Abstract
Apparatus (1, 50) according to the invention for assisting a user during cardiopulmonary resuscitation of a patient (40), which comprises a force transmission unit (10) with a lower plate (11) that can be placed on the patient's chest (40), an upper plate (12) located at a distance from the lower plate (11), and a force sensor (13) arranged between the lower plate (11) and the upper plate (12) for detecting a force that can be exerted on the patient's chest (40) by means of the upper plate (12) and the lower plate (11), an indicator device for generating at least one signal that can be perceived by the user, and an electronic control device for controlling the indicator device based on the force detected by the force sensor, wherein the force transmission unit (10) is embedded in a flexible mat (2).
Claims
1. Apparatus for assisting a user during cardiopulmonary resuscitation of a patient, comprising: a force transmission unit with a lower plate that can be placed on a patient's chest; an upper plate located at a distance from the lower plate; a force sensor arranged between the lower plate and the upper plate for detecting a force that can be exerted on the patient's chest by means of the upper plate and the lower plate; an indicator device for generating at least one signal that can be perceived by the user; and an electronic control device for controlling the indicator device based on the force detected by the force sensor, wherein the force transmission unit is embedded in a flexible mat.
2. Apparatus according to claim 1, wherein at least the lower plate is deformable.
3. Apparatus according to claim 1, wherein the mat comprises at least two layers between which the force transmission unit is embedded.
4. Apparatus according to claim 1, wherein the mat has a non-slip configuration on its underside and/or on its upper side and/or is printable or printed on its upper side.
5. Apparatus according to claim 1, wherein the mat is foldable.
6. Apparatus according to claim 5, wherein the mat comprises a plurality of sections, which are connected to one another via predetermined fold lines.
7. Apparatus according to claim 5, wherein the control apparatus has a sleep mode and a working mode and the apparatus comprises a sensor, wherein based on a signal from said sensor, the control device is switched from sleep mode to work mode on unfolding of the mat.
8. Apparatus according to claim 1, wherein the control device is configured such that the apparatus can only be used once.
9. Apparatus according to claim 8, wherein the control device is configured such that after a predetermined maximum duration of inactivity, which is determined after a final detection of an exerted force by the force sensor or a transition of the control device from sleep mode to working mode, said indicator device is permanently deactivated.
10. Apparatus according to claim 1, wherein the control device is configured to activate the indicator device depending on a maximum force exerted on the force transmission unit, a minimum force exerted on the force transmission unit, a difference between the maximum and the minimum force, and/or the frequency of fluctuations in the force exerted on the force transmission unit.
11. Apparatus according to claim 10, wherein the control device is configured to activate the indicator device based on a target value or a target range depending on conformity of the maximum force exerted on the force transmission unit, the minimum force exerted on the force transmission unit, the difference between the maximum and the minimum force, and/or the frequency of fluctuation in the force.
12. Apparatus according to claim 1, wherein the apparatus comprises an electrical energy storage device for supplying the control device and the indicator device.
13. Apparatus according to claim 1, wherein the control device comprises a storage device and is configured such that data are stored that represent the force detected by the force sensor and/or the course thereof over time.
14. Apparatus according to claim 11, wherein the storage device is readable by wire and/or wirelessly and/or at least some of the stored data can be represented by means of the indicator device.
15. A method for assisting a user during cardiopulmonary resuscitation of a patient, wherein the control device of an apparatus configured according to claim 1 is switched from sleep mode to working mode when the mat of the apparatus is unfolded, a force exerted on the force transmission unit of the apparatus is detected by the force sensor of the force transmission unit, the indicator device of the apparatus is activated by the control device based on the force detected, and data are stored by the control device that represent the force detected by the force sensor and/or the course thereof over time.
Description
[0039] Further aspects of the invention are explained in the following description of two preferred embodiments and the attached drawing. The figures show the following:
[0040] FIG. 1 is a top view of a first embodiment of an apparatus according to the invention in a unfolded state;
[0041] FIG. 2 is an oblique view of the apparatus according to FIG. 1 in a folded state;
[0042] FIGS. 3a and 3b show a top view and a sectional view of a force transmission unit of the apparatus according to FIG. 1;
[0043] FIGS. 4a to 4c are simplified sectional views of the apparatus according to FIG. 1 in an unfolded, folded and partially unfolded state;
[0044] FIGS. 5a and 5b show a top view and a sectional view of an electronic unit of the apparatus according to FIG. 1;
[0045] FIG. 6 shows the apparatus according to FIG. 1 in a position of use;
[0046] FIG. 7 shows a top view of a second embodiment of an apparatus according to the invention in an opened state;
[0047] FIG. 8 shows the apparatus according to FIG. 7 in a position of use.
[0048] As shown schematically in FIG. 1, an apparatus according to the invention for assisting a user during cardiopulmonary resuscitation according to an embodiment of the invention has an approximately rectangular shape overall, wherein the side lengths a, b are e.g. approx. 44 cm or approx. 24 cm. The apparatus 1 comprises a continuously flexible mat 2, which is subdivided into three sections 5, 6, 7 of approximately equal size by two fold lines 3, 4 running parallel to one another and parallel to the narrow sides of the rectangle. The mat 2 is sufficiently flexible overall to adapt itself to the surface of the chest of a patient on whom the apparatus 1 is placed. The fold lines 3, 4 are thinned out by stamping or milling, which provides them with greater flexibility compared to the sections 5, 6, 7. The apparatus 1 further comprises a force transmission unit 10 that is embedded in the mat 2 approximately in the center of the middle section 6 of said mat. Moreover, FIG. 1 shows an electronics unit 20 embedded in the mat 2 with a battery unit 21 and two mutually interacting snap fastener elements 22, 23 (see below). The battery unit 21 serves as the electrical energy supply of the electronics unit 20; for this purpose, for example, a button cell is placed in the battery unit 21 as an electrical energy storage device. FIG. 1 also shows electrical wires 24, 25, 26, 27 by means of which the snap fastener elements 22, 23, the battery unit 21, and the force transmission unit 10 are connected to the electronics unit 20. As can be seen in FIG. 1, the wires 25, 27 run through one or a plurality of fold lines 3, 4 and are correspondingly configured in a flexible manner. The wires 25, 27 can run in sections along the fold lines 3, 4 in order to improve the foldability of the mat 2.
[0049] The sections 5, 6, 7 can be placed on top of one another by folding them up along the fold lines 3, 4. In FIG. 2, the apparatus 1 is shown in a folded state. A first section 5 is folded at the fold line 2 over the second, middle section 6 of the mat 2 and rests on it. The third section 7 is folded along the fold line 4 over the sections 5, 6 that have been placed on top of one another. This gives rise to a highly compact apparatus whose side lengths are approximately b=24 cm, c=15 cm, and d=0.8 to 1.3 cm. The apparatus 1 thus fits in a folded state into a standard first aid kit according to DIN 13157. As shown in FIG. 1, the middle section 6 and the third section 7 have approximately equal side lengths, while the first section 5 is configured to be somewhat narrower in the direction of the long edge of the mat 2 so that it will come to rest within the folded up apparatus according to FIG. 2 without wrinkling.
[0050] The force transmission unit 10 is configured approximately in the form of a circular disk overall having a diameter D of approximately 5 to 12 cm (see FIG. 3a). As shown in a sectional view in FIG. 3b, the force transmission unit 10 is composed of a lower plate 11, an upper plate 12, and a force sensor 13 placed between them. The plates 11, 12 are both configured as flat circular disks that are arranged congruently to each other and are connected to each other via the force sensor 13, which also has a flat configuration. The plates 11, 12 may be composed of a hard plastic and have a thickness of approximately 0.3 to 1.4 mm respectively. In particular, the plates 11, 12 and the force sensor 13 can be flexible so that the force transmission unit 10 as a whole is flexible, and preferably elastically bendable, and has a stiffness that approximately corresponds e.g. to that of an ordinary credit card.
[0051] The force sensor 13, which for example can be a piezoelectric or a resistive force sensor, has e.g. a measuring range of 0.1 to 300 N and a thickness of approximately 0.1 to 2.5 mm, for example 0.45 mm. The force sensor 13 has e.g. a square surface with a side length of approx. 4 cm and has an accuracy of 3%, an operating temperature range of 30 to +70 C., a response time of approx. 5 s, and a useful life of approximately one million compression cycles, which is generally sufficient for the present application.
[0052] As can be further seen in FIG. 3b, the force transmission unit 10 is embedded in the mat 2. The mat 2 is composed of a lower layer 8 and an upper layer 9, which are connected to each other e.g. by gluing. The lower and the upper layer 8, 9 are composed for example of rubber or a suitable foam and each has a thickness of approx. 2 mm. The force sensor unit 10 is embedded between the lower layer 8 and the upper layer 9 and glued to the lower layer 8 and the upper layer 9. The electrical wire 27, via which the force sensor 13 is connected to the electronics unit 20 (see FIG. 1), and which is also embedded between the lower layer 8 and the upper layer 9 of the mat 2, is not shown in FIG. 3b. The underside 14 of the lower layer 8 has a slip-resistant coating or is roughened in order to allow secure and reliable positioning of the mat 2 on the patient's chest. The upper side 15 of the upper layer also has a slip-resistant coating or is roughened, is printable, and has brief instructions for use of the apparatus in cardiopulmonary resuscitation and markings for correct positioning printed on it.
[0053] In FIGS. 4a to 4c, the apparatus 1 is shown in an unfolded state, a folded state, and at the beginning of unfolding in a sectional view, with only the mat 2 and the snap fastener elements 22, 23 being shown. As shown in FIG. 4a, a first snap fastener element 22 that comprises a connector is arranged in the lower layer 8 of the mat 2 in the first section 5 adjacent to the fold line 3. A second snap fastener element 23 interacting with the first snap fastener element 22, which comprises a head that fits into the connector, is arranged in the upper layer 9 of the mat 2 in the third section 7 adjacent to the edge of the mat 2. When the apparatus 1 is in a folded state, the first section 5 is placed over the middle section 6 and the third section 7 is then folded over the first section 5. This brings the second snap fastener element 23 into contact with the first snap fastener element 22 such that the head snaps into the connector and the snap fastener elements 22, 23 are connected to each other. In the apparatus shown in FIG. 4b, the three sections 5, 6, 7 are folded over one another in the manner described, and the snap fastener is engaged with the snap fastener elements 22, 23. This provides a compact and easily portable apparatus (also see FIG. 2). Moreover, in the state in which the head of the second snap fastener element 23 engages with the connector of the first snap fastener element 22, a circuit is closed via the electrical wires 24, 25 by means of which the snap fastener elements 22, 23 are connected to the electronics unit 20 (see FIG. 1). As long as the circuit is closed, it can be assumed that the apparatus 1 is in the folded state shown in FIG. 4b, and is therefore not in use. In this state, the electronics unit 20 is in sleep mode, which consumes only an extremely low amount of energy and in which the circuit is controlled only by the snap fastener elements 22, 23. However, if the apparatus 1 is unfolded to bring it into operation, the head of the second snap fastener element 23 is pulled out of the connector of the first snap fastener element 22 and the circuit is opened; this is shown in FIG. 4c. Opening of the circuit is detected by the electronics unit 20, which is in sleep mode, and causes it to be switched to working mode, in which the further electrical and electronic functions of the apparatus 1 are activated.
[0054] In FIGS. 5a and 5b, the electronics unit 20 is shown in detail in a top view and in a section through the mat 2 in the first section 5. The electronics unit 20 comprises a printed circuit board (PCB) 30 that carries a sound generator 31, a microcontroller 32, and an LED unit 33. The sound generator 31 is for example a piezoelectric sound generator that is suitable for generating sounds in the audible frequency range at a volume high enough to be perceived even in a noisy environment. The LED unit 33 comprises a plurality of light-emitting diodes (LEDs) 34, 35, 36, which produce light of various colors at a brightness high enough to be perceived even in bright daylight, e.g. the LED 34 produces red light, the LED 35 green light, and the LED 36 blue light. The sound generator 31 and the LED unit 33 each have a thickness of approx. 2 to 3 mm. The microcontroller 32 is configured to receive and evaluate the sensor signal generated by the force sensor 13 and to control the sound generators 31 and the LEDs 34, 35, 36. For this purpose, the microcontroller 32 comprises processing means with corresponding drivers and a RAM storage unit in which the target values for the force of the compressions performed in cardiac massage and the frequency of said compressions are stored. The microcontroller 32 comprises a further storage unit in which are stored the measurement values for the force actually exerted, which is detected by the force sensor 13, together with corresponding time data provided by a clock or a pulse generator of the microcontroller 32, and thus the course over time of the cardiac massage. Moreover, the microcontroller 32 can also be equipped with transmission means for preferably wireless transmission of the stored data, e.g. by means of a Bluetooth, to a receiving device, which for example can be a smartphone having a corresponding app.
[0055] FIG. 5a also shows the electrical wires 24, 25 embedded in the mat 2 via which the circuit can be closed by the snap fastener elements 22, 23, the wire 26 via which the electronics unit 20 is supplied by the battery unit 21 with electrical energy, and the wire 27 via which the microcontroller activates the force sensor 13 of the force transmission unit 10 and receives the sensor signal therefrom (see FIG. 1).
[0056] As shown in FIG. 5b, the electronics unit 20 is inserted between the lower layer 8 and the upper layer 9 of the mat 2 and integrated into the upper layer 9 of the mat 2 such that the PCB 30 is embedded between the upper layer 9 and the lower layer 8 and the sound generator 31 and the LED unit 33 are flush with the upper surface 15 or extend slightly beyond it. The LED 30 can be glued to the upper layer 9 and the lower layer 8. The electrical wires 24, 25, 26, 27, which are not visible in FIG. 5b, are also embedded between the lower layer 8 and the upper layer 9 of the mat 2.
[0057] FIG. 6 is a symbolic representation of how the apparatus 1 is positioned in an opened state on the chest of a patient 40. Here, the area of the mat 2 in which the force transmission unit 10 is embedded comes to rest on the sternum so that compressions exerted on the force transmission unit 10 are transmitted to the sternum and cause compression of the chest. For this purpose, the area in which the force transmission unit 10 is embedded is indicated in color on the upper side of the mat 2. There are also markings present that facilitate the proper alignment of the apparatus 1, for example in relation to the neck 41 of the patient 40.
[0058] For use, the apparatus 1 is removed from a package in which it is sealed in a folded or closed state (see FIG. 2, FIG. 4b). The apparatus 1 is then unfolded or opened according to FIG. 4c, wherein the snap fastener elements 22, 23 are separated from each other and the circuit closed via said elements and the wires 24, 25 is opened. This places the microcontroller 32 in working mode, and the sound generator 31 and the blue LED 36 are activated in order to generate acoustic and optical signals in a rhythm corresponding to the target frequency of the compressions during cardiac massage; here, it can be provided that the signals are delayed, e.g. not emitted until approximately 2 seconds after the apparatus 1 is unfolded or opened. At the same time, an optical and an acoustic signal are preferably generated with a brief duration, e.g. approximately 50 ms respectively, and with a repetition frequency of approximately 100/min. The apparatus 1 is placed by a user on the chest of a patient 40 such that the force transmission unit 10, which is marked on the upper side 15 of the mat 2, comes to rest on the sternum in the area in which the compressive force must be exerted in cardiac massage; in this case, the shape of the mat 2 and optionally further markings on the mat 2 aid in correct positioning. The user then begins the cardiac massage, and for this purpose exerts a compressive force on the area marked on the upper side 15 of the mat 2. The compressive force exerted is continually monitored by the force sensor 13 of the force transmission unit 10, and after the end of each full period of the clock signal of approximately 100/min, the maximum and minimum compressive force detected within the period are determined. If the maximum value determined is above a first target value, for example 220 N, and the minimum value determined is below a second target value, for example 50 N, the green LED 35 is activated. If the maximum value is below the first target value and/or the minimum value is above the second target value, the red LED 34 is activated. After a preset number of compressions that fulfill the above conditions, an acoustic or optical signal is generated that indicates that ventilation is needed. After a preset time, a further signal is emitted, indicating that the cardiac massage should be continued. At the same time, the course over time of the exerted force or the compressions is stored in the RAM storage device of the microcontroller 32. In the event that medical personnel arrive after a lay person has performed resuscitation, the stored data are wirelessly read and displayed on a reading device such as a smartphone, and are then available as a basis for decisions with respect to other measures. After no further compressions have been performed for an extended period of time, the sound generator 31 and the LED unit 33 are no longer activated by the microcontroller 32, even after the snap fastener elements 22, 23 are again connected and separated. The microcontroller 32 is then available only for optionally reading the stored data again.
[0059] FIG. 7 is a schematic representation of a further embodiment of the present invention. In the apparatus 50 configured according to this embodiment, a white LED 51 is provided to indicate a preset pace of the compressions performed by a user during cardiac massage, and an LED unit 52 is provided to indicate whether or not the exerted force lies within a target range for cardiac massage. For this purpose, the LED unit 52 comprises a red and a green LED, wherein the green LED lights up when the exerted force is within the target range, and the red LED lights up when the force is too weak; a further LED can also be provided that is activated when the exerted force is too great, which only rarely occurs in practice, however. Moreover, a ventilation indicator is provided, for example in the form of an arrow 53 made up of blue LEDs, which is activated after a preset number of compressions in order to notify the user that ventilation of the patient is required. The mat 2 of the apparatus 50 is configured to be placed across the chest of a patient and has markings 54 in the middle section 6 for alignment in relation to the patient's neck. In other respects, the apparatus 50 shown in FIG. 7 is configured in a manner corresponding to the apparatus 1 described above and is used correspondingly.
[0060] As symbolically shown in FIG. 8, in the embodiment of FIG. 7, the correct position of the apparatus 50 or the mat 2 on the chest of a patient 40 is such that the neck 41 of the patient 40 is above the middle section 6. In order to facilitate corresponding positioning, the mat 2 has markings 54 that indicate the correct positioning of the mat 2 in relation to the neck 41 of the patient 40; there is also an imprint 55 on the upper side of the mat 2 that shows the correct positioning of the apparatus 50.
[0061] For purposes of clarity, not all of the reference symbols are shown in all of the figures. Reference symbols in a figure that are not explained have the same meaning as in the remaining figures.
LIST OF REFERENCE SYMBOLS
[0062] 1 Apparatus [0063] 2 Mat [0064] 3 Folding line [0065] 4 Folding line [0066] 5 Section [0067] 6 Section [0068] 7 Section [0069] 8 Layer [0070] 9 Layer [0071] 10 Force-transmission unit [0072] 11 Plate [0073] 12 Plate [0074] 13 Force sensor [0075] 14 Underside [0076] 15 Upper side [0077] 20 Electronics unit [0078] 21 Battery unit [0079] 22 Snap fastener element [0080] 23 Snap fastener element [0081] 24 Wire [0082] 25 Wire [0083] 26 Wire [0084] 27 Wire [0085] 30 PCB [0086] 31 Sound generator [0087] 32 Microcontroller [0088] 33 LED unit [0089] 34 LED [0090] 35 LED [0091] 36 LED [0092] 40 Patient [0093] 41 Neck [0094] 50 Apparatus [0095] 51 LED [0096] 52 LED unit [0097] 53 Arrow [0098] 54 Marking [0099] 55 Imprint [0100] a Side length [0101] b Side length [0102] c Side length [0103] d Height [0104] D Diameter
