BE1021520B1 - ELASTIC PLASTER SENSOR, USE OF SUCH PLASTER SENSOR, AND A SENSOR SYSTEM WITH SUCH PLASTER SENSOR - Google Patents

Abstract

A stretchable patch sensor (1), comprising: an elastic film layer (2) with a stretchability of at least 100% and at least one elastic DEAP strip (3) with a stretchability of at least 50%. The patch sensor may comprise an integrated circuit (4), a memory (5), an energy source (6), an adhesion layer (7) for adhering the film layer (1) to a skin, and a protective layer (15). A sensor system (25) with such a patch sensor (1) is also discussed.

Description

ELASTIC PLASTER SENSOR, USE OF SUCH PLASTER SENSOR, AND A SENSOR SYSTEM WITH SUCH PLASTER SENSOR

Domain of the invention

The invention generally relates to a stretchable and flexible plaster sensor for measuring and storing and / or forwarding data relating to movements (of, for example, a back or limbs of a human or animal), and to a sensor system that contains such a patch sensor and can read out and / or receive and process the data. The invention also relates to a specific use of such a plaster sensor.

BACKGROUND OF THE INVENTION

Various portable devices for measuring and storing movements such as bending knees during stepping, or movements of the lower back during bending or turning are known.

They range from the use of a measuring strip / adhesive strip and a marker pen, to the hugely popular technique known as "EMG probing" (ElektroMyoGram), where a handful of small and light self-adhesive electrodes are applied to a body. A major disadvantage of EMG probing, however, is that the measurement requires the use of an additional measurement system such as cameras, which limits the use to measurements in a controlled environment (eg in a lab room). FIG. 1 shows a measuring system with the name "The Body Guard®", commercially available from the Belgian company "Seis Instruments". The basic configuration consists of a strain gauge measuring probe and a lightweight portable housing with signal processing and communication electronics. A disadvantage of this system, however, is that the mounting can be released relatively easily, and the measurement is in fact limited to a single sensor. More information about this system is available at the following link "https://www.sels-instruments.be/bodyguardsystem.html". FIG. 2 shows a measuring system called "Vi Move®" from the Australian company "dorsaVi Ltd". This system contains two integrated EMG electrodes. A drawback of this system is that it has a housing of a non-negligible thickness, and that it consists of several separate devices that must be arranged at a certain mutual distance and orientation.

Summary of the invention

It is an object of the present invention to provide a good patch sensor that can be applied to a human or animal skin, and is provided for measuring and storing and / or transmitting motion related data.

It is also an object of the present invention to provide a good sensor system for reading and / or receiving and processing the measured data.

It is also an object of the present invention to provide some specific applications of such plaster sensors.

These objects are achieved by a sensor patch, and a sensor system, and a use according to embodiments of the present invention.

The present invention relates to an elastic plaster sensor comprising an elastic and electrically insulating film layer with a stretchability of at least 100% in all directions in the plane of the film layer (X, Y), and at least one elastic elongated capacitive strip attached to the elastic film layer, wherein the strips comprise a dielectric electro-active polymer, and have a stretchability of at least 50% in their longitudinal direction.

It is an advantage of Dielectric Electro-Active Polymer DEAP strips that they are elastic and have a capacity according to their length. The length (or degree of stretching) can therefore be determined by measuring the capacity.

It is an advantage of a plaster sensor according to the present invention that when applied to the skin of a human or animal, elongation of the elastic strips corresponds to elongation of the underlying skin, which in turn corresponds to movements of body parts such as e.g. movements of joints or of the spine. It is an advantage of DEAP strips that they can be measured, for example, up to a hundred times per second. As a result, it is possible to determine the speed or acceleration of the movements mentioned with high accuracy.

It is an advantage of embodiments of the plaster sensor according to the present invention that the elastically stretchable and bendable shape allows the plaster sensor to be applied (e.g., glued) to a curved surface, such as around a leg, but even around an irregular surface such as a knee.

It is an advantage of embodiments of the present invention that the patch sensor can be watertight, so that the patch sensor does not have to be removed, even in water (e.g., while showering or swimming or when cattle are in the rain).

In some embodiments, the patch sensor may also include an integrated circuit, the integrated circuit being attached to the elastic film layer and electrically connected to at least one said strip (one or more) by means of elastic electrical connections, the integrated circuit being provided for measuring a value indicative of the elongation of said strip.

It is an advantage that the integrated circuit can include a programmable processor. The program can be stored in non-volatile memory (eg embedded flash), or can be hard coded. The integrated circuit can be an ASIC (application-specific integrated circuit).

It is an advantage of a plaster sensor according to the present invention that it can have elastic electrical connections, e.g. in the form of a hose shape or a zigzag shape or concatenation of horseshoe-like shapes. It is furthermore an advantage of such compounds that they can be applied directly to the film layer, e.g. by printing techniques, and that they are very stretchable. Although it is possible to connect the strips in a different way, eg by loose wires with a length corresponding to the maximum length (in stretched state), the proposed technique of printed connections is much thinner, whereby a very thin stretchable patch sensor can be obtained to become.

Said at least one strip may comprise two electrically conductive metal film layers arranged on opposite sides of the strips, the two metal film layers having a geometric shape that allows elastic extension without breaking the metal film. It is an advantage of such geometric shape (e.g., wrinkle structure or wave structure) that such strips allow a very large elastic stretch. In a specific embodiment, the capacitive strips are made from a material called "PolyPower DEAP" commercially available from "Danfoss-PolyPower". But the present invention is not limited to this, and will also work with other structures or materials that have similar properties, even materials that do not yet exist, e.g., second or later generation products from PolyPower DEAP.

The metal films may have a wrinkle structure or a corrugated structure. The shape of the polymer and of the metal film applied to it can be, for example, a wrinkle structure (similar to the corrugated sheet structure for roofing, but then much smaller). Such a structure may, for example, have a sinusoidal cross-section that behaves as a harmonica structure during stretching or contraction without breaking.

It is an advantage of a plaster sensor according to the present invention that it does not consist solely of a DEAP polymer with a double wrinkle structure, but contains strips of such material, since it allows to measure both the elongation but also the stretchable plaster sensor in two directions, while the corrugated structure is not equally stretchable in all directions, or is practically not stretchable in one particular direction.

The at least one strip, for example the plurality of strips, may comprise a first number of at least two strips which are mutually aligned in a first direction and which are spaced apart in the range of 3 mm to 100 mm. The at least two parallel strips may, for example, be spaced apart by a relatively small distance of about 3 mm, or about 5 mm, or about 8 mm, or about 10 mm. By providing a large amount of strips on a relatively small surface, the elongation can be measured with greater accuracy.

But it is also possible to lay the strips at a relatively large distance from each other, such as for example 20 mm or 40 mm or 60 mm or 80 mm or 100 mm, or even more. It is an advantage of such a configuration that the elongation over a relatively large area of the skin can be determined.

The at least one strip, for example the plurality of strips, may comprise a second number of at least two strips which are mutually directed parallel to each other in a second direction, which intersects the first direction.

In one embodiment, the first and second directions are perpendicular to each other. In a specific embodiment, the first number of strips and the second number of strips contain the same number of strips +/- 2, and the strips are arranged in a herringbone structure. The strips can thereby form a letter 'V'.

It is an advantage of certain embodiments of the present invention when two DEAP strips are electrically connected to each other, so that only 3 electrical connections are sufficient to measure two DEAP strips. In this way, 1/4 of the electrical connections as well as the number of pins of the integrated circuit can be saved.

The width (Ws) of the at least one strip can be smaller than 5 mm.

It is an advantage of embodiments of the plaster sensor where the width of the DEAP strips is less than 5 mm. Since the strips are stretchable in the longitudinal direction, but not necessarily in the width direction, limiting the width of the strips offers the advantage that (for an equal number of strips on a given plaster surface), a larger portion of that plaster surface is not covered by the strips (in the width direction), in other words that the plaster remains stretchable over a larger percentage of its surface, also in the transverse direction. This also offers the advantage that several strips can be applied to the same patch, whereby a greater number of measured values can be obtained, whereby the movement of the underlying biostructure (e.g. joint) can be mapped more accurately.

The patch sensor may further comprise an adhesion layer for adhesion of the film layer to a human or animal skin. It is an advantage of embodiments of the present invention that the adhesive layer is already present in the patch so that no separate adhesive is to be applied.

The patch sensor may further comprise a memory for storing the measured values. In the memory, for example, the measured capacity values can be stored (representative of the length of strips), and / or values related thereto, such as the first derivative of these measured values (representative of the rate of elongation or contraction), or the second derivative (representative of the acceleration), or the third derivative (representative of shocks, jerks, nerves, etc.).

The memory can be an internal memory of the integrated circuit. It is an advantage of embodiments of the plaster sensor where the memory is an internal memory, because it can thereby increase integration, thus requiring less surface area, fewer interconnections, lower cost, reduced chance of components loosening, etc. memory could also be an external memory, eg a memory with a serial interface (eg a single-wire connection, or an I2C bus, etc.). The memory can be a volatile memory (e.g., RAM) or a non-volatile memory (e.g., FLASH). Since there is an energy source, a volatile memory is in principle sufficient. The memory may have a data storage capacity that is large enough to store data from a measurement over at least 8 hours. A smaller or larger storage capacity may be required depending on the application. During the measurement, typically 10 to 100 samples are taken per second, and stored in memory, but fewer than 10 samples per second is also possible. The higher the sampling rate, the more accurate the movement, speed, acceleration, etc. can be determined.

The patch sensor may have an energy source connected to the integrated circuit for providing electrical power to the integrated circuit. The energy capacity of the energy source and the storage capacity of the memory can be selected according to the application. They largely determine the autonomy of the plaster sensor. For example, if the sensor patch is used consistently in the vicinity of a receiver, then a patch with a small memory (e.g., 8 kilobytes of RAM, or even less) will suffice. However, if the plaster sensor is used alone for a longer period (e.g., several hours) (e.g., if it is applied to the leg of a cow going to graze for several hours in the pasture), then greater energy storage capacity and greater memory capacity used.

The energy source may be rechargeable, and the patch sensor may further include a charging circuit for wirelessly charging the rechargeable energy source. It is an advantage of embodiments of the patch sensor according to the present invention that use a rechargeable or rechargeable energy source, because such patch sensors may have a longer autonomy, may be thinner, may be elastic over a larger portion of their surface, and may have less mass .

The recharge circuit may be provided to collect electromagnetic energy and store it in the energy source. The recharge circuit may, for example, be provided with a sub-circuit for RF coupling with an external energy source, or with a sub-circuit for capacitive coupling with an external energy source.

It is an advantage of embodiments of the present invention that the charging can be contactless, because it allows waterproof sealing of the plaster sensor.

The energy source may comprise a plurality of electrical energy cells interconnected by means of an elastic electrical connection. The energy cells or energy storage elements may, for example, be small capacities formed by two metal electrodes (e.g. of Al and / or Cu) and a dielectric therebetween. These capacities can be applied, for example, between two stretchable and flexible silicone layers. It is an advantage of using an elastic energy storage structure with respect to, for example, button cell batteries, that a larger surface of the patch sensor is elastic, and that usually the patch sensor can be less thick, and that capacities are (re) chargeable, while the connection of a Alkaline button cell battery, for example, must be done during the production of the plaster sensor. In the latter case, however, it is possible to limit energy consumption through suitable software, for example, by only starting to measure after activation via an appropriate RF command.

The plaster sensor may comprise an elastic stretchable and flexible protective layer for protecting the at least one strip and optionally also the integrated circuit when present. The protective layer can be applied to the film layer in such a way that the film layer is shielded towards the environment. It is an advantage of the present invention if the protective layer consists of an elastic and an electrically insulating material, such as, for example, silicone rubber, because this not only allows elastic extension of the plaster sensor, but also protects the components, but also allows wireless transmission through the protective layer, both of energy (in the case of a rechargeable energy source) and of data.

The protective layer can be a waterproof protective layer. It is an advantage to provide the patch with a waterproof protective layer, or rather that the entire patch sensor is waterproof (between the elastic film layer and the protective layer), because it allows the patch to remain attached to a person's skin for several days , even while sweating or washing or swimming. The patch can even take measurements while swimming. Such a waterproof plaster sensor is also advantageous to be applied to the skin of an animal, so that the plaster sensor is not damaged even if the animal gets wet, or lies down in a moist place.

Keeping the patch in the same place has the advantage over the repeated removal and reapplication of the patch that the location of the patch remains exactly the same, thereby ensuring consistency of data (e.g., before and after washing).

The patch sensor can have a mass (m) of less than 100 grams, preferably less than 50 grams. It is an advantage of such a patch that it is hardly or not at all palpable, and that it allows movement unnoticed and unhindered, without the person or animal on which the patch is applied behaving differently due to the presence of the patch sensor.

The force required to stretch the patch sensor by 50% in any direction in the plane of the patch sensor (X, Y) may be less than 2.0 Newton. It is an advantage of such a patch that it allows movement unnoticed and unhindered, without the person or animal on which the patch is applied starting to restrict movements or to exert more force than normal due to the presence of the patch sensor.

The plaster sensor can have a thickness (d) that is less than 10 mm over its entire surface, for example less than 1 mm. Preferably, the thickness is everywhere less than 5 mm, more preferably less than 3 mm, most preferably less than 2 mm. It is an advantage of a stretchable plaster with such a small thickness that it does not, or hardly, interfere with, and / or hardly or hardly felt. The reader will immediately agree that a stretchable and flexible plaster of, for example, 5 mm thickness on the back hinders much less than a plaster with an undeformable plastic read-out module of, for example, 1 cm thickness. In the first case, for example, the user can lean against a backrest unhindered, in the second case this is not possible. This also considerably reduces the chance of shifting and / or losing the patch.

The patch sensor may further comprise a wireless transmitting circuit operatively connected to the integrated circuit for transmitting data wirelessly, and wherein the integrated circuit is provided for transmitting data from the memory wirelessly. It is an advantage of a plaster sensor with a wireless or contactless transmit circuit that the measurements can be read out even while using the plaster sensor, without disturbing the movement.

It is an advantage of an RF transmitting circuit that the RF signal can be transmitted over a relatively greater distance (e.g. in the order of 10 to 50 meters). It is an advantage of an RF transmitting circuit over a physical connector that no physical contact is required between the patch sensor and the readout unit to exchange the data, thereby drastically reducing the risk of damage. It is an advantage of RF signals that they can be sent through the protective layer, making waterproof sealing of the plaster sensor possible.

The transmission circuit may be provided for transmitting an RF signal. It is an advantage to use an RF signal because it allows you to send data at a relatively large distance (eg 10 to 50 m) from the receiver. It is an advantage to use a standardized protocol such as Zigbee or Bluetooth, because this technology is mature, and is available in various integrated circuits as a single chip. on the other hand, it is also possible to use a different RF signal, for example an analog modulated signal (e.g. AM modulation, FM modulation, etc.). The frequency band used can be any permitted frequency band, but one of the ISM bands is preferred. An additional advantage of RF communication is that most digital communication protocols such as Zigbee and Bluetooth allow two-way communication, making it possible, for example, to perform software upgrades, or, for example, to pass on certain commands or settings in order to Optimize plaster sensor for a specific use. For example, the sampling frequency can be set via the RF interface, or a start command or stop command can be given for starting or stopping sampling. Energy can be saved in this way.

The transmission circuit can be provided for sending a signal by capacitive coupling. Capacitive coupling is another possibility to send data wirelessly, although this is considerably less practical than RF communication. Nevertheless, it is possible to send the data via a capacitive coupling, for example by keeping a read unit close to the patch, for example less than 1 cm. Capacitive coupling through the insulating protective layer is possible, and also has the advantage that the risk of damaging the internal circuit (e.g. by EMC) or the risk of oxidation of the contacts is minimized, and that waterproof protection of the plaster sensor is possible.

The patch sensor may further comprise a temperature sensor, and the integrated circuit may be provided with an algorithm for storing the measured temperature in the memory, and / or for compensating the measured values taking into account the measured temperature. It is an advantage of a plaster sensor with a temperature sensor and a temperature compensation algorithm, because it allows to improve the accuracy of the measured values.

The present invention also relates to the use of the patch sensor as described above, wherein the patch sensor is applied to the skin of an animal for measuring prenatal contractions. It is an advantage of embodiments of the present invention that the plaster sensor is extremely suitable for measuring prenatal contractions of, for example, a cow or a horse or other cattle. In this case, the use of RF signals is a huge advantage because it allows precise monitoring of the animal remotely, which causes less stress to the animal. By following up the animal in time before delivery, optimal treatment can be provided, and it is better to intervene if something goes wrong. The sensor can be connected to a monitoring system so that timely identification of an impending birth can take place.

The present invention also relates to the use of the plaster sensor as described above, wherein the plaster sensor is applied to the skin of an animal, in particular at the height of one of the joints of one of the legs of the animal, for measuring step movements of an animal. It is an advantage of embodiments of the present invention that the plaster sensor is extremely suitable for measuring step movements (the gait) of an animal, in particular a cow or a horse or other cattle. Here, too, the use of RF signals is a huge advantage, because it allows precise tracking of the animal remotely, without impeding the animal in its movement. To increase the distance at which you can read out, you can, for example, place so-called "repeaters" on the perimeter of a meadow. By following the step movements, especially over a longer period (eg several weeks or even months), one can in particular detect "paralyzes" or lameness, but also other diseases and / or problems, and intervene in time to prevent worse .

The use can be for the detection of paralysis in cattle. The sensor system according to the present invention is extremely suitable for observing (and analyzing the evolution) of step movements of cattle for the early detection of paralysis or lameness. Cattle, for example, means cows or horses.

The present invention also relates to the use of the patch sensor as described above, wherein the patch sensor is applied to the skin of a human, in particular on the back at the level of the spine, for measuring back movements. It is an advantage of embodiments of the present invention that the plaster sensor is extremely suitable for measuring movements of a backbone (spine) of a human or animal such as, for example, a cow or a horse. The stretchable plaster sensor is herein preferably applied over at least a portion of the skin above the spine. Depending on the situation, you can mainly monitor the lower back, or the upper back (eg between the shoulder plates), or both. Typical dimensions for such an elastic plaster sensor are: 50 cm x 10 cm, or 75 cm x 10 cm, or 100 cm x 10 cm, but other dimensions can also be used. The use of two sets of parallel strips (e.g. in the form of a herringbone) is particularly advantageous here, because it allows very accurate mapping of all possible movements of the back. The orientation of the strips in this case is preferably chosen such that the herringbone (V-shape) is directed towards the tailbone, and the two "legs" of the V are substantially symmetrical on both sides relative to the backbone. Alternatively, however, a sensor can be used with one or more sensor strips in one direction, to measure or monitor simple movements. The plaster sensor can be applied to said skin in a pre-stretched form. This offers the advantage that the strips can measure both positive and negative values (i.e., skin extension as well as shrinkage). Since the force required to stretch the patch sensor is minimal (see above), it can easily be applied in a slightly stretched state, and the chance of the patch sensor coming off is minimal. In order to apply the patch with a suitable pre-stress, an appropriate imprint (e.g. an ellipse shape) may be applied to the patch sensor, which must be pressed onto the skin if the patch sensor exhibits a circular shape when stretched.

The present invention also relates to a sensor system comprising the patch sensor as described above, a processing system with a receiver provided for receiving the data sent by the patch sensor and with a calculating unit for processing the received data, and with a reading unit for displaying the processed data. The processing system can be, for example, a laptop or PDA or tablet or smartphone or the like with a wireless interface, eg with Bluetooth functionality, and provided with the necessary software for reading the data from the stretchable plaster sensor. This laptop or PDA or table or smartphone or the like differs from known laptops in that it contains a specific software program for the further processing and interpretation of the data, for example by deriving derived variables such as speed and acceleration or force and shocks from the measurement data. The processing system can also be provided for combining and analyzing the data from several plaster sensors on the basis of a mathematical model and / or a biomechanical database, so that, for example, the combined vertical and horizontal movement of a hoof of a cow's front leg can be can be determined, and charted. The result of this analysis can then be shown on the display or monitor or screen.

Specific and preferred aspects of the invention are included in the appended independent and dependent claims. Features of the dependent claims can be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly stated in the claims.

To summarize the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described above. It is, of course, understood that not all of these objectives or advantages can be achieved by any specific embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or implemented in a manner that provides one benefit or a group of benefits as herein disclosed, without necessarily achieving other objectives or benefits that may be offered or suggested herein.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment (s) described below.

Brief description of the figures

The invention will now be further described, by way of example, with reference to the accompanying drawings in which: FIG. 1 shows a measuring system known in the art. FIG. 2 shows another measuring system known in the art. FIG. 3 shows an embodiment of a plaster sensor according to the present invention, wherein a portion of the elastic protective layer (shown in black) is removed for illustrative purposes. FIG. 4 shows another embodiment of a plaster sensor according to the present invention. FIG. 5 shows an example of a man with a third embodiment of a plaster sensor according to the present invention mounted on his backbone. FIG. 6 shows stretchable electrical connections applied to an elastic substrate, as known in the art. FIG. 7 shows an example of a pliable substrate with electronic components, as known in the art. FIG. 8 shows an example of a flexible and stretchable battery known in the art. FIG. 9 shows the basic elements of a classical electrical capacity, as known in the art. FIG. 10 (left) shows an example of an elastic structure with a dielectric electro-active polymer (DEAP) located between two electrodes with a wave structure, known in the art. FIG. 10 (right) shows a function of the electrical capacity of this structure as a function of the length (when stretched). FIG. 11 shows an example of measurement data (displacement) and derived measurement data (speed) available with embodiments of the patch sensor according to the present invention. FIG. 12 shows an example of a graph showing the angular velocity for the front legs of an animal based on an average of angular velocity measurements as well as the effective angular velocity for that movement. FIG. 13 shows an exemplary graph of a normal percent cycle of measurements of a knee flexion angle measured during one step. FIG. 14 shows multiple measurements such as those of FIG. 13, measured at different steps. FIG. 15 shows a cow, wherein several interesting places on the skin are indicated to which a sensor plaster according to the present invention can be applied for, for example, doing a step analysis. FIG. 16 is a schematic representation of the front legs (left) and rear legs (right) of the cow of FIG. 15, showing the joints of each leg. FIG. 17 shows some joints of the front leg or hind leg of the cow during walking, for which measurements can be taken. FIG. 18 is a representation of the degradation that occurs in the step pattern and that is indicative of a particular disease. FIG. 19 shows a relationship between "paralysis" (also called "lameness") and various other aspects that are important in animal husbandry. FIG. 20 shows a block diagram of a sensor system according to embodiments of the present invention for measuring motion data, and processing and displaying it.

The figures are only schematic and non-limiting. In the figures, the dimensions of some parts may be exaggerated and not represented to scale for illustrative purposes. The dimensions and the relative dimensions sometimes do not correspond to the current practical embodiment of the invention.

Reference numbers in the claims may not be interpreted to limit the scope of protection.

In the various figures, the same reference numbers refer to the same or similar elements.

Detailed description of embodiments of the invention

The present invention will be described with reference to particular embodiments and with reference to certain drawings, however, the invention is not limited thereto but is only limited by the claims.

It is to be noted that the term "comprises", as used in the claims, is not to be interpreted as being limited to the means described thereafter; this term does not exclude other elements or steps. It can therefore be interpreted as specifying the presence of the listed features, values, steps or components referred to, but does not exclude the presence or addition of one or more other features, values, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices that consist only of components A and B. It means that with regard to the present invention, A and B are the only relevant components of the device.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a specific feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, occurrence of the expressions "in one embodiment" or "in an embodiment" at various places throughout this specification may not necessarily all refer to the same embodiment, but may do so. Furthermore, the specific features, structures, or characteristics may be combined in any suitable manner, as would be apparent to those skilled in the art based on this disclosure, in one or more embodiments.

Similarly, it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof for the purpose of streamlining disclosure and assisting in understanding one or several of the various inventive aspects. This method of disclosure should not be interpreted in any way as a reflection of an intention that the invention requires more features than explicitly mentioned in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all the features of a single prior disclosed embodiment. Thus, the claims following the detailed description are hereby explicitly included in this detailed description, with each independent claim as a separate embodiment of the present invention.

Furthermore, while some embodiments described herein include some, but not other, features included in other embodiments, combinations of features of different embodiments are intended to be within the scope of the invention, and constitute different embodiments, as would be understood by those skilled in the art . For example, in the following claims, any of the described embodiments can be used in any combination.

Numerous specific details are set forth in the description provided here. It is, however, understood that embodiments of the invention can be practiced without these specific details. In other cases, well-known methods, structures and techniques have not been shown in detail to keep this description clear.

In this document, the words "lame" and "lameness" are used as synonyms.

Where in the present invention reference is made to "elongation" or "elongation" or "displacement" or "movement", reference is made to a movement of a human or animal, e.g. a movement of a joint or spinal column), and / or the corresponding stretch of the skin, and / or the corresponding stretch of the patch sensor applied to the skin. This "stretch" of the plaster sensor can therefore represent various "underlying" movements, eg the raising or stretching of a knee or elbow or other joint, the bending or bending or stretching of the back, depending on the location and orientation of where the patch sensor is applied. FIG. 1 shows a measuring system with the name "The Body Guard®", commercially available from the Belgian company "Seis Instruments". With this system it is possible to measure a stretch of one strain gauge that is stuck to the skin. A disadvantage of this system is that it is not provided for measuring expansion or elongation or displacement with a high density (or resolution), since only one strain gauge is provided. Furthermore, this system is not particularly useful for measuring stretch in multiple directions. FIG. 2 shows a measurement system with the name "Vi Move®" commercially available from the Australian company "dorsaVi Ltd". As far as known to the inventors of the present invention, tilting of the individual components relative to the horizontal and relative to each other is measured with this system, and the underlying elongation or displacement or curvature is not measured directly, but derived / calculated from the tilt data. The accuracy of the measurements strongly depends on accurate placement. Moreover, the speed at which measurements can be performed is limited. Apart from the precise application of the individual components, the main disadvantage of this system is that the casing on the patch is quite thick (in the order of 10 mm), and is inflexible, allowing the system to act as a barrier during certain activities (such as sitting against the back of a chair). FIG. 3 shows an example of a stretchable and flexible plaster sensor 1 according to the present invention.

The plaster sensor 1 comprises an elastic and electrically insulating film layer 2 with a stretchability of at least 100% in all directions in the plane of the film layer X, Y, preferably at least 200% or even at least 300%. A suitable material for this film layer 2 can be, for example, Tegaderm of 3M or EU50 of Smith & Nephew, although the film layer is not limited to these materials. The thickness of the film layer depends on the application. A thinner film layer will be used for a back sensor, while a thick patch based on sticky gel will be used for an animal application.

At least one, for example one or a plurality of, elongated elastic strip 3 is attached to this elastic film layer 2. The attachment of this at least one strip 3 to the film layer 2 can be done in various ways, e.g. by sewing, gluing, clamping, etc. The strips 3 can be attached to the underlying film layer 2 over their entire length, for example. or only at the ends, or at multiple places including the ends. The specific adhesive used is typically specifically selected in function of the application. For human skin contact, specific adhesives can be used that are already available and that differ from, for example, the glue used for animal applications, since the animal house is less slippery.

According to an important aspect of the present invention, the strips 3 are electric capacities, the capacity being a measure of the length of the stretched strip. To that end, the strips 3 comprise an electrically conductive top layer and an electrically conductive bottom layer, with a layer of a dielectric electro-active polymer therebetween, further abbreviated as "DEAP". Furthermore, it is important that the strips 3 have an elastic stretchability of at least 50% in their longitudinal direction. In FIG. 10 one possible specific embodiment will be discussed, but the invention is not limited thereto, and other strips with similar properties can also be used.

On the elastic and electrically insulating film layer 2 of the plaster sensor 1 of FIG. 3, an integrated circuit 4 can further be attached, which is electrically connected to the plurality of said strips 3 by means of stretchable electrical connections 11 (see FIG. 6 for an example of such connections). The integrated circuit 4 is typically provided with the necessary interfaces to be able to measure the capacity of the strips 3, one or more Analog-to-digital converters (ADCs) to digitize the measured value, and a programmable processor which is provided with an algorithm to either store the measured capacitance value as such in a memory, or to first convert it to a length measure (e.g., using a graph as shown in FIG. 10 on the right) and then save the length measure to the memory.

Embodiments of the plaster sensor 1 according to the present invention can have different memories, both with regard to the type (RAM, FLASFI) and with regard to the storage capacity.

The integrated circuit can optionally be provided with an algorithm (in hardware or in software or a combination of both) for applying data compression to save memory. The compression may be lossless (e.g., entropy coding, adaptive coding such as DPCM or ADPCM, etc.) or may be loss-making (e.g., quantization). The compression can also be done over time, for example by linear approximation of a number of samples, or by run-length compression, or by subsampling, but other suitable compression techniques can also be used.

Optionally, the integrated circuit 4 may further comprise a temperature sensor, and the processor may further be provided for storing the measured temperature value in the memory and / or for converting the measured capacity values into lengths, taking into account the measured temperature (temperature compensation). ). The memory is preferably integrated in the integrated circuit, but a separate temperature sensor is also possible, for example a diode. The integrated circuit is preferably provided with a program that regularly measures the temperature (e.g. with a frequency in the range of 2x per second to 1x per minute, preferably in the range of 1x per second to 1x per 10 seconds, preferably approximately every second). The measured temperature can also be stored in the memory and, if desired, sent along with the measurement data, so that the receiver can perform temperature correction. Alternatively, the temperature is not stored in the memory and not sent with the data, but the temperature correction is carried out in the plaster sensor itself.

Optionally, the integrated circuit 4 may further be provided with or be connected to a clock, e.g. a real-time clock that can keep a date and time. If present, the date and time can also be stored in the memory, eg as time-stamps for each measurement, or per block of a predetermined number of measured values (eg one time-stamp per group of measured values corresponding to one second) .

In some embodiments, the integrated circuit 4 itself is not stretchable or pliable and is placed, for example, at an edge or corner of the elastic film layer 2, as shown in the plaster sensor 1 of FIG. 3 and the plaster sensor 1 of FIG. 4. However, the presence of one or more non-stretchable or non-bendable components need not be an obstacle to bending or stretching the rest of the film surface 2 where the elastic and capacitive DEAP strips 3. Alternatively, where available, use could be made of a flexible and / or flexible integrated circuit.

The patch sensor 1 according to the present invention may further comprise an energy source for providing electrical power (e.g. an electrical voltage) to the electronic components (inter alia the integrated circuit). The energy source may, for example, be of a non-elastic type, such as, for example, a button cell battery of known types (e.g., alkaline or lithium or rechargeable). In that case, the battery is preferably located at the edge or corner or end of the patch sensor 1 (such as, for example, the black zones of FIG. 4. But certain embodiments of the patch sensor 1 according to the present invention may also have a "flexible and stretchable battery "as shown, for example, in FIG. 8, but the invention is not limited thereto. The energy source 6 may comprise a plurality of individual electrical energy cells 19 interconnected by means of stretchable and flexible electrical connections (not visible in Fig. 8) The energy cells 19 can be electrical capacities.

The energy source can also be another energy source, such as, for example, an ambient backscatter system that converts ambient radiation into energy or a system that uses an electrochemical process to convert perspiration into energy.

In the case that the energy source is rechargeable, the patch sensor 1 preferably also includes a charging circuit or recharging circuit (not shown) provided for wirelessly charging the rechargeable energy source. A suitable form of wireless charging is by means of capacitive coupling with an external charging circuit. Another suitable form of wireless charging is by means of RF radiation. Circuits for charging by capacitive coupling are known, inter alia, from electric toothbrushes, and therefore need not be further explained. Circuits for charging by RF radiation are known from, among other things, access card readers (so-called "badge readers"), and therefore need not be further explained.

The patch sensor 1 according to the present invention may further comprise means for wirelessly transmitting the measured data by means of wireless communication, for example according to a protocol such as Bluetooth or Zigbee, both of which operate in the ISM band, but the invention is not limited thereto, and other protocols can also be used, even a proprietary protocol.

The plaster sensor 1 according to the present invention can further comprise an adhesion layer 7 for adhesion of the plaster sensor 1, more specifically of the film layer 2 on the skin of a human or animal. This adhesion layer is preferably a self-adhesive layer of medical quality. In some cases, an adhesion layer may be used that is specifically suitable for application to animal skin, where a sufficient degree of adhesion is often difficult to obtain. The adhesion layer can be applied below the entire surface of the film layer, or can only be applied to the circumference of the plaster sensor, e.g. in the form of a double-sided adhesive strip. In the case that the plaster sensor 1 is intended to be applied to a leg of an animal, an extra strong adhesion layer can be used, for example, to reduce the chance of the plaster sensor 1 becoming completely or partially detached. Although it is advantageous that the adhesion layer is already present in advance, in some embodiments it can also be applied separately.

The plaster sensor 1 according to the present invention can further comprise an elastic, stretchable and flexible protective layer 15 for protecting the above-mentioned film layer 2, and the above-mentioned components (inter alia the DEAP strips 3 and the integrated circuit 4). In FIG. 3, the adhesion layer 7 is at the bottom (not visible), and the protective layer 15 is at the top (partially removed for illustrative reasons). In FIG. 4, the adhesion layer is at the back (not visible), and the protective layer 15 has largely been removed (except for the bottom left corner) for illustrative reasons. This protective layer 15 can be applied as a coating. In certain embodiments, the protective layer is a waterproof protective layer. The protective layer may optionally consist of several layers.

In other words, the aforementioned components (the integrated circuit 4, the elastic DEAP strips 3, the elastic electrical connections, the battery (flexible or not), the charging circuit (if any), the RF transmission module, etc.) can all be in between the elastic film layer 2 and the elastic protective layer 15, and apart from any non-flexible electronic components (such as, for example, the integrated circuit 4) located at an edge or an end or at a corner (s) of the plaster sensor 1 , the greater part (e.g. more than 80%) of the surface of the plaster sensor 1 is elastic, stretchable and pliable. Alternatively, the other components, such as electronic components, are chosen flexibly.

According to the present invention, the plaster sensor 1 can further also comprise EMG electrodes, with a read-out circuit as is known in the art. This readout circuit can be part of the aforementioned integrated circuit or can be a separate readout circuit.

The film layer 2 and the optional protective layer can determine the shape of the plaster sensor 1. This shape can be round, or rectangular or square, but other shapes are also possible. The dimensions can also vary widely, with a length in the range of, for example, 5 cm to 100 cm, and a width in the range of 5 cm to 100 cm, depending on the application. However, the dimensions are not limited by this. The sensors can be made roll-to-roll so the length is practically not limited. An example of a typical size of a sensor plaster 1 for measuring movements of a human knee is, for example, 5 cm x 10 cm, while for measuring a neck this is, for example, 1 cm x 20 cm. A typical sensor plaster 1 for measuring the movements of a joint of a leg of an adult cow or horse can be, for example, in the form of a sleeve, sleeve, sheath. A typical sensor patch 1 for measuring movements of a lower back of an adult person is, for example, 10 cm x 100 cm. It is of course also possible to provide a single (long) patch for measuring the entire spine. Such plaster sensor 1 can, for example, also have larger dimensions.

The mass of the plaster sensor is very small, and is almost proportional to the area. In a specific example, the density of the substrate is 55 g / m2 for a thickness of 50 µm, so for a patch of 10 x 100 cm, the substrate (0.1x1x55 =) weighs 5.5 g. In a specific example, the density of the sensor mat is 1100 kg / m3, so for a sensor strip of 1 x 100 cm this results in a weight of (0.01xlx40 * 10'6xll00 =) 0.44 g. This force is necessary, inter alia, to overcome the tension of the elastic film layer 2, the elastic DEAP strips 3, and the elastic protective layer 15, and possibly also (depending on the precise configuration) the tension of the elastic electrical connections and of the elastic battery (if present).

Thanks to this low force, the user does not or hardly notice the presence of the plaster sensor 1, and he is not or hardly hindered in his freedom of movement. This also minimizes the risk of the adhesion layer coming off the skin (due to the small shear forces).

Preferably, the thickness of the plaster sensor 1 is at least 80%, most preferably over its entire surface area, less than a few mm, in some cases even to less than 100 ppm. The substrate can thereby for example be thinner than 50 µm, for example only about 30 µm. The thickness of the sensors themselves can, for example, vary between 40 and 20 µm thick.

The thickness will among other things be determined depending on the application. The thickness can also be influenced by other components that are integrated, such as, for example, the use of so-called "printable electronics". As a result, the plaster sensor 1 is substantially flat with the skin on which it is applied, and consequently the user experiences no or hardly any nuisance from the presence of the plaster sensor 1. Even animals do not experience the plaster sensor 1 as "a block on their leg", are not inclined to remove the patch. The patch can also be in the form of a sleeve, sleeve or sleeve.

In the embodiment of FIG. 3, the patch sensor has only three DEAP strips 3, but the invention is not limited thereto, and fewer than three DEAP strips, e.g., only one or only two, or more than three DEAP strips, e.g., at least four, or at least six, or at least eight, or at least ten DEAP strips 3, is also possible. If the DEAP strips 3 have a narrow width Ws of, for example, a height of 5 mm, or a maximum of 4 mm, or a maximum of 3 mm, then it is possible to place a relatively large number of DEAP strips 3 on the surface of the film layer 2. to provide. These strips can for instance be arranged parallel to each other and at a relatively small mutual distance 32 from each other, for example in the order of 5 mm to 15 mm. As a result, a large concentration of measured values is possible, so that a movement of, for example, a joint can be accurately mapped. This aspect is an important advantage of the plaster sensor 1 of the present invention, because such a large concentration of measurements is not automatically possible with the measuring systems from the prior art. If, for example, one measuring line is provided per 5 mm, in both directions X, Y, a plaster sensor of 300 mm x 200 mm can be used to measure no fewer than 100 movement lines. An example of a sensor in which a two-dimensional measurement can be used effectively is a back sensor in which a herringbone pattern can be used.

Another important advantage of narrow DEAP strips 3 is that the capacity value becomes smaller, so that less energy is needed to charge or unload the capacity, and thus to measure the capacity. This means that for a given amount of energy (eg the same battery), more measurements can be made if narrower strips are used, which means that a longer measurement is possible, or the measuring frequency can be increased. FIG. 4 shows another embodiment of a plaster sensor 1 according to the present invention. A similar electronics as described above can be used (apart from perhaps a larger package with more pins from the integrated circuit 4, for connecting the larger number of elastic connections to the eight DEAP strips 3. The electronics are not the focus of this Fig. 4 shows a patch sensor 1 with two groups of four mutually parallel DEAP strips 3, the four strips 3 of the first group being parallel to each other, and the four strips 3 of the second group are mutually parallel, but the strips of the first group and the strips of the second group are substantially perpendicular to each other In the embodiment shown, the DEAP strips form a figure resembling a herringbone. not necessarily for the present invention that the number of DEAP strips 3 of the first group is the same as the number of DEAP strips 3 of the second group, nor is it necessary for the DEAP strips 3 of the first group to be perpendicular to the DEAP strips 3 of the second group. An orthogonal position of the strips allows a more precise mapping of the underlying movement, regardless of the direction in which the skin is stretched.

The DEAP strips 3 are connected to the electronics (in the black blocks) by means of stretchable and flexible connections 11, such as shown in more detail in FIG. 6. In the embodiment of FIG. 4, the first group (e.g., top) of four parallel DEAP strips 3 is controlled / read out by a first electronics block (top), and the second group (bottom) of four parallel DEAP strips 3 is controlled / read out by a second electronics block (below), but that is not necessary, and preferably all DEAP strips 3 are driven by one and the same electronics block, with only one integrated circuit 4. FIG. 5 shows a schematic drawing of a man with a plaster sensor 1 mounted on his back. The plaster sensor 1 has relatively large dimensions (e.g. 20 cm x 100 cm), but other dimensions are of course also possible. The DEAP strips are positioned in a herringbone structure as described in FIG. 4. The DEAP strips 3 shown all have an angle of substantially 45 ° with respect to the longitudinal direction of the spinal column Y, but the invention is not limited thereto, and other angles can also be used. The distance between the strips 3 shown is relatively large (e.g. approximately 15 cm), but it will be clear that it is also possible to lie the strips 3 much closer together, provided there is sufficient space for the wiring. Optionally, several separate plaster sensors 1 can be provided on the same back, with each plaster sensor covering only a portion of the spinal column, e.g., half, or one third. FIG. 6 shows in more detail an example of the flexible, stretchable, and bendable electrical connections of FIG. 4 between the DEAP strips 3 and the integrated circuit 4. Such connections are known in the art, and can be formed, for example, by printing a zigzag web on the film layer 2. In the specific embodiment of FIG. 6, the zigzag path consists essentially of a concatenation of horseshoe-shaped elements, but this is not absolutely necessary for the invention, and other forms are also possible. FIG. 7 shows an example of a pliable (but not stretchable) substrate with an integrated circuit and some peripheral components (e.g. resistors, capacitances, a clock module, and the like), as known in the art, as an example of how flexible a substrate with can be electronic components. Such electronics are sometimes also referred to as "flexible electronics" or also "printable electronics". In some embodiments, substrates with an integrated circuit can also be provided that are both pliable and stretchable. Since the dimensions of a human leg, or a leg of a cow or a horse or other cattle, are considerably larger than the dimensions of this integrated circuit, it will be apparent to those skilled in the art that even if a small portion (e.g. less than 20%) of the area of the plaster sensor 1 where the electronics are located is not stretchable, this does not have to affect the stretchability and bendability of the rest of the plaster sensor 1, especially when the electronic components are on or near a edge of the plaster sensor 1. In the example of FIG. 4, for example, the "A" zone is stretchable and bendable, and that is the zone where the DEAP strips 3 are located. The zones "B" are not stretchable, but this is not necessary if this zone is applied to a part of the skin whose elongation does not need to be determined (eg next to a joint). FIG. 8 shows an example of a "flexible and stretchable battery" known in the art, specifically from "https://engineering.illinois.edu/news/article/2013-02-28-stretchable-battery-flexible-circuits ", but other so-called" flexible batteries "can also be used. It is an advantage of embodiments in which the energy source "consists of several small cells (e.g. capacities) relative to one large cell, and connect those cells to each other by means of flexible connections, because in this way the entire plaster sensor 1 has its flexibility, stretchability and maintains flexibility and the thickness can be kept small, and it is also possible to configure the energy source (eg by using parallelism) that in the event that one elastic connection should break, energy can still be supplied from the other cells 19. Fig. 9 shows the basic elements of an electrical capacitance, as is well known in the electronics, The capacitance shown consists of two conductive plates (conductors) between which a dielectric is situated. , a certain charge Q will be distributed over the plates.The capacity of this structure is defined as the amount of charge divided by the applied voltage, and is a constant for this structure. The capacitance C can be determined, for example, by applying a known voltage V over the plates (eg 3.0 Volts), and measuring the resulting charge Q (eg by subsequently removing the voltage V, and replacing it with a resistor , and to measure the current flowing through the resistor, noting that it is not necessary to make the entire charge disappear, and that a partial discharge may suffice, for example, a known second voltage (e.g. 1.5 V) ) can be connected in series with the resistor, and can derive the capacitance value from the transient behavior of the discharge, after which the capacitance could be recharged to 3.0 V and the capacitance value determined again. one can perform multiple capacity measurements for the same amount of energy (eg by increasing the measuring frequency), or one can perform measurements over a lower period before recharging the energy source (in the case of a rechargeable energy source). A capacity is a basic component in electronics, and therefore does not need to be described in further detail. FIG. 10 shows an example of a specific structure with a dielectric electro-active polymer (DEAP) 12 disposed between two thin conductive layers 17a, 17b, which act as "electrodes". Because the conductive layers are provided with a ripple structure or a wave structure, the entire structure of FIG. 10 stretchable and bendable. Such elastic structures are known in the art and include. commercially available from "Danfoss-PolyPower", where a silicone dielectric material is balanced between two wavy metal film layers (e.g., of silver). The thickness of the elastomer can be in the order of 40 microns. The waveform and the metal film can be applied by coating. The metal film can be, for example, approximately 100 nm thick. More information can be found on the following link about one specific embodiment of such material: "https://www.polypower.com/Technology/Overview/", but the invention is not limited to this one material, and other materials or structures which exhibit similar properties can also be used, e.g. subsequent generations of this material.

Although the material itself is not new, the application of narrow strips thereof, which are attached to a flexible film layer 2, to form the plaster sensor 1 according to the present invention, as described above, is new. The big advantage is that a large density of measuring lines can be obtained as a result.

The said structure of Danfoss-Polypower shows a very stable signal-strain curve as shown in FIG. 10 (right). The material retains its properties even after stretching and shrinking more than thousands of times. The elongation can be measured on both straight and curved surfaces. The elongation can be up to 100%. When the DEAP strip 3 is mechanically stretched, the length increases, the thickness decreases, and the electrical capacity increases. By measuring the signal, for example the capacity, the elongation of the structure can therefore be determined very accurately. Measurements at a frequency up to approximately 100 Hz are possible. This allows, for example, to calculate the speed of the extension of the DEAP strip 3, which corresponds to the speed of the extension of the skin and of the underlying movement of, for example, the joint.

A preferred embodiment of the plaster sensor 1 according to the present invention uses the DEAP strips 3 of "Danfoss-Polypower" as material for the elastic elongated strips 3. FIG. 11 shows (left) a person with a plaster sensor 1 according to the present invention mounted on the back. This patch sensor 1 could be in the form of the patch sensor 1 according to FIG. 3, but in this specific example only has a single elastic elongated capacitive strip 3 as shown and described in FIG. 10. The capacity of this strip was measured at a frequency of nearly 25 Hz, the capacity was converted to a length measure, using a curve shown in FIG. 10 (right). The displacement was measured during repeated lifting of the knee. The length thus obtained is shown as a continuous (dark) curve with the reference "displacements FIG. 11, which is the extension of the skin at the level of the back where the plaster sensor 1 is arranged, and in the direction determined by the DEAP strip 3 (not visible) shows as a function of time. The lengths thus obtained (although derived from capacity values) are considered as the basic data. From this basic data also derived data can be determined, such as the speed of movement, which can be calculated as the first derivative to Typically, the capacity of the DEAP strips 3 is measured (sampled) at a frequency of 10 Hz to 100 Hz, e.g. at a frequency of substantially 25 Hz Processing of the signal, for example determining the derivative , can happen both in the sensor itself and in the computer system.

In practice, the curve of FIG. 10 (right) for the DEAP strips 3 from "Danfoss-Polypower" to be somewhat temperature dependent. However, this temperature dependence can be greatly reduced or almost completely corrected by making use of temperature compensation. To this end, the integrated circuit 4 preferably comprises a temperature sensor, and the necessary software for the processor to account for the temperature dependence (e.g. by means of a look-up table or a mathematical formula). Tests have shown that the temperature dependence can be almost completely eliminated in this way. FIG. 12 shows an example of the angular velocity of the front legs measured on the basis of displacement sensors and the effective movement (reality). The subtle variations visible in the effective movement (reality) are identifiable using patch sensors in accordance with the present invention. It is thereby an advantage that the rapid variations that occur in reality can be measured with such plaster sensors. The plaster sensor 1 can thus be used to analyze movement exerted on the back or on another joint during certain activities (e.g., lifting the knee), but the invention is not limited thereto, and can make similar measurements for the same which activity. Further analysis is also possible, as will be described further. FIG. 13 shows an exemplary graph of a normal percent cycle of measurements of a knee flexion angle (or knee bend angle) during a person's normal gait (normal walking or walking). The betting shown concerns one cycle of a person's step. FIG. 14 shows multiple graphs such as FIG. 13, measured over multiple routes, e.g. minutes or days or weeks apart. The different measurements are shown here in the same graph to limit the number of illustrations. A comparison of the graphs of FIG. 14 with that of FIG. 13, which can be used as a reference graph, allows to identify "abnormalities" regardless of their cause, eg acute problems, or slow deterioration. It will be clear that various causes can be the cause of an abnormal walk or step, of course acute pain as a result of an injury or injury, but also indirect causes such as fatigue, or the like. FIG. 15 shows a cow, and possibly indicates interesting places to which a sensor patch 1 according to the present invention could be applied for step analysis. To measure panting, which is also an interesting parameter for determining animal welfare, a sensor can be applied to the chest, for example. A patch can also be applied to the lower abdomen for measuring pre-natal contractions. This makes it possible to identify an impending calving. In some embodiments, the sensor may be connected to an analysis and notification system to inform the appropriate persons of the impending calving. FIG. 16 is a schematic representation of the front legs 21 and rear legs 22 of the cow of FIG. 15. In particular, the joints of the legs 21, 22 are shown schematically. FIG. 17 shows different positions on the front legs of an animal during the walk of a cow, for which measurements were made. Separate graphs were prepared for each specific joint of the front leg or the hind leg of the cow during normal walking (normal walking). This yielded several graphs (one per joint of each leg). To measure those graphs, various plaster sensors 1 according to the present invention were applied. It will be clear that the plaster sensors 1 do not all have to have the same dimensions and / or the same number of DEAP strips 3, but it could be. It is of course possible to apply several plaster sensors 1 to the skin of one cow at the same time, and to perform the measurements simultaneously. In this context it is noted that it is even perfectly possible to read the data from all plaster sensors almost simultaneously via, for example, Bluetooth, on the one hand because the required bit rate is very low (eg in the order of 50 Hz x 16 bits = 800 bits / second per DEAP strip). Since Bluetooth works in burst mode and with frequency hopping, this data transfer poses no problem, but other RF protocols can work as well.

A comparison between the movement of a specific joint of, for example, the left front leg and the same joint of the right front leg could, for example, provide information that the animal has sustained a certain injury to the joint in question. But the analysis can go much further than that. FIG. 18 a representation of the vertical movement versus the horizontal movement of the evolution of the step pattern of a left front hoof of the cow (only 3 step movements are mapped). Such graphs can be determined by "translating" the position of multiple joints to the position of the hoof, using a mathematical model and / or a biomechanical model of the cow's legs. By measuring and storing such characteristics, and by comparing the evolution of different "recordings" (eg a week later, or a month later) one can determine a clinical picture, since the evolution of the step pattern is specific and indicative of different syndromes. In other words, an evolution as a function of time can be determined and this evolution is typically characteristic of a healthy animal, or of specific animal disorders. In other words, the sensors according to the present invention allow an analysis of the time evolution of the step behavior. FIG. 19 shows why it is so important to observe the "walking pattern" of an animal, in particular of cattle. One of the reasons is early detection of paralysis (or lameness), but the analysis can go much further than that. Indeed, there appears to be a link between paralysis and various other aspects that are important in animal husbandry, such as, for example, an influence due to infection or due to food. So by measuring the step pattern of one or more animals, one can deduce other important facets related to animal husbandry, and one can correct in time. FIG. 20 shows an example of a sensor system 25 according to embodiments of the present invention. It shows an embodiment of a patch sensor 1 as described above, which is applied to a human or animal skin, and which performs measurements, and which stores measurement data in a local memory. In certain embodiments, the patch sensor 1 has an RF transmitting unit with which the data can be sent to a processing system 33. The data can be transmitted almost instantaneously (e.g. with a delay of less than 10 seconds), or can - if desired - only happen on request (eg only in the morning during milking), depending on the implementation. The measurement data (eg the "movements") can then be further correlated with actual biomechanical movements of the joint or back or other part of the body of the person or animal on which the measurement was made, using a mathematical model , and a biomechanical database.

In some embodiments, the output of the sensors is stored on the sensor patch and possibly preprocessed. Pre-processing may include the removal / summarization of silent episodes, encryption, the use of data packages for bursting, etc. In some cases, an energy management program can also run on a chip in the patch, which can, for example, control the forwarding. In some embodiments, the data is stored on a chip in the patch and only downloaded at the end of the observation. Sometimes the forwarding can take place in phases, sometimes the data can be forwarded directly. The data can be processed on a chip in the patch, but is preferably processed by a fast processor at a different location.

The processing system 33 may be, for example, a computer or laptop with Bluetooth functionality, and provided with the necessary software for reading the data from the stretchable plaster sensor 1. This computer or laptop differs from known computer laptops in that it has a specific software program for further processing and interpretation of the data, by analyzing the measurement data (or derived data, such as speed, acceleration, etc.) on the basis of a mathematical model, linked to a specific biomechanical database with regard to the specific joints ( or back or the like) of the subject (e.g., a human or a cow or horse). The result of this analysis can then be shown on the display or monitor or screen, and / or stored in a file, and / or printed, and / or sent via a network.

However, instead of a computer or a laptop, other, e.g., smaller, portable devices can be used to read out the patch sensor 1, e.g. smartphone or a pda or a tablet, or the like, with Bluetooth functionality and the necessary software. From the laptop or portable device, the data can then be sent on to other stakeholders, such as medical personnel.

Embodiments of the plaster sensor 1 according to the present invention can be conveniently used for measuring prenatal contractions, for example of an animal such as cattle, e.g. a cow or a horse. The patch sensor 1 is then preferably applied to the skin. "

Embodiments of the plaster sensor 1 according to the present invention can also be conveniently used for measuring step movements (the gait) of an animal or human. One or more plaster sensors 1 are thereby applied to the skin of an animal, in particular at the level of at least one of the joints of at least one of the legs 21, 22 of the animal.

Embodiments of the plaster sensor 1 according to the present invention can also be conveniently used to measure step movements (the gait) of an animal for detecting the first signs of "lame" or "lameness", a condition that can have a devastating effect on the entire European herd. Early treatment can drastically improve the cost efficiency of animal husbandry.

Embodiments of the plaster sensor 1 according to the present invention can also be conveniently used to measure the movements of the back of a human or an animal, i.e. for measuring the movements of the spine. One or more plaster sensors 1 are thereby applied to the skin, at the height of the spine, for example on the lower back, or on the neck, or in both places simultaneously.

The plaster sensor 1 is preferably applied to the skin in pre-stretched form. In order to apply the plaster sensor 1 with a suitable pre-stress (not too much, not too little), an elliptical figure (drawing, print) can optionally be provided on the stretchable protective layer 15 of the plaster sensor 1, which in the ideal pre-stretched state forms a circle forms. In this way the plaster sensor 1 can be easily applied with a suitable pre-stress. On the other hand, the bias is not critical, and the patch sensor will also work with a little more or a little less, or even no bias at all. The advantage of applying the plaster sensor 1 with bias is that it is also possible to measure negative elongation (thus shrinkage of the skin).

By way of example, the information flow obtained with a sensor patch according to embodiments of the present invention may proceed as follows. Signals are measured using the sensors. These are stored locally and forwarded at suitable times. This forwarding can for instance be local (low energy transmission) such as to a local mobile device such as a mobile phone or smartphone. For example, a user interface may already be provided on this mobile device to provide preliminary information. From the mobile device, the information can be sent over a network to a data processing unit, where the information can be further processed. The processed information can then be spread further to the direct users, to medical staff, to home help, etc. The specific interface on which the processed information can be offered, as well as the information offered, can be application specific.

Of course, different phases of the processing and presentation of information can take place at different times

While reference is made in the above description to a plaster sensor in the classical form of a plaster, the plaster sensor according to embodiments of the present invention may also relate to a sleeve, sleeve or sleeve (sleeve) integrated with a plaster sensor. In one specific example, a plaster sensor in the form of a sleeve is provided, which can be used, for example, to monitor and / or analyze the movement of a leg of an animal. In specific applications, for example, the movement of a horse's leg is monitored, for example in the context of training or analysis of the horse's walking behavior. In the exemplary plaster sensor, a polymeric stretch sensor is provided that is mounted between an upper and lower textile band. Controllers, processors for processing measurement results, electrical contacts, batteries can be incorporated in the textile belts. Alternatively, these can be mounted on it. The sensor can be attached to the textile straps in any way, such as for example via hook-loop connections, eg velcro connections. Electrical connectors can also be provided. In sensor plasters according to the present invention, moreover, an identification element can also be provided such as an RFID element, a barcode, ... that can be identified remotely, or another identification element as is known to those skilled in the art. This allows not only to identify the sensor but also to link the cycles performed to the life of the sensor.

REFERENCE FIGURES 1 plaster sensor 2 film layer 3 DEAP strip 4 integrated circuit 6 energy source 7 adhesion layer 8 human 11 stretchable electrical connections 12 DEAP material 15 protective layer 17 metal film layer 19 energy cell (eg capacity) 20 cow 21 front leg 22 rear leg 25 sensor system 26 receiver 27 computing unit 28 mathematical model 29 biomechanical database 30 display, screen 32 distance between parallel DEAP strips 33 processing system

Ls length of the strip

Ws width of the strip L length of the film layer / patch W width of the film layer / patch

Claims (29)

CONCLUSIONS An elastic plaster sensor (1), comprising: - an elastic and electrically insulating film layer (2) with a stretchability of at least 100% in all directions in the plane of the film layer (X, Y), and - at least one elastic elongate capacitive strip (3) attached to the elastic film layer (2), the strip (3) comprising a dielectric electro-active polymer, and having a stretchability of at least 50% in their longitudinal direction. The patch sensor (1) according to any of the preceding claims, wherein said at least one strip (3) comprises two electrically conductive metal film layers (17) disposed on opposite sides of the strip (3), the two metal film layers (17) have a geometric shape that allows elastic stretching without breaking the metal film. The patch sensor (1) according to claim 2, wherein the metal films have a wrinkle structure or a corrugated structure. The patch sensor (1) according to any one of the preceding claims, wherein the at least one strip comprises a first number of at least two strips which are mutually aligned in a first direction and are spaced apart in the range of 3 mm to 100 mm. The patch sensor (1) according to claim 4, wherein the at least one strip further comprises a second number of at least two strips that are mutually aligned in a second direction, which intersects the first direction. The patch sensor (1) according to any of the preceding claims, wherein the width (Ws) of the strip (3) is less than 5 mm. The patch sensor (1) according to any of the preceding claims, wherein the patch sensor further comprises an integrated circuit (4) attached to the elastic film layer (1), and electrically connected to the at least one strip (3) by means of elastic electrical connections (11), wherein the integrated circuit (4) is provided for measuring a value indicative of the elongation of said strip (3). The patch sensor (1) according to any of the preceding claims, wherein the patch sensor further comprises an adhesion layer (7) for adhesion of the film layer (1) to a skin of a human (8) or an animal (20). The patch sensor (1) according to any of the preceding claims, wherein the patch sensor further comprises a memory for storing the measured values. The patch sensor (1) according to claim 9, wherein the memory (5) is an internal memory of the integrated circuit (4). The patch sensor (1) according to any of claims 9 or 10, wherein the memory (5) has a data storage capacity that is large enough to store data from a measurement over at least 8 hours. The patch sensor (1) according to any of the preceding claims as far as dependent on claim 7, wherein the patch sensor has a power source (6) connected to the integrated circuit (4), for supplying electrical power to the integrated circuit (4) ). The patch sensor (1) according to claim 12, wherein the energy source (6) is rechargeable, and the patch sensor (1) further comprises a charging circuit for wirelessly charging the rechargeable energy source (6). The patch sensor (1) according to any of claims 12 or 13, wherein the energy source comprises a plurality of electrical energy cells (19) interconnected by means of an elastic electrical connection. The plaster sensor (1) according to any one of the preceding claims, wherein the plaster sensor has an elastic stretchable and flexible protective layer (15) for protecting the at least one strip (13) applied to the film layer (2) such that the film layer (2) ) is shielded to the environment. The plaster sensor (1) according to the preceding claim, wherein the protective layer (15) is a waterproof protective layer. The patch sensor (1) according to any of the preceding claims, wherein the patch sensor has a mass (m) of less than 100 grams, preferably less than 50 grams. The patch sensor (1) according to any one of the preceding claims, wherein the force required to stretch the patch sensor (1) by 50% in any direction in the plane of the patch sensor (X, Y) is less than 2.0 Newton. The patch sensor (1) according to any one of the preceding claims, wherein the patch sensor (1) has a thickness (d) that is less than 10 mm over its entire surface, for example less than 1 mm. The plaster sensor (1) according to any one of the preceding claims insofar as dependent on claim 7, further comprising a wireless transmission circuit functionally connected to the integrated circuit (4) for transmitting data wirelessly, and wherein the integrated circuit is provided for send data from the memory wirelessly. The patch sensor (1) according to claim 20, wherein the transmitting circuit is provided for transmitting an RF signal. The patch sensor (1) according to claim 20 or 21, wherein the transmitting circuit is provided for transmitting a signal through capacitive coupling. The plaster sensor (1) according to any one of the preceding claims, further comprising a temperature sensor, and wherein the integrated circuit (4) is provided with an algorithm for storing the measured temperature in the memory, and / or for storing the measured values. compensate taking into account the measured temperature. Use of the patch sensor (1) according to any of the preceding claims, wherein the patch sensor (1) is applied to the skin of an animal (20) for measuring prenatal contractions. Use of the plaster sensor (1) according to one of claims 1 to 23, wherein the plaster sensor (1) is applied to the skin of an animal (20), in particular at the height of one of the joints of one of the legs ( 21,22) of the animal (20), for measuring step movements of an animal. 26. - Use according to claim 25, for the detection of paralysis in cattle. 27. - Use of the plaster sensor (1) according to any of claims 1 to 23, wherein the plaster sensor (1) is applied to the skin of a human (8), in particular on the back at the level of the spine, for measuring of back movements. The use according to any of claims 24 to 27, wherein the patch sensor (1) is applied to said skin in a pre-stretched form. A sensor system (25) comprising: - the plaster sensor (1) according to any one of the preceding claims 1 to 23; - a processing system (33) with a receiver (26) provided for receiving the data sent by the plaster sensor (1), and with a calculating unit (27) for processing the received data, and with a reading unit (30) for displaying the processed data.