Automated external defibrillator and method for notifying anomalies of an automated external defibrillator

Abstract

The AED (1) has a detector (10) and a notifier. The notifier has a display unit (40) and a sounder (50). The display unit (40) alternately and one or more times respectively performs a first mode and a second mode. In the first mode the display unit (40) causes at least one light source (42) to emit light at a first intensity. In the second mode the display unit (40) causes the light source (42) to emit light at a second intensity having a lower power consumption than the first intensity or causes the light source (42) to emit no light. The sounder (50) alternately and one or more times respectively performs a third mode and a fourth mode. In the third mode the sounder (50) produces a prompt tone at a third intensity. In the fourth mode the sounder (50) produces a prompt tone at a fourth intensity having a lower power consumption than the third intensity or produces no prompt tone. At least half of each period of the first mode overlaps in time with a corresponding period of the fourth mode. At least half of each period of the third mode overlaps in time with a corresponding period of the second mode.

Description

Technical Field

[0001] This disclosure relates to an automated external defibrillator (AED) and a method for notifying the AED of an abnormality. Background Technology

[0002] Typically, automated external defibrillators (hereinafter referred to as AEDs) are equipped with a self-test function. This self-test checks, for example, the remaining battery level, the connection status with the defibrillation pad, and whether various circuits are functioning correctly, to determine whether the AED is working properly.

[0003] When a self-test detects an anomaly, the AED displays the presence of the anomaly or emits a beeping sound to notify the user of the anomaly. In this way, the AED notifies the user of the anomaly. For example, Patent Document 1 discloses a technique in which the user is notified of an AED anomaly by using both an LED (light-emitting diode) display and a beeping sound.

[0004] Reference List

[0005] Patent documents

[0006] PTL1: U.S. Unexamined Patent Application Publication 2011 / 0213433 Summary of the Invention

[0007] Technical issues

[0008] To make it easier for users around the AED to notice any abnormality, it is preferable to provide both a visible and an audible alert, as disclosed in Patent Document 1. On the other hand, when both visible and audible alerts are provided simultaneously, there is a possibility that the instantaneous load on the battery may increase.

[0009] The purpose of this disclosure is to provide an automated external defibrillator (AED) that can suppress battery load while notifying the user of the abnormality via visible and audible methods when an abnormality is detected in the AED, and to provide a method for notifying the user of the abnormality in the AED.

[0010] Solution to the problem

[0011] According to a first aspect of this disclosure, an automated external defibrillator is provided, comprising:

[0012] A detector that detects abnormalities in the automated external defibrillator; and

[0013] The notifier, when the detector has detected the anomaly, notifies the user of the detection of the anomaly within a predetermined time period; wherein,

[0014] The notification device has a display unit including a light source and a speaker that generates a notification sound;

[0015] The display unit alternately and once or multiple times executes a first mode and a second mode respectively, such that in the first mode the display unit causes the light source to emit light with a first intensity, and in the second mode the display unit causes the light source to emit light with a second intensity having a power consumption lower than the first intensity, or causes the light source not to emit light;

[0016] The speaker alternately and once or multiple times executes the third mode and the fourth mode respectively, such that in the third mode the speaker produces a cue tone with a third intensity, and in the fourth mode the speaker produces a cue tone with a fourth intensity having a power consumption lower than the third intensity, or does not produce a cue tone.

[0017] At least half of each time period in the first mode overlaps temporally with a corresponding time period in the fourth mode; and

[0018] At least half of each time period in the third mode overlaps temporally with a corresponding time period in the second mode.

[0019] According to a second aspect of this disclosure, a method is provided for notifying an abnormality of an automated external defibrillator (AED), the method causing the AED to perform:

[0020] The detection steps include detecting abnormalities in the automated external defibrillator; and

[0021] The notification step involves notifying the user of the detected anomaly within a predetermined time period when the anomaly is detected during the detection step; wherein:

[0022] The notification step includes a display step that uses a light source to display the information and a sound step that generates a notification sound.

[0023] The display step is as follows: alternately and once or multiple times, executing a first mode and a second mode respectively, such that in the first mode the light source emits light with a first intensity, and in the second mode the light source emits light with a second intensity having a power consumption lower than the first intensity, or the light source does not emit light;

[0024] The sound generation steps are as follows: the third mode and the fourth mode are executed alternately and once or multiple times, such that a prompting sound is generated at a third intensity in the third mode, and a prompting sound is generated at a fourth intensity with a power consumption lower than the third intensity in the fourth mode, or no prompting sound is generated.

[0025] At least half of each time period in the first mode overlaps temporally with a corresponding time period in the fourth mode; and

[0026] At least half of each time period in the third mode overlaps temporally with a corresponding time period in the second mode.

[0027] Beneficial effects of the invention

[0028] According to the above configuration, when an abnormality is detected in the automated external defibrillator, the battery load can be suppressed while notifying the user of the abnormality through visual and audible methods. Attached Figure Description

[0029] Figure 1 This is a block diagram illustrating an example configuration of an automated external defibrillator according to an embodiment of the present disclosure.

[0030] Figure 2A This is a schematic diagram illustrating a first example of operation of an automated external defibrillator according to an embodiment of the present disclosure.

[0031] Figure 2B It is shown Figure 2A A schematic diagram showing the details of part X.

[0032] Figure 3A This is a schematic diagram illustrating a second example of operation of an automated external defibrillator according to an embodiment of the present disclosure.

[0033] Figure 3B This is a schematic diagram illustrating an example of a third action of an automated external defibrillator according to an embodiment of the present disclosure.

[0034] Figure 3C This is a schematic diagram illustrating an example of the fourth operation of an automated external defibrillator according to an embodiment of the present disclosure.

[0035] Figure 3D This is a schematic diagram illustrating an example of the fifth operation of an automated external defibrillator according to an embodiment of the present disclosure.

[0036] Reference tag list

[0037] 1: Automated External Defibrillator (AED)

[0038] 10: Controller (Detector)

[0039] 20: Memory

[0040] 30: Operating the receiver

[0041] 31: Power button

[0042] 32: Check button

[0043] 40: Display Unit (Notifier)

[0044] 41: Indicator

[0045] 42: Light source

[0046] 43: Monitor

[0047] 50: Voice transmitter (notifier)

[0048] 60: High Voltage Generator

[0049] 70: Pad Connector

[0050] 80: Power supply

[0051] 90: Defibrillation pad Detailed Implementation

[0052] Embodiments of this disclosure will now be described by way of example with reference to the accompanying drawings. In the following description, the same or equivalent elements are designated by the same reference numerals or names accordingly and even separately in different drawings, and therefore repeated descriptions thereof will be appropriately omitted.

[0053] First, we will use Figure 1 Describe the processors that make up AED1. Figure 1 This is a block diagram illustrating an example configuration of an AED1 according to an embodiment of the present disclosure. The AED1 includes a controller 10, a memory 20, an operation receiver 30, a display unit 40, a speaker 50, a high-voltage generator 60, a pad connector 70, and a power supply 80.

[0054] The controller 10 reads and executes programs stored in the memory 20 to control various actions of the AED1. The controller 10 has a processor such as a CPU (central processing unit), a memory such as ROM (read-only memory) or RAM (random access memory), a real-time clock, an A / D converter, etc.

[0055] Controller 10 controls various actions used for lifesaving (hereinafter also referred to as "lifesaving actions"), such as energy charging / discharging control, sequence control, A / D conversion, and electrocardiogram analysis. Additionally, controller 10 performs a self-test to detect abnormalities in AED1. That is, controller 10 also functions as a detector. The self-test can be performed when a preset time arrives, or when the operation receiver 30 receives a predetermined operational input (e.g., the check button 32, described later, is pressed).

[0056] In the self-test, for example, the controller 10 performs checks on the circuitry used to control the lifesaving action (such as confirming the time constant of the ECG input circuit, confirming the circuitry for identifying electrode plate contact, and confirming the energy value during charging to the capacitor / during internal discharge), checks on the power supply 80 (such as voltage value, battery remaining level value, and current consumption value), and checks on the defibrillator pad 90 connected to the pad connector 70 (such as the pad's resistance value and confirmation of its expiration date), to confirm whether they are normal or abnormal.

[0057] The memory 20 stores the procedures required for the operation of the AED1, audio data, adjustment values, electrocardiogram data during the rescue, self-test results, etc. The memory 20 may include, for example, an auxiliary storage device, such as a hard disk. A portion of the memory 20 may be an external storage device that can be removably attached to the AED1.

[0058] The operation receiver 30 receives operation input from the user. The operation receiver 30 includes a power button 31 and a check button 32. The power button 31 is used to initiate a rescue operation. The check button 32 is used to initiate a self-test. Additionally, although not shown, the operation receiver 30 may be equipped with a shock button for administering an electric shock, a button for setting the self-test timing, etc.

[0059] The display unit 40 includes an indicator 41 and a display 43. The display 43 is, for example, a liquid crystal display (LCD). The display 43 displays instructions to the user as graphics or characters, or displays electrocardiogram (ECG) signals. The display 43 may be equipped with a touch panel or may also function as an operation receiver 30.

[0060] The indicator 41 has one or more light sources 42. Each light source 42 is, for example, an LED light source. The light source 42 may include fluorescent material. The indicator 41 uses the illumination form (e.g., color or flashing) of each light source 42 to indicate the status of the AED1. When no abnormality is detected in the AED1 through self-testing, the AED1 is determined to be normal. For example, a color such as green or blue may be displayed on the indicator 41.

[0061] When an anomaly is detected in AED1, the display unit 40 serves as part of a notification device to inform the user of the detected anomaly within a predetermined time period. The use of the display unit 40 as a notification device will be described in detail in the following paragraphs.

[0062] The speaker 50 issues various commands to the user via voice, referencing audio data stored in the memory 20. Furthermore, when an anomaly is detected in the AED1, the speaker 50 serves as part of a notification system to inform the user of the detected anomaly within a predetermined time period. The speaker 50's function as a notification system will be described in detail in the following paragraphs.

[0063] The high-voltage generator 60 performs charging and discharging of energy for defibrillation according to control signals from the controller 10. A pad connector 70 connects to the defibrillation pad 90. The energy released by the high-voltage generator 60 is delivered to the person in need of assistance through the pad connector 70 and the defibrillation pad 90. Additionally, the defibrillation pad 90 acquires the electrocardiogram (ECG) signal of the person in need of assistance. The ECG signal is filtered and amplified, for example, before being sent to the controller 10.

[0064] Power supply 80 includes a battery. Power supply 80 converts the power supplied from the battery into the required voltage and supplies power to the aforementioned processor. The remaining battery level can be confirmed through self-testing.

[0065] The following describes an example of the operation of AED1, particularly its anomaly notification method. AED1 performs a detection step (detection step) via a detector (controller 10) to detect anomalies in AED1. When an anomaly is detected during the detection step, AED1 performs a notification step to notify the user of the detected anomaly within a predetermined time period. The aforementioned "predetermined time period" is not particularly limited. For example, the "predetermined time period" is approximately two to three seconds. Preferably, the notification step is repeated within a predetermined cycle (e.g., every thirty seconds) unless a pause condition is met, which is either that the anomaly of AED1 has been cancelled or that the user has performed an action to pause the notification.

[0066] The notification steps include a display step using a light source 42 on an indicator 41, and an audio step using a speaker 50 to generate a prompt tone. The display step alternately executes a first mode and a second mode based on a command signal issued from the controller 10. In the first mode, the light source 42 emits light with a first intensity. In the second mode, the light source 42 emits light with a second intensity that consumes less power than the first intensity, or does not emit light at all.

[0067] Here, the first intensity is not particularly limited, as long as it is an intensity of light emitted by the light source 42 that is visibly perceptible to the user. The second intensity is not particularly limited, as long as the power consumption of the second intensity is lower than that of the first intensity. However, it is preferable that the power consumption of the second intensity is as low as possible. Light emitted by the light source 42 with the second intensity can be visually imperceptible to the user. Preferably, the second mode is a mode in which the light source 42 does not emit light.

[0068] In the display step, each of the first and second modes is executed once or more, preferably multiple times. The number of times the first mode is executed and the number of times the second mode is executed may be the same or different from each other. At least half of each period of executing the first mode overlaps temporally with a corresponding period of the fourth mode executed by the sound generator 50, which will be described later. Preferably, at least nine-tenths of the period of executing the first mode, more preferably, the entire period of executing the first mode overlaps temporally with the period of executing the fourth mode, which will be described later.

[0069] The sound-emitting steps are performed alternately in the third and fourth modes based on command signals issued from the controller 10. In the third mode, a prompt tone with a third intensity is generated. In the fourth mode, a prompt tone with a fourth intensity and lower power consumption than the third intensity is generated, or no prompt tone is generated.

[0070] Here, the third intensity is not particularly limited, as long as it is an intensity of the prompt tone that the user can recognize. The fourth intensity is not particularly limited, as long as it has lower power consumption than the third intensity. However, it is preferable that the power consumption of the fourth intensity is as low as possible. The prompt tone generated at the fourth intensity may not be recognizable by the user. Preferably, the fourth mode is a mode that does not generate a prompt tone.

[0071] During the sound-generating step, each of the third and fourth modes is executed once or more, preferably multiple times. The number of times the third mode is executed and the number of times the fourth mode is executed can be the same or different from each other. At least half of each period of executing the third mode overlaps temporally with a corresponding period of executing the second mode by the display unit 40. Preferably, at least nine-tenths of the period of executing the third mode overlaps temporally, and more preferably, the entire period of executing the third mode overlaps temporally with the period of executing the second mode.

[0072] The following will use Figure 2A and Figure 2B as well as Figures 3A to 3D A detailed description of the actions performed by AED1. Figure 2A This is a schematic diagram illustrating the first action example of AED1. Figure 2A In this context, time T0 is the moment when an anomaly is detected in AED1. Each bar extending vertically from the axis described as an "indicator" signifies that light source 42 emits light inside indicator 41. Similarly, each bar extending vertically from the axis described as a "beep tone" signifies that sound generator 50 generates a beep tone.

[0073] When an anomaly is detected at time T0, a notification step is executed, as shown in section X. Specifically, light source 42 emits light four times, and sound transmitter 50 produces a prompt tone five times. This notification step is repeated throughout period C unless the aforementioned pause condition is met.

[0074] Figure 2B It is shown Figure 2A A schematic diagram showing details of part X. Figure 2B In this diagram, times T1 to T10 represent the time periods during which the notification step is executed. Intensity S1 represents the first intensity. Intensity S2 represents zero intensity, i.e., the light source 42 is off. Intensity S3 represents the third intensity. Intensity S4 represents zero intensity, i.e., no prompt sound is generated. Incidentally, the intensities S1 to S4 in the other attached diagrams are similar or identical.

[0075] During the time period P1 between times T1 and T2, the display unit 40 executes the second mode, and the speaker 50 executes the third mode. That is, during time period P1, the speaker 40 produces a prompt tone while the light source 42 is turned off. The time periods between times T3 and T4, between times T5 and T6, between times T7 and T8, and between times T9 and T10 are also similar to or the same as time period P1.

[0076] During time period P2, between times T2 and T3, display unit 40 operates in the first mode, and speaker 50 operates in the fourth mode. That is, during time period P2, while light source 42 is on, speaker 40 does not produce a prompt sound. The time periods between times T4 and T5, between times T6 and T7, and between times T8 and T9 are also similar to or the same as time period P2. Therefore, in Figure 2B In the example, each time period of executing the first mode and each time period of executing the third mode do not overlap with each other in time.

[0077] There are no particular restrictions on the lengths of time periods P1 and P2. For example, the lengths of time periods P1 and P2 are preferably no greater than 1000 milliseconds, and may be no greater than 300 milliseconds. Furthermore, the lengths of time periods P1 and P2 may be the same or different from each other. In other words, the lengths of the time periods executing the first mode and the second mode may be the same or different from each other. Similarly, or in the same manner, the lengths of the time periods executing the third mode and the fourth mode may be the same or different from each other.

[0078] Furthermore, the lengths of the time intervals executing the first mode can differ from one another. For example, the time interval between times T2 and T3 could be 100 milliseconds, and the time interval between times T4 and T5 could be 200 milliseconds. Similar or identical rules can also be applied to the time intervals executing the second through fourth modes.

[0079] Figure 3A This is a schematic diagram illustrating a second example of the action of AED1. Figure 3A In this process, display unit 40 executes a first mode during the time periods shown between times T11 and T12 and between times T15 and T16. Similarly, or in the same manner, display unit 40 executes a second mode during the time periods shown between times T12 and T15 and between times T16 and T18.

[0080] Additionally, the speaker 50 executes the third mode during the time periods between T13 and T14 and between T17 and T18. Similarly, the speaker 50 executes the fourth mode during the time periods between T11 and T13 and between T14 and T17.

[0081] exist Figure 3A In the example, each period of executing the second mode overlaps with each period of executing the fourth mode in time. In other words, the periods of executing the notification step include the periods when light source 42 is turned off and no prompt sound is produced.

[0082] Figure 3B This is a schematic diagram of the third action example of AED1. Figure 3B In this process, display unit 40 executes the first mode during the time periods shown between times T21 and T23 and between times T24 and T27. Similarly, or in the same manner, display unit 40 executes the second mode during the time periods shown between times T23 and T24 and between times T27 and T28.

[0083] The speaker 50 performs the third mode during the time periods shown between times T22 and T25 and between times T26 and T28. In a similar or identical manner, the speaker 50 performs the fourth mode during the time periods shown between times T21 and T22 and between times T25 and T26.

[0084] exist Figure 3B In the example, each time period of executing the first mode and each time period of executing the third mode overlap with each other in time. In other words, the time periods of executing the notification step include the time periods when the light source 42 is turned on and a prompt sound is also generated (between times T22 and T23, between times T24 and T25, and between times T26 and T27).

[0085] At least half of each time period in the execution of the first mode overlaps temporally with each time period in the execution of the fourth mode. Specifically, the length between times T21 and T22 is at least half the length between times T21 and T23. Similarly, the length between times T25 and T26 is at least half the length between times T24 and T27.

[0086] In a similar or identical manner, at least half of each time period of the third mode overlaps temporally with each time period of the second mode. Specifically, the length between times T23 and T24 is at least half the length between times T22 and T25. Similarly, the length between times T27 and T28 is at least half the length between times T26 and T28.

[0087] Figure 3C This is a schematic diagram of the fourth action example of AED1. Figure 3C In this process, display unit 40 executes the first mode during the time periods shown between times T31 and T33 and between times T35 and T37. Similarly, or in the same manner, display unit 40 executes the second mode during the time periods shown between times T33 and T35 and between times T37 and T38.

[0088] Additionally, the speaker 50 executes the third mode during the time periods between T32 and T34 and between T36 and T38. Similarly, the speaker 50 executes the fourth mode during the time periods between T31 and T32 and between T34 and T36.

[0089] exist Figure 3C In the example, with Figure 3A In a similar or identical manner to the example, the time periods for executing the second mode and the time periods for executing the fourth mode overlap in time (between times T34 and T35).

[0090] In addition, Figure 3C In the example, with Figure 3B In a similar or identical manner to the example, the time periods for executing the first mode and the time periods for executing the third mode overlap in time (between times T32 and T33, and between times T36 and T37).

[0091] At least half of each time period in the first mode overlaps temporally with each time period in the fourth mode. Specifically, the length between times T31 and T32 is at least half the length between times T31 and T33. Similarly, the length between times T35 and T36 is at least half the length between times T35 and T37.

[0092] In a similar or identical manner, at least half of each time period of the third mode overlaps temporally with each time period of the second mode. Specifically, the length between times T33 and T34 is at least half the length between times T32 and T34. In a similar or identical manner, the length between times T37 and T38 is at least half the length between times T36 and T38.

[0093] Figure 3D This is a schematic diagram illustrating an example of the fifth action of AED1. Figure 3D The intensity S2' shown is the second intensity. That is, intensity S2' refers to the state where each light source 42 is turned on to emit light with an intensity lower than that of intensity S1. Furthermore, intensity S4' is the fourth intensity. That is, intensity S4' refers to the state where the speaker 50 emits a cue tone with a volume lower than that of intensity S3.

[0094] exist Figure 3D In this process, display unit 40 executes a first mode during the time periods shown between times T41 and T42 and between times T43 and T44. Similarly, display unit 40 executes a second mode during the time periods shown between times T42 and T43 and between times T44 and T45, in which light source 42 emits light in a dimmer state than in the first mode. Furthermore, light source 42 is turned off during the time periods before time T41 and after time T45.

[0095] Additionally, the speaker 50 executes the third mode during the time periods between T42 and T43 and between T44 and T45. Similarly, the speaker 50 executes a fourth mode during the time periods between T41 and T42 and between T43 and T44, whereby the speaker 50 produces a lower volume prompt tone than in the third mode. Furthermore, no prompt tone is produced during the time periods before T41 and after T45.

[0096] Next, the effects obtained by the various configurations included in the AED1 according to this embodiment and the exception notification method of the AED1 will be described.

[0097] At least half of each period in the first mode, which operates with high power consumption, overlaps temporally with a corresponding period in the fourth mode, which operates with low power consumption; and at least half of each period in the third mode, which operates with high power consumption, overlaps temporally with a corresponding period in the second mode, which operates with low power consumption. This configuration allows for the suppression of transient battery load while simultaneously notifying the user of AED1's malfunction via both visible and audible methods.

[0098] Furthermore, at least nine-tenths of each time period in the first mode overlaps temporally with a corresponding time period in the fourth mode, and at least nine-tenths of each time period in the third mode overlaps temporally with a corresponding time period in the second mode. This configuration further significantly suppresses instantaneous battery load.

[0099] Furthermore, the time periods of the first mode, which operates with high power consumption, do not overlap with the time periods of the third mode, which also operates with high power consumption. This configuration further significantly suppresses the instantaneous load on the battery.

[0100] Furthermore, the second mode is set to a mode that disables the light source, and the fourth mode is set to a mode that does not produce a beep. The fourth mode is executed during each period of the first mode, and the second mode is executed during each period of the third mode. This configuration further significantly suppresses the instantaneous load on the battery.

[0101] Additionally, when each period of execution in modes one through four is set to have a length of no more than 1000 milliseconds, visible and audible prompts are repeated at short intervals. This makes it easier for users to recognize the anomaly.

[0102] The above embodiments are merely exemplary to facilitate understanding of the subject matter disclosed herein. Configurations according to the foregoing embodiments may be appropriately modified / improved without departing from the spirit of this disclosure. This application is based on Japanese Patent Application No. 2020-098727, filed on June 5, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. An automated external defibrillator, comprising: A detector that detects abnormalities in the automated external defibrillator; as well as The notifier, when the detector has detected the anomaly, notifies the user of the detection of the anomaly within a predetermined time period; wherein, The notification device has a display unit including a light source and a speaker that generates a notification sound; The display unit alternately and once or multiple times executes a first mode and a second mode respectively, such that in the first mode the display unit causes the light source to emit light with a first intensity, and in the second mode the display unit causes the light source to emit light with a second intensity having a power consumption lower than the first intensity, or causes the light source not to emit light; The speaker alternately and once or multiple times executes a third mode and a fourth mode respectively, such that in the third mode the speaker produces a prompt tone with a third intensity, and in the fourth mode the speaker produces a prompt tone with a fourth intensity having lower power consumption than the third intensity, or does not produce a prompt tone. At least half of each time period executing the first mode overlaps temporally with a corresponding time period executing the fourth mode, and a portion of each time period executing the first mode overlaps temporally with a corresponding time period executing the third mode; and At least half of each time period of the third mode is executed in time with a corresponding time period of the second mode, and a portion of each time period of the third mode is executed in time with a corresponding time period of the first mode.

2. The automated external defibrillator according to claim 1, wherein, At least nine-tenths of the time period during which the first mode is executed overlaps with the time period during which the fourth mode is executed. and At least nine-tenths of the time period during which the third mode is executed overlaps with the time period during which the second mode is executed.

3. The automated external defibrillator according to claim 1 or 2, wherein, Each of the time periods for executing the first mode, the second mode, the third mode, and the fourth mode has a length of no more than 1000 milliseconds.

4. The automated external defibrillator according to claim 1 or 2, wherein, The second mode is a mode in which the display unit does not emit light from the light source; The fourth mode is a mode in which the speaker does not produce a prompt tone; The speaker executes the fourth mode during the period when the display unit executes the first mode; and The display unit executes the second mode during the period when the speaker executes the third mode.

5. A method for notifying an automated external defibrillator of an abnormality, the method causing the automated external defibrillator to perform: The detection step involves detecting any abnormalities in the automated external defibrillator. as well as The notification step involves notifying the user of the detected anomaly within a predetermined time period when the anomaly is detected during the detection step; wherein: The notification step includes a display step that uses a light source to display the information and a sound step that generates a notification sound. The display step is as follows: alternately and once or multiple times, executing a first mode and a second mode respectively, such that in the first mode the light source emits light with a first intensity, and in the second mode the light source emits light with a second intensity having a power consumption lower than the first intensity, or the light source does not emit light; The sound generation step is as follows: alternately and once or multiple times, executing the third mode and the fourth mode respectively, such that in the third mode a prompt tone is generated at a third intensity, and in the fourth mode a prompt tone is generated at a fourth intensity with lower power consumption than the third intensity, or no prompt tone is generated; At least half of each time period executing the first mode overlaps temporally with a corresponding time period executing the fourth mode, and a portion of each time period executing the first mode overlaps temporally with a corresponding time period executing the third mode; and At least half of each time period of the third mode is executed in time with a corresponding time period of the second mode, and a portion of each time period of the third mode is executed in time with a corresponding time period of the first mode.

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