Shape detection device

Abstract

The invention relates to surface shape detection device and method for detecting a surface shape (2) of a human or animal body surface (1) comprising several electromagnetic field generators (12), several sensors, in particular magnetometers (40) or antenna, an electronic control unit (50) and a signal processing unit (52) for determining the body shape (2). The several electromagnetic field generators (12) are arranged spatially distributed to each other in contact with the body surface (1) for generating electromagnetic fields (26) in the vicinity of the body surface (1). The several magnetometers (40) are positioned distant from each other in the vicinity of the body surface (1) within the electromagnetic fields (26) for measuring (130) the electromagnetic fields (26). Surface measurement signals (48) including measuring data (47) indicating position and advantageously orientation of an electromagnetic field generator (12) on the body surface (1) are transmitted to the signal processing unit (52). The surface shape (2) is determined based on position and advantageously orientation of each electromagnetic field generator (12).

Description

[0001] Shape detection device

[0002] Field of the Invention

[0003] The invention relates to a surface shape detection device and method for detecting a surface shape of a human or animal body surface comprising several electromagnetic field generators, several sensors, in particular magnetometers or antenna, and a signal processing unit for determining a three-dimensional body shape based on surface measurement signals provided by the several sensors.

[0004] Background of the Invention

[0005] The design and construction of customized orthotics and prosthetics is based on three-dimensional models of a body surface shape. Common techniques are for example using plaster casting with later optical digitization or optical digitizing systems scanning the body surface. Plaster casting offers the possibility to apply a plaster material and Mold a body shape while a therapist or surgeon performs a therapeutic correction on the body or while the body is resting on supporting devices. For example, a casting is taken during the straightening of a spastic deformity of the lower extremities in order to develop a splint for holding a straightened position of a body limb. This is not possible with optical systems, because the hands of the therapist correcting the body part or the supporting devices represent an obstacle to optical scanners, which require a line of sight onto the body surface.

[0006] Thus, different scanning and detection systems have been developed, which are using textile material with integrated sensors, which can be worn on the body, e.g. in the form of clothing. Such systems can detect biosignals, including e.g. bioelectric, biomagnetic or biochemical signals. This involves integrating sensors of different types into the textiles, such as accelerometers, gyroscopes and magnetometers. The sensor system sends the detected signals to a signal processing unit for evaluating and displaying healthrelevant information. For acquiring a model of a three-dimensional body surface, a network of magnetometers is integrated in a textile material, like a sock. The magnetometers measure a magnetic field generated by a set of coils located near the body surface. These magnetic measurements allow the detection system to obtain a point cloud of measuring points on the body surface, which is eventually used to reconstruct the body surface shape by the signal processing unit.

[0007] For example, CN 108195336 A describes a tunnel-like measuring device recording data of a three-dimensional shape of an object, like a hand. The object is placed on or in a flexible substrate, like a sponge or silicone gel, so that the substrate is deformed according to the three- dimensional shape of the object. The substrate is equipped with a magnetic sensor field, which also deforms according to the shape of the object. A layer of magnetic material is provided at a distance from the sensor field. The deformation of the substrate causes a change in the distance between each of the sensors of the sensor field and the magnetic layer in order to detect changes in the strength of the magnetic field signals and generate measurement data. Data about the distance between the sensors is determined and evaluated. However, the position or orientation of the sensors relative to each other is not recorded. Only a distance signal relating to a sensor distance to the magnetic material layer is captured. Accordingly, the measuring device can only be used to determine a change in shape, but not the shape itself.

[0008] WO 2021 / 1 10547 shows a system and a method for detecting a surface shape of a body surface. A plurality of magnetic field sensors are arranged relative to one another in or on a textile material and define a sensor field, which is placed on a the body surface. A magnetic field generator generates a magnetic field in the vicinity of the sensor field, so that a plurality of surface signals are generated by the magnetic field sensors, each signal corresponding to a surface region measured by one of the sensor. The surface signals serve as position signals with regard to the orientation and position of the magnetic field sensors in the magnetic field at the associated surface region, so that the surface shape of the body surface is determined from the plurality of surface signals of the magnetic field sensors by a signal processing unit. However, manufacturing of the sensor fields in the textile material is intricate and hygienic procedures for reusing the material is cumbersome.

[0009] Further, the used magnetic field sensors are usually rigid, e.g. in the form of electronic chip components, and represent a hard spot on the body surface to be measured, which can be uncomfortable. Soft magnetic field sensors provide measurements that are impacted by their often arbitrary deformation, which leads to distorted measurements and difficult shape reconstruction. The magnetic field sensors require at least two but usually four connection lines, e.g. for power supply, communication components and the like, which is a challenge in terms of manufacturing on a textile material and reliable operation. Since the sensors shall be located on body shapes of limbs, connection lines will move and be under mechanical constraints and may break easily.

[0010] Summary of the Invention

[0011] It is an object of the present invention to provide a surface detection device and method for detecting a surface shape of a human or animal body surface, which can reliably and completely detect the surface shape, reduce a need of post-processing of measurements for acquiring the surface shape, simplify application at the body surface, can be realized and operated in a cost- and energy-effective manner, provide a simple way of reusing the device and streamline manufacturing of the device.

[0012] These and other objects, which will appear from the description below, are achieved by a surface shape detection device and a surface shape detection method set forth in the appended independent claims. Preferred embodiments are defined in the dependent claims.

[0013] A surface shape detection device for detecting a surface shape of a human or animal body surface according to the present invention comprises several electromagnetic field generators for generating electromagnetic fields in the vicinity of the body surface, several sensors, in particular magnetometers or antenna, distributed in the electromagnetic fields for measuring the electromagnetic fields, and a signal processing unit configured to determine the surface shape of the body surface based on surface measurement signals provided by the several sensors. The several electromagnetic field generators or the several sensors, in particular magnetometers or antenna, are arranged on a number of individual patch units comprising a contact surface for contact with the body surface. The individual patch units are preferably designed of flexible flat patch material pieces of a small size, for example below 10 cm in diameter, preferably below 5 cm. Each individual patch unit may carry one or more of the several electromagnetic field generators or the several sensors. The number of individual patch units provided in contact with the surface depends on the size of the surface shape to be measured. The individual patch units are arranged distributed relative to each other when in contact with the body surface. Preferably, the individual patch units are spatially distanced from each other. However, the individual patch units may partially overlap on the body surface. The several electromagnetic field generators, respectively the several sensors, that are not in contact with the body surface are positioned distant relative to the individual patch units that are in contact with the body surface. For example, if the electromagnetic field generators are arranged on individual patch units for contact with the surface, then the sensors, in particular the magnetometers or the antenna, are positioned distant to these individual patch units, i.e. at a distance to the body surface, and vice versa. The sensors detect the electromagnetic fields of the electromagnetic field generators. They capture position and advantageously orientation data for the surface measurement signals of the electromagnetic field generators, respectively of the sensors, that are in contact with the body surface. The surface measurement signals build a basis for a three-dimensional surface shape detection of the body surface.

[0014] Providing electromagnetic field elements of the surface shape detection device, i.e. the electromagnetic field generators or the sensors, in particular magnetometers or antenna, on or in individual patch units that can easily be attached to a body surface to be measured simplifies the attachment process on the surface and allows for customized spatial application of the electromagnetic field elements depending on bodyspecific requirement. The small patches are easy to handle before, during and after a surface shape detection, for example easy to clean, store, inspect or be tested. The patch material can be a non-stretch material, which avoids breaking of connection lines, wires or traces provided on or in the patches. Different individual patch units may carry different types of measuring elements, which allows for optimizing the surface shape detection device according to varying surface measuring conditions. Also, a mix of different types of electromagnetic field elements can be selected for the surface shape detection device or even for a single individual patch unit. Overall, the surface shape detection device according to the invention enables reliable and customized detection of the surface shape that is comfortable for a patient and simple to perform by a trained health care person, like a physician, therapist, medical assistant, etc..

[0015] In one embodiment of the surface shape detection device according to the invention, each individual patch unit comprises electronic operating components, like an electronic patch controller, a communication unit and / or a power supply, for operating the at least one electromagnetic field element that is provided on the individual patch unit. In case an individual patch unit comprises more than one electromagnetic field element, each of them may be operated independently from the others. For example, the electronic patch controller controls the at least one electromagnetic field generator with respect to an electromagnetic field strength or frequency, or controls the at least one sensor, in particular magnetometer or antenna, with respect to a sensing frequency, signal strength and measuring signal frequency, etc. The surface shape detection device may comprise a control unit that controls the electronic operating components of the individual patch units according to a specific detection method performed by the surface shape detection device. For example, the control unit controls the several electronic patch controllers of the individual patch units, which then control the electromagnetic field elements. A communication unit of the individual patch units advantageously is realized as a wireless communication unit configured for communication between the several individual patch units and / or between the control unit and the individual patch units. A communication unit can be an electronic communication module as commonly known, comprising a transmitter and receiver for exchanging communication signals.

[0016] In one embodiment of the surface shape detection device, the individual patch units comprise a flexible printed circuit board (PCB) carrying the electronic operating components and the electronic components of the electromagnetic field elements, i.e. the at least one electromagnetic field generator or the at least one sensor in particular one magnetometer or one antenna, respectively. The PCB has a flexible substrate material that may serve as the patch material building the foundation of the individual patch unit. For example, the PCB is made of polyimide, polyester or polymer film. Connection lines between the components in the PCB material are protected from breaking when attaching or detaching the individual patch units, even in case of repeated use of the units, due to the design of the lines as conductive traces. The components may be arranged on one side of the printed circuit board while an opposite side thereof may provide a contact or attachment surface of the individual patch units.

[0017] In an advantageous embodiment of the surface shape detection device, the several electromagnetic field generators are configured to generate an electromagnetic field frequency such that different electromagnetic field generators generate electromagnetic fields at different frequencies. For example, an electromagnetic field generator may be capable of generating electromagnetic fields of different frequencies or different electromagnetic field generators may have different pre-set frequencies. The control unit may control the electronic patch controllers of each individual patch unit such that each electromagnetic field generator of an individual patch unit generates a different field frequency. Further, the number of individual patch units used for detection can be controlled such that each of the several electromagnetic field generator of the surface shape detection device generates a different field frequency. Additionally or alternatively, the several electromagnetic field generators may be operated such that they sequentially generate their electromagnetic fields. The control unit, the electronic patch controllers and / or the communication unit may trigger the several electromagnetic field generators in a sequence to generate their respective electromagnetic field. The sequence may be predefined or chosen by a user of the surface shape detection device. Thus, the sensors, in particular the magnetometers or the antenna, measure only one electromagnetic field at a time and are able to discriminate the electromagnetic field measurements, which allows for identifying a location of each of the electromagnetic field generators.

[0018] In a further embodiment of the surface shape detection device, the individual patch units may have a star-shape or a number of electromagnetic field elements may be arranged in a star-shape on an individual patch unit. The star-shape is defined by a center and several beams extending radially from the center. Each beam can carry one or more electromagnetic field elements. Also, the center can carry an electromagnetic field element. Advantageously, the electronic operating components are concentrated in one area of the individual patch unit. Preferably, they are located at an end of a beam of the star-shape for easy access.

[0019] In another embodiment of the surface shape detection device, at least three magnetometers are combined in an interrogator unit and are arranged distanced to each other in the interrogator unit. The interrogator unit comprises a signal processing algorithm for generating a surface measurement signal based on measuring data of the three magnetometers indicating position and advantageously orientation of an electromagnetic field generator on the body surface. One or more interrogator units may be used to measure the electromagnetic fields. The interrogator units support known 3-axis magnetic sensing methods, wherein the electromagnetic field generators generate a 3-axis electromagnetic field. Therefore, the surface measurement signal provided by the signal processing algorithm comprises three spatial components captured by each of the three magnetometers of the interrogator unit providing the position and advantageously orientation data.

[0020] In a first variant of the surface shape detection device according to the present invention, the several electromagnetic field generators are arranged on several individual generator patch units, wherein each individual generator patch unit comprising one or more of the several electromagnetic field generators. That means in this first variant of the surface shape detection device, the several electromagnetic field generators are arranged distributed relative to each other on the individual generator patch units, and the individual generator patch units are arranged distributed relative to each other on the body surface. Together the individual generator patch units form a magnetic generator network spread out on the body surface, which provides a point cloud of detection points. Arranging the electromagnetic field generators on the body surface opens new manufacturing and application possibilities compared to placing the magnetometers on the body surface. Electromagnetic field generators have in particular the advantages that they can be provided in a two-dimensional form and in a flexible form. This allows for providing the generators in a flexible textile that can be pulled over the body part to be measured. Furthermore, active generators only need two wires in comparisons to magnetometers that require four wires. This represents a big advantage since several elements must be provided to measure the body part. Finally, generators can be provided as passive elements eliminating the need to have any wire connection or any external energy source.

[0021] In an example embodiment, the several electromagnetic field generators are realized as miniaturized electromagnetic field generator components in form of a coil component and / or a magnetic mechanical resonator component. The coil component requires only two wires per coil, which supports the flexible nature of the individual generator patch units. Further, magnetoresistive components, Hall-Effect components, permanent magnet components or antenna components may be used. Preferably, the several electromagnetic field generators of the individual generator patch units are realized as passive electrical components, such as the magnetic mechanical resonator component. In this case the electromagnetic field elements on the body surface do not need wires or batteries.

[0022] In this first variant, the several magnetometers or interrogator units are positioned above the body surface at a distance relative to the electromagnetic field generators within the electromagnetic fields of the individual generator patch units. The several sensors, in particular magnetometers or antenna, or interrogator units for example can be arranged on a carrier structure, on a hand of a health care person, on a patient’s limb next to the body surface to be detected or the like. The sensors detect the point cloud of the electromagnetic generator network and provide surface a plurality of measurement signals to the signal processing unit. The interrogators measure only one 3-axis electromagnetic field at a time and are able to discriminate the electromagnetic field measurements originating from specific individual generator patch units and even of individual electromagnetic field generators on an individual generator patch unit, which allows for identifying a location of each of the electromagnetic field generators provided by the position data.

[0023] In a second variant of the surface shape detection device according to the present invention, the several magnetometers are realized as several individual magnetometer patch units, each comprising one or more of the several electromagnetic field sensors. Together the magnetometer patch units form a sensor system spread out over the body surface to be detected. The several magnetometers of the individual magnetometer patch units can be realized as ultra-low noise and high sensitivity room temperature magnetic sensors, such as quantum magnetometers, magneto-inductance sensors, magneto-resistance sensors and / or as an array of pickup coils. In this variant the interrogator unit can be realized as an individual patch unit, wherein an interrogator patch unit may include more than one interrogator.

[0024] In this second variant, the several electromagnetic field generators are positioned above the body surface at a distance relative to the individual magnetometer patch units for generating electromagnetic fields at the body surface. The several electromagnetic field generators for example can be arranged on a carrier structure, on a hand of a health care person, on a patient’s limb next to the body surface to be detected or a similar arrangement.

[0025] In yet a further embodiment of the surface shape detection device according to the present invention, the individual patch units comprising the electromagnetic field elements are integrated in or are releasably attached to a textile material or glove. For example, the individual patch units may be attached by using a Velcro fixation, an attachment gel, a releasable glue or the like. One of the sides of the individual patch units comprise an attachment surface for attachment to the textile material / glove, while the textile material / glove provides the contact surface for contact with the body surface. In case of a textile material with the integrated or attached electromagnetic field elements, the elements are oriented according to a surface region of the body surface they are resting on. In case the individual patch units are attached to a glove, a health care person wearing the glove performing the body surface detection can bring the individual patch units in contact with the body surface through laying on the hand. Thus, a position of the limb may be corrected by the person while the body surface shape is detected. No auxiliary means for positioning the electromagnetic field elements are needed while the person performs the limb correction.

[0026] Alternatively, the individual patch units can be attached directly on body surface.

[0027] It should be noted that both of the electromagnetic field elements, i.e. the electromagnetic field generators and the sensors, in particular magnetometers or antenna, can be arranged on individual patch units. However, ether the individual generator patch units or the individual sensor patch units are arranged in contact with the body surface, while the other is positioned in the vicinity of the body surface, for example on a carrier structure or the like.

[0028] In still another embodiment of the surface shape detection device, the signal processing unit for determining the surface shape comprises a point interpolation structure including a statistic shape modelling algorithm for determining the 3-dimensional shape of the body surface based on the surface measurement signals. The shape modelling algorithm receives the plurality of surface measurement signals comprising the position data and advantageously the orientation data, each signal indicating position and advantageously orientation of a point on the surface. Thus, surface measurement signals provide a point cloud dataset and processes this dataset to reconstruct the surface shape through interpolation shape modelling. The algorithm may for example be based on a principal component analysis algorithm, point distribution models and / or Gaussian process morphable models.

[0029] A surface shape detection method for detecting a surface shape of a human or animal body surface according to the invention uses a surface shape detection device comprising several electromagnetic field generators, several sensors, in particular magnetometers or antenna, an electronic control unit and a signal processing unit for determining the body shape. The several electromagnetic field generators are arranged spatially distributed to each other in contact with the body surface for generating electromagnetic fields in the vicinity of the body surface. The several electromagnetic field generators are located on the body surface according to the position and advantageously orientation f the body surface region they are resting on. Together the several electromagnetic field generators define a generator network that extends over the body surface shape to be measured. The generators may contact the body surface directly or via a textile material or a glove. The several sensors are positioned distant from each other in the vicinity of the body surface within the electromagnetic fields for measuring the electromagnetic fields of the several electromagnetic field generators and providing a surface measurement signal for each of the electromagnetic field generators. The several sensors, in particular magnetometers or antenna, can for example be mounted on a carrier structure or the like to be positioned at a distance to the body surface. Preferably, at least three magnetometers, together representing a 3-axis magnetic sensor unit, are positioned within a 3-axis electromagnetic field providing by the electromagnetic field generators. A surface measurement signal includes measuring data indicating position and advantageously orientation of an electromagnetic field generator that is arranged on the body surface. The surface measurement signal for each of the electromagnetic field generators is transmitted to the signal processing unit. The signal processing unit determines the surface shape based on the measuring data indicating position and advantageously orientation of each electromagnetic field generators.

[0030] According to the surface shape detection method of the present invention the electromagnetic field generators are positioned on the body surface and are oriented according to the body surface shape. The orientation and the relative location of each of the electromagnetic field generators can be measured by the magnetometers and used for determining the three-dimensional surface shape. As mentioned earlier, placing the electromagnetic field generators on the body surface instead of the sensors allows for alternative and improved detection methods and manufacturing of the surface shape detection device.

[0031] Preferably, the several electromagnetic field generators are controlled such that each of the electromagnetic field generators generates an electromagnetic field at a different signal frequency and / or such that the several electromagnetic field generators are sequentially activated, as mentioned earlier. As a result, the sensors, in particular magnetometers or antenna, located above the body surface are able to discriminate the surface measurement signals of each of the electromagnetic field generators.

[0032] In one variant of the surface shape detection method the several electromagnetic field generators are provided in form of individual generator patch units. The surface shape detection device used for the method outlined above, is for example realized according to the first variant of the surface shape detection device as described above. The individual generator patch units can be arranged in a pre-defined attachment pattern directly on the body surface or at a textile material that is adapted to be arranged on the body surface. The attachment pattern may include predefined landmarks. For instance, they can be placed on the Achilles tendon or the hill or any other pre-defined body parts. These pre-defined attachment patterns and landmarks facilitate determining the body shape using a point interpolation and statistic shape modelling. A user can identify such landmarks following a color code or a limb model to know where to place the individual generator patch units. In an advantageous variant of the surface shape detection method, the several individual generator patch units are attached to a glove, for example made of textile material, and a user wearing the glove touches the body surface to arrange the several individual generator patch units in contact with the body surface. This way a health care person can perform palpations on a limb, e.g. to correct the limb posture, while the body surface of the limb is detected. Preferably, the sensors, in particular magnetometers or antenna, are also carried by the glove. They are located distanced to the electromagnetic field generators though.

[0033] However, it should be noted that for performing the surface shape detection method according to the invention the electromagnetic field elements, particularly the electromagnetic field generators to be placed on the body surface, do not need to be arranged in individual patch units. The method provides precise and accurate shape detection in case the electromagnetic field generators are placed directly on the body surface or integrated in a flexible material, like a sock or long-sleeve gauntlet, that can rest on the body surface. Nevertheless, features of the second variant of the surface shape detection device as described above, that do not relate to the design of individual patch units may still be incorporated in the detection device used for performing the surface shape detection method according to the invention.

[0034] Brief Description of the Drawings

[0035] Preferred embodiments of the invention will be described in the accompanying drawings, which may explain the principles of the invention but shall not limit the scope of the invention. The drawings illustrate: Fig. 1 ci-c schematically illustrate three versions of an individual generator patch unit according to the invention, each comprising a different type of electromagnetic field generator,

[0036] Fig. 2a schematically illustrates a first version of a surface shape detection device with an interrogator unit according to the present invention applied on a foot,

[0037] Fig. 2b schematically illustrates a second version of the surface shape detection device applied on a foot with a glove according to the present invention, and

[0038] Fig. 3 a flow diagram illustrating the surface shape detection method according to the invention.

[0039] Detailed Description of the Preferred Embodiments

[0040] Figures 2a and 2b illustrate two examples of a surface shape detection device for detecting a surface shape of a human or animal body surface 1 according to the present invention comprising a plurality of electromagnetic field elements in form of several magnetometers 40 and several electromagnetic field generators 12, 12’, 12”, an electronic control unit 50 and a signal processing module 52 for determining the body shape as explained in more detail with reference to the Figures 2a and 2b.

[0041] Figures l a to 1 c show examples of individual patch units 10, 10’, 10” each comprising a number of electromagnetic field generators 12, 12’, 12”. In the shown examples, the electromagnetic field generators 12, 12’, 12” are realized as miniaturized electromagnetic field generators in form of spiral coils. The individual patch unit 10 comprises a first type of electromagnetic field generator 12 designed as spiral coils with a winding axis parallel to a patch surface (Figure l a). The individual patch unit 10’ comprises a second type of electromagnetic field generator 12’ designed as spiral coils with a winding axis vertical to the patch surface and a small number of coil windings, e.g. five windings (Figure 1 b). The individual patch unit 10” comprises a third type of electromagnetic field generator 12” designed as spiral coils with a winding axis parallel to the patch surface and a large number of coil windings, e.g. ten windings (Figure 1 c). The use of miniaturized spiral coils as generators requires only two wires per coil. The coils can be slightly flexible, and their bending does not significantly affect the ability of the detection device to precisely locate the generator. The coils do not introduce any hard spots on a patient’s limb. Their flexibility offers a better fit to the anatomy of the body surface. Alternatively, magnetic mechanical resonators, antenna, or other generators can be used, as mentioned earlier. Particularly, magnetic mechanical resonators can be used because they are passive components and have a small size.

[0042] All the individual patch units 10, 10’ and 10’ ’ are individual generator patch units. Other features of the individual patch units 10, 10’ and 10” are identical or very similar and will be explained below with reference to Figure la.

[0043] The individual patch unit 10 comprises a flexible printed circuit board 14, which serves as a base material of the patch. The electromagnetic field generators 12 are laid out in a star-shape on the printed circuit board 14, wherein the star-shape comprises a center 15 and seven beams 16 extending from the center 15. The electromagnetic field generators 12 are positioned at an outer end of the beams 16 and in the center 15. They are approximately equidistant to each other.

[0044] Beam 16’ carries at its outer end a group of electronic operating components of the individual patch unit 10. The group comprise: ( 1 ) an electronic patch controller 18 controls operation of the individual patch unit, particularly of the electromagnetic field generators 12, (2) a wireless communication unit 20 provides communication with the electromagnetic field generators 12 and (3) a power supply 22 provides power for the electromagnetic field generators 12. The electronic patch controller 18, the communication unit 20 and the power supply 22 are connected to the electromagnetic field generators 12 via connection traces 24. In the shown example, the electromagnetic field generators and the electronic operating components are arranged on a top side of the patch. A bottom side can serve as a contact surface for direct or indirect contact with the body surface 1 . Each of the electromagnetic field generators 12 generates an electromagnetic field 26, as schematically indicated for one of the generators in Figure la.

[0045] As shown in Figures 2a and 2b the examples of surface shape detection devices comprise a number of individual generator patch units 10’. There are seven individual generator patch units 10’ illustrated, but there can be more or less depending on the size of the surface to be detected. The individual generator patch units 10’ are arranged distributed relative to each other in contact with the body surface 1 . The individual generator patch units 10’ are directly attached on the skin of the body surface 1 . Each of the electromagnetic field generators 12’ generates an electromagnetic field 26 in the vicinity of the body surface 1 . As depicted, there is a network of several electromagnetic field generators 12’ extending over the body surface 1 across an area, the shape of which will be detected. Further, the surface shape detection device comprises several magnetometers 40, which are provided in form of interrogator units 42. The several magnetometers 40 are realized as ultra-low noise and high sensitivity room temperature magnetic sensors such as quantum magnetometers, magneto-inductance sensors, magneto-resistance sensors and / or as an array of pickup coils. Each interrogator unit 42 comprises at least three magnetometers 42 arranged offset from each other for being capable of measuring different coordinates of the electromagnetic field generators received as measuring signal 47.

[0046] One or more interrogator units 42 are provided in the vicinity of the body surface 1 at a distance thereto. In the example detection device of Figure 2a, there are two interrogator units 42, which are, for example, arranged on a carrier structure (not shown) next to the body surface 1 such that the interrogator units 42’ are positioned in the vicinity of the body surface 1 within the electromagnetic fields 26 of the electromagnetic field generators 12’. In the example detection device of Figure 2b, an interrogator unit 42’ is attached to a glove 3 that can be worn by a health care person. When the person touches the body having the body surface 1 to be detected, for example for correcting the posture of a limb, the interrogator unit 42’ is brought into the vicinity of the body surface 1 within the electromagnetic fields 26 of the several electromagnetic field generators 12’. The individual generator patch units 10, 10’, 10”, the interrogation units 42, the control unit 50 and the glove 3 together define a system for detecting a surface shape of a human or animal body surface.

[0047] In both examples, the interrogator units 42 are positioned distant relative to the individual generator patch units 10’ and are located distributed along the body surface 26 such that they are able to measure all of the electromagnetic fields 26 generated by the network of electromagnetic field generators 12’.

[0048] Further, the interrogator units 42 comprise a communication unit 44 and a measuring data processing module 46 having a signal processing algorithm. The magnetometers 40 of an interrogation unit 42 capture orientation data and position data of electromagnetic field generators 12’ transmitted by the measuring signal 47. The measuring data processing modules 46 prepares the data and generates a surface measurement signal 48, which can be communicated to the control unit 50 by the communication unit 44.

[0049] The electronic control unit 50 comprises the signal processing module 52 and a communication module 54. Advantageously, the communication module 54, the communication unit 22 of the individual generator patch units 10’ and the communication unit 44 of the interrogator units 42 are realized as wireless communication means transmitting and receiving digital signal without the wire connections. The signal processing module 52 comprises a point interpolation structure including a statistic shape modelling algorithm for determining a 3-dimensional shape of the body surface based on the surface measurement signal 48. Alternatively, the measuring data processing modules 46 of the interrogator units 42 may comprise a point interpolation structure for providing interpolated surface measurement signal 48, and the signal processing unit 52 may comprise the shape modelling algorithm. Information defining the determined 3-dimensional shape can for example be displayed on a screen 56 of the control unit 50.

[0050] Figure 3 illustrates an advantageous surface shape detection method for detecting the surface shape the body surface 1 using for example a surface shape detection device according to Figure 2a or 2b. In an arrangement step 100, the several electromagnetic field generators 12, 12’, 12’ ’ are arranged spatially distributed to each other in contact with the body surface by attaching the individual generator patch units 10, 10’, 10” to the body surface 1 for generating electromagnetic fields 26 in the vicinity of the body surface 1 . The individual generator patch units 10, 1 O’, 10” may be attached directly on the skin of the body surface 1 , as is suggested for the first version of the surface shape detection device of Figure 2a. Alternatively, the several individual generator patch units 10, 10’, 10” are attached to the glove 3 for example made of textile material, e.g. by using a Velcro system. A user wearing the glove 3 touches the body surface 1 to arrange the several individual generator patch units 10, 10’, 10” in contact with the body surface 1. Further alternatively, the electromagnetic field generators 12, 12’, 12” may be individually placed spatially distributed directly on the skin of the body surface 1 without using individual patch units.

[0051] In a positioning step 1 10, the several magnetometers 40 are positioned distant from each other in the vicinity of the body surface 1 within the electromagnetic fields 26 by positioning the interrogator units 42 in the vicinity of the body surface 1 . Thus, the several magnetometers 40 are not in contact with the body surface. In a field control step 120, the control unit 50 sends a generator control signal 58 to the individual generator patch controllers 18 of each of the individual generator patch units 10, 1 O’, 10” for controlling the several electromagnetic field generators 12, 12’, 12” such that each of the electromagnetic field generators 12, 12’, 12” generates an electromagnetic field 26 at a different signal frequency and / or such that the several electromagnetic field generators 12, 12’, 12” are sequentially activated.

[0052] In a measuring step 130, the magnetometers 40 measure the electromagnetic fields 26 by receiving a measuring signal 47 of the several electromagnetic field generators 12, 12’, 12”. The interrogator units 42 positioned in the electromagnetic fields 26 discriminate each measuring signals 47 generated by a specific electromagnetic field generator 12, 12’, 12” according to the different signal frequencies and / or according to the sequence of signals received. The interrogator units 42 generate a surface measurement signal 48 including orientation data and position data with respect to body surface for each of the electromagnetic field generators 12, 12’, 12”. In a transmission step 140, the surface measurement signals 48 are transmitted to the control unit 50, respectively the signal processing unit 52. In a surface shape determination step 150, a surface shape 2 of the body surface 1 is determined by the signal processing module 52 based on the orientation data and position data of each electromagnetic field generator provided by the several surface measurement signals 48. Finally, the surface shape 2 can be displayed on the screen 56 of the control unit 50. After detection of a surface shape, the individual generator patch units can easily be detached from the body surface or the glove and re-used for further surface detections.

[0053] The surface detection device and method for detecting a surface shape of a human or animal body surface according to the invention allows for complete detection of the surface shape without the need of bridging measurement gaps or post-processing of detected surface areas. They allow for detecting the shape while performing palpation on a limb. The surface shape is reliably detected in real-time, while the electromagnetic field elements are easy to apply to the surface to be detected. List of Reference Numbers body surface surface shape glove , 10’, 10” individual patch units , 12’, 12” electromagnetic field generator printed circuit board center , 16’ beam electronic patch controller communication unit power supply connection traces electromagnetic field magnefomefer inferrogafor unit communicafion unit measuring data processing module measuring signal surface measurement signal electronic control unit signal processing module communication module screen generator control signal 100 arrangement step no positioning step

[0054] 120 field control step

[0055] 130 measuring step 140 transmission step

[0056] 150 surface shape determination step

Claims

Claims1 . Surface shape detection device for detecting a surface shape(2) of a human or animal body surface (1 ) comprising several electromagnetic field generators (12) for generating electromagnetic fields (26) in the vicinity of the body surface (1 ), several sensors, in particulars magnetometers (40) or antenna, distributed in the electromagnetic fields (26) for measuring the electromagnetic fields (26), and a signal processing unit (52) configured to determine the surface shape (1 ) based on surface measurement signals (48), characterized in that the several electromagnetic field generators (12) or the several sensors, in particular magnetometers (40) or antenna, are arranged on individual patch units (10) comprising a contact surface for contact with the body surface (1 ), wherein the individual patch units (10) are arranged distributed relative to each other in contact with the body surface (1 ), and wherein the several electromagnetic field generators (12), respectively the several sensors, that are not in contact with the body surface ( 1 ) are positioned distant relative to the individual patch units (10).

2. Surface shape detection device according to claim 1 , characterized in that each individual patch unit (10) comprises an electronic patch controller (18) for controlling the at least one electromagnetic field generator (12) or sensor, respectively, that is arranged on the individual patch unit (10).

3. Surface shape detection device according to claim 1 or 2, characterized in that the individual patch units (10) comprise a flexible printed circuit (14) board carrying electronic components of the associated at least one electromagnetic field generator (12), respectively sensor.

4. Surface shape detection device according to one of the preceding claims, characterized in that each individual patch unit (10) comprises a wired and / or a wireless and advantageously battery powered supply and communication unit (20) configured for communication between the several individual patch units (10) and / or between a control unit (50) and the individual patch units (10).

5. Surface shape detection device according to one of the preceding claims, characterized in that a number of electromagnetic field generators (12) or a number of sensors, in particular magnetometers (40) or antenna, are arranged in a star-shape on the individual patch unit (10).

6. Surface shape detection device according to one of the preceding claims, characterized in that the several electromagnetic field generators (12) are configured to generate an electromagnetic field frequency such that different electromagnetic field generators (12) generate electromagnetic fields (26) at different frequencies.

7. Surface shape detection device according to one of the preceding claims, characterized in that the several electromagnetic field generators (12) comprise an electronic controller for controlling the several electromagnetic field generators (12) such that their electromagnetic fields (26) are generated sequentially.

8. Surface shape detection device according to any of the preceding claims, characterized in that at least three magnetometers (40) are combined in an interrogator unit (42) and are arranged distanced to each other in the interrogator unit (42), which comprises a signal processing algorithm for generating a surface measurement signal (48) based onmeasuring data (47) indicating position and advantageously orientation of an electromagnetic field generator (12) on the body surface (1 ).

9. Surface shape detection device according to one of the preceding claims, characterized in that the several electromagnetic field generators (12) are arranged on several individual generator patch units (10), wherein each individual generator patch unit (10) comprises one or more of the several electromagnetic field generators (12).

10. Surface shape detection device according to claim 9, characterized in that the several electromagnetic field generators (12) are realized as miniaturized electromagnetic field generator components in form of a coil component and / or a magnetic mechanical resonator component.1 1 . Surface shape detection device according to claim 9 or 10, characterized in that the several electromagnetic field generators (12) are realized as passive electrical components.

12. Surface shape detection device according to one of the claims 9 to 1 1 , characterized in that one or more interrogator units (42) are arranged within the electromagnetic fields in the vicinity of the body surface ( 1 ) .

13. Surface shape detection device according to one of the claims claim 1 to 8, characterized in that the several magnetometers (40) are realized as several individual magnetometer patch units, each comprising one or more of the several magnetometers (40).

14. Surface shape detection device according to claim 13, characterized in that the several magnetometers (40) are realized asquantum magnetometers, magneto-inductance sensors, magneto-resistance sensors, Hall effect sensors and / or as an array of pickup coils.

15. Surface shape detection device according to any of the preceding claims, characterized in that the individual patch units (10) are integrated in or are releasably attached to a textile material or glove (3).

16. Surface shape detection device according to any of the preceding claims, characterized in that the signal processing unit (52) comprises a point interpolation structure including a statistic shape modelling algorithm for determining a 3-dimensional shape of the body surface based on the surface measurement signal.

17. Surface shape detection method for detecting a surface shape (2) of a human or animal body surface ( 1 ) using a surface shape detection device comprising several electromagnetic field generators (12), several sensors, in particular magnetometers (40) or antenna, an electronic control unit (50) and a signal processing unit (52) for determining the body shape (2), the surface shape detection method comprising:- arranging (100) the several electromagnetic field generators (12) spatially distributed to each other in contact with the body surface (1 ) for generating electromagnetic fields (26) in the vicinity of the body surface (1 ),- positioning (1 10) the several sensors, in particular magnetometers (40) or antenna, distant from each other in the vicinity of the body surface (1 ) within the electromagnetic fields (26) for measuring (130) the electromagnetic fields (26) of the several electromagnetic field generators (12),- transmitting (140) surface measurement signals (48) including measuring data (47) indicating position and advantageously orientation of anelectromagnetic field generator (12) on the body surface ( 1 ) to the signal processing unit (52), and- determining (150) the surface shape (2) based on position and advantageously orientation of each electromagnetic field generator (12) provided by the several surface measurement signals (48).

18. Surface shape detection method according to claim 17, further comprising controlling (120) the several electromagnetic field generators (12) such that each of the electromagnetic field generators (12) generates an electromagnetic field (26) at a different signal frequency and / or such that the several electromagnetic field generators (12) are sequentially activated.

19. Surface shape detection method according to claim 17 or 18, wherein the several electromagnetic field generators (12) are provided in form of individual generator patch units (10) according to one of the claims 9 to 12, and the individual generator patch units (10) are arranged, advantageously in a predefined attachment pattern, directly on the body surface (1 ) or to a textile material that is adapted to be arranged on the body surface.

20. Surface shape detection method according to the previous claim, wherein the several individual generator patch units (10) are attached to a glove (3) , and a user wearing the glove (3) touches the body surface ( 1 ) to arrange the several individual generator patch units (10) in contact with the body surface ( 1 ) .

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