Patent Publication Number: US-2023147473-A1

Title: Hypoglycemia and/or hyperglycemia detector

Description:
FIELD 
     The present invention relates to detecting hypoglycemia and/or hyperglycemia. 
     BACKGROUND 
     Hypoglycemia is a state, where blood sugar has fallen below normal. If untreated, this condition can be serious and life threatening for a diabetic person. Consequently, an important factor in diabetes treatment is regular measuring and monitoring of blood sugar levels. Current commercially available glucose monitoring systems are invasive and thus require skin to be penetrated with a needle. Various currently available monitoring systems have offered a great relief to everyday life of a diabetic person but, unfortunately, cannot always be fully utilized due to high price and limited availability. A challenge is also presented by hyperglycemia, which is a condition in which an excessive amount of glucose circulates in the blood plasma. 
     OBJECTIVE 
     An objective is to provide a hypoglycemia and/or hyperglycemia detector for detecting the presence of hypoglycemia and/or hyperglycemia. 
     In particular, it is an objective to provide a non-invasive and affordable hypoglycemia and/or hyperglycemia detector that can be comfortably used. 
     Additionally, it is an objective to provide a detector that can provide automatic monitoring and alarming for hypoglycemia and/or hyperglycemia. 
     Finally, it is an objective to provide a reliable hypoglycemia and/or hyperglycemia detector for all diabetic persons, including both type I and II, regardless of age or living standards. 
     SUMMARY 
     According to a first aspect, a hypoglycemia and/or hyperglycemia detector (herein also “the detector”) comprises an enclosure comprising a bottom surface configured for positioning against skin. This allows the detector to be easily used for continuous monitoring as it can be positioned on the body of a person, for example on an arm of the person (herein, “continuous monitoring” may refer to monitoring with substantially continuous measurements and/or monitoring with repeated measurements, for example once in an hour or more often, the monitoring with repeated measurements, in particular, allowing cost-efficient monitoring). The detector further comprises one or more gas sensors (herein also “the sensors”), such as a volatile organic compound (VOC) sensor, positioned within the enclosure and configured for detecting gas emissions from the skin for providing one or more measurement signals. The positioning of the sensors within the enclosure allows the sensors to be at least partially isolated from ambient gases while being focused on detecting gas emissions from the skin. The detector also comprises one or more processors (herein also “the processors”) configured for detecting an indication of hypoglycemia and/or an indication of hyperglycemia from the one or more measurement signals (herein also “the measurement signals”) for providing an alarm signal when the indication of hypoglycemia and/or the indication of hyperglycemia is detected. This allows detecting hypoglycemia and/or hyperglycemia without necessarily measuring any actual blood sugar levels. Instead, the detection can be performed based on an indication of hypoglycemia and/or an indication hyperglycemia, for example a deviation of the one or more measurement signals from one or more baseline signals. 
     The detector, or the processors in particular, may be specifically configured for detecting either one of hypoglycemia or hyperglycemia. As an alternative, it may be specifically configured for detecting both hypoglycemia and hyperglycemia. The detector, or the processors in particular, can be specifically configured for detecting changes in the gas emissions, or to determine one or more indications correlating with blood glucose level. This may be done continuously, or repeatedly, to obtain a real-time indication of blood-glucose level. Regardless of whether the actual measurement allows the determination of a continuous indicator for blood-glucose level, the indication of hypoglycemia and/or the indication of hyperglycemia may be provided as discrete categories. 
     The detector as a whole allows non-invasive detection of hypoglycemia and/or hyperglycemia. Moreover, it allows automatic monitoring of hypoglycemia and/or hyperglycemia, as the processors may be configured for causing the detection to be performed automatically, for example according to a schedule. The detector therefore allows also self-monitoring of an unconscious person, for example during sleep, when blood sugar level may change unexpectedly. This allows particularly efficient monitoring of hypoglycemia and/or hyperglycemia for children. It also allows monitoring without waking up a sleeping person using the detector, unless desired. The detector can be repositioned during continuous use, for example once a day, to reduce stress on the skin. The detector can be configured to provide an alarm signal, when the indication of hypoglycemia and/or the indication of hyperglycemia is detected, which in turn allows an unconscious person using the detector or another person to be alerted for the presence of hypoglycemia and/or hyperglycemia. 
     One important observation of the present disclosure is that for a hypoglycemia and/or hyperglycemia detector it is enough to detect an indication of hypoglycemia and/or an indication of hyperglycemia. This means that the detector does not need to be able to measure the actual blood sugar levels but only observe changes in measurement signals to indicate the presence of hypoglycemia and/or hyperglycemia. This allows the hypoglycemia and/or hyperglycemia detector to be provided at reduced cost in comparison to more complex devices. For a diabetic person, a blood glucose level below a threshold level 3.9 mmol/1 or 4 mmol/l may be considered indicative of hypoglycemia. In units of mg/dl, a threshold level of 70 mg/dl may also be used, as an upper limit as above. Similarly, a blood glucose level above a threshold level 11 mmol/1 or 11.1 mmol/l may be considered indicative of hyperglycemia. However, even more stringent threshold may be used, for example at 7.0 mmol/1 or 126 mg/dl, as a lower limit as above. This can be used, in particular, for fasting plasma glucose. Instead of utilizing these values, the detector allows hypoglycemia and/or hyperglycemia to be detected as a sudden change in the gas emissions, which are indicative of hypoglycemia and/or hyperglycemia and may develop quickly, even substantially instantly in response to hypoglycemia and/or hyperglycemia. By utilizing the sensors, the change in gas emissions can be translated into a change in the measurement signals. As an example, the change can be quantified utilizing one or more baseline signals that indicate the absence of hypoglycemia and/or hyperglycemia (herein also “the baseline signals”). The detector may also utilize a calibration measurement, when the user is in non-hypoglycemia and/or non-hyperglycemia state, to determine the baseline signals, allowing user-specific calibration of the detector for detecting hypoglycemia and/or hyperglycemia. Comparing any measurement signals to the baseline signals can be used to detect hypoglycemia and/or hyperglycemia, since a deviation from the baseline signals can be accurately interpreted as the indication of hypoglycemia and/or an indication of hyperglycemia. The actual amount of deviation may depend on the particulars of the sensors used, but this can be straightforwardly determined, for example through clinical trials. Similarly, sensitivity of the sensors for gas emissions indicative of hypoglycemia and/or hyperglycemia can be similarly ensured, for example by varying the thickness of sensor materials. Naturally, while the detector allows detection of hypoglycemia and/or hyperglycemia without measurement of actual blood sugar levels, it may also be compounded or used in conjunction with such measurements. 
     Another important observation is that while gas emissions, which may be used for an indication of hypoglycemia and/or an indication of hyperglycemia, are in large parts provided through exhalation, there is enough gas emissions also from the skin so that a reliable detector can be provided. Moreover, it has been observed that while it may take a longer time for the gas emissions to be transmitted from the skin than from exhalation, they can still be detected quickly and reliably enough for the detector to be able to provide an actionable alarm for hypoglycemia and/or hyperglycemia. 
     In an embodiment, the detector comprises one or more flanges (herein also “the flanges”) for supporting an adhesive patch for attaching the detector to the skin. This allows the detector to be easily used as it can be attached to skin for an extended period of time during which it may repeatedly perform measurements for detection of hypoglycemia and/or hyperglycemia. During use of the detector, the flanges can be positioned to form a substantially uniform plane with the skin for attaching an adhesive patch so that the grip of the adhesive patch is maintained both with respect to the skin and to the detector. 
     In an embodiment, the one or more flanges comprise elastic material for bending the one or more flanges against the skin. This allows the attachment of the flanges to the skin to be improved. Also, this may be used to make wearing the detector more comfortable. 
     In an embodiment, the enclosure comprises an elevated portion, such as a cover, for elevated positioning with respect to the one or more flanges and the one or more flanges are positioned at least partially surrounding the elevated portion. This allows one or more of the electronic components of the detector, such as the sensors and/or the processors, to be fitted within the elevated portion for elevated positioning with respect to the flanges, while the flanges can still a surface for attachment to the skin. This allows a compact detector to be formed. The detector may still be attached to the skin utilizing the adhesive patch, which may define an opening for accommodating the elevated portion. This substantially reduces the bending of the adhesive patch when used to attach the detector to the skin. 
     In an embodiment, the bottom surface is made of biocompatible material, such as biocompatible plastic. This allows the detector to be maintained against the skin for an extended period of time. The detector may be worn for several hours at a time, for example from morning to evening, or even one or more days at a time. When the parts of the detector maintaining contact with the skin during use are of biocompatible material, any irritation caused by the detector may be mitigated or removed altogether. 
     In an embodiment, the one or more gas sensors comprise a metal-oxide semiconductor (MOS) sensor. This has been found to allow reliable and cost-effective detection of gases relevant for hypoglycemia and/or hyperglycemia. Such gases include VOC gases and the MOS sensor can therefore also be a VOC sensor. 
     In an embodiment, the one or more gas sensors are configured for detecting at least acetone and/or isoprene emissions. Sensors sensitive to these gases have been found to allow improved detection for hypoglycemia and/or hyperglycemia. 
     In an embodiment, the one or more measurement signals are indicative of resistance for the one or more gas sensors. It has been found that this allows an efficient measure for the measurement signal, from which measure hypoglycemia and/or hyperglycemia can still be detected. 
     In an embodiment, the one or more processors are configured to detect the indication of hypoglycemia and/or the indication of hyperglycemia by obtaining one or more measurement values from the one or more measurement signals and comparing the one or more measurement values to one or more baseline values indicative of a non-hypoglycemia and/or non-hyperglycemia state, i.e. the absence of hypoglycemia and/or hyperglycemia. This has been found to allow an efficient detection of hypoglycemia and/or hyperglycemia without actually measuring the blood sugar level. The one or more baseline values may be determined from a measurement of a user, such as a diabetic person, when the user is not in hypoglycemia and/or hyperglycemia. Then, at any time one or more measurements may be performed with the detector for the same user, providing one or more measurement values. A comparison of these values may then be performed to provide an indication of hypoglycemia and/or an indication of hyperglycemia. For example, if a measurement value differs from the baseline value by a threshold value such as a threshold percentage, an indication of hypoglycemia and/or an indication of hyperglycemia may be provided. Since the detector allows hypoglycemia and/or hyperglycemia to be detected as a clear change with respect to non-hypoglycemia and/or non-hyperglycemia state, the threshold value can be used to correspond the blood sugar level indicative of hypoglycemia, such as 3.9-4 mmol/l, and/or the blood sugar level indicative hyperglycemia, such as 11-11.1 mmol/1 or 7.0 mmol/l. 
     In an embodiment, the one or more measurement signals correspond to one or more measurements over a period of time. This allows a temporal measurement profile to be used and it has been found to allow notable improvement in accuracy for detecting hypoglycemia and/or hyperglycemia. 
     In an embodiment, the detector is configured to operate the one or more gas sensors utilizing temperature cycling for detecting gas emissions from the skin. This has been found to allow notable improvement in the sensitivity of the sensors for hypoglycemia and/or hyperglycemia detection, while allowing the sensors to be compactly packed within the enclosure. Moreover, temperature cycling allows maximizing the sensitivity of the sensor for particular gases or gas mixtures for detecting hypoglycemia and/or hyperglycemia. For temperature cycling, the sensors may be cyclically heated and cooled. The heating and/or cooling may be performed rapidly, even substantially instantaneously, for improved sensitivity. In some embodiments, it has been found that heating and/or cooling period of up to 30-60 seconds may be used for a particularly improved sensitivity for hypoglycemia and/or hyperglycemia detection. Cooling, in particular, can be very rapid, for example with a cooling period of less than one second, to allow improved sensitivity. Similarly, a heating period may range, for example, from 1 millisecond to 10 seconds. It has also been found that a heating up to 400-500 Celsius can be utilized efficiently for particularly improved sensitivity for hypoglycemia and/or hyperglycemia detection for a detector as described herein. 
     In an embodiment, the detector is configured to provide the one or more measurement signals during one or more cooling phases of the temperature cycling. This has been found to particularly improve sensitivity of the sensors for hypoglycemia and/or hyperglycemia detection. A cooling phase includes at least the cooling period, where the temperature of the sensors is decreased but it may additionally include an additional recovery period for the sensors, during which the response of the sensors returns towards a steady-state response. While the initial cooling period may be less than a second, the subsequent additional recovery period may last for more than a second, for example 5-10 seconds or more, allowing the measurement signals to be provided over a period of time, for example 2-5 seconds or more. 
     In an embodiment, the detector is configured for providing the alarm signal to a remote device and/or as a local alarm signal for sensory perception. The detector may comprise a wireless transmitter, for example as a part of a transmitter-receiver, for transmitting the alarm signal to a remote device, such as a mobile phone. Alternatively or additionally, the detector may comprise an alarm such as a an audible and/or vibration alarm for providing a local alarm for sensory perception. This in particular removes the need for any application interfaces to be operated, for example a mobile-phone application to be installed, for being able to utilize the detector, improving the ease of use. 
     According to a second aspect, an arrangement comprises the hypoglycemia and/or hyperglycemia detector according to the first aspect or any of its embodiments alone or in any combination. The arrangement also comprises an adhesive patch for attaching the detector to the skin. The adhesive patch may be separable from the detector, allowing the adhesive patch to be replaced while the use of the detector is continued. 
     In an embodiment, the adhesive patch defines an opening for accommodating an elevated portion of enclosure of the detector. This substantially reduces the bending of the adhesive patch when used to attach the detector to the skin. The opening allows the adhesive patch to at least partially surround the elevated portion, thereby improving the attachment of the adhesive patch to the detector and to the skin. Simultaneously, it allows the adhesive patch to be positioned to form a substantially uniform plane with the skin for attaching the detector so that the grip of the adhesive patch is maintained both with respect to the skin and to the detector. 
     It is to be understood that the aspects and embodiments described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding and constitute a part of this specification, illustrate examples and together with the description help to explain the principles of the disclosure. In the drawings: 
         FIG.  1   a    illustrates a detector according to an example in a cross-sectional view from one side, 
         FIG.  1   b    illustrates a detector according to an example in an exploded view, 
         FIG.  2    schematically illustrates detection of hypoglycemia and/or hyperglycemia according to an example, and 
         FIG.  3    schematically illustrates measurement values for detection of hypoglycemia and/or hyperglycemia according to an example. 
     
    
    
     Like references are used to designate equivalent or at least functionally equivalent parts in the accompanying drawings. 
     DETAILED DESCRIPTION 
     The detailed description provided below in connection with the appended drawings is intended as a description of examples and is not intended to represent the only forms in which the example may be constructed or utilized. However, the same or equivalent functions and structures may be accomplished by different examples. 
       FIGS.  1   a  and  1   b    show an example of a hypoglycemia and/or hyperglycemia detector  100  (herein also “the detector”) in a cross-sectional side view and in an exploded view, respectively. 
     In use, the detector  100  can be positioned on skin  10  for hypoglycemia and/or hyperglycemia detection. In some embodiments, the detector  100  is configured for positioning on the arm of a person for hypoglycemia and/or hyperglycemia detection as this has been found to allow comfortable and precise monitoring. Other positionings are also possible, for example on the leg or the torso of a person. The detector  100  can be configured for being maintained on the skin  10  for hypoglycemia and/or hyperglycemia detection for an extended period of time involving a plurality of measurement cycles. For this purpose, the detector  100  may be configured for being attached to the skin  10  by an adhesive patch  20  such as a plaster. This allows accurate positioning of the detector  100  easily together with maintaining the positioning during the use of the detector  100 . This, in turn, allows increased measurement precision since repeated measurements, which may include an initial calibration measurement, can be performed at the same position with respect to the skin  10 . However, the detector  100  may also be repositioned during use since it can easily be reattached. This way, any irritation caused by the detector  100  on the skin may be reduced. If necessary, the detector  100  may be recalibrated when repositioning. Alternative or additionally to attachment with an adhesive patch  20 , the detector  100  may comprise or be configured to be attached to a strap, such as an arm band or a wrist band, for strapping attachment of the detector  100  with respect to the skin  10 , for example to an arm or a wrist of a person using the detector  100 . 
     The detector  100  comprises an enclosure  110 , which can be configured for positioning against the skin  10  for hypoglycemia and/or hyperglycemia detection. The enclosure  110  comprises a bottom surface  112  configured for positioning against the skin  10  for hypoglycemia and/or hyperglycemia detection. The bottom surface  112  may be configured to allow gas emissions from the skin  10  into the enclosure  110 . The bottom surface  112  may comprise one or more holes  122 , such as through-holes, for directing the gas emissions from the skin  10  into the enclosure  110 . Alternatively or additionally, the bottom surface  112  may comprise a gas-permeable surface such as a gas-permeable membrane for allowing the gas emissions from the skin  10  to enter the enclosure  110 . The bottom surface  112  may be flat. The enclosure  110  may comprise one or more holes  118  for allowing air circulation through the enclosure  110 . The enclosure  110  may comprise or be made of plastic, for example biocompatible plastic. It is noted that any or all parts of the detector  100 , such as the bottom surface  112 , maintaining contact with the skin  10  while the detector  100  is in use may be made of biocompatible material such as biocompatible plastic, thereby mitigating any irritation caused by prolonged use of the detector  100 . In any case, the enclosure  110  and/or the detector  100  as a whole may be waterproof. 
     The enclosure  110  may be composed of one or more parts. As an example, the enclosure  110  may comprise a bottom cover  120 , such as a bottom plate, which may be detachable for providing a hatch for the enclosure  110 . The bottom cover  120  may at least partially form the bottom surface  112 . The bottom cover  120  may comprise one or more of the one or more holes  122 , for example at the center of the bottom cover  120 . The enclosure  110  may also comprise an elevated portion  116 , such as a cover, for elevated positioning with respect to the bottom surface  112 . The elevated portion  116  may be arranged for separable coupling with the bottom cover  120  or they may together constitute a single monolithic part. As an example, the bottom cover  120  may be circular, in which case it may be configured also for screw-in coupling, directly or indirectly, to the elevated portion  116 . Similarly, the elevated portion  116  may have a circular shape but other shapes are possible as well, for example an oval shape or a rectangular shape. With circular shape, the elevated portion may be configured for screw-in coupling, directly or indirectly, to the bottom cover  120 . In addition, it may allow an adhesive patch  20  defining a circular opening  22  to be used for easy and reliable attachment of the detector  100  to the skin  10 . 
     The detector  100  may comprise one or more flanges  114  (herein also “the flanges”), which can be configured for supporting an adhesive patch  20  for attacking the detector to the skin  10 . In some embodiments, the flanges  114  may be formed as a monolithic part with respect to the enclosure  110 , wherein the enclosure itself may be formed as a single monolithic part or as multiple parts. For example, the flanges  114  may be formed as a monolithic part with the elevated portion  116  of the enclosure  110 , such as the cover, and/or with the bottom cover  120  of the enclosure  110 . In one convenient structure, the flanges  114  and the elevated portion  116  are coupled together, for example as a single monolithic part, for forming a top cover  150  of the detector  100 . The flanges  114  may comprise or be formed of a material that is biocompatible material, such as biocompatible plastic, and/or that is same as a material of the enclosure  110 , for example that of the elevated portion  116  and/or the bottom cover  120 . Alternatively or additionally, the flanges  114  may comprise or be formed of an elastic material for bending the flanges  114  against the skin  10 . The flanges  114  can be thin so that the adhesive patch can be applied across the flanges  114  and the skin  10  in a substantially uniform plane for attachment. With “substantially uniform” it should be understood that while slight changes in the elevation of the adhesive patch may still be visible, particularly where the adhesive patch  20  crosses from the flanges  114  to the skin  10 , the flanges  114  are still thin enough for the plane to remain substantially uniform for the attachment. While the flanges  114  may have a substantially flat bottom and/or top for attachment, some texture may also be provided for attachment. The flanges  114  may be positioned around the enclosure  110  for providing an attachment surface for the adhesive patch  20 . As an example, the flanges  114  may, continuously or discontinuously, encircle the enclosure  110 , or its elevated portion  116 , thereby surrounding it. The elevated portion  116  such as a cover may be configured for elevated positioning with respect to the flanges  114 , in particular. While the illustration in  FIG.  1   b    involves a single, continuous flange  114  continuously encircling the elevated portion  116 , the detector  100  may also comprise two separate flanges  114 , for example on the opposite sides of the enclosure  110  or the elevated portion  116  thereof. 
     The detector  100  may be made small and/or light for convenient use. It may be configured for fitting within a diameter of 10 centimeters when in use, for example within a diameter of 3-5 centimeters, wherein the diameter may be measurable in the plane of the skin  10 . The detector  100  may be configured for fitting within a height of 2-3 centimeters when in use, even within a height of 5-10 millimeters, wherein the height may be measurable perpendicular to the plane of the skin  10 . For a light embodiment, the detector  100  may have a weight of 100 grams or less, even 5-10 grams or less. 
     The enclosure  110  defines an interior space  30 , where one or more components, such as electrical components, of the detector  100  may be positioned. The detector  100  comprises one or more gas sensors  132  (herein also “the sensors”), which are positioned within the enclosure  110 . The enclosure  110  may be configured to, at least partially, prevent ambient gases from reaching the sensors  132 . However, as noted above, the enclosure  110  may also be configured for air circulation through the enclosure  110 . Importantly, the sensors  132  are configured for detecting gas emissions from the skin  10  for providing one or more measurements signals (herein also “the measurement signals”) for hypoglycemia and/or hyperglycemia detection. Correspondingly, the sensors  132  are positioned and configured so that the ambient gases do not prevent the detection of hypoglycemia and/or hyperglycemia. For this purpose, the sensors may be also directed towards the gas emissions from the skin, for example directly towards the bottom surface  112 . Alternatively or additionally, the enclosure  110  may be configured for directing the gas emissions from the skin  10  towards the sensors  132 , for example directly through the bottom surface  112  or through one or more channels of entry into the enclosure  110 . 
     The sensors  132  may comprise one or more metal oxides, which change their electrical properties when exposed to gas emissions. The one or more metal oxides may comprise tin oxide (SnO 2 ) allowing wide reactivity and strong changes in resistance for hypoglycemia and/or hyperglycemia detection. The sensors  132  may comprise one or more digital sensors. The sensors  132 , and the detector  100 , may be configured for hypoglycemia and/or hyperglycemia detection in an ambient temperature, for example corresponding to 0-40 degrees Celsius, or room temperature, in particular. The sensors  132  may comprise one or more metal-oxide semiconductor (MOS) sensors, for example Bosch BME680 sensors. The sensors  132  may be VOC sensors. As an example, the sensors may be sensitive to at least acetone and/or isoprene emissions for providing the measurement signals for hypoglycemia and/or hyperglycemia detection. In some embodiments, the measurement signals are indicative of resistance for the sensors  132 . For example, the measurement signals  132  may directly correspond to the resistance and/or the conductance for the sensors  132 . In general, the measurement signals provided from the sensors  132  are different when the gas emissions from the skin  10  correspond to hypoglycemia and/or hyperglycemia and when the gas emissions from the skin  10  correspond to a non-hypoglycemia and/or non-hyperglycemia state. It is not necessary to know the exact difference, only that there is a difference. Since the difference can be straightforwardly verified for different sensor configurations, for example through clinical trials, the hypoglycemia and/or hyperglycemia detector  100  and any processors  134  therein can be configured depending on the actual sensor configuration utilized. 
     The detector  100  also comprises one or more processors  134  (herein also “the processors”). In particular, the processors  134  may comprise one or more microcontroller units (MCU), allowing a very cost-efficient solution for a cheap, easy-to-use hypoglycemia and/or hyperglycemia detector. Alternatively or additionally, the processors  134  may comprise one or more microprocessors. The detector  100  may also comprise a system-on-chip (SoC) comprising one or more of the processors  134 . 
     In general, the processors  134  may comprise, for example, one or more of various processing devices, such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing circuitry with or without an accompanying DSP, or various other processing devices including integrated circuits such as, for example, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. 
     The detector  100  may further comprise one or more memories (herein also “the memories”). The processors  134  may be configured to perform any of the processes described herein for the processors  134  according to program code comprised in the memories. The memories may be configured to store, for example, computer programs and the like. The memories may include one or more volatile memory devices, one or more non-volatile memory devices, and/or a combination of one or more volatile memory devices and non-volatile memory devices. For example, the memories may be embodied as magnetic storage devices (such as hard disk drives, floppy disks, magnetic tapes, etc.), optical magnetic storage devices, and semi-conductor memories (such as mask ROM, PROM (programmable ROM), EPROM (erasable PROM), flash ROM, RAM (random access memory), etc.). 
     The processors  134  and/or the memories may be arranged within the enclosure  110 , for example within the elevated portion  116  of the enclosure  110 . 
     Functionality described herein may be implemented via the various components of the detector  100 . For example, the memories may comprise program code for performing any functionality disclosed herein or causing any functionality disclosed herein to be performed, and the processors  134  may be configured to perform the functionality, or cause the functionality to be performed, according to the program code comprised in the memory. When the detector  100  is configured to implement some functionality, some component and/or components of the detector  100 , such as the processors  134  and/or the memories, may be configured to implement this functionality. Furthermore, when the processors  134  are configured for implementing some functionality, this functionality may be implemented using program code comprised, for example, in the memories. For example, if the detector  100  is configured for performing an operation, such as detecting an indication of hypoglycemia and/or an indication of hyperglycemia from the measurement signals for providing an alarm signal when the indication of hypoglycemia and/or the indication of hyperglycemia is detected, the memories and the computer program code can be configured to, with the processors  134 , cause the detector  100  to perform that operation. 
     In addition, the detector  100  may comprise one or more electronic components  136 . For example, the detector  100  may comprise a transceiver. The transceiver may be configured to, for example, transmit and/or receive data using, for example, a 3G, 4G, 5G, LTE, Bluetooth or WiFi connection. The processors  134  may be configured for causing the transceiver to transmit an alarm signal to a remote device such as a mobile phone, a wearable electronic device or any other kind of computing device. Alternative or additionally, the detector  100  may comprise an alarm for providing a local alarm signal for sensory perception. The local alarm signal may comprise an auditory signal and/or a haptic signal, for example a vibration signal. Alternatively or additionally, the local alarm signal may comprise a visual signal. Correspondingly, the alarm may comprise, alone or in any combination, a speaker for the auditory signal, a light for the visual signal and/or a haptic actuator for the haptic signal. The processors  134  may be configured for causing the alarm to produce the local alarm signal. The detector  100  may also comprise a power source  140  for providing electricity to the processors  134  and/or the sensors  132 . The power source  140  may also be configured for providing electricity to any of the electronic components  136 . The power source  140  may be replaceable or fixed. For replacing the power source  140 , the detector  100  may comprise a detachable cover such as the bottom cover  120  and/or the top cover  150 . In particular, it has been found that the detachable cover may be efficiently provided as part of the elevated portion  116 , when the elevated portion is configured as a cover for the enclosure  110 . 
     The detector  100  may comprise a support  130  for electronic components, which may comprise a circuit board such as a printed circuit board (PCB). The sensors  132  may be arranged on the support  130 . Similarly, the processors  134  and/or the memories may be arranged on the support  130 . 
     The support  130  and/or the power source  140  may be arranged within the enclosure  110 , for example within the elevated portion  116  of the enclosure  110 . As an example, the detector  100  may comprise a top cover  150  and a bottom cover  120 , which may be part of the enclosure  110 . The detector  100  may further comprise the support  130 , for example an integrated circuit board, and/or the power source  140 , for example a battery  140 . The support  130  and/or the battery  140  may be arranged for positioning between the bottom cover  120  and the top cover  150 , for example within an elevated portion  116  of the enclosure  110 . The top cover  150  and/or the bottom cover  120  may be detachable, for example for replacement of the power source  140 . 
     An arrangement comprises the detector  100  and the adhesive patch  20 , such as a plaster. The detector  100  and the adhesive patch are configured for the detector to be attached to the skin  10  by the adhesive patch  20 . For this purpose, the detector  100  and the adhesive patch  20  may have a complementary shape. In particular, the detector  100  may comprise the flanges  114  for supporting the adhesive patch  20  for attaching the detector  100  to the skin. Moreover, the enclosure  110  of the detector  110  may comprise the elevated portion  116  and the adhesive patch  20  may define an opening  22 , such as a through-hole, for accommodating the elevated portion  116 . The adhesive patch  20  may thereby be made to contact the detector  114  predominantly, or even solely, to the flanges  114  for attachment between the adhesive patch  20  and the detector  100 . The opening  22  may be positioned at any place within the adhesive patch  20 , for example at the center of the adhesive patch  20 . 
     As an example, the adhesive patch  20  comprises an opening  22 , such as a through-hole, or a cutout for the opening  22 . The opening  22  may have a circular shape but other shapes are possible as well, for example an oval shape or a rectangular shape. The adhesive patch  20  may comprise or be made of biocompatible material for attachment to the skin  10 . The adhesive patch  20  may be disposable so that it may be replaced while the use of the detector  100  is continued. Use of the adhesive patch  20  for attachment allows the position of the detector  100  to be changed during use so that irritation to the skin  10  may be reduced. For example, the adhesive patch  20  may be changed daily. The adhesive patch may be breathable and/or waterproof. It may be siloxane-free for minimizing contamination of the sensors  132  from siloxane for hypoglycemia and/or hyperglycemia detection. Similarly, it may be VOC-free for minimizing contamination of the sensors  132  from VOC. The adhesive patch  20  may be glue-free. The adhesive patch  20  may be customizable, for example having a customizable pattern. 
     The processors  134  are configured for detecting an indication of hypoglycemia and/or an indication of hyperglycemia from the measurement signals, directly or indirectly, for providing an alarm signal when the indication of hypoglycemia and/or the indication of hyperglycemia is detected. The processors  134  may be configured for causing the alarm signal to be provided, for example by utilizing the transceiver and/or the alarm. As an example, the indication(s) may be detected by obtaining one or more measurement values (herein also “the measurement values”) from the measurement signals and comparing the measurement values to one or more baseline values (herein also “the baseline values”) indicative of a non-hypoglycemia and/or non-hyperglycemia state. As the measurement signals can be indicative of resistance for the sensors  132 , the measurement values may also correspond to resistance for the sensors  132 . As an example, the measurement values may comprise one or more values corresponding to resistance for the sensors  132  at one or more points or periods in time. The measurement values may be processed from the measurement signals, for example as accumulated values and/or average values. In some embodiments, the measurement values correspond to an integral of resistance for the sensors  132  over one or more periods of time. A change, such as a drop or an increase, in such integral may then be obtained as an indication of hypoglycemia and/or an indication of hyperglycemia. In general, the indication of hypoglycemia and/or the indication of hyperglycemia may be obtained when the measurement values indicate a difference to the baseline values, for example a difference larger than a threshold difference. The threshold difference may correspond to a percentage of the baseline value, for example 10-20 percent thereof or more. It has been found that rather high values, such as 50-70 percent or more may also be used, as the change indicative of hypoglycemia and/or hyperglycemia may be large. The detector  100  does not need to measure the actual blood sugar level as it can reliably detect an indication of hypoglycemia and/or an indication of hyperglycemia from the gas emissions from the skin  10 , which themselves are indicative of hypoglycemia and/or hyperglycemia. The indication of hypoglycemia and/or the indication of hyperglycemia may correspond, for example, a drop in resistance for the sensors  132 . 
     In some embodiments, the detector  100  is configured, for example by utilizing the processors  134 , to operate the sensors  132  utilizing temperature cycling for detecting gas emissions from the skin  10 . For temperature cycling, the sensors  132  are rapidly heated up and cooled down for detection allowing sensitivity of the sensors  132  to be improved. An example of temperature cycling is provided by Schutze et al. (Environments  2017 ,  4 ,  20 ). While Schutze et al. relates to monitoring indoor air quality, it has been found that similar principles may be used also herein for detecting hypoglycemia and/or hyperglycemia. For this purpose, the sensors  132  may comprise, for example, a MOS sensor, which may also be a VOC sensor. In particular, the detector  100  may be configured, for example by utilizing the processors  134 , to provide the measurement signals during one or more cooling phases of the temperature cycling. Utilizing the sensors  132  during the one or more cooling phases for providing the measurement signals has been found to allow improved detection of hypoglycemia and/or hyperglycemia. 
     The detector  100  may be configured, for example by utilizing the processors  134 , for performing a calibration measurement for determining the one or more baseline values indicative of a non-hypoglycemia and/or non-hyperglycemia state. This allows user-specific calibration for the detector  100 , which may be used to improve accuracy of the detector  100 . A deviation from the baseline values may be used as an indication of hypoglycemia and/or an indication of hyperglycemia. Such a deviation may correspond to a change in resistance of the sensors  132 , for example a decrease in resistance. 
     The detector  100  may be configured, for example by utilizing the processors  134 , for providing the one or more measurement signals according to a schedule, for example at least once an hour. In an example, this is done at least once each 15-30 minutes. Each time, one or more measurements may be made, where several measurements may be used, for example, for improving accuracy by averaging. This allows also mitigating any inaccuracy that may result from the movement of the adhesive patch  20  with respect to the skin  10 . A measurement or a measurement cycle for detecting a single indication of hypoglycemia and/or hyperglycemia may be performed in 30-60 seconds or faster, for example in 5-10 seconds or even faster. 
       FIG.  2    shows an example for detection of hypoglycemia and/or hyperglycemia. While the example is specifically illustrated in terms of hypoglycemia, a similar example can be given for hyperglycemia as well. Therefore, any references to hypoglycemia herein may be considered to include, additionally or alternatively, also hyperglycemia. The example is illustrated in terms of a graph  200  corresponding to a measurement cycle, where a measurement signal, such as resistance of the sensors  132 , is provided (vertical axis) as a function of time (horizontal axis). Measurement signal over a period of time is illustrated both when the user of the detector  100  is in hypoglycemia state  210  and when the user of the detector  100  is in non-hypoglycemia state  220 . In the illustration, an effect of temperature cycling is visualized as dynamic changes for both states. However, the example may also be considered for a detector  100  not utilizing temperature cycling. 
     For both states, the measurement signal, for example corresponding to the resistance of the sensors  132 , first has a rapid increase  230  when the temperature of the sensors  132  is increased. This corresponds to an increase in the sensitivity of the sensors  132 . For both states, the measurement signal also has a rapid decrease  210 ,  220  when the temperature of the sensors is decreased. The steepness of the decrease may, however, correspond to the amount of gas emissions detected, for example so that a more rapid decrease indicates a larger amount of gas emissions detected. Correspondingly, in hypoglycemia state  210  the decrease for the measurement signal may be more rapid than in non-hypoglycemia state  220 . The difference between the measurement signal for the hypoglycemia state  210  and the measurement signal for the non-hypoglycemia state  220  may be used for detecting hypoglycemia, for example if the difference  240  is larger than a threshold value. The threshold value may, for example, correspond to a percentage of the measurement signal in non-hypoglycemia state  220 . It is noted that while the sensors  132  may reach saturation  250  at one or more points in time, this is not necessarily any problem since this could simply be interpreted as the measurement signals for the two states being equal. The measurement may in any case be performed so that at least one point in time or a time period is situated after the saturation  250 . It is also noted that while the cooling period initiating the decrease for the measurement signals may be short, for example less than one second and coinciding with the saturation  250 , the cooling phase during which the measurement signals for detecting the indication of hypoglycemia (and/or the indication of hyperglycemia) can be provided may be larger, for example comprising the whole illustrated period after the saturation  250 . As an example, in  FIG.  2    the illustrated horizontal axis may correspond to a time period of 30 seconds with the sensors  132  in a steady state  260  during a time period of 0-4 seconds from the beginning. A rapid heating period of 1 second initiated at 4 seconds from the beginning may then correspond to the increase  230 , whereas a rapid cooling period of less than 1 second initiated directly thereafter takes place during the saturation  250 . The cooling phase may here comprise the period of 5-30 seconds from the beginning as the response of the sensors  132  recovers towards the steady state  260 . An indication for hypoglycemia and/or an indication of hyperglycemia may be obtained from the accumulated or averaged difference between the measurement signals for the two states  210 ,  220  over a time period such as 0-30 seconds, 5-25 seconds or 10-15 seconds, for example. 
     As an important example, the one or more measurement signals may correspond to one or more measurements over a period of time so that the indication of hypoglycemia and/or the indication of hyperglycemia may correspond a compound value for the one or more measurement signals over time, for example a cumulated and/or averaged difference for the measurement signals in hypoglycemia and/or hyperglycemia state  210  and the measurement signals in non-hypoglycemia and/or non-hyperglycemia state  220  over a period of time. Naturally, this principle may be utilized to generate indicators with various different kinds of details. In any case, any single measurement cycle, for example as illustrated in  FIG.  2   , corresponding to one or more measurements over a period of time, may be represented by a single scalar value, where the scalar value corresponds to the measurement signals over a period of time. 
     For a detector  100  not utilizing temperature cycling, the same principles may be utilized with the distinction that in such case the measurement signal in non-hypoglycemia and/or non-hyperglycemia state  220  may remain substantially constant over time. Correspondingly, the measurement signal in hypoglycemia and/or hyperglycemia state  210  may correspond to smaller values but may also be substantially constant or change in accordance with any changes in the gas emissions from the skin  10 . Also here, the indication of hypoglycemia and/or the indication of hyperglycemia may correspond a compound value for the one or more measurement signals over time, for example a cumulated and/or averaged difference as indicated above. 
       FIG.  3    shows an example of measurement values for detection of hypoglycemia and/or hyperglycemia. Also here, the example is specifically illustrated in terms of hypoglycemia but a similar example can be given for hyperglycemia as well. Therefore, any references to hypoglycemia herein may be considered to include, additionally or alternatively, also hyperglycemia. Here, the measurement values correspond to the area under the curve for the measurement signals as a function of time, for example as illustrated in  FIG.  2   . The graph  300  thereby illustrates such measurement values as a function of an index for the measurement cycle. Importantly, each point on a curve  310  of the graph  300  thereby corresponds to a single measurement cycle, where the point may be obtained, for example, as a scalar value corresponding a cumulated difference between the measurement signal in the two states as illustrated in  FIG.  2    over some time period during the cooling phase of the sensors  132 . A change  320 , such as a drop, in the curve  310  may be used as an indication that the user of the detector  100  is in hypoglycemia and/or hyperglycemia state. 
     Measurements in accordance with the illustrations of  FIGS.  2  and/or  3    may also be used for screening sensor configurations for the detector  100 . Sensor configurations providing a clear indication for hypoglycemia and/or hyperglycemia, such as a clear difference  240  or a clear change  320 , may be utilized and suitable sensor configurations may be selected based on the application requirements, for example cost-efficiency requirements. 
     The different functions discussed herein may be performed in a different order and/or concurrently with each other. 
     Any range or device value given herein may be extended or altered without losing the effect sought, unless indicated otherwise. Also any example may be combined with another example unless explicitly disallowed. 
     Although the subject matter has been described in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims. 
     It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be understood that reference to ‘an’ item may refer to one or more of those items. 
     The term ‘comprising’ is used herein to mean including the method, blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements. 
     Expressions such as ‘plurality’ are in this text to indicate that the entities referred thereby are in plural, i.e. the number of the entities is two or more. 
     Although the invention has been the described in conjunction with a certain type of apparatus and/or method, it should be understood that the invention is not limited to any certain type of apparatus and/or method. While the present inventions have been described in connection with a number of examples, embodiments and implementations, the present inventions are not so limited, but rather cover various modifications, and equivalent arrangements, which fall within the purview of the claims. Although various examples have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed examples without departing from the scope of this specification.