Sensor structure

Abstract

To provide a sensor structure for non-invasively measuring a parameter of a human tissue.SOLUTION: A sensor unit of a sensor structure designed as a flexible printed circuit board having an optical component, includes: a light detector for detecting at least the light emitted into and passes through a human tissue; and a conductive track and a first contact means for dynamically connecting the sensor unit to a contact head. A sensor mat of the sensor structure having a multi-layered structure, includes: a lower layer having a lower contact surface which is in contact with a human skin surface and an upper contact surface which is in contact with the sensor unit; and an upper layer which is aligned with the optical component of the sensor unit and provided with an opening that forms an optical path, and connected to the upper contact surface of the lower layer in an attachable / detachable manner.SELECTED DRAWING: Figure 2A

Description

Technical Field

[0001] The present invention relates to a sensor structure, and more particularly to a sensor structure for non-invasive measurement of human parameters such as brain parameters such as the oxygen content of the brain.

Background Art

[0002] For measuring human parameters, particularly brain parameters such as deoxygenation of cerebral blood flow and the concentration of oxyhemoglobin, or tissue oxygen saturation index, a measuring device is arranged on the human body surface such as the head surface, for example, and measurement is performed by a near-infrared spectrometer (NIRS).

[0003] Therefore, by using a light source that irradiates near-infrared light having specific different wavelengths and measuring the change in the absorption of the detected light or the reflected light, the change in the oxygen concentration of deoxygenated and oxyhemoglobin is monitored. By another spectrophotometric method called so-called pulse oximetry, for example, the arterial oxygen concentration in the peripheral tissues of the finger, ear, nose can be determined by monitoring the pulsatile optical absorption change of the detected light.

[0004] Conventional NIRS monitoring structures for non-invasive monitoring of, for example, blood oxygen content consist of reusable components and disposable components. Therefore, for example, International Publication WO94 / 27494 describes a spectroscopic optical sensor having a flexible layer of a foam material for placement on the human body surface, which has a support frame for receiving sensor elements.

[0005] European Patent No. 2916716 discloses a non-invasive measuring device for measuring parameters of human tissue, comprising a sensor unit and a sensor mat for detachable attachment to a part of the human body. The sensor unit has a sensor array housed in a receptacle having a sensor surface facing downward in the direction of the human body surface, and the sensor unit is sealed and shielded by a cover or foil. The receptacle is housed in a corresponding cutout created on a flexible and / or compressible sensor mat, thereby the sensor mat is entrusted to a contact surface on the human body surface and bonded to it by an adhesive layer. The sensor unit, sensor mat, and cover are bonded to each other in a detachable manner, thereby the sensor mat and cover may be disposable products. Thus, the sensor unit has a sensor structure housed in a partially flexible receptacle, which is designed to have the shape of a flat housing or dish, i.e., a base area and peripheral walls. The sensor structure has contact units, power supplies, and connections to external control and processing units and / or control units, which are located on and firmly coupled thereto, for inputting and outputting electrical and optical signals.

[0006] International Publication WO2012 / 109661 discloses a NIRS sensor structure having a sensor section including a light source and at least one photodetector, along with flexible electrical circuitry and connector elements. The flexible electrical circuitry can be multilayered and, in the communication layer, has multiple conductor tracks for electrical contact with the connector elements and signal transmission of the sensor structure, as well as EMI shielding. The connector elements have a fiber optic coupler as an optical interface and a wiring coupler as an electrical interface, both of which are integrated, for example, within a hybrid connector.

[0007] Conventional measuring devices lack the desired flexibility to be positioned on extremely curved or bent human body surfaces, thanks to their nearly rigid receptacles for the sensor unit. Furthermore, the operational contact of the sensor unit is not resolved independently of the measuring structure. [Overview of the project] [Problems that the invention aims to solve]

[0008] The object of the present invention is to provide a non-invasive sensor structure for determining individual parameters of human body parameters or human tissues, thereby providing a sensor structure with reduced manufacturing costs, increased structural flexibility, and independently designed operational contact. In terms of manufacturing costs, the reuse of at least individual components should be considered, and therefore the present invention particularly aims to design reusable, albeit expensive, components. In particular, uniform contact between the sensor structure and the human tissue surface should be ensured, and the sensor structure should be at least partially reusable.

[0009] The above and other objectives are achieved by non-invasive sensor structures that conform to the independent clauses. Specific embodiments and / or modifications arise from the dependent clauses. [Means for solving the problem]

[0010] According to the present invention, a sensor structure for non-invasive measurement of parameters comprises a sensor unit and a sensor mat for detachable arrangement, or an attachment for mounting the sensor structure to one or more curved or bent body surfaces. The sensor unit is thus coupled to a contact head, which is electrically in contact with the sensor unit and designed to supply light from a light source to the sensor unit. The sensor unit is also designed as a flexible printed circuit board having optical components, and comprises at least one photodetector for detecting light irradiated into and passing through human tissue, a first contact means, and a conductive track for operatively connecting the sensor unit to the contact head, the first contact means comprising a magnetic contact element and an electrical contact element. The sensor mat of the sensor structure according to the present invention has a multilayer structure including a lower layer, the lower layer having a lower contact surface for support on a human body surface, an upper contact surface for supporting the sensor unit, and is aligned with the optical components of the sensor unit and provided with openings that form optical paths. Furthermore, at least one other layer facing the human body surface can be positioned beneath the lower layer, and this other layer has an optically transparent portion in the area of ​​the opening, thus forming a kind of foil window with respect to the optical input or optical output portion, respectively. Optically transparent means that a large amount of light can pass through the layer, and that amount is sufficient, for example, for NIRS analysis. On the other hand, other areas of this layer may be optically opaque. Alternatively, a first optically transparent layer and another optically opaque layer having a corresponding optical path may be positioned beneath the lower layer of the sensor mat. The optically opaque portion, or the other optically opaque layer, each provides a kind of insulating layer, which is positioned between the optically active regions of the sensor structure, and thus prevents the influence of light detection by, for example, lateral incident light and / or background light.Such covering of optically active components has a favorable effect with respect to sterile sensor structures. The sensor mat further has an upper layer, which is bonded to the upper contact surface of the lower layer in a manner that allows it to be detached from each other. The external shape of the sensor structure is designed to have notches or indentations, and as a result, this shape can be placed on most diverse human body surfaces and provides a particularly good fit.

[0011] The sensor structure consists of components that are separable from one another, with the contact head and sensor unit being operationally coupled, and the sensor mat designed to easily and safely attach the coupled sensor unit to the human skin to be tested. Designing the sensor unit and / or contact head as reusable elements is more economical and at the same time satisfies the high requirements for hygiene and sterilization for use in healthcare. The sensor unit can be housed within a multi-layer sensor mat, whose individual layers are separated from each other, so that the sensor unit placed between them can be removed and reused after the preparation process.

[0012] A sensor unit of this type of optoelectronic sensor according to the present invention is designed as a flexible or flex-rigid printed circuit board and as a flexprint. For example, one or more light output ports of light sources, such as light-emitting diodes, laser diodes, or multiple light sources themselves, and one or more sensor surfaces, such as photodetectors designed as photodiodes and spaced apart therefrom, as well as electrical wiring for conducting, for example, light or electrical signals from the light sources between the elements of the sensor unit, can be arranged on the sensor unit. Other elements may also be provided, for example, a control unit that measures the background light between each individual light pulse of the light source and / or current via a correspondingly given sensor surface. Thus, the control unit can automatically measure the background light in each case between laser light pulses based on the light source via the sensor surface, and it is used to adjust the light measured during the laser light pulse. The background light changes due to the partially or complementaryly detached sensor structure, resulting in the generation or triggering of either an interference signal or an automatic interference mechanism, thereby automatically switching off each of the light-emitting diodes or laser diodes. The control unit can also be used for calibration or other measurement tasks.

[0013] As an auxiliary measure, means for capturing temperature and / or heat flux may be provided. For example, it is expected that the temperature of the tissue to be tested by NIRS will be determined, based on the temperature dependence of the water absorption spectrum. Also, one of the included sensor surfaces may be used to measure the temperature of a light source, such as an LED light source, and a light source integrated within the sensor structure for verification of the temperature effect on the radiative properties of the determined measurement results. Heat from a light source placed in close proximity to the human body surface is known to be uncomfortable for the patient, and if the temperature is too high, individual components of the sensor structure may fail.

[0014] Preferably, at least four different light-emitting diodes or laser diodes of different wavelengths are provided as light sources, which can be switched on and off in stages. The light sources can be selectively operated to generate or emit infrared light in particular, where the light sources either generate the optical signal themselves as a light source integrated within the sensor structure, or generate the optical signal at a location outside the sensor structure and conduct it to the sensor structure by an optical fiber element. Thus, one or more light sources designed as light-emitting diodes or laser diodes can be directly integrated within the contact head, thereby avoiding losses of the light-emitting diodes at the optical coupling point. These integrated light sources are designed as internal light sources.

[0015] When light from a remote light source is radiated via an optical fiber through a contact head to the human tissue to be tested, a large portion of the transmission loss is prevented. In an advantageous manner, particularly with light sources located outside the sensor structure, i.e., external light sources, the effects of increased heat from the light source in the test chamber or blood flow are prevented.

[0016] Photodetectors, particularly one or more photodiodes, are arranged on the sensor unit, resulting in these photodetectors being spaced a few millimeters to 20 mm away from the light input point. Preferably, the spatial separation distance from at least a first photodiode, called a nearby detector, to the light input point is about 20 mm, and to one or more second photodiodes, which may be designed as farther detectors, is about 40 mm. The relative position and separation distance of the photodetectors from the light input point may be based on the size of the object to be tested. The number of photodiodes in the photodetector may vary depending on the application. Multiple photodiodes may be used to monitor different depths of blood oxygenation within the object, or they may be used as reference detectors in an algorithm, for example, to compensate for interference effects of the detection signal.

[0017] Sensor units are generally designed as flexprints, which are flexible or flex-rigid printed circuit boards with printed conductor tracks, and have a substrate made of insulating polymer material with fibers of electrically conductive material embedded on or within it to form a flexible circuit. Flexible circuits combined with a flexible substrate improve the flexibility of such sensor units. Sensor units designed as flexible printed circuit boards consist of a multilayer structure, and in particular have a communication layer having, for example, a flexible copper-clad laminate, as well as a cover layer or insulating layer and a corresponding adhesive layer. The multilayer structure of the sensor unit may be laminated, bonded, or otherwise joined together to form a single structure. The number of layers can also be varied. For example, one or more layers may have at least an optically transparent portion aligned with respect to the area of ​​the optical input point and the photodetector surface, through which a large amount of light can pass. For example, the optically transparent portion may include a wire mesh of an electrically conductive material, such as a copper net. Other parts of the sensor unit may not be optically transparent and may be made from, for example, copper metal foil. Sensor units designed in this way are characterized by minimal weight and volume, which increases design flexibility and provides dynamic and mechanical strength.

[0018] In one embodiment, reinforcing elements are provided at least in the corner direction of the sensor unit. These reinforcing elements, also called reinforcements, may be designed as molded pieces made from a rigid material in particular in the form of a polymer enricher or expander, which hardens a desired area of ​​a flexible printed circuit board, such as the area of ​​a photodiode. For further reinforcement of the shape and uniformity of the sensor unit, a copper net may be provided as a woven layer. The provided copper net also provides some kind of shielding against electromagnetic interference.

[0019] The sensor unit is preferably designed as a body that extends along the longitudinal axis. The design of the sensor unit takes into account the circular transistor and the corresponding molded components, and as a result, failure points are avoided even when the sensor unit is positioned at extreme curvature or with significant bending, such as when it is placed around a finger.

[0020] Sensor units designed as elongated bodies preferably have tabs that extend substantially perpendicular to both sides and / or along the longitudinal axis of the body. The tabs, also called noses, along with the basic design of the sensor unit body, enable a uniform contact surface on the sensor mat. Optical components, i.e., photodetectors and / or emitters, are positioned, for example, on an optically transparent surface or on a window in the sensor mat, or directly on the human body surface for efficient measurement. With the design of the sensor unit according to the present invention, the sensor unit does not necessarily need to be fixed internally by silicon casting so that it is housed in a somewhat rigid receptacle and subsequently housed on or within the sensor mat. Thus, flexibility is increased.

[0021] According to one embodiment, the sensor unit has a first contact means having a contact geometry designed for electrical contact and connection to a contact head. Thus, the first contact means provides a dynamic connection of the sensor unit to a power source and a light source, as well as a connection for transmitting detected signals. In other words, the first contact means is a coupling element or connector element which can be detachably coupled to a correspondingly designed mating piece. The coupling can be designed, among other things, as a plug contact or catch. In a preferred embodiment, the contact geometry has magnetic and electrical contact elements for this purpose. Thus, the first contact means can be designed as a contact ring which is designed as a flexible or flex-rigid printed circuit board on the sensor unit in a position that allows it to make proper contact with the contact head (as described in detail below). In particular, the contact ring has the form of a PCB ring containing a counter piece provided on the contact head and a number of elements for electrical and magnetic contact. Thus, it is expected that the couplingable contact head can be positioned in a predetermined orientation relative to the sensor unit. In particular, for example, an alignment aid in the form of a positioning ring may be placed on the contact ring, which pre-defines a predetermined alignment of the connectable contact head through an asymmetric shape or molded portion. Thus, the cable connected to the contact head for electrical and / or optical coupling can be aligned in a direction that does not obstruct a person by the attached sensor structure. In particular, the positioning ring is contactable to the sensor unit.

[0022] The first contact means has a contact geometry that includes electrical and magnetic contact elements. In particular, the contact elements are integrated on a contact ring, and the contact geometry is arranged on an annular surface, so that, for example, multiple electrical contact elements, in particular, contact points for electrical contact of the sensor surface, i.e., near and / or far photodiodes, and one or more magnetically effective contact elements are available. The magnetically effective contact elements can be designed as tin points. Preferably, the electrical and magnetic contact elements are arranged in an alternating sequence, meaning that the electrical contact elements are positioned between adjacent magnetic contact elements. Interaction of the electrical contact elements is thus prevented. The magnetic contact elements are selected so that reliable contact exists between the sensor unit and the contact head. Furthermore, reliable contact between the sensor unit and the contact head is expected to be detected and indicated by corresponding detection means or each control means.

[0023] The sensor unit of the sensor structure according to the present invention can be manufactured in a simple manner, such that pre-fabricated components are brought into contact with each other, preferably by pick and place.

[0024] An operationally connectable sensor unit and contact head may be attached to the sensor mat in a detachable manner. The sensor mat has recesses, openings, or transparent windows, which are arranged and designed to correspond to the optical components of the sensor unit, i.e., the photodetector and / or emitter. Basically, the sensor mat is preferably designed as a long, flat mat having a multilayer structure, which includes at least one foam layer made from a thin biocompatible foam material with adhesive layers on one or both sides.

[0025] The sensor surface, i.e., the area of the photodiode, includes a lower layer having an opening or path, or a transparent window, and on its lower surface, a coupling area or a light emitting surface (i.e., emitter) can be contacted and attached to the human body surface by an adhesive layer. The corresponding upper surface is similarly adhesive, and as a result, the sensor unit placed thereon is held by a tab or nose designed thereon. Also, at least one other layer, i.e., an upper layer, is included, which has only one opening in the area of light input, i.e., the area of the contact head. The upper layer has a lower adhesive layer, which adhesively bonds to the upper side of the lower layer, and as a result, the sensor unit is received so as to be stably arranged between them. The center mat of the multilayer structure can be designed as a single-use unit, i.e., after measurement, the sensor structure is removed from the human body surface, and the individual components, i.e., the sensor unit, the sensor mat, and the contact head, are separable from each other, and the sensor mat can be discarded or reused.

[0026] Preferably, the sensor mat is designed to be flexible or bendable, and as a result, the sensor mat can adapt to the human body surface and adapt itself to its curve, convexity or concavity. The design of the sensor mat can, for example, provide an outer periphery having notches and / or narrow areas, which are provided along the entire outer periphery. In particular, the outer periphery can be designed in a wing shape within the area where the tab or nose of the sensor unit is placed on the sensor mat, and as a result, simple application of the sensor mat to the contour of the human body surface becomes possible.

[0027] In an alternative embodiment of the sensor mat, an intermediate layer may be provided between the lower layer and the upper layer.

[0028] In one embodiment, a sensor structure is activated to measure human body parameters, as a result of which coupling with light waves and electrical contacts is caused by a contact head connected to the sensor unit. The contact head connectable to the sensor unit has a housing, at least two contact means having a contact geometry corresponding to the first contact means of the sensor unit, and a wiring that can be fixed in the housing and is conductively connectable to the electrical contact element of the second contact means. The contact head has means for supplying and inducing light in one direction perpendicular to the human body surface, and a light emitting surface through which the light is radiated into the human tissue. In one embodiment, the means has an optical fiber element for guiding light from an external light source, and a deflection element for deflecting the light guided in one direction in a direction perpendicular to the human body surface. The deflection element may be provided as a reflecting surface for deflecting the light incident from the first direction in the second direction, the second direction being substantially perpendicular to the human body surface, and the light is radiated into the human tissue through the light emitting surface.

[0029] What is predicted from the alternative embodiment is that the means for supplying and inducing light has, for example, an internal light source integrated in the contact head in the form of one or more light emitting diodes or laser diodes, and an optical guide element, and as a result, the light radiated therefrom is directed in a direction perpendicular to the human body surface and is radiated through the light emitting surface. Therefore, in this embodiment, an optical fiber is not required, and instead, the light wave emitted from the internal light source is radiated into the human tissue contacting there through the light emitting surface by the optical guide element.

[0030] Furthermore, an energy source housed within the contact head is provided for the electrical contacts of an internal light source integrated within the contact head and / or for the electrical contacts of a sensor unit connectable to the contact head. As a result, electrical wiring is provided within the contact head for the electrical contacts of at least one photodetector of the sensor structure, but no external connection is required. Signal transmission, i.e., data transmission, from at least one photodetector and / or control unit to an external control and / or processing unit may occur via wireless communication.

[0031] When there is no contact with the human body surface, or when the contact head is not securely connected to the sensor unit, the provided control means ensure that no light is emitted. For this purpose, the control means is provided to measure background light, which is used to achieve emergency switch-off of the sensor structure. As soon as the value or intensity of the background light exceeds a predetermined maximum value, one or more light sources are switched off to ensure that there is no danger when the sensor structure is intentionally, accidentally, partially or completely detached from the human body surface.

[0032] The electrical wiring and the optical supply designed within the optical fiber system having at least one optical fiber can be integrated into a hybrid cable system that can be fixed to the contact head.

[0033] The electrical contact of the sensor unit of the sensor structure according to the present invention is provided by a second contact means, which can be housed as a separate annular component within the housing of the contact head. In one embodiment, the second contact means includes a first contact ring disposed on a first surface, spring contact pins arranged at predetermined positions on a second surface, a connector element that forms a plug contact with a mating component provided on electrical wiring, and a second contact ring including a through hole through which the spring contact pins extend, and through which a magnetic contact element disposed on the first surface is capable of contacting the magnetic contact element of the first contact means.

[0034] Therefore, the second contact means is designed to have a contact geometry complementary to that of the first contact means. The second contact means can be designed as a ring shape, particularly as a substantially annular printed circuit board, i.e., a PCB, where connecting elements, preferably spring contact pins, are provided on the first surface for electrical contact. The connecting elements are configured and arranged on one surface of the second contact means in such a way that they can contact the electrical contact elements of the first contact means in a predetermined direction, and the precise orientation can be given by the molding of the second contact means. The second contact means can be positioned on the underside of the contact head or housing, i.e., substantially parallel to the surface of the human body. The connector elements are positioned on the second contact means, particularly on the microplug, on the second surface opposite to the first surface having the spring contact pins. Thus, electrical wiring can make conductive contact with the spring contact pins via the plug connection.

[0035] Furthermore, the second contact means includes a second contact ring having an arrangement of corresponding magnetic elements on its annular surface, and through-holes through which connecting elements, i.e., spring contact pins, are inserted, and which are designed to protrude above the annular surface. In particular, the through-holes and magnetic elements are arranged alternately on the annular surface of the second ring, thereby providing secure electrical and magnetic contact between the contact head and the counter piece on the first contact means of the sensor unit.

[0036] In embodiments having an external light source, an optical fiber element is fixable to a contact head, and the element has at least one optical fiber fixed within a housing or fixed within an element sizable within the housing. Thus, in addition to electrical contact, the contact head provides, for example, induction of light from a remote light source and coupling of light waves into the tissue to be tested. Light, for example near-infrared light, is directed along a first direction according to the optical fiber element and deflected on a reflective surface, so that the light is emitted outward from the light-emitting surface of the contact head in a second direction that is generally perpendicular to the first direction and particularly perpendicular to the human body surface. Thus, the light is irradiated from the contact head to the target, for example, via a coupling element that is correspondingly designed and sizable to directly contact the human body surface. The optical fiber element is housed within the housing of the contact head or within a bore of a retaining element sizable within it, and has one or more optical fibers held within it. The holding element may be in direct contact with the deflection element that provides a reflective surface, so that the light beam is deflected accordingly and radiated substantially perpendicularly to the tissue to be tested through a large contact area. For example, the deflection element may be designed as a prism.

[0037] The deflection element may be designed as a cylinder with a closed chamfered end face. For this purpose, the deflection element is designed as a galvanized plastic part, and the light waves emitted from the optical fiber element are deflected and / or reflected on a given reflective surface in the direction of the light emission surface.

[0038] Alternatively, the deflection element is designed as a hollow cylinder with a closed hemispherical end face. The deflection element is specifically made from a reflective material. Thus, the bore for receiving the optical fiber element is realized at the hemispherical end face, and the emitted light is deflected at the hemispherical reflective surface in a second direction, and consequently in the direction of the light emission surface.

[0039] In accordance with the present invention, the sensor unit and the complementary contact head are designed as separate units, and as a result, optimal manufacturing is possible independently of other components of the sensor structure. Only the contact means of the contact head and the contact means of the sensor unit are harmonized with each other. Therefore, the contact of the sensor unit of the sensor structure according to the present invention can be realized in a simple manner, designing the direction of input and output wiring in a way that is as comfortable as possible for the patient, and also taking local conditions into consideration.

[0040] Preferred embodiments of the present invention are given below with reference to the drawings, but these are illustrative only and should not be construed as limiting the invention. The features of the invention shown in the drawings, individually or in any combination, should be considered to be part of the disclosure of the invention. [Brief explanation of the drawing]

[0041] [Figure 1] Figure 1 is a schematic cross-sectional view of a sensor structure according to the present invention. [Figure 2A] Figure 2A shows a sensor unit of a sensor structure according to the present invention, designed as a flexible printed circuit board having first contact means for electrical and optical contact. [Figure 2B]Figure 2B shows a positioning ring that can be placed on the sensor unit according to Figure 2A. [Figure 3] Figure 3 is a bottom view of the sensor mat of a sensor structure according to the present invention. [Figure 4] Figure 4 is a plan view of the sensor mat of a sensor structure according to the present invention. [Figure 5] Figure 5 is a detailed view in the form of a cross-sectional view of a contact head according to one embodiment. [Figure 6] Figure 6 is a detailed view in the form of a cross-sectional view of a contact head according to the second embodiment. [Figure 7] Figure 7 is a detailed view of the deflection element of a contact head according to one embodiment. [Modes for carrying out the invention]

[0042] In the following description of the sensor structure according to the present invention, the lower side should be understood as the side facing the human body surface, and the upper side should be understood as the side opposite to the lower side. The upper and lower sides are at least substantially parallel, or at least partially parallel, to the human body surface.

[0043] Figure 1 is a schematic diagram of the structure of a sensor structure 1 according to the present invention for non-invasive measurement of parameters of human tissue, which has a sensor unit 10 and a sensor mat 12 for detachably positioning the sensor structure 1 on a human body surface 20.

[0044] In the illustrated embodiment, the sensor structure 1 comprises an essentially reusable sensor unit 10, a sensor mat 12, and a contact head 16 for electrical and optical contact of the sensor structure 1. The sensor unit 10 has a photodetector 2 (also called a sensor surface) spaced apart from the contact head 16, and a conductor track 5. Other elements, such as a control unit, may be provided within the sensor structure 1. Light may be emitted from a light source via the contact head 16, or through a light source (having multiple light-emitting diodes or laser diodes, preferably including four laser diodes) positioned directly on or within the sensor unit 10, preferably in the near-infrared region (NIRS) to measure parameters over time. For example, a photodiode is used as the sensor surface 2. The sensor unit 10 is designed as a long, flat body shape along its longitudinal axis 18 and has a defined external contour that harmonizes or coordinates with the external contours of the elements it contains and the human body surface to which it is applied. The sensor unit 10 is designed as a flexible printed circuit board and can be bent at a certain angle. The sensor unit 10 is mounted on the sensor mat 12 and has a lower layer 13 and an upper layer 14.

[0045] The lower layer 13 has a base region on its underside that includes multiple openings 15, which provide an optical path. The base region is oriented toward the human body surface 20. The underside of the base region is designed as a contact surface for support on the human body surface 20. The base region completely covers the sensor unit 10, and its external contour is harmonized or coordinated with the sensor unit 10, and in particular, wings are provided, which are located on both sides of the longitudinal axis 18 and substantially perpendicular to the longitudinal axis. The shape of the sensor mat 12 determines the size of the contact surface and, consequently, the size of the support on the human body surface 20 for fixing the sensor structure 1. An adhesive layer is placed on the contact surface of the lower layer 13.

[0046] The upper side of the lower layer 13 is in contact with the upper layer 14 of the multilayer sensor mat 12, and in particular, the lower layer 13 and the upper layer 14 are detachably connected to each other on the contact surface, for example, through an adhesive layer. The upper layer 14 also has an opening 17 through which the contact head 16 is guided, at least partially. Thus, the upper layer 14 of the sensor mat 12 covers the sensor unit 10 as a cover. The sensor mat 12 is designed to be flexible so as to be adaptable to the contours of the human body surface 20.

[0047] The sensor mat 12 is provided as a single-use unit and is discarded after one use. The multilayer sensor mat 12 has at least one foam layer.

[0048] Figure 2A is a schematic diagram of the sensor unit 10, which is designed as a flexible or flex-rigid printed circuit board. The sensor unit 10 is designed in a flat body shape extending along a longitudinal axis 18, where the first and second photodetectors 2 or sensor surface 2 are located. The photodetectors 2 are separated at different distances from the optical coupling point on the contact surface 22, or from the optical emission surface or optical coupling point. The separation distance is based on the application environment, and the illustrated embodiment refers to photodetectors 2 for measuring deeper human tissue near the human body surface 20. A conductor track 5 extends along the longitudinal axis 18, which is designed for both signal transmission and electrical contact, and is provided with a first contact means 30 having contact geometry 32. The first contact means 30 is designed to be substantially annular in conjunction with the sensor unit 10, which is designed as a flexible or flex-rigid printed circuit board. One or more regions on the outer circumference of the large annular first contact means 30 are provided, for example, in recessed positioning elements 31. The shape of the annular first contact means 30 is designed to complement the shape of the positioning ring 33, as shown in Figure 2B. The positioning ring 33 has positioning elements 35 (e.g., projections) designed to correspond to its inner circumference, thereby enabling the positioning ring 33 to be positionable and fixed in a predetermined direction on the sensor unit 10. The positioning ring 33 enables the contact head 16 to contact the sensor unit 10 and to be positioned in a predetermined direction by the shape of the positioning ring 33. Magnetic contact elements 34 and electrical contact elements 36 are arranged on the annular surface of the first contact means 30 according to the contact geometry 32. The electrical contact elements 36 may be made in contact to conduct electricity in order to operate the photodetector 2 via the conductor track 5. As described below, the magnetic contact elements 34, together with the corresponding counter piece provided on the contact head 16, form a detachable coupling of the sensor unit 10 to the contact head 16.The electrical contacts of the sensor unit 10 are provided by magnetic coupling.

[0049] A tab 38 or nose is formed on the elongated body of the sensor unit 10, in particular in the area of ​​the optical component or on the sensor surface 2, along with the optical coupling point 22, and the tab extends vertically and / or along the longitudinal axis 18. The molded tab 38 forms a contact surface on the multilayer sensor mat 12. Although not shown in perspective view, the sensor unit 10, designed as a flexible or flex-rigid printed circuit board, has a reinforcing element 39, which may be designed as a material that thickens or bulges at the location of the optical component.

[0050] Figure 3 shows the sensor mat 12 viewed from below, with the base region of the lower layer 13 visible. The sensor mat 12 is designed as a long, flat body, and in particular it extends along the longitudinal axis 18. The base region, which forms the contact surface for support on the human body surface 20, has a plurality of openings 15 in the area where the optical components of the sensor unit 10, such as the optical coupling point 22 and the photodetector 2, are located. The external contour of the sensor mat 12 may have different shapes, and in particular, wings may be provided in the area of ​​the optical components. These wings are indicated by reference numeral 24 and extend at least partially perpendicular to the longitudinal axis 18.

[0051] Figure 4 shows the upper layer 14 of the sensor mat 12, which substantially corresponds to that of the lower layer 13 in terms of the shape of its outer contour. However, in the upper layer, only one opening 17 is created in the area of ​​the contact surface 22 or optical coupling point 22, and this opening provides an optical path for light to be irradiated onto the human body surface 20 located below.

[0052] Figure 5 is a detailed cross-sectional view of a contact head 16 according to a first embodiment that is operationally coupled to a sensor unit 10. The contact head 16 has a housing 40 in which electrical wiring 42 and an optical fiber element 44 may be flexibly housed in a receptacle or receiving area (not shown in detail). The electrical wiring 42 is electrically connected to a spring contact pin 46 provided on a second contact means 47. In the illustrated embodiment, the spring contact pin 46 protrudes downward from the first contact ring 48 of the second contact means 47 and, on the opposite side of the first contact ring 48, is connected to the electrical wiring 42 by a connector element 50, for example by a plug 52 located thereon, so as to be conductive. A second contact ring 49 may be located on the first contact ring 48, which has a through-hole 54 through which the spring contact pin 46 extends. Furthermore, a magnetic element or magnetic contact element 45 is positioned below the second contact ring 49, and it is arranged in a complementary arrangement to the contact geometry of the first contact means 30 (not shown).

[0053] Furthermore, Figure 5 shows that the optical fiber element 44 is housed and fixed within the retaining element 60 and is housed within the housing 40, and light emitted from the optical fiber element 44 in one direction is deflected or reflected in a second direction on a given reflective surface 62, the second direction being substantially perpendicular to the first direction and output substantially perpendicular to the human body surface 20 through the contact surface 22 or optical coupling point 22. The reflective surface 62 is formed by the closed chamfered end face of the deflection element 64, which is designed as a cylinder, and is housed and held within the housing 40 of the contact head 16.

[0054] Figure 6 shows an alternative embodiment of the contact head 16, in particular, in which an internal light source 70 is provided within the housing 40 in the form of a light-emitting diode or laser diode. The contact of the contact head 16 to the contact geometry 32 of the first contact means 30 of the sensor unit 10 corresponds to that of the embodiment shown in Figure 5. Specifically, an internal light source 70 that can be electrically contacted by electrical wiring 42 is shown in Figure 6. Light (preferably light waves having different wavelengths) emitted from the internal light source 70 is guided along an optical guide element 72 toward the surface of the human body 20. The optical guide element 72 can be designed as a cylinder made from, for example, a light-transmitting material such as polycarbonate and can be housed within the contact head 16.

[0055] Figure 7 shows one embodiment of the deflection element 64. The deflection element 64 is housed within the contact head 16 and is designed as a separate, flexible element. In the illustrated embodiment, the deflection element 64 is designed as a hollow cylinder having a closed hemispherical end face 66. The contact for the optical fiber element 44 is realized at this closed hemispherical end face 66, and as a result, the light output from the optical fiber element 44 is reflected over the hemispherical structure, deflected substantially perpendicular to the optical fiber element 44, and radiated from the optical coupling point 22 or contact surface 22 to the human body surface 20. [Prior art documents] [Patent Documents]

[0056] [Patent Document 1] International Publication WO94 / 27494 [Patent Document 2] European Patent No. 2916716 [Patent Document 3] International Publication No. WO2012 / 109661

Claims

1. A sensor structure (1) for non-invasively measuring parameters of human tissue, comprising a sensor mat (12) and a sensor unit (10) for detachably positioning the sensor structure (1) on the surface of the human body (20), The sensor unit (10) is connectable to a contact head (16) designed to make electrical contact with the sensor unit (10) and to supply light from a light source to the sensor unit (10). The sensor unit (10) is An optical component having at least one photodetector (2) for detecting light emitted into and passing through the human tissue, The sensor unit (10) is connected to the contact head (16) by a first contact means (30) for electrically and magnetically contacting it and a conductor track (5) for operational coupling. It is designed as a flexible printed circuit board having, The first contact means (30) is designed as a contact ring having an annular surface, and a plurality of magnetic contact elements (34) and a plurality of electrical contact elements (36) are arranged alternately along the annular surface. The contact head (16) has a second contact means (47) for connecting the contact head (16) to the sensor unit (10), the second contact means (47) includes a plurality of spring contact pins (46) corresponding to the plurality of electrical contact elements (36) of the first contact means (30) of the sensor unit (10) and a plurality of magnetic contact elements (45) corresponding to the plurality of magnetic contact elements (34) of the first contact means (30) of the sensor unit (10). The sensor structure (1) further includes a positioning ring (33) on the first contact means (30) for positioning the contact head (16) in a predetermined orientation. The positioning ring (33) includes a plurality of positioning elements (35) arranged asymmetrically on the inner circumference of the positioning ring (33), The first contact means (30) has a shape that complements the plurality of positioning elements (35), When the positioning ring (33) is placed on the contact ring, the positioning ring (33) is positioned and fixed in a predetermined direction relative to the sensor unit (10) by the plurality of positioning elements (35), and thereby the contact head (16) is also positioned in a predetermined direction relative to the sensor unit (10) by the plurality of positioning elements (35). The aforementioned sensor mat (12) A lower layer (13) including a lower contact surface for contacting the human body surface (20) and an upper contact surface for supporting the sensor unit (10), wherein the lower layer (13) is aligned with respect to the optical components of the sensor unit (10) and is provided with openings (15, 17) that form an optical path, The upper layer (14) is connected to the upper contact surface of the lower layer (13) so that it can be attached to and detached from each other. A sensor structure having a multilayer structure including [a specific element].

2. The sensor structure (1) according to claim 1, characterized in that the sensor unit (10) has reinforcing elements (39) at least at the corners.

3. The sensor unit (10) is designed as a body extending along a longitudinal axis (18) and has a tab (38) designed substantially perpendicular and / or along the longitudinal axis (18), characterized in that the sensor structure (1) according to claim 1 or 2.

4. The contact head (16) is Housing (40) and An electrical wiring (42) that is flexible within the housing (40) and can be electrically connected to the plurality of spring contact pins (46), Means (44, 64, 70, 72) for emitting and guiding light in one direction perpendicular to the surface of the human body (20), A light-emitting surface (22) through which light is emitted into human tissue, and A sensor structure (1) according to any one of claims 1 to 3, characterized by having the following:

5. The second contact means (47) has a first contact ring (48) and a second contact ring (49) as separate annular components, which can be housed within the housing (40) of the contact head (16). The first contact ring (48) has a first surface side and a second surface side, the spring contact pin (46) is arranged on the first surface side in a predetermined configuration, and the connector element (52) that forms a plug contact (50) with a mating component provided on the electrical wiring (42) is arranged on the second surface side. The sensor structure (1) according to claim 4, characterized in that the second contact ring (49) has a through hole (54) through which the plurality of spring contact pins (46) extend, and the plurality of magnetic contact elements (45) are arranged on the first surface side thereof, and the plurality of magnetic contact elements (45) each make contact with the plurality of magnetic contact elements (34) of the first contact means (30).

6. The sensor structure (1) according to claim 4 or 5, characterized in that the means (44, 64, 70, 72) includes an optical fiber element (44) for guiding light from a first light source in a first direction, and a deflection element (64) for deflecting the irradiated light in a direction perpendicular to the human body surface (20).

7. The sensor structure (1) according to claim 6, characterized in that the optical fiber element (44) has at least one optical fiber fixed within the housing (40) or fixed to an element (60) that can be housed within the housing (40), and as a result, light is output from the optical fiber element (44) to the deflection element.

8. The sensor structure (1) according to claim 6 or 7, characterized in that a reflective surface (62) of the deflection element (64) that can be housed within the housing (40) is provided.

9. The sensor structure (1) according to claim 8, characterized in that the deflection element (64) is designed as a cylinder having a closed chamfered end face as a reflective surface (62).

10. The sensor structure (1) according to claim 9, characterized in that the deflection element (64) is manufactured as a plastic element that is at least partially zinc-plated.

11. The sensor structure (1) according to any one of claims 6 to 8, characterized in that the deflection element (64) is designed as a hollow cylinder having a closed hemispherical end face (66) as a reflective surface (62).

12. The sensor structure (1) according to claim 11, characterized in that the deflection element (64) is made of a reflective material.

13. The sensor structure (1) according to claim 4, characterized in that the means (44, 64, 70, 72) are designed as an internal light source (70) and an optical fiber guide (72) that can be housed within the housing (40) of the contact head (16).

14. The sensor structure (1) according to any one of claims 4 to 13, characterized in that an energy source that makes electrical contact with at least one photodetector (2) of the sensor structure (1) via the electrical wiring (42) is provided in the contact head (16).

15. The sensor structure (1) according to claim 14, characterized in that an external control and processing unit provides wireless data transmission to the sensor structure (1).

Images