Fiber optic pressure sensor array or grid for detecting position, vibration and / or motion and mattress including same - Patents.com

Abstract

The present invention relates to an optical fiber pressure sensor array or grid for sensing position, vibration and / or motion, comprising a plurality of receiving optical fibers (10) and a plurality of transmitting optical fibers (20), arranged in a planar array to define a pressure sensor (30) at each point, and a mechanical structure (40) is provided on one or both sides of each pressure sensor (30) to enhance fiber bending when pressure is applied to the pressure sensor (30), the mechanical structure (40) including a first inner layer (40.1) made of a flexible light scattering material in contact with the optical fibers (10, 20) and a second outer layer (40.2) made of a rigid material, the plurality of receiving optical fibers (10) and / or the plurality of transmitting optical fibers (20) being curved at the intersections that define the pressure sensors (30).

Description

[Technical field]

[0001] The present invention relates to the field of fiber optic pressure sensors, particularly for sensing position, vibration and / or motion.

[0002] More specifically, the present invention relates to a fiber optic pressure sensor, preferably a polymer optical fiber (POF) pressure sensor, that can be used within or placed under a mattress to detect and monitor movement and / or vibration of a subject. [Background technology]

[0003] For example, the pressure sensor may be configured and adapted to detect and monitor a human's heart rate and / or breathing.

[0004] The use of optical sensors to detect and monitor the movement or vibration of an object is known in the art. For this purpose, sensors that do not require structural means (such as wires) to be attached to the body of the object are preferred, as the sensor does not interfere with the object with human movements.

[0005] In particular, fiber optic pressure sensor arrays are known in the art that include a matrix of receive and transmit optical fibers arranged in a planar array, and in these known configurations, pressure sensors are defined at each intersection between the fibers.

[0006] An example of a prior art two-dimensional pressure sensor array is shown in Figure 1. In this case, the vertical columns are scanned one at a time.

[0007] In particular, the transmitting fiber is connected to a light source, and the perpendicularly extending receiving fiber is connected to a highly sensitive optical receiver. At each intersection, an amount of optical power can be coupled from the light-carrying fiber to the fiber connected to the receiver, depending on the pressure applied to the intersection. Thus, each fiber intersection of the grid acts as an independent pressure sensor.

[0008] 2a-c show details of an exemplary sensor array according to the prior art, in which a plurality of receiving optical fibers, in particular polymer optical fiber (POF), and a plurality of transmitting optical fibers, in particular polymer optical fiber (POF), are arranged in a planar configuration.

[0009] In the example of Figures 2a-c, a mechanical structure is provided on either side of each pressure sensor, including a first inner layer made of a flexible light-scattering material (e.g., flexible white silicone rubber) and a second outer layer made of a rigid material (e.g., polyvinyl chloride (PVC)) (Figures 2b-c). The first layer is 10 x 10 x 1.5 mm 3 The second layer may have a dimension of 0.3 mm.

[0010] When pressure is applied to the pressure sensor, as shown in Figure 2c, the flexible scattering material exerts pressure on the optical fiber, causing it to bend slightly. As a result, a small amount of light proportional to the applied pressure escapes from the transmitting optical fiber. The leaked light is then scattered in all directions within the optical scattering material in the first layer, and a portion is coupled back into the receiving optical fiber.

[0011] The flexible light-scattering material results in the optical fiber having a flatter bend radius when pressure is applied, so that a portion of the force is absorbed by the flexible material outside the fiber crossing point. A rigid material tends to concentrate the pressure at the intersection between the optical fibers. Thus, without the flexible material, the force would be concentrated at the intersection with the risk of causing permanent deformation.

[0012] Figures 3a-c show details of another exemplary sensor array according to the prior art. In particular, Figures 3a-c show an arrangement similar to that of Figures 2a-c, but where the mechanical structure is provided only on one side of the pressure sensor, and a thin layer of light-scattering rigid material is provided on the opposite side of the pressure sensor to the mechanical structure. By way of example, the light-scattering rigid material can be white polyvinyl chloride (PVC) (Figures 3b-c).

[0013] EP 3420331 A1 discloses an optical waveguide pressure sensor array comprising two or more rows and two or more columns of optical waveguides arranged in a planar array to define pressure sensors at the intersections between the optical waveguides, and a mechanical structure is provided on one or both sides of the pressure sensor to enhance the waveguide bending when pressure is applied to the pressure sensor. In particular, the mechanical structure includes a first rigid ring arranged in contact with one of the row optical waveguides or the column optical waveguides. A hole in the first rigid ring laterally surrounds the intersection of the pressure sensor. The optical waveguide pressure sensor array is configured to sense pressure by providing light to the row optical waveguides and measuring the light coupled into the column optical waveguides, or vice versa. The optical waveguide pressure sensor array of EP 3420331 A1 is configured and adapted for use in a mattress to sense and monitor the movement of a subject.

[0014] EP 0 089 237 A1 discloses a photo-optical switch apparatus comprising a photopolymerized orthogonal matrix of horizontal and vertical intersecting light channels or light guides formed monolithically by exposing a flat, planar plastic substrate to ultraviolet light. Each intersection has a higher refractive index than either the channels or the adjacent substrate regions. Curved taps or optical couplers couple the horizontal channels of the array to the vertical channels of the array. The intersections of the channels are arranged on an array of upstanding protrusions on a flat mounting substrate, each protrusion being located at a respective intersection of a horizontal and vertical light channel. A light absorbing keypad is positioned over each intersection to couple light from the channels into the keypad. A relative loss of light indicates that a key is depressed.

[0015] US Patent No. 4,733,068 discloses a fiber optic sensor array including rows of transmitting optical fibers and columns of detecting optical fibers overlapping the transmitting fibers. A planar compliant spacer separates the transmitting fibers from the detecting fibers, thus defining a sensor element at each location where the detecting fibers overlap the transmitting fibers. The surface of each transmitting fiber and each receiving fiber is modified at each sensor element location to increase optical coupling between the transmitting and receiving fibers at that element. A spacer in the array includes an opening between the transmitting and detecting fibers at each sensor element location. A support surface is attached to the detecting fiber opposite the compliant spacer, and a protective cover layer is attached to the transmitting fiber opposite the compliant spacer. An array of light emitting elements is provided such that each element in the light emitting array transmits light into one of the transmitting fibers, and an array of light detecting elements is provided such that each element in the detecting array detects light emanating from one of the detecting fibers. A clock determines the time to emit light from each light emitting element and the time to detect light at each detecting element. A clock is connected to cause each detection element to detect light in sequence after each light emitting element emits light. Summary of the Invention

[0016] However, there is a need for improved fiber optic sensor arrays for position sensing with increased sensitivity, which will enable more precise and reliable detection and monitoring of object movement.

[0017] SUMMARY OF THE PRESENT EMBODIMENT It is therefore an object of the present invention to provide a fiber optic pressure sensor array for position sensing with improved sensitivity.

[0018] The aforementioned object is achieved by providing a fiber optic pressure sensor array or grid for sensing position, vibration and / or motion according to claim 1.

[0019] A fiber optic pressure sensor array or grid can be incorporated into the mattress.

[0020] Alternatively, a fiber optic pressure sensor array or grid can be placed under the mattress.

[0021] The sensor array or grid includes a plurality of receiving optical fibers.

[0022] The sensor array or grid further includes a plurality of transmit optical fibers.

[0023] Preferably, the optical fibre is a polymer optical fibre (POF), thereby defining a POF pressure sensor array or grid.

[0024] Preferably, the optical fiber is made of poly(methyl methacrylate) (PMMA).

[0025] The plurality of receive optical fibers and the plurality of transmit optical fibers are arranged in a planar array or grid to define pressure sensors at their respective intersections.

[0026] Mechanical structures may be provided on either side of the pressure sensor.

[0027] Alternatively, the mechanical structure may be provided to one side of the pressure sensor.

[0028] In such a case, a rigid light scattering layer is provided on the opposite side of the pressure sensor from the mechanical structure.

[0029] Preferably, the rigid light scattering layer is made of white polyvinyl chloride (PVC).

[0030] In particular, the mechanical structure around the intersection could be made of either a flexible light scattering silicon-based material on one side and nothing on the other side (first possible option), or made of a flexible light scattering silicon-based material on both sides (second possible option), or made of a flexible light scattering silicon-based material on one side and a hard rigid light scattering material like PVC on the other side (third option). For all three options, another possibility is to put a thin flexible light scattering silicon-based material between the fibers. Of course, other options or combinations of options are also possible.

[0031] The mechanical structure allows for enhanced fiber bending when pressure is applied to the pressure sensor.

[0032] The mechanical structure includes a first inner layer that contacts the optical fiber.

[0033] The first layer is made of a flexible light scattering material.

[0034] The mechanical structure further includes a second outer layer made of a rigid material.

[0035] In this embodiment, the plurality of receive optical fibers and / or the plurality of transmit optical fibers are curved at the intersections that define the pressure sensors.

[0036] As an example, only the transmitting optical fiber may be curved at the intersection that defines the pressure sensor.

[0037] Alternatively, only the receiving optical fiber may be curved at the intersection that defines the pressure sensor.

[0038] Alternatively, both the transmit and receive optical fibers can be curved at the intersection that defines the pressure sensor.

[0039] By providing the transmit and / or receive optical fibers that are curved at their respective intersections, sensor sensitivity can be significantly increased. In particular, the curvature of one or both optical fibers at the intersection (defining the pressure sensor) allows more light to escape the transmit optical fiber at the intersection. Furthermore, more light is allowed to couple into the receive optical fiber at the intersection, thereby increasing sensor sensitivity.

[0040] Preferably, the first layer of the mechanical structure is made from white silicone rubber.

[0041] Preferably, the second layer of the mechanical structure is made from polyvinyl chloride (PVC).

[0042] Furthermore, the above mentioned object is achieved by providing a fiber optic pressure sensor array or grid for sensing position, vibration and / or motion as claimed in claim 5.

[0043] A fiber optic pressure sensor array or grid can be incorporated into the mattress.

[0044] Alternatively, a fiber optic pressure sensor array or grid can be placed under the mattress.

[0045] The sensor array or grid includes a plurality of receiving optical fibers.

[0046] The sensor array or grid further includes a plurality of transmit optical fibers.

[0047] Preferably, the optical fibre is a polymer optical fibre (POF), thereby defining a POF pressure sensor array or grid.

[0048] Preferably, the optical fiber is made of poly(methyl methacrylate) (PMMA).

[0049] Mechanical structures may be provided on either side of the optical fiber.

[0050] Alternatively, the mechanical structure may be provided to one side of the pressure sensor.

[0051] In such a case, a corresponding rigid light scattering layer is provided on the opposite side of the pressure sensor from the mechanical structure.

[0052] Preferably, the rigid light scattering layer is made of white polyvinyl chloride (PVC).

[0053] The mechanical structure allows for establishing an optical coupling between the transmitting optical fiber and the receiving optical fiber when pressure is applied to the optical fibers.

[0054] The mechanical structure includes a first inner layer that contacts the fiber.

[0055] The first layer is made of a flexible light scattering material.

[0056] The mechanical structure further includes a second outer layer made of a rigid material.

[0057] Preferably, the second layer is made of a corrugated rigid material.

[0058] In this embodiment, the plurality of receive optical fibers and the plurality of transmit optical fibers extend parallel in a planar array or grid.

[0059] In this embodiment, when pressure is applied across a short or longer length of the optical fiber, the first layer of flexible light scattering material establishes optical coupling between the transmitting and receiving optical fibers, where the optical coupling is dependent on the applied pressure and length. Additionally, the second layer of corrugated rigid material allows extra macro bending of both the transmitting and receiving optical fibers, thereby enhancing optical coupling and sensor sensitivity.

[0060] Adjacent optical fibers may be in contact with each other.

[0061] Alternatively, gaps may be defined between adjacent optical fibers.

[0062] Preferably, the first layer of the mechanical structure is made from white silicone rubber.

[0063] Preferably, the second layer of the mechanical structure is made from polyvinyl chloride (PVC).

[0064] More preferably, the second layer of the mechanical structure is made from corrugated polyvinyl chloride (PVC).

[0065] The mechanical structure may include multiple segments.

[0066] Preferably, the multiple segments are individually controllable.

[0067] Furthermore, the aforementioned object is achieved by providing a fiber optic pressure sensor array or grid for sensing position, vibration and / or motion as claimed in claim 13.

[0068] A fiber optic pressure sensor array or grid can be incorporated into the mattress.

[0069] Alternatively, a fiber optic pressure sensor array or grid can be placed under the mattress.

[0070] The sensor array or grid includes a plurality of receiving optical fibers.

[0071] The sensor array or grid further includes a plurality of transmit optical fibers.

[0072] Preferably, the optical fibre is a polymer optical fibre (POF), thereby defining a POF pressure sensor array or grid.

[0073] Preferably, the optical fiber is made of poly(methyl methacrylate) (PMMA).

[0074] The plurality of receiving optical fibers and the plurality of transmitting fibers are arranged in a planar array or grid to define pressure sensors at their respective intersections.

[0075] Mechanical structures may be provided on either side of the pressure sensor.

[0076] Alternatively, the mechanical structure may be provided to one side of the pressure sensor.

[0077] In such a case, a rigid light scattering layer is provided on the opposite side of the pressure sensor from the mechanical structure.

[0078] Preferably, the rigid light scattering layer is made of white polyvinyl chloride (PVC).

[0079] The mechanical structure allows for enhanced fiber bending when pressure is applied to the pressure sensor.

[0080] The mechanical structure includes a first inner layer that contacts the optical fiber.

[0081] The first layer is made of a flexible light scattering material.

[0082] The mechanical structure further includes a second outer layer made of a rigid material.

[0083] In this embodiment, an additional layer of flexible light-scattering material is interposed between the optical fibers at their crossing points.

[0084] The additional layer makes it possible to provide protection to the optical fibers at the intersection points.

[0085] Preferably, the additional layer is made of a flexible white silicone rubber.

[0086] Alternatively, the additional layer is made of flexible white latex.

[0087] Preferably, the first layer of the mechanical structure is made from white silicone rubber.

[0088] Preferably, the second layer of the mechanical structure is made from polyvinyl chloride (PVC).

[0089] Furthermore, the aforementioned object is achieved by providing a fiber optic pressure sensor array or grid for sensing position, vibration and / or motion as claimed in claim 18.

[0090] A fiber optic pressure sensor array or grid can be incorporated into the mattress.

[0091] Alternatively, a fiber optic pressure sensor array or grid can be placed under the mattress.

[0092] The sensor array or grid includes a plurality of receiving optical fibers.

[0093] The sensor array or grid further includes a plurality of transmit optical fibers.

[0094] Preferably, the optical fibre is a polymer optical fibre (POF), thereby defining a POF pressure sensor array or grid.

[0095] Preferably, the optical fiber is made of poly(methyl methacrylate) (PMMA).

[0096] The plurality of receive optical fibers and the plurality of transmit optical fibers are arranged in a planar array or grid to define pressure sensors at their respective intersections.

[0097] Mechanical structures may be provided on either side of the pressure sensor.

[0098] Alternatively, the mechanical structure may be provided to one side of the pressure sensor.

[0099] In such a case, in this embodiment, a first inner layer made of white scattering tape and a second outer layer made of black shielding material are provided on the side opposite the mechanical structure of the pressure sensor.

[0100] In this embodiment, the mechanical structure includes a first inner layer in contact with the optical fiber.

[0101] The first layer is made of white scattering tape.

[0102] In this embodiment, the mechanical structure further includes a second intermediate layer.

[0103] The second layer is made of a black shielding material.

[0104] In this embodiment, the mechanical structure further includes a third outer layer.

[0105] The third layer is made of a flexible material.

[0106] The above-described configuration of the mechanical structure makes it possible to increase the sensor sensitivity.

[0107] Finally, the present invention provides a mattress including a fiber optic pressure sensor array or grid for detecting position, vibration and / or movement according to any one of the above-mentioned embodiments of the invention. By providing a mattress with a fiber optic pressure sensor array or grid according to the present invention, it is possible to more reliably detect and monitor the movement and / or vibration of an object, preferably a human being, located (e.g. lying) on ​​the mattress.

[0108] Further details and advantages of the invention will now be disclosed in connection with the drawings. [Brief description of the drawings]

[0109] [Figure 1] FIG. 1 shows an example of a two-dimensional pressure sensor array according to the prior art. [Diagram 2]Figure 2a is a schematic diagram of a detail of an exemplary prior art optical fiber pressure sensor array for position sensing with mechanical structures on either side of a pressure sensor defined at the intersection between optical fibers, Figure 2b is a side view of the detail of Figure 1a with no pressure applied to the pressure sensor, and Figure 2c is a side view of the detail of Figure 1a with pressure applied to the pressure sensor. [Diagram 3] Figure 3a is a schematic diagram of a detail of another exemplary prior art fiber optic pressure sensor array for position sensing with mechanical structures on one side of the pressure sensor defined at the intersection between the optical fibers; Figure 3b is a side view of the detail of Figure 2a with no pressure applied to the pressure sensor; and Figure 3c is a side view of the detail of Figure 2a with pressure applied to the pressure sensor. [Figure 4] FIG. 2 is a schematic diagram of details of an experimental setup for a fiber optic pressure sensor array for sensing position, vibration and / or motion in accordance with the present invention. [Diagram 5] Figure 5a is a schematic diagram of a detail of a fiber optic pressure sensor array for sensing position, vibration and / or motion according to a first embodiment of the invention, with mechanical structures provided on one side of the pressure sensor defined at the intersections between the optical fibers, and Figure 5b is a side view of the detail of Figure 5a with no pressure applied to the pressure sensor. [Figure 6] FIG. 5b shows the receiver output voltage as a function of applied weight for the embodiment of FIG. 5a. [Figure 7] Figure 7a is a schematic diagram of a fiber optic pressure sensor array for sensing position, vibration and / or motion according to a second embodiment of the invention, with mechanical structures on both sides of the fibers, Figure 7b is a side view of the fiber optic pressure sensor array of Figure 7a with no pressure applied to the fibers, and Figure 7c is a side view of the fiber optic pressure sensor array of Figure 7a with pressure applied to the fibers. [Figure 8] FIG. 7b is a side view of an arrangement similar to that of FIG. 7a, but with the mechanical structure located on one side of the fiber. [Figure 9]FIG. 9 shows the receiver output voltage as a function of applied weight for the configuration of FIG. 8. [Figure 10] Figure 10a is a top view of another configuration of a fiber pressure sensor array according to this embodiment, where the mechanical structure includes multiple segments, and Figure 10b is a side view of the configuration of Figure 10a. [Figure 11] 1 is a schematic top and side view of yet another configuration according to the present embodiments, where the mechanical structure includes multiple individually detectable segments. [Figure 12] Figure 12a is a schematic diagram of a detail of a fiber optic pressure sensor array for sensing position, vibration and / or motion according to a third embodiment of the invention, and Figure 12b is a side view of the detail of Figure 12a with no pressure applied to the pressure sensors defined at the intersections between the optical fibres. [Figure 13] FIG. 12b shows the receiver output voltage as a function of applied weight for the embodiment of FIG. 12a. [Figure 14] Figures 14a and 14b are schematic and side views of a detail of a fiber optic pressure sensor array for position sensing according to a fourth embodiment of the invention; [Figure 15] Figure 15a is a schematic diagram of a detail of a fiber optic pressure sensor array for sensing position, vibration and / or motion according to another configuration of this embodiment, and Figure 15b is a side view of the detail of Figure 15a. [Figure 16] FIG. 13 is a diagram of a POF pressure sensor with multiple intersections for detecting a larger area. [Figure 17] FIG. 1 is a diagram of a POF pressure sensor having a series of multiple intersections. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0110] A detailed description of embodiments of the present invention is provided below.

[0111] Experimental measurement setup The experimental results discussed below refer to experiments carried out by using the experimental measurement setup shown diagrammatically in FIG.

[0112] In particular, the following experimental measurement setup is used:

[0113] [Table 1]

[0114] The embodiments described below relate to a fiber optic pressure sensor array for sensing the position, vibration and / or movement of an object, preferably a human.

[0115] Alternatively, a fiber optic pressure sensor grid can be used.

[0116] A fiber optic pressure sensor array or grid according to the present invention may be incorporated into a mattress to detect movement and / or vibration of an object, preferably a human being, placed (eg, lying) on ​​the mattress.

[0117] Alternatively, a fiber optic pressure sensor array or grid can be located under the mattress.

[0118] FIG. 5a shows a detailed schematic diagram of a fiber optic pressure sensor array for sensing position, vibration and / or motion according to a first embodiment of the present invention.

[0119] The fiber optic pressure sensor array includes a plurality of receiving optical fibers 10 .

[0120] The fiber optic pressure sensor array further includes a plurality of transmitting optical fibers 20 .

[0121] In this embodiment, the optical fibers 10, 20 are polymer optical fibers (POF).

[0122] Preferably, the optical fibers 10, 20 are made of poly(methyl methacrylate) (PMMA).

[0123] A plurality of receive optical fibers 10 and a plurality of transmit optical fibers 20 are arranged in a planar array to define pressure sensors 30 at their respective intersections (FIG. 5b).

[0124] In the illustrated configuration, a mechanical structure 40 is provided to one side of the pressure sensor (Figure 5b).

[0125] In particular, a mechanical structure 40 is provided over the pressure sensor 30 .

[0126] According to an alternative configuration (not shown), the mechanical structure 40 may be provided on both sides of the pressure sensor 30 .

[0127] The mechanical structure 40 allows for enhanced fiber bending when pressure is applied to the pressure sensor 30 .

[0128] In this embodiment, the plurality of receiving optical fibers 10 and / or the plurality of transmitting optical fibers 20 are curved at the intersections that define the pressure sensors 30 .

[0129] In the illustrated configuration, only the transmitting optical fiber 20 is curved at the intersection that defines the pressure sensor 30 (FIG. 5a).

[0130] According to an alternative configuration (not shown), only the receiving optical fiber 10 may be curved at the intersection that defines the pressure sensor 30 .

[0131] According to yet another alternative configuration, both the receive optical fiber 10 and the transmit optical fiber 20 may be curved at the intersection that defines the pressure sensor 30 .

[0132] The mechanical structure 40 includes a first inner layer 41, which is in contact with the optical fibers 10,20.

[0133] The first layer 41 is made of a flexible light scattering material.

[0134] In this embodiment, the first layer 41 is made of white silicone rubber.

[0135] The mechanical structure 40 further includes a second outer layer 42 made of a rigid material.

[0136] In this embodiment, the second layer 42 is made from polyvinyl chloride (PVC).

[0137] In this embodiment, a rigid light scattering layer 50 is provided on the opposite side of the pressure sensor 30 from the mechanical structure 40 .

[0138] In this embodiment, the light scattering layer 50 is made of white polyvinyl chloride (PVC).

[0139] By providing the transmit optical fiber 20 and / or the receive optical fiber 10 that are curved at the intersection point C (also called crossing C) that defines the pressure sensor 30, the sensor sensitivity can be significantly increased. In particular, the curvature of the fibers 10, 20 allows a greater amount of light to escape from the transmit fiber 20 at the intersection point.

[0140] Furthermore, more light is allowed to couple into the receiving fiber 10 at the intersection, thereby increasing the sensor sensitivity.

[0141] FIG. 6 shows the receiver output voltage as a function of applied weight for various diameters of the curved transmitting optical fiber 20 in the configuration of FIG. 5a.

[0142] Experimental data shows that by reducing the diameter of the curve of the transmitting optical fiber 20 at the intersection point, it is possible to obtain increased sensitivity due to the effect of macro-bending already present in the transmitting optical fiber 20, which allows more light to leak out.

[0143] in particular, a) shows the receiver output voltage as a function of applied weight when a straight transmitting optical fiber is used (no bending); b) shows the receiver output voltage as a function of applied weight when a curved transmitting optical fiber with a diameter of 50 mm is used; c) shows the receiver output voltage as a function of applied weight when a curved transmitting optical fiber with a diameter of 40 mm is used; d) Receiver output voltage as a function of applied weight when a curved transmitting optical fiber with a diameter of 30 mm is used.

[0144] FIG. 7a illustrates diagrammatically a fiber optic pressure sensor array for sensing position, vibration and / or motion according to a second embodiment of the present invention.

[0145] The fiber optic pressure sensor array includes a plurality of receiving optical fibers 110 .

[0146] The fiber optic pressure sensor array further includes a plurality of transmit optical fibers 120 .

[0147] In this embodiment, the optical fibers 110, 120 are polymer optical fibers (POF).

[0148] Preferably, the optical fibers 110, 120 are made of poly(methyl methacrylate) (PMMA).

[0149] In this embodiment, the plurality of receiving optical fibers 110 and the plurality of transmitting optical fibers 120 extend parallel to each other in a planar array (FIGS. 7a to 7c).

[0150] A mechanical structure 140 is provided on one or both sides of the optical fibers 110,120.

[0151] In the configuration of Figures 7a-7c, mechanical structures 140 are provided on either side of the optical fibres 110,120.

[0152] The mechanical structure 140 makes it possible to establish an optical coupling between the transmitting optical fiber 120 and the receiving optical fiber 110 when pressure is applied to the optical fibers 110, 120 (Figure 7c).

[0153] The mechanical structure 140 includes a first inner layer 141 that contacts the optical fibers 110 , 120 .

[0154] The first layer 141 is made of a flexible, light scattering material.

[0155] In this embodiment, the first layer 141 is made of white silicone rubber.

[0156] The mechanical structure 140 further includes a second outer layer 142 made of a rigid material.

[0157] In this embodiment, the second layer 142 is made from polyvinyl chloride (PVC).

[0158] Advantageously, the second layer 142 may be corrugated.

[0159] In particular, Figures 7b-7c show a configuration in which the second layer 142 of the mechanical structure 140 disposed over the fibres 110,120 is corrugated.

[0160] In the configuration of FIG. 7 a , a gap 160 is defined between adjacent optical fibers 110 , 120 .

[0161] Alternatively, adjacent optical fibers 110, 120 may be in contact with each other (FIGS. 10a-10b).

[0162] When pressure is applied across a short or longer length (depending on the dimensions and / or shape of the mechanical structure 140) of the optical fibers 110, 120, the first layer 141 establishes an optical coupling between the transmitting optical fiber 120 and the receiving optical fiber 110, the optical coupling depending on the pressure and the length.

[0163] The use of a corrugated stiff material for the second layer 142 allows for the introduction of extra macro-bends in both optical fibers 110, 120, thereby increasing optical coupling and enhancing sensor sensitivity.

[0164] Figure 8 shows a similar configuration to that of Figure 7a, but with multiple mechanical structures 140 having first layer 141 and second layer 142 on one side of the fibers 110, 120, used for experimental validation. In this experiment, the corrugated layer 142 is realized with a flat rigid piece of material with a small diameter round material underneath.

[0165] In this case, a rigid light scattering layer 150 is provided on the opposite side of the optical fibers 110 , 120 from the mechanical structure 140 .

[0166] In this embodiment, the light scattering layer 150 is made of white polyvinyl chloride (PVC).

[0167] Figure 9 shows the receiver output voltage as a function of applied weight for the configuration of Figure 8. When pressure is applied to the rigid light scattering layer 150, the rounded material underlying this layer 150 determines macro-bends in both the receive optical fiber 110 and the transmit optical fiber 120, thereby increasing the optical power coupling between both fibers 110, 120.

[0168] The mechanical structure 140 having a first layer 141 and a second layer 142 may have a rectangular shape (Figure 7a).

[0169] Alternatively, the mechanical structure 140 may have a substantially square shape (Figure 10a).

[0170] Other configurations of the machine structure are possible as long as they are suitable for the purpose.

[0171] 10a-10b show another configuration of a fiber optic pressure sensor array according to the present embodiment, where a mechanical structure 140 includes multiple segments 160. FIG.

[0172] FIG. 11 shows yet another configuration of an optical fiber pressure sensor array according to this embodiment, which is similar to the configuration of FIGS. 10a-b, except that multiple segments 160 of a mechanical structure 140 having a first layer 141 and a second layer 142 are individually detectable.

[0173] FIG. 12a illustrates generally details of a fiber optic pressure sensor array for sensing position, vibration and / or motion according to a third embodiment of the present invention.

[0174] The fiber optic pressure sensor array includes a plurality of receiving optical fibers 210 .

[0175] The fiber optic pressure sensor array further includes a plurality of transmit optical fibers 220 .

[0176] In this embodiment, the optical fibers 210, 220 are polymer optical fibers (POF).

[0177] Preferably, the optical fibers 210, 220 are made of poly(methyl methacrylate) (PMMA).

[0178] A plurality of receive optical fibers 210 and a plurality of transmit optical fibers 220 are arranged in a planar array to define pressure sensors 230 at their respective intersections (FIG. 12b).

[0179] A mechanical structure 240 is provided on one or both sides of each pressure sensor 230 .

[0180] In the illustrated configuration, the mechanical structure 240 is provided to one side of the pressure sensor 230 .

[0181] According to an alternative configuration (not shown), the mechanical structure 240 may be provided on either side of the pressure sensor 230 .

[0182] The mechanical structure 240 allows for enhanced fiber bending when pressure is applied to the pressure sensor 230 .

[0183] In this embodiment, an additional layer 270 made of a flexible light-scattering material is interposed between the optical fibres 210, 220 at the crossing point (Figure 12b).

[0184] Preferably, the additional layer 270 is made from a flexible white silicone rubber.

[0185] Alternatively, the additional layer 270 is made of flexible white latex.

[0186] The presence of the additional layer 270 interposed between the optical fibers 210, 220 provides protection to the fibers 210, 220 at the crossing point.

[0187] The mechanical structure 240 includes a first inner layer 241 that contacts the optical fibers 210 , 220 .

[0188] The first layer 241 is made of a flexible light scattering material.

[0189] In this embodiment, the first layer 241 is made of white silicone rubber.

[0190] The mechanical structure 240 further includes a second outer layer 242 made from a rigid material.

[0191] In this embodiment, the second layer 242 is made from polyvinyl chloride (PVC).

[0192] In this embodiment, a rigid light scattering layer 250 is provided on the opposite side of the pressure sensor 230 from the mechanical structure 240 .

[0193] In this embodiment, the light scattering layer 250 is made of white polyvinyl chloride (PVC).

[0194] Figure 13 shows the receiver output voltage as a function of applied weight for various thicknesses of the additional layer 270 for the configuration of Figures 12a-b. The additional layer 270 of flexible scattering material determines a decrease in sensitivity since the macro bending is reduced by adding a flexible material between the receiving optical fiber 210 and the transmitting optical fiber 220. In particular, experimental results show that the thicker this flexible layer 270, the lower the sensitivity. However, the overall robustness is improved.

[0195] in particular, a) shows the receiver output voltage as a function of applied weight when no additional layer is provided; b) shows the receiver output voltage as a function of the applied weight when an additional layer of 0.05 mm thickness is interposed between the fibers at the intersection; c) shows the receiver output voltage as a function of the applied weight when an additional layer of 0.1 mm thickness is interposed between the fibers at the intersection; d) shows the receiver output voltage as a function of applied weight when an additional layer of 0.15 mm thickness is interposed between the fibers at the intersection; e) shows the receiver output voltage as a function of the applied weight when an additional layer of 0.2 mm thickness is interposed between the fibers at the crossing point.

[0196] 14a-b and 15a-b show schematic details of a fiber optic pressure sensor array for sensing position, vibration and / or motion according to a fourth embodiment of the present invention.

[0197] The fiber optic pressure sensor array includes a plurality of receiving optical fibers 310 .

[0198] The fiber optic pressure sensor array further includes a plurality of transmit optical fibers 320 .

[0199] In this embodiment, the optical fibers 310, 320 are polymer optical fibers (POF).

[0200] Preferably, the optical fibers 310, 320 are made of poly(methyl methacrylate) (PMMA).

[0201] A plurality of receive optical fibers 310 and the plurality of transmit optical fibers 320 are arranged in a planar array to define a pressure sensor 330 at each intersection (FIGS. 14b and 15b).

[0202] A mechanical structure 340 may be provided on one or both sides of each pressure sensor 330 .

[0203] The mechanical structure 340 allows for enhanced fiber bending when pressure is applied to the pressure sensor 330 .

[0204] In this embodiment, the mechanical structure includes a first inner layer 341 in contact with the optical fibers 310,320.

[0205] The first layer 341 is made of white scattering tape.

[0206] In this embodiment, the mechanical structure 340 further includes a second intermediate layer 342 .

[0207] The second middle layer 342 is made of a black shielding material.

[0208] In this embodiment, the mechanical structure 340 further includes a third outer layer 343 .

[0209] The third layer 343 is made of a flexible material.

[0210] There is also an intersection C of the optical fibers 310, 320.

[0211] 14a-b show a configuration in which the mechanical structure 340 is provided to one side (eg, above) of the pressure sensor 330. FIG.

[0212] In this configuration, a first inner layer 351 and a second outer layer 352 are provided on an opposite side of the pressure sensor 330 from the mechanical structure 340 .

[0213] The inner layer 351 is made of white scattering tape.

[0214] The second layer 352 is made of a black shielding material.

[0215] 15a-b show an alternative configuration in which a mechanical structure 340 is provided on either side of the pressure sensor 330. FIG.

[0216] By providing a mechanical structure 340 including white scattering tape 341, an intermediate layer of black shielding material 342, and flexible material 343, sensor sensitivity can be significantly enhanced.

[0217] The invention further provides a mattress (not shown) including a fiber optic pressure sensor array or grid for sensing position, vibration or motion according to any one of the above-mentioned embodiments. By implementing a fiber optic pressure sensor array or grid for sensing position, vibration and / or motion according to the invention in a mattress, it is possible to reliably detect and monitor the movement of an object, preferably a human being, present (e.g. lying) on ​​the mattress.

[0218] FIG. 16 shows another possible embodiment of the present invention, in this case a fiber optic pressure sensor 430, namely a POF pressure sensor 430 having multiple intersections C for detecting a larger area.

[0219] FIG. 16 shows a sensor configuration with only one receiving fiber 410 and only one transmitting fiber 420 and multiple intersections C for detecting a larger area.

[0220] Each intersection can be provided with flexible white scattering material on one or both sides and a rigid material as previously described. This simplified configuration can be used in situations where only vibration and / or motion must be detected over a large area and location is not critical.

[0221] 17 illustrates another possible embodiment of the present invention, in this case another fiber optic pressure sensor 530, a POF pressure sensor 530 having a series of multiple intersections C. Again, there is a receiving fiber 510 and a transmitting fiber 520.

[0222] 17 again shows a sensor configuration with only one transmit fiber and only one receive fiber and multiple intersections for detecting vibration and / or motion in only one direction. Each intersection C can be provided with flexible white scattering material on one or both sides and a rigid material as described above.

[0223] Potential Applications The fiber optic pressure sensor array or grid of the present invention is suitable for use in the following applications:

[0224] patient monitoring Additionally, the fiber optic pressure sensor array or grid of the present invention may be used to monitor posture, bodily functions or disease symptoms of a patient (either adult or child) reclining in bed.

[0225] This allows, for example, sudden infant death syndrome (SIDS) to be detected. The infant's breathing, e.g. heart rate, as well as normal movements may be detected by the mattress. If a non-physiological condition is detected, this can trigger an alert to the parent, thus allowing for advance warning and fast reaction times.

[0226] In the case of monitoring adults, such a mattress can be used to monitor whether the elderly person uses the bed during nighttime sleep time, and if not, can trigger a warning message to the nurses or people who care for such people. In particular, a fall event of such people is dangerous because if the fall event is discovered late, serious injury, and also dehydration, and other serious conditions may exist or develop until the person is discovered. This increases safety for such people, especially when the elderly person only receives part-time assistance, does not have full-time care personnel around, and still lives alone. Also, the mattress can be placed on the floor of the bathroom or other room to detect a fall event.

[0227] A fiber optic pressure sensor array or grid can be incorporated into the mattress.

[0228] Alternatively, a fiber optic pressure sensor array or grid can be placed under the mattress.

[0229] Specifically, the fiber optic pressure sensor array or grid serves the following purposes: Providing out-of-bed alarms; Fall detection and / or prevention; Sleep tracking, Health monitoring, Detecting and / or preventing sleep disorders; Early detection of epileptic seizures, Preventing Sudden Infant Death can be used for

[0230] For premature infants, the fiber optic pressure sensor array or grid of the present invention may be incorporated into a mattress suitable for placement within an incubator.

[0231] Alternatively, a fiber optic pressure sensor array or grid can be placed under a mattress suitable for placement within an incubator.

[0232] Specifically, the fiber optic pressure sensor array or grid serves the following purposes as an incubator: pressure point location, Measuring or monitoring weight; Body movement detection (2D) can be used for

[0233] Furthermore, the fiber optic pressure sensor array or grid of the present invention may be used in physical therapy.

[0234] As an example, fiber optic pressure sensor arrays or grids can be incorporated into specially designed mattresses or physical therapy seating and / or motion monitoring systems.

[0235] In particular, a fiber optic pressure sensor array or grid can be adapted to detect and monitor weight distribution across the sole of the foot or the patient's body posture during physical therapy.

[0236] Security Monitoring The optical fiber pressure sensor array or grid of the present invention can be used for security purposes against unauthorized body or object intrusion and / or unwanted departure of bodies or objects within predefined areas in domestic environments, offices, industrial buildings, government buildings, etc.

[0237] In particular, a fiber optic pressure sensor array or grid can be configured to detect the presence of one or more intruders or deviants, or a change in the physical location of an object, and therefore activate an alarm accordingly.

[0238] Specifically, the fiber optic pressure sensor array or grid includes: Distinguishing human subjects from other objects that may be present within a predefined area; Recognize initiatives to leave or enter the monitored area; Recognize the direction of the object's movement, Recognize changes in the target's posture, Recognize changes in the weight of objects, Recognize the physical state of one or more objects within a monitored area It can be configured as follows.

[0239] safety monitoring The fiber optic pressure sensor array or grid of the present invention can be used to monitor large objects.

[0240] Traffic light efficiency / crossing safety / traffic safety The fiber optic pressure sensor array or grid of the present invention may be used to detect the presence of targets and / or objects approaching a pedestrian crossing or the like.

[0241] Specifically, the fiber optic pressure sensor array or grid includes: Detect the presence of an approaching human, animal or object; Detect one or more directions of the approaching human, animal or object. It can be configured as follows.

[0242] Traffic congestion detection and control The optical fiber pressure sensor array or grid of the present invention can be used to detect the number of vehicles traveling within a predefined area (e.g., a predefined portion of a road) as well as the direction of travel of each of those vehicles, and can be used to predict if or when traffic conditions may become a traffic jam, and therefore can provide input to control traffic and prevent or significantly reduce the occurrence of traffic jams.

[0243] Sports and Training The fiber optic pressure sensor array or grid of the present invention can be used in sports / training applications.

[0244] Specifically, the fiber optic pressure sensor array can be used in the following applications: Virtual Line Monitoring: Fiber optic pressure sensor arrays precisely detect if and when the ball and / or player cross a pre-set (virtual) line. Posture Improvement: A fiber optic pressure sensor array detects the pressure profile and posture of a subject (e.g., an athlete) for the purpose of training and posture improvement. Game Statistics / Data: The fiber optic pressure sensor array serves as an additional data source for the purpose of obtaining more accurate game statistics.

[0245] Gaming The optical fiber pressure sensor array or grid of the present invention can be used to provide feedback regarding the posture, movement or pressure profile of one or more objects interacting in a (virtual reality) game or program, in particular to ensure that said object or objects do not leave a predefined active area.

[0246] This makes it possible to prevent possible damage to the surroundings of the space in which the (virtual reality) gamer is playing, or the occurrence of dangerous situations or even injuries for the gamers involved.

[0247] As an example, in a virtual reality game, one or more subjects may use VR glasses that increase the risk of accidental collisions with other subjects (e.g., other players) or objects (e.g., walls or other obstacles) in the vicinity by causing the subject to accidentally leave a predefined area that the subject is expected to occupy during play.

[0248] Car / Truck Safety The fiber optic pressure sensor array or grid of the present invention can be used to provide continuous monitoring of changes in the vital functions and / or pressure profile of a subject driving a car or truck to detect if the subject is falling asleep so that an alarm signal can be activated accordingly. [Explanation of symbols]

[0249] 10, 110, 210, 310, 410, 510 Receiving optical fiber 20, 120, 220, 320, 420, 520 Transmission optical fiber 30, 230, 330, 430, 530 Pressure Sensors 40, 140, 240, 340 mechanical structure 41, 141, 241 First layer of mechanical structure 42, 142, 242 Second layer of mechanical structure 50, 150, 250 rigid light scattering layer 160 Multiple Segments 270 additional layers 341 First (inner) layer of mechanical structure (white scattering tape) 342 Second (middle) layer of the machine structure (black shielding material) 343 Third (outer) black shielding material (flexible material) 351 1st layer (white scattering tape) 352 Second layer (black shielding material) C intersection

Claims

1. A plurality of receiving optical fibers (10); and A plurality of transmitting optical fibers (20) 1. A fiber optic pressure sensor array or grid for sensing position, vibration and / or motion, comprising: the plurality of receiving optical fibers (10) and the plurality of transmitting optical fibers (20) are arranged in a planar array to define a pressure sensor (30) at each point; A mechanical structure (40) is provided on one or both sides of each pressure sensor (30) to enhance fiber bending when pressure is applied to said pressure sensor (30); The mechanical structure (40) comprises a first inner layer (40.1) made of a flexible light scattering material in contact with the optical fibers (10, 20), and a second outer layer (40.2) made of a rigid material; A fiber optic pressure sensor array or grid, wherein the plurality of receiving optical fibers (10) and / or the plurality of transmitting optical fibers (20) are curved at the intersections that define the pressure sensors (30).

2. The optical fiber (10, 20) is a polymer optical fiber (POF), preferably the optical fiber (10, 20) is made of poly(methyl methacrylate) (PMMA).

2. The fiber optic pressure sensor array or grid of claim 1 .

3. 3. The optical fiber pressure sensor array or grid according to claim 1 or 2, characterized in that the first layer (40.1) of the mechanical structure (40) is made of white silicone rubber and / or the second layer (40.2) of the mechanical structure (40) is made of polyvinyl chloride (PVC).

4. 4. The optical fiber pressure sensor array or grid according to claim 1, wherein the mechanical structure (40) is provided on one side of the pressure sensor (30) and a rigid light scattering layer (50) is provided on the opposite side of the pressure sensor (30) to the mechanical structure (40), preferably the rigid light scattering layer (50) being made of white polyvinyl chloride (PVC).

5. A plurality of receiving optical fibers (110); and A plurality of transmitting optical fibers (120) 1. A fiber optic pressure sensor array or grid for sensing position, vibration and / or motion, comprising: a mechanical structure (140) is provided on one or both sides of the optical fibers (110, 120) for establishing an optical coupling between the transmitting optical fiber (120) and the receiving optical fiber (110) when pressure is applied to the optical fibers (110, 120); The mechanical structure (140) includes a first inner layer (140.1) made of a flexible light-scattering material in contact with the optical fibers (110, 120), and a second outer layer (140.2) made of a rigid material; A fiber optic pressure sensor array or grid, wherein the plurality of receiving optical fibers (110) and the plurality of transmitting optical fibers (120) extend parallel in a planar array.

6. 6. The optical fiber pressure sensor array or grid according to claim 5, characterized in that the optical fibers (110, 120) are polymer optical fibers (POF), preferably the optical fibers (110, 120) are made of poly(methyl methacrylate) (PMMA).

7. 7. An array or grid of optical fiber pressure sensors according to claim 5 or 6, characterized in that adjacent optical fibers (110, 120) are in contact with each other.

8. 7. The optical fiber pressure sensor array or grid of claim 5 or 6, wherein gaps (160) are defined between adjacent optical fibers (110, 120).

9. A fiber optic pressure sensor array or grid according to any one of claims 5 to 8, characterised in that the second layer (140.2) is made of a corrugated rigid material.

10. 10. The optical fiber pressure sensor array or grid according to claim 5, characterized in that the first layer (140.1) of the mechanical structure (140) is made of white silicone rubber and / or the second layer (140.2) of the mechanical structure (140) is made of polyvinyl chloride (PVC).

11. 11. The optical fiber pressure sensor array or grid according to claim 5, wherein the mechanical structure (140) is provided on one side of the optical fibers (110, 120) and a corresponding rigid light scattering layer (150) is provided on the opposite side of the optical fibers (110, 120) to the mechanical structure (140), preferably the rigid light scattering layer (150) being made of white polyvinyl chloride (PVC).

12. 12. The optical fiber pressure sensor array or grid of claim 5, wherein the mechanical structure (140) comprises multiple segments (160), preferably constructed and arranged such that the multiple segments (160) are independently controlled.

13. A plurality of receiving optical fibers (210); and A plurality of transmitting optical fibers (220) 1. A fiber optic pressure sensor array or grid for sensing position, vibration and / or motion, comprising: the plurality of receiving optical fibers (210) and the plurality of transmitting optical fibers (220) are arranged in a planar array to define pressure sensors (230) at their respective intersections; A mechanical structure (240) is provided on one or both sides of each pressure sensor (230) to enhance fiber bending when pressure is applied to said pressure sensor (230); The mechanical structure (240) includes a first inner layer (240.1) made of a flexible light-scattering material in contact with the optical fibers (210, 220), and a second outer layer (240.2) made of a rigid material; A fiber optic pressure sensor array or grid, characterized in that an additional layer (270) made of a flexible light scattering material is interposed between said optical fibers (210, 220) at said intersections.

14. 14. The optical fiber pressure sensor array or grid according to claim 13, characterized in that the optical fibers (210, 220) are polymer optical fibers (POF), preferably the optical fibers (210, 220) are made of poly(methyl methacrylate) (PMMA).

15. A fiber optic pressure sensor array or grid according to claim 13 or 14, characterized in that the additional layer (270) is made of flexible white silicone rubber or flexible white latex.

16. 16. The optical fiber pressure sensor array or grid according to claim 13, characterized in that the first layer (240.1) of the mechanical structure (240) is made of white silicone rubber and / or the second layer (240.2) of the mechanical structure (240) is made of polyvinyl chloride (PVC).

17. 17. The optical fiber pressure sensor array or grid of claim 13, wherein the mechanical structure (240) is provided on one side of the pressure sensor (230) and a rigid light scattering layer (250) is provided on the opposite side of the pressure sensor (230) to the mechanical structure (240), preferably the rigid light scattering layer (250) being made of white polyvinyl chloride (PVC).

18. A plurality of receiving optical fibers (310); and A plurality of transmitting optical fibers (320) 1. A fiber optic pressure sensor array or grid for sensing position, vibration and / or motion, comprising: the plurality of receiving optical fibers (310) and the plurality of transmitting optical fibers (320) are arranged in a planar array to define pressure sensors (330) at their respective intersections; A mechanical structure (340) is provided on one or both sides of each pressure sensor (330) to enhance fiber bending when pressure is applied to said pressure sensor (330); The optical fiber pressure sensor array or grid, wherein the mechanical structure (340) includes a first inner layer (340.1) made of white scattering tape in contact with the optical fibers (310, 320), a second middle layer (340.2) made of black shielding material, and a third outer layer (340.3) made of a flexible material.

19. 19. The optical fiber pressure sensor array according to claim 18, characterized in that said optical fibers (310, 320) are polymer optical fibers (POF), preferably said optical fibers (310, 320) are made of poly(methyl methacrylate) (PMMA).

20. 20. The optical fiber pressure sensor array or grid of claim 18 or 19, characterized in that the mechanical structure (340) is provided on one side of the pressure sensor (330) and a first inner layer (350.1) made of white scattering tape and a second outer layer (350.2) made of black shielding material are provided on the opposite side of the pressure sensor (330) to the mechanical structure (340).

21. 21. A mattress comprising a fibre optic pressure sensor array or grid for sensing position, vibration and / or movement according to any one of claims 1 to 20.

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