Claims:CLAIMS
What is claimed is:

1. A system for detecting apnea and stimulating breathing in a patient, comprising:
a base device having a sensor, wherein the sensor is configured to detect movement of the patient indicative of a non-apneic state, and wherein the base device is positioned such that movement of the patient is detectable by the sensor;
a stimulator operable to provide a stimulation to the patient; and
a control module in communication with the sensor and the stimulator, wherein the control module monitors an elapsed time since movement of the patient was last detected, and wherein the control module activates the stimulator when the elapsed time exceeds a predetermined threshold.

2. The system according to claim 1, wherein the base device is a mattress.

3. The system according to claim 2, wherein the sensor is integral to the mattress.

4. The system according to claim 1, wherein the base device wraps around the patient.

5. The system according to claim 1, wherein the sensor is a plurality of load cells.

6. The system according to claim 1, wherein the stimulator generates a tactile stimulation.

7. The system according to claim 6, wherein the stimulator is a piezo-electric transducer.

8. The system according to claim 1, wherein the stimulator generates an audible stimulation.

9. The system according to claim 1, further comprising an alarm device that is configured to communicate with the control module, wherein the control module activates the alarm device when the elapsed time exceeds a second predetermined threshold.

10. The system according to claim 9, wherein the second predetermined threshold is greater than the predetermined threshold.

11. A method for detecting apnea and stimulating breathing in a patient, comprising the steps of:
providing a base device having a sensor, wherein the sensor is configured to detect movement of the patient indicative of a non-apneic state;
providing a control module in communication with the sensor;
providing a stimulator in communication with the control module;
positioning the base device such that movement of the patient is detectable by the sensor;
monitoring with the control module an elapsed time since movement of the patient was last detected; and
activating the stimulator if the elapsed time exceeds a predetermined threshold, wherein the predetermined threshold is indicative of apnea.

12. The method according to claim 11, wherein the base device is a mattress.

13. The method according to claim 12, wherein the sensor is integral to the mattress.

14. The method according to claim 11, wherein the base device wraps around the patient.

15. The method according to claim 11, wherein the sensor is a plurality of load cells.

16. The method according to claim 11, wherein the stimulator generates a tactile stimulation.

17. The method according to claim 15, wherein the stimulator is a piezo-electric transducer.

18. The method according to claim 11, wherein the stimulator generates an audible stimulation.

19. The method according to claim 11, further comprising the steps of providing an alarm device in communication with the control module, wherein the control module activates the alarm device when the elapsed time exceeds a second predetermined threshold.

20. A system for detecting apnea and stimulating breathing, comprising:
a mattress configured to support an infant;
a plurality of load cells each positioned relative to the mattress to detect a force exerted thereon by the infant, wherein movement of the infant causes a change in the force detected by at least one of the plurality of load cells, and wherein movement of the infant is indicative of a non-apneic state;
a control module in communication with the plurality of load cells, wherein the control module identifies the change in the force detected by the at least one of the plurality of load cells, wherein the control module calculates an elapsed time since the change was last identified;
a stimulator in communication with the control module and configured to generate a vibration motion, wherein the control module causes the stimulator to generate the vibration motion when the elapsed time exceeds a first predetermined threshold, wherein the first predetermined threshold is indicative of apnea of the patient;
an alarm device that communicates with the control module and is configured to generate an alarm, wherein the control module causes the alarm device to generate the alarm when the elapsed time exceeds a second predetermined threshold. , Description:SYSTEMS AND METHODS FOR DETECTING APNEA AND STIMULATING BREATHING

BACKGROUND
[0001] The present disclosure generally relates to systems and methods for detecting apnea in a patient and stimulating the patient to restart breathing. More specifically, the present disclosure relates to detecting apnea by monitoring movement of the patient and stimulating the patient to breathe when no movement is detected.
[0002] Apnea is defined as the suspension of breathing for a period of time. Apnea may occur voluntarily, through drug or mechanical inducement, or as a consequence to a neurological disease or trauma. Apnea that occurs during sleep is referred to as sleep apnea, which can affect patients of all ages. In many cases, a patient suffering a apneic episode will automatically recover on her or his own, meaning that the patient will resume breathing without any intervention. However, the persistent state of apnea will eventually lead to death, which some believe may be a leading cause in sudden infant death syndrome (SIDS).
[0003] In the context of infants and neonatal care, caregivers often monitor for signs of apnea, which include blue or purple coloration of the patient and a lack of motion. Whether associated with breathing or other motor function, motion of any kind serves as an indication of a non-apneic condition. By detecting an apneic condition early, the caregiver has the opportunity to stimulate the patient to resume breathing instead of relying upon the patient resuming breathing on her or his own.
[0004] In many cases, detecting apnea requires the caregiver to continuously monitor the infant patient at very short intervals. If apnea is detected, the caregiver can typically physically touch or jostle the infant to end the apnea state. While such action is possible, it requires the caregiver to be in constant proximity to the infant, which is most times not possible. Thus, it would be beneficial for an automated system to both detect apnea and respond in a way similar to how a caregiver would respond.

SUMMARY
[0005] The present disclosure relates to a system for detecting apnea and stimulating breathing. In one embodiment, the system includes a base device with a sensor that is configured to detect movement of a patient indicative of a non-apneic state. The base device is positioned such that movement of the patient is detectable by the sensor. The system includes a control module in communication with the sensor and a stimulator in communication with the control module. The control module monitors an elapsed time since movement of the patient was last detected and activates the stimulator if the elapsed time exceeds a predetermined threshold. The control module identifies a possible apnea event when the elapsed time exceeds the predetermined threshold and activates the stimulator stimulates the patient to breathe.
[0006] Another disclosed embodiment relates to a method for detecting apnea and stimulating breathing. The method includes providing a base device having a sensor that is configured to detect movement of a patient, which is indicative of a non-apneic state. A control module communicates with the sensor and a stimulator communicates with the control module. The base device is positioned such that movement of the patient is detectable by the sensor. The control module monitors an elapsed time since movement of the patient was last detected and activates the stimulator if the elapsed time exceeds a predetermined threshold. The control module identifies a possible apnea event when the elapsed time exceeds the predetermined threshold and activates the stimulator stimulates the patient to breathe.
[0007] In another embodiment, a system for detecting apnea and stimulating breathing is disclosed. The system includes a mattress having a plurality of load cells. The mattress is configured to support an infant and the plurality of load cells each detect a force exerted thereon by the infant. Movement of the infant causes a change in the force detected by at least one of the plurality of load cells, whereby movement of the infant is indicative of a non-apneic state. A control module communicates with the plurality of load cells and identifies the change in the force detected by the at least one of the plurality of load cells. The control module calculates an elapsed time since the change was last identified. A vibration device communicates with the control module and is configured to generate a vibration motion. The control module causes the vibration device to generate the vibration motion when the elapsed time exceeds a first predetermined threshold. An alarm device communicates with the control module and is configured to generate an alarm when the elapsed time exceeds a second predetermined threshold. The control module identifies a possible apnea event when the elapsed time exceeds the predetermined threshold and activates the stimulator stimulates the patient to breathe.
[0008] Various other features, objects and advantages of the disclosure will be made apparent from the following description taken together with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The drawings illustrate the best mode presently contemplated of carrying out the disclosure. The same numbers are used throughout the Figures to reference like features and like components. In the drawings:
[00010] Fig. 1 is an environmental view of an infant care device;
[00011] Fig. 2 is a schematic illustration of the apnea detecting and breathing stimulating system operating in accordance with one embodiment of the present disclosure;
[00012] Fig. 3A illustrates an alternate embodiment of an apnea detecting and breathing stimulating system;
[00013] Fig. 3B is a schematic illustration of the alternate embodiment of Fig. 3A; and
[00014] Fig. 4 is a flowchart illustrating the operating sequence carried out by the control module of the discloses system.

DETAILED DISCLOSURE
[00015] The present inventors have identified that in practice, when a caregiver detects that a patient is in an apneic state, the caregiver generally provides a gentle, physical touch to the patient to stimulate the patient to restart breathing. Recognizing that this simple touch is often sufficient to stimulate the patient to breath, and that a caregiver is not always present to detect the apnea and provide such contact, the present inventors developed the presently disclosed systems and methods.
[00016] Fig. 1 discloses a patient care device 10 incorporating the systems and methods for detecting apnea and stimulating breathing in accordance with the present disclosure. In the embodiment shown, the patient care device 10 incorporates an infant incubator 12 for providing medical care to an infant patient. However, it should be noted that while Fig. 1 and other embodiments of the present disclosure are directed to applications involving infant patients and an incubator, the systems and methods of the present disclosure are applicable to other types of devices, such as infant warmers, and for patients of any age.
[00017] Fig. 2 illustrates an embodiment of a patient care device 10 having a support system 20 as its base device. In the embodiment shown, the support system 20 includes a mattress 22 that is supported from below by a support platform 24. At least one sensor 26 is positioned between the support platform 24 and a foundation 28 such that the foundation 28 supports the mattress 22 through the support platform 24 and the at least one sensor 26. Although not shown in Fig. 2, the support system 20 is configured to support a patient from below, whereby the patient rests on top of the mattress 22 while the patient care device 10 is in operation and the patient is receiving care. It should be noted that in some embodiments, the patient care device 10 need not be designed for or used in associated with delivering medical care beyond detecting apnea and stimulating breathing as presently disclosed.
[00018] The at least one sensor 26 is configured to detect movement of the patient supported by the mattress 22, which indicates that the patient is in a non-apneic state by virtue of the patient moving. Through experimentation and development, the present inventors have determined that the sensor 26 can be selected to have sufficient sensitivity to detect movement caused by breathing, even in the smallest patients. For example, the inventors have identified that a load cell may be used for the sensor 26. By monitoring the changing output signal from the sensor 26 over time, the support system 20 can identify movements of the patient related to breathing or other motor activity.
[00019] In some embodiments, multiple sensors are used in place of a single sensor 26 to improve sensitivity, provide redundancy and error detection to support larger patients, to provide different types of sensors having differing sensitivities or performance characteristics, or to provide robustness in accuracy and precision of performance regardless of patient position on the patient care device 10. Additional advantages of using multiple sensors would be known to a person having ordinary skill in the art.
[00020] As shown in Fig. 2, the support system 20, and specifically the at least one sensor 26, is in communication with a control module 30. Although a wired connection is shown, the communication between the sensor 26 and the control module 30 could be through any one of numerous wireless communication protocols, such as Bluetooth. The control module 30 is configured to detect a state of apnea when the support system 20 via sensor 26 does not detect movement of the patient over a period of time, which will be discussed further below.
[00021] The control module 30 is in communication with a non-transitory memory 32, which stores a program for operating the control module 30, as well as various thresholds for consequent actions when a state of apnea is detected. The control module 30 is also in communication with an input/output device 34 such that the support system 20 can communicate with additional devices, such as a display 60 or an alarm 50. The input/output device 34 may also allow configuration of the support system 20, including changes to the various thresholds previously discussed or allowing inputs relating to the type of patient, such as whether the patient is an infant, child, adolescent, or adult.
[00022] A stimulator 40 is incorporated into the support system 20 to simulate the gentle touch a caregiver may provide to stimulate the patient to restart breathing. As shown in Fig. 2, the stimulator 40 is coupled to the mattress 22 via the support platform 24 such that the stimulator 40 can stimulate the patient through movement of the support platform 24 and mattress 22. In the embodiment shown, the stimulator 40 is coupled to the support platform 24 on a side opposite of the mattress 22 such that stimulation to the patient can be provided but such that the stimulator 40 remains protected from the patient and elements associated with providing medical care.
[00023] In one embodiment, the stimulator 40 provides a motion-based stimulation to the patient, such as a vibration or pulse, to replicate the manual touch of a caregiver. This may be accomplished using a piezo-electric transducer operating at a desired frequency, a micromotor, an offset weighted rotating shaft and motor, or other motion-based generators known in the art. In other embodiments, the stimulator 40 can be a sound generator, can cause movement of air, or some combination of motion-based, audible, and other sensory stimulation. Depending on the type of stimulator 40 used, as well as the particular application of patient care device 10 that incorporates the support system 20, the stimulator 40 may be integral to the support system 20, or may be external. An exemplary method for operating the system shown in Fig. 2 is provided in Fig. 4, which will be discussed further below.
[00024] Figs. 3A and 3B illustrates an alternative base device in accordance with the present disclosure, wherein the base device is a chest system 70. As shown in Fig. 3A, the chest system 70 includes a chest unit 72 that is placed on the chest of a patient 14. An adjustable strap 74 holds the chest unit 72 in place over the chest of the patient 14 such that the chest system 70 remains in position during use.
[00025] In the embodiment shown in the schematic of Fig. 3B, the chest unit 72 includes at least one sensor 26 that is in communication with a control module 30 in the manner previously discussed. The chest unit 72 also includes a memory 32, a battery 36, a stimulator 40, and an input/output device 34 that provides communication through an antenna 38. It should be recognized that while the sensor 26, control module 30, memory 32, input/output device 34, battery 36, antenna 38, and stimulator 40 are each shown to be integrated within the chest unit 72, one or more of these may be external to the chest unit 72 while retaining the necessary functionality. It should also be noted that while lines are provided from each of the sensor 26, the memory 32, the input/output device 34, the battery 36, and the stimulator 40 to the control module 30, these lines represent one embodiment for communication and are not indicative of required wiring schematics.
[00026] The chest system 70 shown in Figs. 3A and 3B may include the same types of sensors previously discussed. For example, when a load cell is used as the sensor 26, forces are generated on the load cell when the patient breathes by virtue of the patient’s chest expanding and contracting while the strap 74 remains a fixed length. Alternatively, the sensor 26 could detect the tension on the strap 74, or could contain a gyroscope to detect the rise, fall, or changing angle of the chest as the patient 14 breathes. Additional types of sensors 26 would also be known to one having ordinary skill in the art.
[00027] Fig. 4 depicts an exemplary method for detecting apnea and stimulating breathing in accordance with the present disclosure. In the embodiment illustrated in Fig. 4, the patient care device uses load cells as the sensors to detect motion of the patient. In step 400, force measurements are acquired from each of the load cells. The force measurements are typically a voltage reading from each of the load cells. The voltage reading from the load cells change depending upon the weight of the infant patient. If the infant patient moves on the mattress, the voltage reading from the load cells will change until the patient is at rest. An elapsed time timer is started from 0:00 at step 402. In step 404, the system monitors for changes in the force measurements detected by any of the load cells over time.
[00028] In step 406, which may be completed by the control module 30, it is determined whether any of the changes in force measurements from any of the load cells exceeds a change threshold. In this regard, the change threshold is set to identify changes that are clinically relevant and not merely fluctuation in measurements beyond the sensitivity of the particular load cells being used as the sensors 26. Specifically, the change threshold is determined and saved in the memory 32 such that a change in force measurement caused by actual movement of a patient will exceed the change threshold, but such that noise in the electronics or physical environment of the device does not exceed the change threshold.
[00029] If at least one change associated with at least one sensor 26 is determined at step 406 to exceed the change threshold, the system determines that movement of the patient has occurred and restarts the elapsed time timer at 0:00 in step 406. In the event that the stimulator 40 or alarm 50 have previously been activated (see steps 430, 450), step 410 provides that the stimulator and alarm are both reset to off states. The method then returns to step 404 and the system continues to monitor for changes in the force measurements by any load cell.
[00030] Alternatively, if no change is determined to exceed the change threshold at step 406, this indicated the infant patient is not moving. The control module 30 proceeds to step 420 to determine whether the current elapsed time exceeds a first threshold. The first threshold, which is a relatively short predetermined threshold, like the change threshold previously discussed, represents the duration of elapsed time before the absence of detected motion will be considered to constitute an apneic state. For example, one second of elapsed time between detected movements of a patient would not be considered apnea, since one second between breaths is not considered clinically relevant and thus does not yet indicate a patient’s cessation of breathing.
[00031] In one embodiment, the first threshold of step 420 is set to 15 seconds. This first threshold is selected since it exceeds the expected elapsed time during normal breathing, while also not excessively delaying the detection of apnea when a true apneic state is present. However, it should be recognized that a clinically appropriate first threshold may depend upon the type of patient being monitored, the medical condition of the patient, or the impacts of drugs and other mechanically induced stimuli having an impact on the patient’s expected respiratory rate. Many of these factors can be selected through the input device described above.
[00032] If the elapsed time does not exceed the first threshold in step 420, the system continues to monitor for changes in the force measurements by each of the load cells, returning to step 404. Thus, if the system detects a change in the force measurements at any time before elapsed time exceeds the first threshold, the elapsed time timer is reset and no apnea event is indicated.
[00033] Alternatively, if the elapsed time does exceed the first threshold in step 420, the patient is stimulated in an attempt to start breathing at step 430. As previously discussed, the control module 30 causes the stimulator 40 to generate some type of patient stimulation, such as a vibrating motion, to stimulate the patient and end the apnea event. The present inventors have found that providing one to two seconds of vibration can be sufficient in most cases to stimulate the patient to restart breathing following detection of an apneic state.
[00034] In some embodiments, the method also includes a second threshold, also predetermined, that corresponds to an elapsed time at which an alarm will be generated to indicate that the system has not detected movement of the patient within at least the elapsed time of the second threshold. In the embodiment shown in Fig. 4, the second threshold may be 30 seconds and thus exceeds the first threshold such that an alarm is generated at step 450 only when efforts to stimulate the patient at step 430 have not succeeded in ending the apneic state and the elapsed time has now exceeded the second threshold.
[00035] It should be noted that multiple attempts to stimulate patient breathing at step 430 are anticipated by the present disclosure, as are additional or alternative times to generate the alarm at step 450. Furthermore, even when an alarm is not generated at step 450, other indications may be provided to inform the caregivers that apnea was detected and/or that attempts to stimulate the patient to restart breathing were made.
[00036] The present inventors have identified that in practice, when a caregiver detects that a patient is in an apneic state, the caregiver generally provides a gentle, physical touch to the patient to stimulate the patient to restart breathing. Recognizing that this simple touch is often sufficient to stimulate the patient to breath, and that a caregiver is not always present to detect the apnea and provide such contact, the present inventors developed the presently disclosed systems and methods.
[00037] In the above description, certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different assemblies described herein may be used alone or in combination with other devices. It is to be expected that various equivalents, alternatives and modifications are possible within the scope of any appended claims.
[00038] This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. Aspects from the various embodiments described, as well as other known equivalents for each such aspects, can be mixed and matched by one of ordinary skill in the art to construct additional embodiments and techniques in accordance with principles of this application.