The present invention relates to devices and methods for detecting the motion of a subject. More particularly, the present invention relates to devices and methods for detecting and/or monitoring the motion of a subject, such as an infant.
Sudden Infant Death Syndrome (SIDS) typically occurs in infants under one year of age where the infant may stop breathing and cease movement. In many cases, parents or caregivers typically await for the movement or motion of the infant as an indicator that the infant is merely sleeping and not in distress.
SIDS may occur in healthy infants as a result of simultaneous occurrence of a series of biological events such as periods of apnea, difficulty in breathing, changes in muscle tone, etc. These episodes may occur during sleep, feeding, or while awake and are potentially life-threatening events.
Previous devices have utilized breathing monitors and alarm systems to monitor the breathing of infants. These monitors have typically utilized electrodes attached to the skin of the infant. Other types of SIDS monitoring equipment have utilized various mechanisms such as accelerometers. However, these home monitoring systems are subject to false alarms making monitoring of an infant difficult. Video monitoring equipment is widely utilized but they are relatively expensive and fail to adequately convey information when an infant is quite and not moving. Additionally, audio monitoring equipment likewise fails to transmit adequate information and can confusingly transmit undesirable background noise.
Other types of devices have included pulse oximeter devices for monitoring the oxygen saturation levels in the infant. Unfortunately, such devices particularly when used with accelerometer-type devices are still subject to many false alarms. Other types of monitoring systems have proven to be overly complex and expensive.
Thus, a relatively inexpensive monitoring system which can be readily applied to an infant (or adult) for detecting movement (or lack of movement) and/or breathing is desirable.
A system for detecting motion and/or breathing from a subject, e.g., for preventing SIDS, can be configured in a number of different ways while optionally combining audio and/or video monitoring systems. Such a system may incorporate a motion and/or breathing sensor module which may comprise a sensor in communication with a fluid-filled chamber. The sensor itself may be in contact with the fluid-filled chamber or alternatively it may be partially or completely enclosed within the chamber. The sensor module may have a housing to which one or more connectors may be attached for coupling or connecting, e.g., to an article of clothing worn by the subject. The sensor may be entirely enclosed within the housing which may also be filled with a vibrationally transmissive medium such as a fluid or gas, e.g., water (such as de-ionized water), saline, air, gel, etc.
While the sensor may be positioned within the fluid-filled housing in a cantilevered configuration where a single end of the sensor is securely coupled or attached within the housing, the sensor may be positioned within the fluid-filled housing in various locations and configurations.
An electronics assembly, e.g., a circuit board, may also be integrated within or upon the housing such that the assembly is in electrical communication with the sensor. The electronics assembly may provide for various functions of the signals detected by the sensor. For instance, the assembly may be configured to amplify the detected signals as well as provide for filtering of the signals as well as various other functions.
The housing may also have a contact surface for positioning against the subject's body. Thus, the contact surface may be optionally configured to be made of a soft and/or flexible material such as silicone, polyurethane, etc. which is also transmissive of movements and/or vibrations from the subject through the surface and into the housing. The other portions of the housing may be fabricated similarly or made from any variety of materials such as various plastics and/or metals.
In use, with the sensor module positioned against or in proximity to the subject, any movements or motion such as the movement of a limb or the movement the subject's chest or abdomen resulting from respiration, may be transmitted through the contact surface and into the housing. The movements or motion may then be captured by the fluid-filled chamber and vibrationally transmitted through the transmissive medium such that these signals impinge upon the sensor which may then capture these signals (or the absence of these signals) for processing.
Generally, the sensor may comprises a piezoelectric film sensor but other sensors such as electroactive polymers including ionic polymer metal composite (IPMC) sensors, piezoelectric sensor strain gauges, variable resistance sensors, etc., can also be used. Typically, IPMC sensors are ionic electroactive polymers which may comprise an ion exchange membrane such as Nafion or Flemion which may be plated on either side with a conductive material, e.g., platinum, gold, etc. Alternative electroactive polymer materials which may also be utilized for the sensor may also include, e.g., conducting polymers such as polypyrrole, polyaniline, polythiophene, polyacetylene, carbon nanotube based sensors, ionic gels, dielectric elastomers, etc. Various shapes for the sensor which are practicable may be utilized.
The circuit board itself may generally comprise a printed circuit board having a sensor signal conditioning circuit which may clean or filter the sensor signal received from the sensor through the conductor. The cleaned or filtered sensor signals may then be transmitted through the conductor to a sensor signal amplifier which may amplify the sensor signal, if necessary. The microcontroller may be electrically coupled to the amplifier via conductor and may continuously monitor the signal received. The microcontroller may have a preprogrammed algorithm which may take in the sensor signal and based on the signal, indicate a particular status of the monitored subject. A wireless transmitter in communication with the microcontroller may also be located on the circuit board for transmitting the processed information from the microcontroller to a remote receiver. The wireless transmitter may transmit the information either continuously based on the sampling rate and transmission frequency or intermittently. Alternatively, the transmitter may transmit the information only when a fault condition is detected to alert the caregiver monitoring the subject.
In an example of monitoring an infant to determine whether breathing has ceased, once the system has been started or initiated the sensor module may be set to await the detection of any vibrations through the transmissive medium. Movement or motion from the infant's chest or abdomen normally moving during respiration (or other typical body movements and even including vibrations from the infant's beating heart) may transmit vibrations through the fluid-filled chamber via the transmissive medium where the sensor may receive these transmitted vibrations. Thus, if or when vibrations are detected by the sensor such as when a breathing event may create ripples in the fluid or gas and when these vibrations impinge upon the sensor, the sensor may output an electrical signal. Because the sensitivity of the sensor may be varied or adjusted (e.g., preset or adjusted by the parent or caretaker), the output of the electrical signal may accordingly vary depending upon the adjustment.
For every movement or breathing event by the monitored subject, the sensor will output a value which may be compared against a nominal threshold signal value. Thus, if the sensor output is greater than or equal to the programmed threshold signal value, this will indicate to the microcontroller that a movement or breathing event is occurring and the system may continue to monitor the subject. However, if the sensor output is less than the programmed threshold signal value, then the microcontroller may be programmed to signal an alarm to a third party, such as the parent or caretaker, that the monitored subject has ceased movement or breathing.
Typically, an infant is estimated to take about 30 to 50 breaths/minute. If no movement or breathing is detected in the infant for a predetermined period of time by the sensor module, for example, 10 sec, 15 sec, 20 sec, or any other minimum time period preset and/or set by the parent or caretaker, the microcontroller may automatically signal an alarm to alert the parent or caretaker of this cessation of movement and/or breathing.
In positioning or placing the sensor modules over, upon, or in proximity to the monitored subject, a single sensor module may be positioned for instance upon the subject's chest or abdomen to detect the subject's movements associated with respiration, e.g., as the subject inhales and/or exhales, the sensor module may detect the associated movement of the chest or abdomen. Yet in other examples, multiple sensor modules may be used in combination with one another and positioned along various regions upon or in proximity to the subject's body. In one example, a central monitoring system (which may be monitored by the parent or caretaker) may be in communication with multiple sensor modules. In this example, a first module may be positioned, e.g., on the belly or abdomen, a second module may be positioned, e.g., on the lower back, a third module may be positioned, e.g., on the chest, while a fourth module may be positioned, e.g., on the upper back. Each of the sensor modules may be integrated along an article of clothing such as a diaper or a bodysuit within pockets or they may be positioned via one or more optional straps which are flexible and may be integrated within or along the bodysuit or worn separately from the bodysuit. Although four separate sensor modules are illustrated, a single sensor module may be used and selectively positioned upon the infant or along an article of clothing worn by the infant. Alternatively, more than four sensor modules may be used over various regions of the infant, if so desired or necessary.
In addition to sensing the motion and/or breathing of the monitored subject, the monitoring system may further include a number of additional features such as audio and/or video monitoring, each of which may be used individually or in combination with one another. In this example, the monitoring system may include at least one sensor module in contact or in proximity to the monitored subject, e.g., infant. The at least one sensor module may be in electrical communication, e.g., wireless or wired, with the stationary transmitter which may be positioned in proximity to the monitored subject. Wireless transmission between the sensor module and transmitter may be based on the any number of wireless transmission protocols, such as ZIGBEE® (Zigbee Alliance, San Ramon, Calif.) or any other similar data transmission protocol such as BLUETOOTH® (Bluetooth Sig., Inc., Bellevue, Wash.) which allow for wireless communication in ranges up to 100 feet or more from the receiver unit. The stationary transmitter may optionally include an audio module (including, e.g., a microphone) for detecting any auditory information from the subject, such as crying, movement, auditory signs of respiration, etc. The transmitter may also include an amplifier as well as an amplifier gain control for adjusting the amplifier gain. A power button may also be incorporated to separately power on or off the transmitter if so desired while the transmitter may be powered by battery or through a standard outlet.
Aside from the sensor module and optional audio module, an additional video camera may also be included for visually monitoring the subject. The video camera may be in communication, e.g., wireless or wired, with the receiver unit as well such that the parent or caretaker may also optionally visually monitor the subject. Wireless video communication may likewise be based on the any number of wireless transmission protocols as described above. The video camera may be accordingly located in proximity to the monitored subject, e.g., mounted on a wall or on a crib or stand to capture video images of the subject. The video camera may also incorporate an audio module for also capturing auditory information from the subject. As the video camera may also incorporate a wireless or wired transmitter and/or receiver to transmit or receive signals from the sensor module and/or audio module as well as the transmitter, the camera may also include a microcontroller or video processor to integrate the sensor signal along with the video and/or audio signal as well. As the video camera provides visual images of the monitored subject, the receiver unit may accordingly incorporate a visual display, such as an LCD display, to show the video and movement and/or breathing patterns from the subject, as described in further detail below. Additionally, the receiver unit may also incorporate a microcontroller to set an alarm threshold as well, as also described in detail herein.
In another variation, a sleep positioner comprising a bedding having one or two adjustable protrusions or obstructions, e.g., side wedges, which protrude from the bedding may also be used. One or more sensor modules may be enclosed within or protrude from one or both wedges such that the infant is in contact with at least one sensor module when positioned upon the bedding. The bedding, which may be used in combination with the wedges or alone, may also be configured to include one or more sensor modules in contact with a fluid filled chamber. Such a bedding may include a base layer, a second fluid or gas filled layer laid atop the base layer, and a third bedding layer laid atop the fluid or gas filled layer. The fluid or gas filled layer may transmit movement of the monitored subject through the fluid or gas as vibrations to an integrated sensor module, which may be integrated within the base layer or fluid or gas filled layer. The vibrations sensed by the sensor module may be detected and transmitted via a communication cable to a receiver or other external unit.
A low cost and low power monitoring system for detecting motion and/or breathing from a subject can be configured in a number of different ways while optionally combining audio and/or video monitoring systems. Generally, such a system may incorporate a motion and/or breathing sensor module which may comprise a sensor in communication with a fluid-filled chamber. The sensor itself may be in contact with the fluid-filled chamber or alternatively it may be partially or completely enclosed within the chamber. As shown in the transparent perspective view of
While sensor 18 is illustrated as being positioned within the fluid-filled housing 12 in a cantilevered configuration where a single end of sensor 18 is securely coupled or attached within housing 12, sensor 18 may be positioned within the fluid-filled housing in various locations and configurations. In other variations, rather than having sensor 18 directly surrounded by the transmissive medium 20, sensor 18 may be external to the fluid chamber and/or to the housing and merely in contact with the fluid chamber. Alternatively, sensor 18 may be partially surrounded by the transmissive medium 20.
An electronics assembly 24, e.g., a circuit board, may also be integrated within or upon housing 12 such that assembly 24 is in electrical communication with sensor 18. Electronics assembly 24 may provide for various functions of the signals detected by sensor 18. For instance, assembly 24 may be configured to amplify the detected signals as well as provide for filtering of the signals as well as various other functions, as described in further detail below.
Housing 12 may also have a contact surface 22 for positioning against the subject's body. Thus, contact surface 22 may be optionally configured to be made of a soft and/or flexible material such as silicone, polyurethane, etc. which is also transmissive of movements and/or vibrations from the subject through the surface 22 and into housing 12. The other portions of the housing 12 may be fabricated similarly or made from any variety of materials such as various plastics and/or metals.
In use, with the sensor module 10 positioned against or in proximity to the subject, any movements or motion such as the movement of a limb or the movement of the subject's chest or abdomen resulting from respiration or vibrations through the chest from the beating heart, may be transmitted through contact surface 22 and into housing 12. The movements or motion may then be captured by the fluid-filled chamber and vibrationally transmitted through the transmissive medium 20 such that these signals impinge upon the sensor 18 which may then capture these signals (or the absence of these signals) for processing.
Such IPMC sensors can be made to work in both wet and dry environments. In the case of sensor 30 being positioned in a dry environment within housing 12, such as where a gas may be used as the transmissive medium, sensor 30 may be soaked in a ionic liquid (e.g., liquids comprised predominantly of ions and ion-pairs at some given temperature) and then coated with parylene or other similar material. In the case of sensor 30 being positioned in a wet environment within housing 12, such as where a fluid like saline is used as the transmissive medium, sensor 30 may be configured into its sodium form to operate within such a saline environment. In either case, the sensitivity of sensor 30 may be optionally varied and/or adjustable to suit different environments and/or operating conditions. Optionally, piezoelectric film sensors can also be covered with a fluid-impermeable coating such as parylene, silicone, polyurethane, etc., for use when the sensor is either partially or fully submerged within the transmissive medium.
Aside from an elongate rectangular shape, sensor 30 may be alternatively configured into a variety of shapes. For example,
As previously mentioned, the on-board electronics assembly integrated within or along the housing 12 of the sensor module may be programmed to provide any number of functions. As illustrated in the schematic layout of
Microcontroller 50 may have a preprogrammed algorithm which may take in the sensor signal and based on the signal, indicate a particular status of the monitored subject. A wireless transmitter 48 in communication with the microcontroller 50 may also be located on the circuit board 40 for transmitting the processed information from the microcontroller 50 to a remote receiver (as described in further detail below). The wireless transmitter 48 may transmit the information either continuously based on the sampling rate and transmission frequency or intermittently. Alternatively, transmitter 48 may transmit the information only when a fault condition is detected to alert the caregiver monitoring the subject.
Circuit board 40 may also include a rechargeable, permanent, or replaceable power supply 52, e.g., battery, to provide power to each of the individual components. Because the power usage of the system may be relatively low, the power consumption of the entire system may allow for a lengthened life of the power supply 52, e.g., at least one year or longer. Moreover, a power switch 54 may also be included for switching the power off when not in use. Additionally, an audible and/or visual alarm 56, e.g., LED, may also be optionally included to indicate the status of the system or indicate any cessation of motion in the monitored subject, e.g., stoppage in breathing movements.
An example of an algorithm for programming the microcontroller 50 for use with the sensor 18 within housing 12 may utilize the movements and/or motion of the monitored subject or the lack of movement from the subject. In the example of monitoring an infant to determine whether breathing has ceased, as shown in
For every movement or breathing event by the monitored subject, the sensor 18 will output a value P. A nominal threshold signal value of Q may be programmed into microcontroller 50 to indicate a threshold movement or breathing rate. Thus, if the sensor output P is greater than or equal to the programmed threshold signal value Q, this will indicate to microcontroller that a movement or breathing event is occurring and the system may continue to monitor the subject, as indicated in step 69. However, if the sensor output P is less than the programmed threshold signal value Q, then microcontroller may be programmed to signal an alarm to a third party, such as the parent or caretaker, that the monitored subject has ceased movement or breathing, as indicated in step 71. Microcontroller may update an internal counter R for every detected breathing event P.
Typically, an infant is estimated to take about 30 to 50 breaths/minute. If no movement or breathing is detected in the infant for a predetermined period of time by the sensor module, for example, 10 sec, 15 sec, 20 sec, or any other minimum time period preset and/or set by the parent or caretaker, the microcontroller 50 may automatically signal an alarm to alert the parent or caretaker of this cessation of movement and/or breathing, as indicated in steps 65 and 71.
The sensor module itself may be configured in a manner as previously described or in any number of alternative configurations. Another example is illustrated in the partially transparent side view of
Sensor 94 may be positioned within the fluid-filled chamber connected to housing 72 in a cantilevered configuration via attachment 96 while surrounded by the transmissive medium 92. Sensor 94 may be cantilevered within the fluid chamber while positioned at any number of angles relative to housing 72. In this variation, contact surface 90 may be placed against the monitored subject with coupling members 82, 84 maintaining a position of sensor module 70 relative to the subject. As the subject moves or breathes normally, one or both of the coupling members 82, 84 may move in accordance, as indicated respectively by the direction of movement 86, 88, such that the resulting movements are transmitted as vibrations through housing 72 and/or transmissive medium 92. Additionally and/or alternatively, movement and/or breathing motions may also be transmitted directly through contact surface 90 and through transmissive medium 92 for detection by sensor 94.
In yet another variation,
Another variation is shown in
Another variation is shown in
In positioning or placing the sensor modules over, upon, or in proximity to the monitored subject, a single sensor module may be positioned for instance upon the subject's chest or abdomen to detect the subject's movements associated with respiration, e.g., as the subject inhales and/or exhales, the sensor module may detect the associated movement of the chest or abdomen. Yet in other examples, multiple sensor modules may be used in combination with one another and positioned along various regions upon or in proximity to the subject's body.
In addition to sensing the motion and/or breathing of the monitored subject, the monitoring system may further include a number of additional features such as audio and/or video monitoring, each of which may be used individually or in combination with one another, as shown schematically in the layout of
Transmitter 206 may further be in communication, e.g., wireless communication 220 as previously above, with a separate receiver unit 218, e.g., mobile receiver, which may be monitored by the parent and/or caretaker. Aside from the sensor module 204 and optional audio module 212, an additional video camera 236 may also be included for visually monitoring the subject 202. The video camera 236 may be in communication 238, e.g., wireless or wired, with the receiver unit 218 as well such that the parent or caretaker may also optionally visually monitor the subject 202. Wireless video communication may likewise be based on the any number of wireless transmission protocols as described above. The video camera 236 may be accordingly located in proximity to the monitored subject 202, e.g., mounted on a wall or on a crib or stand to capture video images of the subject 202. As the video camera 236 may also incorporate a wireless receiver to receive signals from the sensor module 204, transmitter module 206, and/or audio module 212, camera 236 may also include a microcontroller or video processor to integrate the sensor signal along with the video and/or audio signal as well. While the audio module 212 may detect audio signals from the subject 202, video camera 236 may also optionally include a separate audio detector, such as a microphone, to monitor any noise from the subject 202. The camera 236 may be configured to operate in both daytime and in nighttime and may operate in ranges up to 100 feet or more from the receiver unit 218 and/or monitored subject 202.
The receiver unit 218 may generally comprise a processor 222 for processing the audio and/or visual information as well as optionally processing any information relating to the subject's movement and/or breathing. Accordingly, receiver unit 218 may incorporate a respiration module 226, e.g., for detecting breathing patterns, from information received from sensor module 204, an audio module 228 for processing the optional audio signals from transmitter 206, as well as a video module 224 for processing the optional video signals from video camera 236. To view the images from video camera 236, receiver unit 218 may include a screen 239, such as an LCD screen, to display the visual images as well as the detected motion and/or breathing signals sensed by sensor module 204 either separately or simultaneously.
In one example of combining the visual signals captured by camera 236 with the information detected by sensor module 204, the system may be set to indicate the absence of any detected movement and/or breathing over a predetermined period of time. If no movement and/or breathing is detected by the sensor module 204 yet video data captured by camera 236 shows or indicates movement by the subject 202, then processor 222 in receiver unit 218 may set a false alarm code as an indication to the parent or caretaker to investigate. If movement and/or breathing is still not detected, then the alarm may increase in intensity at some predetermined time interval, e.g., 5 sec, or if the parent or caretaker fails to shut off the false alarm.
Receiver unit 218 may also include an adjustment control 234 (e.g., for adjusting volume, brightness or contrast of screen 239, etc.) as well as an adjustment control 232 for sensor module 204, e.g., for adjusting time level settings for the interval between detected movement and/or breathing episodes, for example, 10 sec, 15 sec, 20 sec, or any other minimum time period preset and/or set by the parent or caretaker. As previously described, a separate processor may be incorporated directly into sensor module 204 while processor 222 incorporated in receiver unit 218 may be utilized to optionally program the detection time interval in the sensor module 204. Processor 222 may also be programmed, as previously described, to sound a visual and/or auditory alarm to alert the parent or caretaker if the detected episodes between the subject's movement and/or breathing exceeds the programmed allowable time period. A power button 230 may also be incorporated in receiver unit 218 for powering the receiver unit 218 on or off.
In displaying the detected motion and/or breathing signals sensed by sensor module 204 on screen 239, a waveform generator optionally incorporated in receiver unit 218 may be utilized to generate and display the detected breathing patterns and/or other waveforms illustrating normal motion/breathing states or abnormal motion/breathing states (or lack of motion/breathing), as illustrated by the exemplary detected respiration 242 in respiration graph 240 of
In incorporating the system with respect to the monitored subject, the one or more sensor modules may be integrated into or along an article of clothing worn by the monitored subject, as previously described,. However, one or more sensor modules may be utilized in various other articles or objects such as furniture. An example is shown in the front assembly view of
In another variation,
Turning now to the bedding, which may be used in combination with wedges 264, 266 or alone, an example of a bedding directly integrating a sensor assembly is illustrated in the perspective views of bedding assembly 290 in
As previously described, one or more sensor modules may be used in combination with other detection features such as audio and/or video features.
The applications of the devices and methods discussed above are not limited to the detection and/or monitoring of infants but may include any number of further detection and/or monitoring applications. Modification of the above-described device and methods for carrying out the invention, and variations of aspects of the invention that are obvious to those of skill in the art are intended to be within the scope of the claims.
This application is a continuation of U.S. patent application Ser. No. 12/537,540 filed Aug. 7, 2009, which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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Parent | 12537540 | Aug 2009 | US |
Child | 14276283 | US |