, in particular current, position of at least one finger (34a, 34b, 34c, 34d, 34e, 50) of the user as a function of the first power signal detected by means of the computing unit (20). [14] Method according to claim 13, characterized by that the procedure includes the following additional procedural steps: - Determining (100) a first position of at least one finger (34a, 34b, 34c, 34d, 34e, 50) of the user as a function of a first power signal, in particular a first voltage signal, of the at least one laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c) detected at a first time by means of the computing unit (20), and - Determining (110) a second position of the at least one finger (34a, 34b, 34c, 34d, 34e, 50) as a function of a second power signal, in particular a second voltage signal, of the at least one laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c) detected at a second time following the first time by means of the computing unit (20), and - Determining (120) a movement of at least one finger (34a, 34b, 34c, 34d, 34e, 50) of the user depending on the determined first and second position of the at least one finger (34a, 34b, 34c, 34d, 34e, 50) using the computing unit (20). [15] Method according to claim 14, characterized by that the procedure includes the following additional procedural steps: - Modulating (130) an optical power, in particular an operating current, of the at least one laser feedback interferometer sensor (25, 30a, 30b, 30c, 40a, 40b, 40c) by means of the computing unit (20), and - Determining (140) a speed of the determined movement of at least one finger (34a, 34b, 34c, 34d, 34e, 50) as a function of the detected, in particular modulated, first and second power signal by means of the computing unit (20).

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