KR101033195B1 - Portable device with relaxation response provision capability - Google Patents

Abstract

A portable device having a relaxation effect providing function is a measurement sensor for measuring a biosignal including at least one of a user's breathing and a heart rate signal during a respiratory training, and at least one of the user's five senses during the respiratory training. By providing a stimulus, a stimulus module that induces the user to focus on the stimulus and to remain indifferent to non-stimulation, analyzes vital signs to estimate respiratory rate and autonomic nervous system, and estimates the respiratory rate or target for the target respiratory state. A breath evaluator for determining an arrival rate indicating an arrival degree of the autonomic nerve state, and a control unit for controlling an output unit and components for providing a target breathing state, a respiration rate, and an arrival rate to a user. If the biometric signal is detected from the measurement sensor or the analysis determines that the mental stress is high, the controller forcibly switches the running task to the background task and forces the portable device to enter the respiratory training task. The present invention enables users to perform respiratory training regardless of time and place, thereby improving health and enhancing the competitiveness of portable devices.

Portable device, meditation, relaxation effect, relaxation response

Description

Portable device with relaxation response provision capability

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable device, and more particularly, to a biofeedback technique that measures the breath rate (BR) or autonomic nerve state of a user's breath and induces the measured current breathing state to approximate the breathing state at the time of relaxation of the user. By using the present invention, a portable device having a relaxation effect providing function to assist a user in reaching a relaxation state suitable for the user.

 Since modern people often live in front of computers, they have an absolute lack of exercise other than simple repetitive movements such as mouse and keyboard manipulation, so the health of modern people is serious. Also, with the rapid spread of the Internet, the time spent in front of computers of modern people is increasing. Therefore, various adult diseases caused by lack of exercise are threatening the health of modern people, raising awareness about this.

In order to improve the health of modern people, various exercise equipments or exercise aids have been introduced. In addition, a variety of interest-inducing mechanisms are developed to encourage users to continue to manage their health. The use of such exercise equipment or interest-inducing apparatus can improve the health effect of the user in a limited time.

However, it is known that not only physical health but also mental health is very important for human health. Mental health refers to the degree of stress received by the user and the user's satisfaction with the current life. In order to improve physical and mental health, medications and surgery are used, of course, but self-managing methods in which an individual manages his own health for his own health is highly desirable. Such self-management is widely used for controlling the weight through nutrition, how to promote health through exercise, and how to promote mental health through meditation and the like.

Among these, as the importance of mental health is increasingly recognized, methods using a relaxation response are widely recognized. The relaxation effect is a physiological effect named by Dr. Herbert Benson and is often used as the opposite of a fight-or-flight response. Fighting or running away is the way our body reacts when a crisis occurs.When this reaction begins, blood pressure rises, pulses increase, and the amygdala of the brain is activated. . Therefore, it can cause an immediate and explosive reaction, but on the other hand it is not good for the mental health of the user, and even if this fighting or runaway reaction is too intense, it may cause permanent damage to the amygdala, resulting in post traumatic stress syndrome. It may also cause Traumatic Stress Disorder (PTSD). On the other hand, a relaxing effect decreases metabolism, reduces heart rate, and slows blood pressure, respiration and brain waves. Various methods can be used to induce a relaxation effect. However, it is not easy for a user to perform such self-care for mental health. For example, the theories and effects of breathing suitable for meditation are well known, but it is not easy to perform this training individually and efficiently.

On the other hand, with the development of information and communication technology, users possess various portable devices. The functionality of portable devices owned by users is also improving, and competition for selling portable devices with new technologies is fierce.

However, the development of portable devices has been mainly developed toward adopting new technologies. For example, it is expected that the marketing strategy will be determined and superior in the market depending on how new technologies are integrated into the handheld device. However, among the various new technologies included in portable devices, the technologies used by real users are limited, and almost all users except the few professional users are rather troubled to study to use the new technologies of portable devices. I feel it. This phenomenon is called digital fatigue. Therefore, the marketing direction that has been developed from humans to functions is changing to a user-friendly direction, and a marketing strategy that can appeal to the user's emotion rather than a complicated new technology is in the spotlight.

Therefore, by designing a portable device that users always have to provide a relaxation effect that can directly improve the user's health, it promotes the user's health as well as human-oriented from the dry marketing strategy of the new technology. There is an urgent need for skills that will enable you to use your marketing strategy.

It is an object of the present invention to provide a portable device having a relaxation effect providing function that enables the user to easily reach the optimum relaxation effect by continuously biofeeding the user's breath.

Another object of the present invention is to maximize the sales of the portable device through emotion-oriented marketing by embedding the function to provide a relaxation effect in the portable device.

Another object of the present invention is to automatically enter a portable device into respiratory training mode when a sensor signal is detected from a measurement sensor of the portable device.

One aspect of the present invention for achieving the above object relates to a portable device having a relaxation effect providing function, the portable device is a measurement sensor for measuring a bio-signal including at least a user's heart rate signal while breathing training is performed By providing a stimulus for at least one of the five senses of the user while the respiratory training is performed, analyzing the stimulus module to induce the user to focus on the stimulus and to remain indifferent to the thoughts other than the stimulus; And a breath evaluator for determining an arrival rate indicating a degree of arrival of the respiration rate with respect to a target breathing state of the user, and a control unit for controlling an output unit and components for providing the user with the target respiration state, respiration rate, and arrival rate. do. Preferably, when the biological signal is detected from the measurement sensor, the controller forcibly switches the task being executed to the background task and forcibly enters the portable device into the respiratory training task. Further, the control unit provides at least one of stretching, music, and images to alleviate the user's mind and body tension before initiating breathing training, and is prepared to provide the user with a suitable breathing cycle and breathing pattern according to the target breathing condition. And perform a main workout action that induces the user to breathe in accordance with the provided breathing cycle and breathing pattern.

According to an embodiment of the present invention, the measurement sensor further measures at least one of the user's breath, body temperature, and blood oxygen saturation as an input variable, the respiration evaluation unit calculates the rate of change of the input variable, the user from the rate of change of the input variable Determine your breathing rate (BR). Preferably, the portable device may be any one of a gaming console, a mobile phone, an MP3 player, a personal digital assistant (PDA), a personal multimedia player (PMP), a digital camera, a notebook computer, a laptop computer and a navigation device. have. Alternatively, the portable device may be a book stand, and the output unit may include LEDs that emit light of different colors depending on the rate of achievement.

According to the present invention, since the portable device continuously biofeeds back the breath of the user, the portable device can induce the user to easily reach the optimum relaxation effect.

In addition, by incorporating a relaxation effect providing function into the portable device according to the present invention, it is possible to maximize the sales of the portable device through the user-specific emotion-oriented marketing, rather than a list of new technologies irrelevant to the user.

Furthermore, according to the present invention, when a sensor signal is detected from the measuring sensor of the portable device, the user automatically enters the respiratory training mode and switches the conventional work to the background task, thereby allowing the user to easily perform the respiratory training anytime and anywhere. can do.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. For each figure, like reference numerals denote like elements.

1 is a block diagram conceptually illustrating a portable device having a function of providing a relaxation effect according to the present invention.

The portable device 100 shown in FIG. 1 includes a built-in measurement sensor 110, a stimulation module 180, a portable device processing unit 150, an input / output unit 140, a respiration evaluation unit 170, and a display 190. do.

When respiratory training is initiated, measurement sensor 110 measures the current respiratory state of the user. The measurement sensor 110 may include a heart rate sensor, a pulse wave sensor, an SPO ₂ sensor, and a respiration / temperature sensor. Heart rate sensors detect pulse wave signals and SPO ₂ sensors detect oxygen saturation. In addition, the measurement sensor 110 may measure the normal breathing state and the maximum relaxation breathing state of the user. The normal breathing state and the maximum relaxation breathing state are used to obtain a target breathing state of the user. In addition, various biological signals measured in the present invention may be used to estimate the autonomic nerve state of the user. The autonomic nervous system is a concept that indicates how smoothly the user's autonomic nervous system is operating and how stable the user's mind and body are. The autonomic nervous system works independently of the cerebral direction and allows for smoothly performing operations such as temperature control and digestion. Breathing is also done automatically without the user's awareness under the control of the autonomic nervous system. However, research has shown that consciously controlling breathing can reversely control the autonomic nervous system. Thus, once the rate of arrival to the target respiratory state is obtained by analyzing the respiratory rate, this element can also be used as a measure of the state of the autonomic nervous system. When the user indirectly stabilizes the autonomic nervous system by controlling breathing, the autonomic nervous system may be enhanced, and thus, the operation of various autonomic nervous systems that the user cannot directly control may also be stabilized.

Since different users have different degrees of meditation practice and different health conditions, it is not desirable to apply a uniform target breathing state. Therefore, in the present invention, the normal breathing state and the maximum relaxation breathing state of the user are measured and the target breathing state is calculated using this result. For example, the average of the normal breathing state and the maximum relaxation breathing state may be set as the target breathing state, or the weighted average may be set as the target breathing state. In addition, the respiratory / body temperature sensor can measure the user's breathing state and body temperature. Using a breathing / temperature sensor has the advantage of directly detecting the breathing rate (BR) of the user.

Breathing is the most essential element of 'relaxation' for reaching relaxation effect. Because breathing is an unconscious action that proceeds automatically, most people are insensitive to their breathing. However, the state of breathing reflects feelings and the mind. In other words, people get shallow and fast breathing when they are anxious or afraid. This breathing makes the body very tired while deep and regular breathing stabilizes the autonomic nervous system. On the other hand, even and deep breathing stimulates the diaphragm and promotes parasympathetic activity. Parasympathetic nerves work to relieve the activity of the sympathetic nerves when they are stressed. Therefore, it is important to train as long and naturally as possible to breathe.

The respiratory state of the user can be measured in various ways. First, inhalation and exhalation can be measured directly to measure inhalation and exhalation as well as breathing rate (BR). This is the simplest way. Alternatively, the breathing state may be measured using other biometric information. For example, blood oxygen saturation (SPO2) may be measured, and the change amount may be calculated to measure respiratory rate (BR). In addition, heart rate can be measured and respiratory conditions calculated. The respiratory state measurement method will be described later with reference to FIG. 2.

When the respiratory state of the user is measured from the biosignal from the measurement sensor 110, the current respiratory state is acquired. The current respiratory state can be provided by displaying the respiratory rate BR as a numerical value, or it can be graphically displayed as the rate of change of the continuous respiratory rate BR. In this process, depending on the current breathing state, the user may easily recognize the current breathing state with various colors and various sound effects.

The breath evaluator 170 presents a breathing cycle and a breathing method corresponding to a target breathing state to perform a user's breathing training. In the present specification, the training means a training performed by a user to obtain a relaxation effect. Continued training has been shown to alleviate a variety of stress-related disorders. For example, it has been found that inducing relaxation effects regularly results in long-term physiological changes (Hoffman et al., 1982). For example, it has been found that training the mind and body through relaxation effects can also be effective in treating hypertension, cardiovascular disease, chronic pain, insomnia, depression, psychopathy, and infertility, therefore, evidence-based medicine. In view of the above, relaxation therapy is recommended in standard medical references, as well as a number of related practitioners practicing relaxation effect therapy. Therefore, through the respiratory training, the user can practice his breath to approximate the respiratory state at the time of relaxation, thereby increasing the relaxation effect.

In order to maximize the effect of meditation, the breath evaluator 170 may quantify the degree of meditation or provide it in the form of a game. For example, scores based on achievement rate can cause competition among multiple users, as well as allowing users to control their avatars with the accuracy of the achievement rate so that they can enjoy competitive games such as martial arts games or cycle games. You can do that. In this case, the portable device 100 may include a network interface (not shown) connected to an external network.

The stimulation module 180 helps to maintain indifferent to thoughts other than the applied stimulus by providing a stimulus for at least one of the five senses of the user during the respiratory training to induce the user to focus on the applied stimulus. The stimulation module 180 may include a tactile module, a fan, a vision module, an auditory module, and an olfactory module. The haptic module may apply warm or cold air to a stimulus position of the user's body. At this time, the location of the stimulus is preferably located on the menstrual blood, and in particular, it is preferable that the location of the uterus blood and the core eye. Aung blood is a position that is described as very important as the acupuncture points corresponding to the 'sympathoscope' in the synonym and the position between the areas where the third and fourth fingers reach the palm of the hand when the fist is slightly clenched. Agung blood means the palace of fatigue, that is, the place where fatigue gathers. Therefore, by appropriately stimulating the archery blood can not only have the effect of releasing fatigue, but also relax the muscles can induce the user to fall into the relaxation effect more easily. In addition, the eye is the eye of the heart other than two eyes, and often refers to the point between the brow. By stimulating the deep eye, the user can feel at ease and can easily immerse themselves in the relaxation effect.

As the haptic module, a heat generating element or a thermoelectric element can be used. The fan can provide a soft tactile sensation by blowing in the stimulus position. The visual module displays a natural landscape, a user's preferred picture, a favorite picture, a monotonous pattern, and the like. The auditory module reproduces sounds of nature, music preferred by the user, preferred sounds, and the like. Music stabilizes the listener's emotions. The olfactory module stabilizes the emotional state of the user by releasing a natural scent and a user's preferred scent. Natural scents, such as the smell of cool showers in the middle of summer or the smell of soil in spring warm fields, are desirable because they can further stabilize the user's feelings. The olfactory module may be configured to radiate aroma by applying heat or wind to a capsule that emits a predetermined aroma.

The portable device processor 150 controls various devices of the portable device 100. In FIG. 1, the function of the breath evaluator 170 is not necessarily to be performed in a separate device from the processor 150, and the function of the breath evaluator 170 may be integrated into the processor 150.

The display 190 may display the user's current breathing status, target breathing status, and achievement rates, and may display an image that may cause emotional stability to the user. The input / output unit 140 may receive various user inputs and transmit various information to the user while respiratory training is in progress. For example, the input / output unit 140 may be used to input information about health information such as gender, age, and weight of the user. The current achievement rate of the user during the respiratory training may be provided to the user as an acoustic signal through the input / output unit 140.

When the biosignal is received from the measurement sensor 110, the processor 150 may force the portable device 100 to enter a respiratory training mode. At this time, the processor 150 switches the existing work to the background job, and activates the breath training mode as the foreground job. The processor 150 temporarily stores the data of the previously performed job so that the background job can be continuously performed. Thus, regardless of what task the portable device 100 is performing, the user can activate the respiratory training function only by using the measurement sensor 110. Therefore, health can be enhanced because the breathing training can be performed anytime and anywhere, and the portable device 100 can appeal greatly to potential users as a user-friendly device having the function of providing a relaxing effect. The processor 150 of the portable device 100 may record a participation rate in which the user participates in respiratory training, and provide various incentives for increasing the participation rate of the user. For example, if the user participates in the respiratory training more than a certain number of times every day, the brightness of the screen may be brightened. If the participation rate is low, the brightness of the screen may be darkened. The user may feel homogeneity while watching a portable device where the screen becomes dark due to a low participation rate and an unstable mental health.

By using the portable device 100 shown in FIG. 1, the user can perform breathing training anytime and anywhere, thereby improving mental health. In addition, the portable device 100 having a user friendly health promotion function will have a strong marketing point in the market unlike other portable devices.

FIG. 2 is a flowchart for conceptually describing an operation of the breath evaluator 170 illustrated in FIG. 1.

In the embodiment shown in FIG. 2, the heart rate is measured using a built-in measurement sensor as an input variable for measuring a user's breathing state (S210). Then, the measured heart rate is converted into a frequency function by applying a fast Fourier transform (FFT) to the measured heart rate (S230). The output signal of the sympathetic nervous system related to heart rate and blood pressure is a relatively low frequency signal, whereas the output signal of the parasympathetic nervous system which limits or suppresses the sympathetic nervous system is a relatively high frequency signal, and thus the signal processing is easy using a frequency function. For example, during inhalation, the parasympathetic nervous system is suppressed while the parasympathetic nervous system is more active, resulting in increased heart rate. On the other hand, during exhalation, the parasympathetic nervous system becomes active and heart rate decreases. In this case, the energy spectral distribution of the obtained frequency function may be measured. Therefore, when a frequency function of an input variable such as heart rate and blood oxygen saturation is obtained, a respiratory state may be obtained by applying a band pass filter (BPF) to the obtained frequency function (S250). In this process, the change amount of the frequency function or the like may be calculated and used. However, in order to measure the respiratory rate from the heart rate, it is not necessary to convert to the frequency domain, and the respiratory rate can be obtained by applying various signal processing techniques even in the time domain.

When the respiratory rate (BR) is measured, it is induced to obtain a relaxation effect by providing the measured respiratory rate (BR) (S270).

In the embodiment shown in Figure 2 is shown that the respiratory rate (BR) is measured using the heart rate. However, the present invention is not limited thereto, and the respiratory rate BR may be directly measured by using a respiratory measurement device, and the respiratory rate BR may be measured by other known methods. For example, the information that can be measured in the measurement step can include the number of breaths and body temperature. If respiration is measured, the respiratory rate can also be calculated directly. Accordingly, it should be understood that FIG. 2 is not intended to limit the invention, but is provided only as an example for measuring respiratory rate BR.

3 is a diagram illustrating a notebook computer as an embodiment of a portable device having a function of providing a relaxation effect according to the present invention. The notebook computer 300 shown in FIG. 3 includes a display 390, a keyboard 340, a pulse wave sensor 350, an electrocardiogram electrode 360, 362, 364, and an implantable measurement sensor 370. Display 390 indicates the operating status of notebook computer 300. The keyboard 340 operates as the input / output unit 140 shown in FIG. 1. The pulse wave sensor 350 is in close contact with a user's palm, irradiates light, and measures a pulse wave by measuring a reflected signal reflected from the close body. The electrocardiogram electrodes 360, 362, 364 measure the electrocardiogram by contacting both palms. At this time, one sensor is attached to one palm, while two sensors are attached to the other palm to measure the potential difference of the sensors. The insertable measuring sensor 370 includes a heart rate sensor formed in a hole having a size enough to insert a user's finger.

When the notebook computer 300 is booted, the user uses the functions of the existing notebook computer 300 by using the keyboard 340. At any time during use, the user may insert a finger into the built-in measurement sensor 370 or contact the palm with the pulse wave sensor 350. Then, the processing unit (not illustrated) of the notebook computer 300 converts the work being performed to the background job and immediately executes the breath training application. The user can then immediately perform breathing training as instructed by the breathing training application. After the respiration training, it is obvious that the training results of the user can be recorded in a storage unit (not shown) of the notebook computer 300 and used to manage the health history.

4 is a diagram illustrating a digital camera as another embodiment of a portable device having a relaxation effect providing function according to the present invention. The digital camera 400 shown in FIG. 4 includes a display 490, an input button 440, and a built-in measurement sensor 470.

In particular, the digital camera shown in FIG. 4 is considered to be a digital camera that includes the function of a personal multimedia player (PMP), but this is not a limitation of the present invention. The user may perform a photo and video capturing function, which is a basic function of the digital camera 400. Furthermore, various additional functions such as a video file playing function, which is a function of the PMP, can also be used.

However, the user can insert a finger into the embedded measurement sensor 470 at any time. When a finger is inserted into the built-in measurement sensor 470, the biosignal is detected from a heart rate sensor (not shown) included in the built-in measurement sensor 470. Then, the processing unit (not shown) of the digital camera 400 temporarily stores the work to be performed at the moment the biosignal is detected and enters the respiratory training mode.

While breathing training is being performed, the user's current breathing status, target breathing status and rate of achievement, etc., are shown in detail in display 490. The user may select a training method desired by the input button 440 or input his or her personal information.

The digital camera 400 as shown in FIG. 4 is becoming an essential device that many people carry thanks to technological developments. Thus, users can perform respiratory training at any time using the digital camera 400 shown in FIG. 4 and health is improved. In addition, emphasizing other digital cameras and other user-friendly features can provide a significant advantage in the marketing market over other competing products.

5 is a diagram illustrating a reading stand as another embodiment of a portable device having a function of providing a relaxation effect according to the present invention. The reading table 500 illustrated in FIG. 5 includes an output LED unit 590, an input button 540, an earphone jack 530, and a built-in measurement sensor 570.

At the beginning of the study, the user can perform respiratory training by inserting a finger into the built-in measurement sensor 570. The processor (not shown) of the reading table 500 immediately executes respiratory training when the biosignal is received from the built-in measurement sensor 570. In this case, the user may select a training method desired by the user using the input button 540 or input his or her health information.

While the respiratory training is performed, the user's achievement rate and current respiratory state may be converted into a voice signal and output to the user through the earphone jack 530. When the user inserts the earphone into the earphone jack 530, the user can hear not only the progress of the respiratory training but also the auditory stimulus that can enhance the relaxation effect of the user.

The output LED unit 590 includes three different colors of LEDs, and different colors of LEDs are emitted according to a user's current breathing state. For example, the user may perform breath training until the green LED is lit before starting to study.

Using the reading table 500 illustrated in FIG. 5, the user may continuously maintain an optimal mental health state for studying.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. For example, a laptop computer, a digital camera, and a reading table are illustrated in the present invention as a portable device having a relaxation effect providing function, but this is not a limitation of the present invention. That is, the respiratory enhancement application according to the present invention is applicable to any device capable of measuring the respiratory rate from signals obtained from pulse wave sensors or electrocardiogram sensors. That is, the measuring sensors of the present invention can be installed on the handle of a vehicle or the armrest of a chair. In this case, if the user wants to rest while driving or working, the user can easily execute the breathing application by touching the sensor installed in the handle or armrest.

Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

The portable device according to the present invention can be used to promote mental health of a user.

1 is a block diagram conceptually illustrating a portable device having a function of providing a relaxation effect according to the present invention.

FIG. 2 is a flowchart for conceptually describing an operation of the breath evaluator 170 illustrated in FIG. 1.

3 is a diagram illustrating a notebook computer as an embodiment of a portable device having a function of providing a relaxation effect according to the present invention.

4 is a diagram illustrating a digital camera as another embodiment of a portable device having a relaxation effect providing function according to the present invention.

5 is a diagram illustrating a reading stand as another embodiment of a portable device having a function of providing a relaxation effect according to the present invention.

Claims (6)

In a portable device having a relaxation effect providing function, Control unit; A measurement sensor that measures a biosignal including at least one of a user's breath, pulse wave, and heart rate signal while breath training is performed; A stimulation module for providing a stimulus for at least one of the five senses of the user while performing breathing training under the control of the controller, thereby inducing the user to concentrate on the stimulus and to remain indifferent to thoughts other than the stimulus; A respiration rate evaluator configured to analyze the biosignal to obtain a respiratory rate and an autonomic nerve state, and to determine an arrival rate indicating a degree of arrival of the respiratory rate and the autonomic nerve state with respect to a target respiratory state and a target autonomic nerve state; And An output unit configured to provide the target breathing state, the breathing rate, and the arrival rate to the user under the control of the controller, wherein the control unit comprises: A preparatory action for controlling the stimulation module to provide at least one of stretching, music, images to alleviate the user's mind and body tension before initiating breathing training; and The main walk which determines the breathing cycle and breathing pattern for inducing the target breathing state and provides the user with the determined breathing cycle and breathing pattern through the output unit, induces the user to breathe according to the provided breathing cycle and breathing pattern. A portable device having a relaxation effect providing function, adapted to perform an out operation. The method of claim 1, wherein the control unit, Analyze the bio-signal from the measurement sensor to determine the user's stress level, and if the stress level is more than a predetermined value, forcibly converts the running task to the background task and forcibly enters the portable device into the respiratory training task. A portable device having a function of providing a relaxation effect. delete The method of claim 1 or 2, wherein the measurement sensor, Further measuring at least one of the user's body temperature and blood oxygen saturation degree as an input variable, the breathing evaluator, And calculating a rate of change of the input variable and determining a respiration rate of the user from the rate of change of the input variable. The method according to claim 1 or 2, The portable device is selected from the group consisting of a gaming console, a mobile phone, an MP3 player, a personal digital assistant (PDA), a personal multimedia player (PMP), a digital camera, a notebook computer, a laptop computer and a navigation device. A portable device having a function of providing a relaxation effect, characterized in that the element. The method of claim 1, The portable device is a book stand, The output unit is a portable device having a function of providing a relaxation effect, characterized in that it comprises an LED that emits a different color in accordance with the arrival rate.

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