Technical field

The present invention relates to a voiding data logging device to be used with a sensor array arranged to sense a filling state of an absorbent material . The present invention further relates to the use of absorbent articles such as diapers in daycare , homecare , nursing home and hospital environments . The present invention in particular relates to improving the aspects of monitoring and managing the use of absorbent articles .

Background

Absorbent articles are used for addressing conditions such as leakage issues or incontinence . Such absorbent articles , mostly in the form of diapers , are likewise used for individuals but applied and managed by nursing personnel in the context of nursing homes , hospitals and home care environments . In each such environment , the filling state and the need for replacement of a full absorbent article are of considerable interest , as well as the assessment of an individual ' s speci fic voiding behavior . Especially the latter is an important input regarding the possibility of forecasting the use of absorbent articles , the planning of replacement schedules and the managing of suf ficient supply in both individual environments as well as in larger contexts of the aforementioned nursing homes and the like .

For example , there are techniques for detecting the filling state of absorbent articles that consider the use of conducting wires integrated into a e . g . diaper' s liquid absorbent layer . A logging device is attached to these wires for sensing physical observables so as to determine the occurrence of voiding events and/or to measure some indication to the voided volume , absorbed volume , and/or absorption capacity . Such logging devices are usually collocated with the patient and in most cases af fixed to the absorbent article in the form of a diaper . Likewise , the logging devices are usually battery powered and thus power consumption by both measuring the base observables as well as storing and/or communicating the measured results are to be considered .

There is the desire to decouple the sensor arrangement from the absorbent article as such, so that the former can be reused several times , while the latter can be disposed of whenever required at keeping the involved cost low . However, the application of external sensor arrangements suf fers from reliability issues as close or direct contact solutions are not feasible , but other alternatives provide only little sensitivity and/or reliability while being prone to external conditions , such as a patient ' s movement and the direct close environment of the bed or patient station .

There is therefore a need for improved voiding data logging devices that make ef ficient use of battery power resources while taking into account speci fic and di f ferent situations and application scenarios in the relevant environments of daycare , homecare , nursing homes and hospitals . Likewise , there is a need for an accordingly improved absorbent article , such as a diaper . Summary

The mentioned problems and drawbacks are addressed by the subj ect matter of the independent claims . Further preferred embodiments are defined in the dependent claims . Speci fically, the embodiments of the present invention may provide substantial benefits that are described in part herein .

According to one aspect of the present invention there is provided a voiding data logging device comprising a connector to a sensor array comprising a plurality of sensor areas arranged to sense a filling state of an absorbent material in the vicinity of a corresponding one of said sensor areas ; a data processor configured to read out via the connector at least a part of the plurality of sensor areas when a sensor array is connected, the data processor being further configured to determine a type of a connected sensor array and to adj ust an acquisition scheme based on the determined array type .

According to another aspect of the present invention there is provided an absorbent article comprising a number of sensor areas arranged to sense a filling state of an absorbent material in the vicinity of a corresponding one of said sensor areas , a connector to a voiding data logging device configured to read out via the connector at least a part of the number of sensor areas when the data logging device is connected, and an encoding circuit encoding a type of said sensor array in relation to the number of sensor areas .

According to another aspect of the present invention there is provided a sensor array comprising a number of sensor areas arranged to sense a filling state of an absorbent material in the vicinity of a corresponding one of said sensor areas , a connector to a voiding data logging device configured to read out via the connector at least a part of the number of sensor areas when the data logging device is connected, and an encoding circuit encoding a type of said sensor array in relation to the number of sensor areas . Brief description of the drawings

Embodiments of the present invention, which are presented for better understanding the inventive concepts but which are not to be seen as limiting the invention, will now be described with reference to the figures in which :

Figures 1A and IB show schematic views of applications of respective voiding data logging devices according to embodiments of the present invention;

Figures 2A and 2B show schematic views of voiding data logging devices according to embodiments of the present invention;

Figures 3A and 3B show schematic views of sensor arrangements to be used with voiding data logging devices according to embodiments of the present invention; and

Figures 4A to 4D show schematic views of encoding di f ferent types in the context of embodiments of the present invention .

Detailed description

Figures 1A and IB show schematic views of applications of respective voiding data logging devices according to embodiments of the present invention . Figure 1A focusses on embodiments in which the sensor array is as such independent from an absorbent article . Namely, this figure shows as an example for this situation the absorbent article as a diaper 9 that has an absorbent material 99 in the form of a liquid absorbent layer located across the applicable and as such usual areas of the diaper 9 . The sensor array is shown as a strip-like sensor arrangement 8 , which can be af fixed to an outer surface 91 of the diaper 9 by means of , for example , a part of a hook-and-loop- f astener, an adhesive , etc . Likewise , any other suitable means , for example including the option to have some kind of pocket , pouch, hooks or strips at the diaper 9 so as to keep the sensor arrangement 8 at a suf ficiently constant position relative to the diaper during use ( i . e . during a time the diaper is worn by a user or patient and/or the logging of voiding shall take place ) .

A voiding data logging device 1 is provided comprising a connector 11 which can establish the desired electric contacts to the sensor array as part of the strip-like sensor arrangement 8 . For this purpose , the strip-like sensor arrangement 8 may comprise a corresponding connector 81 that mates with the connector 11 of the voiding data logging device 1 and which may arranged to establish not only a reliable electric connection for the applicable data- , measurement- , and supply-lines , but also a mechanical engagement so as to hold the voiding data logging device 1 reliably at the striplike sensor arrangement 8 during a time when the user/patient wears the diaper 9 . In general , the sensor array, here shown as a part of the strip-like sensor arrangement 8 , comprises a plurality of sensor areas that arranged to sense a filling state of an absorbent material in the vicinity of a corresponding one of said sensor areas . The sensor array can thus be a sensor strip with the plurality of sensor areas arranged along a line in a main extension direction of the sensor strip .

For example , the sensor areas may comprise electrodes , coplanar capacitors , inductive coils , resistors , and the like for establishing a predetermined relation between the filling state of the absorbent material in the corresponding vicinity of a sensor area and the electrical observable that may depend on the chosen type of the sensor areas ( i . e . capacitance , inductivity, resistance , etc . ) . The voiding data logging device 1 further comprises a data processor 100 that is configured to read out via the connector 11 at least a part of the plurality of sensor areas when a sensor array 8 is connected .

In some embodiments the data processor can be configured to read out one of the plurality of sensor areas of a connected sensor array and to determine whether or not the sensor area is present based on a sensing response . For example , the data processor 100 may comprise a network analyzing functionality that applies an AC signal to capacitor electrodes of a sensor array and determines the reflected and/or absorbed power, which will change due to a change in ef fective impedance of the sensor area ( in the form of a capacitor ) in response to the dielectric properties change for the capacitor as the absorbent material absorbs a liquid ( e . g . bodily fluid) .

The data processor 100 is further configured to determine a type of a connected sensor array and to adj ust an acquisition scheme based on the determined array type . The determining of a type of a connected sensor array is described in some greater detail elsewhere in the present disclosure . An acquisition scheme may generally refer to a collection o f information that determines whether, when and/or how a signal is acquired from a sensor array . Namely, a signal may be acquired in an acquisition sequence during which a test s ignal is applied to a sensor and the response is measured . For example , an ac signal can be implied for measuring the impedance response by the sensor . Likewise , a voltage may be applied so as to measure a current , and, with this , an ef fective resistance of the sensor . This measurement of the desired observable may thus take place at speci fic timings whereas substantially no acquisition takes place in the time spans between two subsequent acquisition sequences . Further, the voiding data logging device 1 may consume a relative high power from a power source during acquisition sequences , while it may consume a relative low power from the power source during times between acquisition sequences . In case there is no particular sequence of actions concerned for acquiring the sensor data one may also refer to an instance of reading out the corresponding sensor area . In some embodiments of the voiding data logging device 1 , the acquisition scheme includes any one of an acquisition interval , an acquisition order and a sampling rate .

For example , an acquisition interval may be defined by means of information that indicates a time between two subsequent acquisition sequences . Said information may directly code a time , e . g . 1 or 60 for defining 1 minute and, respectively 1 hour, or indirectly code a time , e . g . 1 meaning every minute , 2 meaning every hour, 3 every second hour, and so forth . Generally, said acquisition interval may relate to how often an acquisition sequence takes place . A first acquisition interval may define roughly every minute , which is relatively often, while a second acquisition interval may define roughly every hour, which is relatively rare . In general , though, the data processor 100 can be configured to adj ust an acquisition interval by selecting at least one of a relatively long acquisition interval for a first determined type and a relatively short acquisition interval for a second determined type .

An acquisition order may be def ined by means of information that indicates what sensor area of the plurality of sensor areas should be addressed . In this way, the acquisition order may indicate that a speci fic one of the plurality of sensor areas is to be read out during an upcoming acquisition sequence . The acquisition order may well indicate what speci fic one of the plurality of sensor areas is to be read out during any following acquisition sequence . In this way, it can be speci fied what sensor area is read out at what time or under what conditions .

A sampling rate may be defined by means of information that indicates how many individual data acquisitions are made for a single sensor area during an acquisition sequence . Usually, a data acquisition may at least at some point involve an analog- to-digital conversion (ADC ) during which an analog level ( e . g . representing a voltage , current , resistance , or reflected power as part of a network analysis) is converted into a digital representation. During such conversion, an analog comparison level is generated and the analog input level is compared to that. This process, also referred to as sampling or supersampling, may involve a successive approximation and is thus an iterative process requiring energy and power resources. For example, 1 or more than 1, for instance up to 100, 50, 30, or 20 individual data acquisitions for a single acquisition sequence and a single sensor area may be averaged into a single acquisition data, optionally after removing non- plausible data points and/or applying other as such known data filtering techniques. A higher super sampling rate may provide a higher accuracy, however, will consume more energy.

Generally, any one or two of the acquisition interval, the acquisition order and the sampling rate may be the same, while the remaining one is changed. In some embodiments, the acquisition interval may be the same, but the degree of sampling, i.e. the number of measurements that are averaged into one measurement value may be different. For example, the interval may be 1 second, but the degree of sampling can be from 1 to 16 measurements. The higher degree of sampling results in higher battery consumption, but gives more reliable measurements. Thus, the data processor 100 is configured to adjust the acquisition scheme based on the determined array type and, in this way, it may adjust the acquisition interval, and/or the acquisition order and/or the sampling rate.

For example, the strip-like sensor arrangement 8 may comprise the plurality of sensor areas 82-1, 82-2, ... 82-n. These sensor areas can thus be located at different and specific positions relative to the absorbent article, i.e. the diaper 9. For example, the strip-like configuration of the sensor arrangement may result in that some sensor area(s) are closer to a source of voiding (e.g. close to the center of diaper 8 at a site of an ureter opening) , while that some other sensor area(s) are farther away from that voiding source. It may thus be of interest to consider the sensor area(s) close to the voiding source toward the beginning of a use of a diaper, while other sensor area ( s ) may be of more interest toward the end of the li fe-time of a diaper, i . e . at times when the absorption reaches a maximum or desired target absorption capacity of the absorbent material of the diaper 9 .

Figure IB focusses on embodiments in which the sensor array is integrated into or forms part of an absorbent article . Namely, this figure shows , as an example for this situation, the absorbent article as a diaper 9 that has again an absorbent material 99 in the form of a liquid absorbent layer located across the applicable and as such usual areas of the diaper 9 . In these embodiments , the sensor array 93 is integrated into the absorbent layer or is located on the absorbent layer ( the types of sensors again apply to this embodiment as they have been described elsewhere in the present disclosure ) . Further, the absorbent article may compri se connector 92 that engages with the connector 11 of the voiding data logging device 1 j ust in the same or in a similar way as does connector 81 that was described in conj unction with Figure 1A.

Figures 2A and 2B show schematic views of voiding data logging devices according to embodiments of the present invention . In Figure 2A the suitable functional ities and features are shown and described schematically . A voiding data logging device 1 according to the respective embodiments of the present invention comprises a connector 11 to a sensor array comprising a plurality of sensor areas arranged to sense a filling state of an absorbent material in the vicinity of a corresponding one of said sensor areas . The connector 11 is preferably arranged to establish not only a reliable electric connection for the applicable data- , measurement- , and supplylines , but also a mechanical engagement so as to hold the voiding data logging device 1 reliably at the strip-like sensor arrangement 8 during use . For this purpose , the connector 11 may comprise one or more electrical contacts 111 , for example in the form of some resilient contact tongue or a contact strip . The surface of such tongues and strips may be coated, for example with gold so as to ensure good contact also in wet or humid environments . The connector 11 may further comprise one or more mechanical elements 112 , such as indents or springs which will then hold the connector 11 , and, with this , the voiding data logging device 1 suf ficiently secure at sensor array, sensor arrangement or strip .

The voiding data logging device 1 further comprises a data processor 100 configured to read out via the connector 11 at least a part of the plurality of sensor areas when a sensor array is connected, the data processor being further configured to determine a type of a connected sensor array and to adj ust an acquisition scheme based on the determined array type . Further details of these functionalities are described elsewhere in the present disclosure . Generally, the voiding data logging device 1 may comprise a power source 101 , e . g . a battery or high-capacity/ultra-capacitor , further elements 102 including optional memories and/or communication modules ( e . g . for communication via Bluetooth™, BLE , WiFi , GPRS , GSM, PCM, UMTS , LTE , 2G, 3G, 4G, 5G and related or accordingly evolving standards ) . All or some of the electronic elements may be mounted on a printed circuit board ( PCB ) 110 that is accommodated by a logging device housing 10 . The latter may be sealed against air, liquids , humidity, dust , and the like so as to provide reliable operation in the intended environments .

Figure 2B shows a voiding data logging device 1 ' according to further embodiments of the present invention . In principle , the device 1 ' may be similar to the device j ust described in conj unction with Figure 2A and comprise at least some of the mentioned elements and components . The voiding data logging device 1 ' , however, comprises an operation element 119 that is accessible by a user U who can execute a setting by operating the element 119 . For example , the operation element 119 may comprise a switch or a push button so as to internally generate a signal to the processor 100 .

In this way, the data processor can be configured to determine a type of a connected sensor array and to adj ust the acquisition scheme accordingly by reading the signal produced by the operation element 119 . The voiding data logging device 1' may thus comprise an encoding circuit in the form of or including the operational element 119 (e.g. a switch) and the data processor 100 can be configured to read out the encoding circuit for determining the type of a connected sensor array. For example, the operation element 119 may be a switch connecting a signal line readable by the processor 100 to some relatively high potential for determining a first type, and to some relatively low potential for determining a second type of a connected sensor array.

Figures 3A and 3B show schematic views of sensor arrangements to be used with voiding data logging devices according to embodiments of the present invention. In Figure 3A there is shown schematically a strip-like sensor arrangement comprising a sensor array of a first type. Namely, the strip-like sensor arrangement 81-1 comprises a sensor array of sensor areas 82- 1, 82-2, ... 82-n, wherein n may be a relatively high number. In this way, the strip-like sensor arrangement with such a first type sensor array can provide a relatively high resolution as the measurement can be differentiated relatively fine by means of the relatively high number n of sensor areas. Likewise, Figure 3B shows schematically a strip-like sensor arrangement 81-2 comprising a sensor array of a second type, i.e. with a sensor array of sensor areas 82-1, 82-2, ... 82-m, wherein m may be a relatively low number, so that n < m. In this way, the strip-like sensor arrangement with such a second type sensor array can provide a relatively low resolution as only a relatively coarse differentiation is provided.

For example, the strip-like sensor arrangement 81-1 can be used during applications when a relatively fine differentiation is desired, e.g. when a specific patient's voiding behaviour is monitored and assessed. On the other hand, though, the strip-like sensor arrangement 81-2 can be used during applications when only a relatively coarse differentiation is desirable, e.g. when a specific patient's voiding behaviour is already known and the monitoring may more focus on the remaining absorption capacity and/or determining the need for a replacement of the absorbent article (e.g. diaper ) . This may provide advantages including the ef ficient use of power resources ( e . g . that of a battery, such as battery 101 shown in Figure 2A) . When only a smaller number of sensor areas need to be read out then the processor 100 may adj ust the acquisition scheme based on the determined array type and to reduce the acqui sition frequency ( inversely related to the acquisition interval ) and omit any attempts to read out further sensor areas that are not present in the first-type sensor array . This will all contribute to the reduction of power consumption of the voiding data logging device which will translate into a substantially prolonged use or li fetime .

This may further provide advantages including also the reduction of cost . Speci fically, the at least two types of sensor arrangement may have implication to the manufacturing cost of the related sensor arrangements . I f the sensor array comprises fewer sensor areas then this may have implications regarding the cost as fewer sensor areas and corresponding contact pads , lines , and paths need to be manufactured . Such lower-cost sensor arrangements may then be used for longer times and periods , while the more sophisticated arrays , e . g . that of a second type , can then be reserved to times when a finer assessment is desired .

In the Figures 3A and 3B there are shown the sensor areas 82- 1 , ... are shown in the exemplary form of coplanar capacitors comprising corresponding electrode 821 , 822 . Speci fically, the electrode layouts are such that the capacitor electrodes assume a concentric and circular shape , while also concentric and pad-like shapes or parallel pads may be possible . Such layouts may contribute to focusing the electric field distribution within the dielectric, i . e . within the liquid absorbent article . The response may thus be focused on liquid that is locali zed in a speci fic and predeterminable manner, as the traj ectories of the maj ority of the electric field lines concentrate to a volume defined by the footprint of the outer one 822 of the concentric electrodes as compared to the inner electrode 821 . In general, the determining of a type of a connected sensor array involves considerations on a type as such. Namely, the type classifies sensor arrays with regard to some common characteristic that is to ultimately influence the adopted acquisition scheme, as the latter is adjusted based on the determined array type. The sensor array can thus carry some explicit or implicit characteristic that is determined by the processor of the voiding data logging device as said type for adjusting the acquisition scheme. The characteristic may be explicit in the sense that it manifests itself as a tangible property of the sensor array, such as a number of present or connected sensor areas, a hard-wired electrical property incl. resistance, impedance, capacitance, open or short circuits, a value stored in a memory, a state of switching or operation element as an optional part of an encoding circuit and the like .

The characteristic may however well be also implicit as it does not manifest itself as a tangible property of the sensor array. The sensor arrays of different types may thus be physically identical but information may be associated for sensor arrays, by means of information on the sensor arrangement (e.g. a label on a strip) or on a packaging of one or more sensor arrays. This information may be conveyed to the processor so as to determine a "virtual" type and, nevertheless, adjust the acquisition scheme based on such a virtual intended use.

Figures 4A to 4D now show schematic views of schemes for encoding different types in the context of embodiments of the present invention.

In a first scheme, strip-like sensor arrangements 8-1 (Fig. 4A) and 8-2 (Fig. 4B) comprise sensor arrays of the respective type but - in manufacturing tolerances - identical connectors 81-1, 81-2. However, in one case a first, relatively high number of signal lines 83-1, ... 83-n may be connected to connector 81 (Fig. 4A) , while in another case a second, relatively low number of signal lines 83- 1 , ...83-m may be connected ( Fig . 4B ) . In this way the processor may determine that some signal lines are not connected as the application of a test signal ( e . g . test voltage or AC signal ) does not yield a sensible response ( e . g . open circuit or full power reflectance ) .

In general , the data processor 100 can be configured to read out one of the plurality of sensor areas of a connected sensor array and to determine whether or not the sensor area is present based on a sensing response . In this way, the processor can determine the type of the connected sensor array and adj ust the acquisition scheme based on the determined array type . This may be a speci fic form voiding data logging device in which the data processor is configured to determine a number of sensor areas of a connected sensor array and to adj ust the acquisition scheme based on the determined number as an array type . This may involve determining whether or not a sensor area is present on a connected sensor array . Subsequently, the data processor can then proceed by reading out via the connector a relatively large number of sensor areas for a determined first type ( e . g . that of Fig . 4A) and a relatively small number of sensor areas for a determined second type ( e . g . that of Fig . 4B ) .

Figure 4C shows a schematic view of an embodiment considering an encoding circuit co-implemented together with the sensor array . This is an embodiment for a voiding data logging device in which the data processor is configured to read out an encoding circuit for determining the type of a connected sensor array . For example and as shown, a strip-like sensor arrangement 8-3 may again comprise a connector 81 of which one or more signal lines lead to an encoding circuit 84 . The latter can be relatively simple by di f ferentiating between a short circuit and an open circuit between at least two signal lines toward the connector 81 , or also relatively complex by comprising a number of such open/closed circuits to encode a binary value or even some ( discrete ) electronic component , such as passives incl. resistors, capacitors, inductors, and the like.

Figure 4D shows a schematic view of an embodiment considering an encoding circuit co-implemented together with the sensor array. This is another embodiment for a voiding data logging device in which the data processor is configured to read out an encoding circuit for determining the type of a connected sensor array. The strip-like sensor arrangement 8-4 again comprises a connector 81 of which one or more signal lines lead to an encoding circuit 84-2 which may be or comprise a relatively complex by comprising an active or integrated component, such as a memory, a read only memory (ROM) , a serial ROM, a FLASH memory, an I2C-memory, an SPI-memory and the like. The data processor can thus read out via the connector also any stored information for determining the type of a connected sensor array. For example, the information may represent a type identifier, a serial number and/or even information on the acquisition scheme to be adopted as such. In a further embodiment the encoding circuit can provide for sending information on the type as payload together with the sensor read out to the processor.

In a further embodiment of the voiding data logging device of the present invention, the data processor may be configured to determine a parameter of a connected sensor array and to adjust the acquisition scheme based on the determined parameter. The sensor number of sensor areas may then not necessarily differ between different types. Specifically, they can be identical, except for a parameter in the possible form of a "strip type identifier" read out by the data processor. This type identifier can act as a hardware key to activate different settings regarding the acquisition interval, acquisition order, sampling rate, different settings in the back-end and/or presentation modes in the user interface, i.e. the acquisition scheme.

Different strip type identifiers may for example trigger the voiding data logger device to go into different modes adapted for different use cases, where the different use cases include different acquisition schemes. For example, a first strip type identifier may cause the voiding data logging device to go into a first operation mode suitable for performing an assessment of a wearer' s continence behaviour over a relatively short period of time, e.g. over the course of a few days, whereas the a second strip type identifier may cause the voiding data logging device to go into a second operation mode suitable for acting as a change indicator for indicating to the wearer or a carer the need to change an absorbent article, e.g. over a relatively long period of time in the order of several weeks or months. At the same time, the power and energy resources available in connection with the logging device can be employed accordingly, e.g. for investing more power in a higher accuracy in the first mode and investing less power in the second mode for individual data acquisition sequences for obtaining a longer service and/or battery life time .

Although detailed embodiments have been described, these only serve to provide a better understanding of the invention defined by the independent claims and are not to be seen as limiting .