Patent Application
20200196979
The present invention relates to a bladder monitoring system comprising a wearable bladder monitoring device and to a method of monitoring a bladder with such a system.
In medicine, there is an on-going interest in monitoring the bladder volume of a subject, e.g. a patient. As is well-known per se, the bladder is a triangularly shaped hollow organ for storing urine, with elastic walls such that the bladder can expand upon receiving urine from the kidneys before expelling the urine through the subject's urethra.
There are a number of reasons why such bladder volume monitoring is of interest. For example, the bladder retention volume (i.e. the amount of urine retained by the bladder after the subject's urinating) is an indicator of prostate and urinary tract conditions, which conditions may be triggered by bacteria and other pathogens in the retained urine; consequent bladder stretching is a key contributor to the occurrence of delirium in elderly subjects; the bladder filling rate is an indicator for the hydration state and kidney function of the subject, and so on. In addition to such diagnostic reasons, bladder volume monitoring may be used as a tool for bladder control training, as well as used as a monitor of a hydration state of the monitored subject.
It is desirable to have a wearable bladder monitor to facilitate (semi-)continuous bladder monitoring. An example of such a wearable bladder monitor is disclosed in US 2007/0167768 A1, which discloses a non-invasive method and apparatus for monitoring the bladder volume in humans or animals. The monitoring measurements are based on the analysis of ultrasound signals from at least two individual ultrasound transducer arrays. Each one individual ultrasound transducer array has a contact face, which is arranged in order to transmit an ultrasonic signal through an abdominal surface of an individual being monitored. The method and apparatus includes the arranging of each individual transducer array on the abdominal surface around an axis which extends from a point on the abdominal surface through a point on or within the urinary bladder. The method and apparatus further comprises that each individual transducer array is arranged to scan the bladder using a two-dimensional scan plane which extends radially from the transducer array through the bladder.
In practice, this apparatus suffers from a number of drawbacks. Firstly, it is rather involved in terms of signal processing, which therefore reduces the battery life of the apparatus, even if the bulk of the signal processing is done remotely. What is more, the operation of the apparatus is based on a presumed fixed relationship between the orientation of the ultrasound transducer arrays of the apparatus and the bladder of the individual. In practice, this fixed relationship does not exist such that the bladder volume estimations provided with this apparatus may be unreliable in certain scenarios, e.g. depending on the body posture of the individual, e.g. the individual standing, lying down, sitting, crouching, and so on. Also, in order to estimate the bladder volume, a full (unimpeded) view of the bladder by the ultrasound transducer arrays may be required. Such an unimpeded view is typically not available, at least not in adult individuals, as in such individuals the bladder is at least partially obscured by the pelvic bone.
The present invention seeks to provide a non-invasive bladder monitoring system that does not need to rely on actual bladder volume estimation for bladder monitoring purposes.
The present invention further seeks to provide a non-invasive method of monitoring a bladder with such a bladder monitoring system.
According to an aspect, there is provided a bladder monitoring system comprising a wearable bladder monitoring device including securing means for securing the device to a subject's body; a phased array of ultrasound transducers; and a phased array controller adapted to control the phased array to direct a plurality of ultrasound beams into the subject's body under a range of beam angles; and a signal processor adapted to receive data pertaining to echo signals of said ultrasound beams from the phased array and to process said data in order to identify an edge of the subject's pelvic bone proximal to the subject's bladder from data pertaining to at least one of said echo signals; determine an orientation of the wearable bladder monitoring device relative to the pelvic bone based on beam angle information associated with the at least one of said echo signals; and derive bladder information from the data based on the trajectories of the ultrasound beams passing through the bladder in the determined orientation.
The present invention is based on the insight that by generating a plurality of ultrasound beams under a range of beam angles with such a phased array, the echoes of such ultrasound beams can be categorized into three distinguishable categories, namely a first category of echoes incident on the pelvic bone, a second category of echoes passing through the bladder and a third category of echoes passing through tissue adjacent to the bladder. In this manner, based on the beam angle information the orientation of the wearable bladder monitoring device relative to the pelvic bone can be retrieved from the echoes, which orientation can be used to accurately estimate the bladder volume from the subset of echoes relating to ultrasound beams passing through the bladder, which echoes may be further sub-categorized in echoes passing through the bladder wall and echoes passing through urine in the bladder.
In some embodiments of the present invention, the bladder monitoring device does not necessarily form part of the bladder monitoring system, as the data processing of such a bladder monitoring device may be performed on a separate device comprising the signal processor, e.g. a remote (electronic) device forming the bladder monitoring system. In order to maintain battery life, the processing of the echo signals acquired with the phased array may be performed on a remote device containing the signal processor, e.g. a wearable smart device such as a smart watch, a portable smart device such as a mobile phone or tablet computer, a laptop computer, a personal computer or the like, as such signal processing typically is rather computationally intensive. To this end, the wearable bladder monitoring device may be configured to perform some pre-processing of the echo signals, e.g. down conversion or the like, in order to reduce the amount of data that needs to be communicated to the remote device, thereby further extending battery life. However, in an alternative embodiment the wearable bladder monitoring device further comprises the signal processor, thereby providing a self-contained device, which may be configured to communicate minimal amounts of data, e.g. processing results, to a remote device, e.g. for visualization purposes.
In an embodiment, the wearable bladder monitoring device further comprises an orientation sensor for determining an orientation of the subject, and wherein the signal processor is adapted to determine an orientation of the wearable bladder monitoring device relative to the pelvic bone based on beam angle information associated with the at least one of said echo signals and an orientation signal from the orientation sensor. Such an orientation sensor, e.g. an accelerometer or the like, may be used to help determine the body posture of the subject, to further aid the accuracy of any bladder data processing, e.g. bladder volume estimation.
For example, the wearable bladder monitoring device may further comprise a data storage device storing a plurality of bladder models, each associated with a particular orientation of the subject, wherein the signal processor is adapted to retrieve the defined bladder model from the data storage device based on the received orientation signal. In this manner, a bladder model that is particularly accurate for a particular body posture of the subject may be deployed, e.g. in response to the information provided with the orientation sensor, to further improve the accuracy of the processing of the bladder monitoring data acquired with the phased array.
In an embodiment, the signal processor is adapted to estimate a diameter of the subject's bladder for each echo signal from the data pertaining to a subset of said echo signals. In the context of the present application, the term ‘diameter’ is used to refer to a cross-sectional length or width of the bladder between opposing bladder wall sections through which the ultrasound beam responsible for the echo signal propagates. Such a collection of diameters may be used to estimate a volume of the bladder, e.g. using an appropriate bladder model, and to derive a fill level of the bladder from the estimated volume. For example, the signal processor may be adapted to estimate a bladder volume by fitting the estimated diameters of the subject's bladder to a defined bladder model and estimating the bladder volume from the fitting result.
In a particularly advantageous embodiment, the signal processor is further adapted to, for each echo signal in said subset, calculate a first optimal frequency of its associated ultrasound beam for imaging an anterior boundary of the bladder; calculate a second optimal frequency of its associated ultrasound beam for imaging a posterior boundary of the bladder; instruct the phased array controller to generate at least one further ultrasound beam under the beam angle of the associated ultrasound beam with the phased array, said at least at least one further ultrasound beam having a frequency based on at least one of the first optimal frequency and the second optimal frequency; and estimate the diameter of the subject's bladder for said beam angle from the at least one further echo signal of the at least one further ultrasound beam. This facilitates a more accurate determination of the bladder diameter as the opposing boundaries (wall portions) of the bladder are more accurately imaged, thereby improving the accuracy of the interpretation of the bladder data acquired with a phased array, e.g. an estimated bladder volume and/or fill level. The at least one further ultrasound beam may comprise a first further ultrasound beam having the first optimal frequency and a second further ultrasound beam having the second optimal frequency; or a further ultrasound beam having a frequency that is based on the first optimal frequency and the second optimal frequency.
The phased array controller may be adapted to periodically generate said plurality of ultrasound beams in order to monitor changes to a bladder state over time. In order to optimise the battery life of the wearable bladder monitoring device, a frequency of said periodic generation is based on a previously determined bladder function by the signal processor. The signal processor may be adapted to derive a bladder function from the data pertaining to the respective echo signals of the periodically generated pluralities of ultrasound beams, e.g. to monitor a change in a fill level of the bladder over time, from which useful information such as the subject's dehydration or rehydration rates may be derived.
The securing means may include a strap, e.g. a belt, attached to the wearable bladder monitoring device and/or an adhesive layer on a subject-facing surface of the wearable bladder monitoring device. The adhesive layer is particularly preferred as this is capable of securely fastening the wearable bladder monitoring device with minimal risk of the device accidentally moving into another location relative to the subject's bladder, and has the further advantage of being minimally intrusive compared to the strap, which may be perceived as less comfortable at least by some users.
In order to facilitate communication between the wearable bladder monitoring device and a remote device as previously explained, the wearable bladder monitoring device may further comprise a wireless communication module for communicating a processing result of the signal processor to a remote device or to communicate (pre-processed) echo signals to a signal processor of such a remote device.
Preferably, the ultrasound transducers are capacitive micromachined ultrasound transducers (CMUTs) or piezoelectric micromachined ultrasound transducers (PMUTs), or piezoelectric ceramic transducers, with CMUTs being particularly preferred due to the large resonance frequency range of such transducers, which makes them particularly suitable for use in the wearable bladder monitoring device according to embodiments of the present invention.
According to another aspect, there is provided a wearable bladder monitoring device for use in the bladder monitoring system according to embodiments of the present invention. The bladder monitoring device comprises securing means for securing the device to a subject's body; a phased array of ultrasound transducers; and a phased array controller adapted to control the phased array to direct a plurality of ultrasound beams into the subject's body under a range of beam angles; wherein the bladder monitoring device is adapted to generate data pertaining to echo signals of said ultrasound beams from the phased array to facilitate the processing of said data by a signal processor in order to identify an edge of the subject's pelvic bone proximal to the subject's bladder from data pertaining to at least one of said echo signals; determine an orientation of the wearable bladder monitoring device relative to the pelvic bone based on beam angle information associated with the at least one of said echo signals; and derive bladder information from the data based on the determined orientation. Such a wearable bladder monitoring device for example may be adapted to transmit this data to a remote signal processor not being part of the wearable bladder monitoring device, e.g. by means of a wireless communication module, or may comprise such a signal processor as previously explained.
According to another aspect, there is provided a method of monitoring a bladder with the bladder monitoring system of any of the herein described embodiments, the method comprising securing the wearable bladder monitoring device to a subject's body; generating a plurality of ultrasound beams under a range of beam angles with the phased array; receiving echo signals of said ultrasound beams from the phased array; and processing data pertaining to said echo signals in order to identify an edge of the subject's pelvic bone proximal to the subject's bladder from data pertaining to at least one of said echo signals; determine an orientation of the wearable bladder monitoring device relative to the pelvic bone based on beam angle information associated with the at least one of said echo signals; and derive bladder information from the data pertaining based on the trajectories of the ultrasound beams passing through the bladder in the determined orientation.
Embodiments of the invention are described in more detail and by way of non-limiting examples with reference to the accompanying drawings, wherein:
It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.
The phased array 10 may take any suitable shape, e.g. a one-dimensional array or two-dimensional array of ultrasound transducer elements 11 of any suitable size, such as a 4×4 mm array 10 having 16 ultrasound transducer elements 11 with a pitch in a range of 200-300 microns, by way of non-limiting example. Other dimensions are of course equally feasible. In an embodiment, the ultrasound transducer elements 11 are operable in a frequency range of 2-12 MHz, although other frequency ranges may be contemplated. As will be explained in more detail below, preferably the operation frequency of the ultrasound transducer elements 11 may be altered, although in alternative embodiment the ultrasound transducer elements 11 are arranged to be operated at a fixed resonance frequency, e.g. about 3-4 MHz.
The phased array controller 13 typically is arranged to steer ultrasound beams generated with the ultrasound transducer elements 11 of the phased array 10 under a range of angles, as schematically depicted in
Now, upon returning to
The echo signals may be pre-processed by a down conversion stage 17, which may form part of the phased array controller 13 or may be a separate entity. The down conversion stage 17 may apply noise filtering and frequency down conversion of the echo signals, e.g. from the MHz domain to the KHz domain, and employ a signal envelope to the down converted echo signals to reduce the amount of data that needs to be provided to a signal processor for deriving the desired bladder information from the acquired echo signals. Other suitable data reduction techniques will be immediately apparent to the skilled person.
In
To this end, the down conversion stage 17 may be communicatively coupled to a data storage device 19, e.g. a memory or the like, on-board the wearable bladder monitoring device 1, with a wireless communication module 21 communicatively coupled to the data storage device 19 such that the data pertaining to the acquired echo signals as stored in the data storage device 19 may be periodically communicated to the remote device 5, e.g. in response to a communication request from the remote device. Any suitable wireless communication protocol, e.g. Bluetooth, Wi-Fi, a mobile communication protocol such as 3G, 4G, 5G or the like, a near field communication protocol (NFC), and so on, may be deployed for the communication between the wearable bladder monitoring device 1 and the remote device 5. As mentioned previously, the data pertaining to the acquired echo signals communicated from the wearable bladder monitoring device 1 to the remote device 5 preferably is reduced in size to minimize the amount of data that needs to be communicated in this manner in order to extend the lifetime of the battery 15. However, it should be understood that in alternative embodiments the signal processor 23 may be contained within the wearable bladder monitoring device 1. In such embodiments, the wireless communication module 21 may be used to communicate a processing result of the signal processor 23 to the remote device 5, e.g. for visualization of the processing result on a display 7 of the remote device 5.
In yet a further embodiment, the wearable bladder monitoring device 1 is configured to upload the data pertaining to the acquired echo signals with a wireless communication module 21 into a remote data repository acting as an intermediary data storage device from which the remote device 5 may download the stored data. This has the advantage that the remote device 5 does not have to be within communication range of the wearable bladder monitoring device 1 but instead may download the data at any suitable point in time to evaluate this data. For example, the remote data repository may be a cloud storage solution or the like, which may be accessed by both the wearable bladder monitoring device 1 and the remote device 5 over a network connection such as the Internet, in which case the wearable bladder monitoring device 1 may establish a wireless connection with an Internet hub such as a router or the like within communication range of the wireless communication module 21 through which the data pertaining to the acquired echo signals may be uploaded into the remote data repository.
Any suitable type of battery 15 may be used within the wearable bladder monitoring device 1. The battery 15 may be non-rechargeable, which for example may be acceptable where the wearable bladder monitoring device 1 is a disposable device. Alternatively, the battery 15 may be a rechargeable battery in which case the wearable bladder monitoring device 1 may comprise a recharging port (not shown) through which the battery 15 may be recharged in any suitable manner. In the absence of such a recharging port, the battery 15 may be recharged using wireless recharging, e.g. NFC recharging as is well-known per se.
As is schematically depicted in
An important aspect of embodiments of the present invention is that such different paths of the ultrasound beams 30, 30′, 30″ lead to clearly distinguishable echo signals, as is schematically depicted in
The distance between the intensity changes in an echo signal 31′ indicative of the anterior and posterior wall portions imaged by an ultrasound beam 30′ from which this echo signal originates may be used to estimate a diameter of a section of the bladder 41, as schematically depicted in
However, the ultrasound beam 30′ may exit the bladder through its posterior wall portion 41c if the wearable bladder monitoring device 1 is oriented relative to the abdominal region of the subject 40 under a second angle θ2, giving rise to an estimated bladder diameter d2, with typically d2≠d1. In this context, the angle θ may be defined as the angle between the subject-facing surface plane of the wearable bladder monitoring device 1 and the plane of the abdominal skin contact region onto which the wearable bladder monitoring device 1 is placed. This therefore shows that the relative orientation of the wearable bladder monitoring device 1 to the abdominal region of the subject 40 has an impact on the bladder monitoring data, in particular on the length of a path of an ultrasound beam 30′ through a section of the bladder 41 as explained above.
The operation of the bladder monitoring system according to embodiments of the present invention is designed to factor in such orientational dependency of the wearable bladder monitoring device 1 on the bladder monitoring results, as will now be explained in more detail with the aid of
Each received echo signal may be pre-processed by the pre-processing state 17 in operation 107, which pre-processing may include one or more or noise filtering, signal down conversion, signal enveloping and signal digitization, and which may further include storing the pre-processed signal in data storage device 19 for subsequent processing by the signal processor 23, either on a remote device 5 or on the wearable bladder monitoring device 1 as previously explained. It is checked in operation 108 if all ultrasound signals 30 under the desired beam angles have been generated, the respective echo signals 40 have been collected and pre-processed. If this is not the case, the method 100 reverts back to operation 103 in which the next ultrasound beam 30 is generated, e.g. under an adjusted beam angle.
Otherwise, the method 100 proceeds to operation 109 in which the acquired (pre-processed) ultrasound echo signals 40 are passed on to the signal processor 23, which may involve a wireless communication between the wearable bladder monitoring device 1 and the remote device 5 as previously explained in case the signal processor 23 is located on the remote device 5, in which the signal processor 23 processes the received data in order to determine the orientation angle θ of the wearable bladder monitoring device 1 relative to the abdomen of the subject 40. Specifically, the signal processor 23 evaluates the respective echo signals 40 to identify the subset of echo signals 40 reflected by the pelvic bone 43, which echo signals may be identified as previously explained with the aid of
In operation 113, the signal processor 23 fits the echo signals 31′ of the ultrasound beams 30′ passing through a section of the bladder 41 to a bladder model. In operation 115, the signal processor 23 may estimate a diameter or cross-sectional length of the bladder section from the distance or time delay between the respective edges 33 and 33′ of each echo signal 31′ indicative of the anterior and posterior wall sections of the bladder 41 delimiting this bladder section. The positioning of the trajectory of the ultrasound beams 30′ onto this bladder model may be based on the determined orientation angle θ of the wearable bladder monitoring device 1, such that a distinction can be made between trajectories resulting from different orientation angles of the wearable bladder monitoring device 1, such as example orientation angles θ1 and θ2 as schematically depicted in
Based on the trajectories fitted onto the bladder model and the respective diameters (cross-sectional lengths) of the bladder 41 along these respective trajectories, the signal processor 23 may in operation 117 estimate a bladder volume of the bladder 41. This for example may be based on the number of ultrasound beams 30′ and the respective beam angles of these beams as well as on a defined orientation of the bladder model relative to the pelvic bone 43, such that a portion of the bladder model obscured from the ultrasound beams 30 by the pelvic bone 43 as a function of the orientation angle θ of the wearable bladder monitoring device 1 can be estimated from the determined orientation angle θ. Consequently, the volume of the portion of the bladder 41 visible to the ultrasound beams 30′ may be extrapolated to a total bladder volume in this manner.
In an embodiment, the wearable bladder monitoring device 1 may be adapted to periodically repeat the monitoring of the bladder at a defined monitoring frequency such as to monitor changes in the bladder volume over the monitoring period. This for example may be used to determine a rate of change in the bladder volume, from which diagnostic observations may be derived, such as a rehydration or dehydration rate of the subject 40. Also, monitoring the bladder volume over a period of time may provide valuable insights into the retention volume of the bladder 41, which has previously explained is an indicator of prostate and urinary tract conditions, with the consequent bladder stretching being a key contributor to the occurrence of delirium in elderly subjects 40. In order to preserve the battery life of the battery 15, the defined monitoring frequency should be chosen as low as possible. In an embodiment, the signal processor 23 is adapted to define the monitoring frequency from an evaluation of a previous bladder monitoring event or set of bladder monitoring events, e.g. based on a previously determined filling or emptying rate of the bladder 41 or on a suspected pathology of the bladder 41.
The method 100 optionally may further comprise the generation of a warning signal in operation 119 with the signal processor 23, which warning signal for example may be generated as an audible or visible warning signal with the remote device 5 under control of the signal processor 23. The signal processor 23 may generate the warning signal in response to the estimation of a particular bladder volume or change in the bladder volume. Such a warning signal for example may be generated to wake a sleeping subject 40 in case of the bladder 41 of the subject 40 gets overly full, e.g. in order to prevent wetting of the subject's bed in case of incontinence. Alternatively, such a warning signal may be used to inform an athlete about his or her hydration levels, e.g. to ensure appropriate post-exercise rehydration. Alternatively, the warning signal may be generated by an alarming system connected to the remote data repository, which alarming system may be adapted to process the data uploaded into the remote data repository by the wearable bladder monitoring device 1 and to generate the warning signal based on said processing. The method 100 may subsequently terminate in operation 121.
In order to further refine the bladder volume estimation from the data pertaining to the echo signals generated with the wearable bladder monitoring device 1, this device may further comprise an orientation sensor 25 as schematically depicted in
In an embodiment, the signal processor 23 has access to a plurality of bladder models, e.g. stored in a data storage device (not shown), which may be contained by the device also containing the signal processor 23, e.g. the remote device 5 or the wearable bladder monitoring device 1, or may be a remote data storage device accessible over a network such as the Internet by the signal processor 23, e.g. through wireless communication module as will be readily understood by the skilled person. Each bladder model may be associated with a particular orientation (posture or pose) of the subject 40, such that the appropriate bladder model may be selected by the signal processor 23 based on the orientation data generated with the orientation sensor 25.
A further refinement of the accuracy of the bladder volume estimation may be obtained by optimizing the resonance frequencies of the ultrasound beams 30′ passing through the bladder 41. This can be understood as follows. As previously explained, the echo signals 31′ of the ultrasound beams 30′ exhibit a pair of ‘steep’ intensity changes 33 and 33′ corresponding to the ultrasound beam 30′ passing through an anterior wall section and a posterior wall section respectively of the bladder 41. In order to accurately locate the respective positions of these anterior and posterior wall sections, this intensity change preferably should be as steep as possible, such that the distance over which this intensity change is spread is minimized, thereby minimizing the uncertainty in the exact locations of these wall sections and consequently improving the accuracy of the estimated distance, i.e. bladder diameter or cross-sectional length, between these wall sections.
This may be achieved by tuning the frequency of the ultrasound beams 30′ as a function of the actual depth and size of the bladder 41, as will be explained in further detail with the aid of
Hence, in an embodiment the wearable bladder monitoring device 1 is adapted to tune the ultrasound frequency of the ultrasound beams 30′, i.e. at least of the ultrasound beams passing through the bladder 41, in order to improve the accuracy of the anterior and posterior wall section localizations. To this end, in operation 103 the phased array controller 13 may control the phased array 10 to generate ultrasound beams at various beam angles at an initial frequency fi, which initial frequency typically is a relatively low frequency, e.g. a frequency of about 2 MHz, in order to generate a relatively wide angle ultrasound beam, with the echo signals induced by these ultrasound beams being acquired in operation 105 as previously explained. This enables the bladder monitoring system to roughly determine the position and size of the bladder 41 due to the wide angled nature of the low frequency ultrasound beam.
This rough estimation of the position and size of the bladder 41 is used in operation 201 to determine a first distance da to the anterior wall of the bladder 41 and a second distance db to the posterior wall of the bladder 41, which distances in combination with the attenuation rate of ultrasound waves in fat tissue, e.g. about 0.5 dB/MHz/cm, to determine an optimal ultrasound frequencies f1 and f2 for imaging the anterior and posterior walls of the bladder 41, e.g. using the formula f=M/(0.5*D), in which f is the optimal ultrasound frequency, M is the maximum attenuation threshold for the signal to noise ratio specific phased array 10 and D is the distance to the wall section to be imaged.
Subsequently, the bladder 41 may be imaged in operation 203 with ultrasound signals at the determined optimal ultrasound frequencies f1 and f2 with the respective echoes of these ultrasound signals being acquired in operation 205 such that the bladder volume estimation with the signal processor 23 may be based on the echo signals of the ultrasound beams at the optimal ultrasound frequencies f1 and f2 in order to improve the accuracy of the bladder volume estimation. This for example may be achieved by combining the ultrasound beams at the optimized frequencies under various beam angles as previously explained into a single evaluation, e.g. by mapping the echo signals of these ultrasound beams onto a bladder model as previously explained. Alternatively, rather than performing multiple ultrasound measurements at the respective optimal ultrasound frequencies f1 and f2, a single measurement (scan) may be performed at an ultrasound frequency that is an average of the optimal ultrasound frequencies f1 and f2, e.g. a weighted average at 110% of the optimal ultrasound frequency f2 for imaging the posterior wall sections, as f2 typically is lower than f1.
As previously explained, the acquired echo signals may be pre-processed in operation 107 and further processed as explained in more detail with the aid of the flowchart of
It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several distinct elements. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
| Number | Date | Country | Kind |
|---|---|---|---|
| 17164540.1 | Apr 2017 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/058032 | 3/29/2018 | WO | 00 |
