WO2009151411A1 - Method for detecting the critical position in orientation and indicating the change of the position of a human being body - Google Patents
Method for detecting the critical position in orientation and indicating the change of the position of a human being body Download PDFInfo
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- WO2009151411A1 WO2009151411A1 PCT/UA2009/000016 UA2009000016W WO2009151411A1 WO 2009151411 A1 WO2009151411 A1 WO 2009151411A1 UA 2009000016 W UA2009000016 W UA 2009000016W WO 2009151411 A1 WO2009151411 A1 WO 2009151411A1
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- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
- G08B21/02—Alarms for ensuring the safety of persons
- G08B21/04—Alarms for ensuring the safety of persons responsive to non-activity, e.g. of elderly persons
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/103—Measuring devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
- A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor or mobility of a limb
- A61B5/1116—Determining posture transitions
- A61B5/1117—Fall detection
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
- A61B2562/02—Details of sensors specially adapted for in-vivo measurements
- A61B2562/0219—Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
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- the proposed method can be used in control systems designed for detecting the critical position and indicating the change of the position of a human being body over a short time interval, within which the physiological state of the human being may significantly change so that substantial medical assistance would be required.
- the method provides a possibility to monitor the state of solitary aged people or invalids that live in isolated rooms or in remote areas without attendance.
- the falling of the human being in certain unpredicted conditions is associated with the unique time and amplitude characteristics of the output signal of the accelerometer, so the waveforms of the signal are not represented by the corresponding data in the data base.
- the unique time and amplitude characteristics of the output signal may be in the conditions of the falling that are caused by movements of the human being, collision of the human being with an obstacle, unsuccessful settling of the human being in a chair, or another event.
- the no-coincidence state detected when comparing the waveform of the output signal of the accelerometer with the specified waveforms represented by the corresponding data in the data base would be considered as the absence of the critical position of the human being body.
- the temperature measurement may increase the probability of detection only in the event when a temperature sensor is attached to the human being body, so the proposed method is limited due to the necessity to use additional equipment. Additionally, the critical change, specifically the decrease, of the human being body temperature is possible only within a certain period of time. As a result, the alarm signal that indicates the critical position of the human being body might be generated too late, that is, when medical assistance is unnecessary.
- This method does not allow the reliable proofs of the falling of the patient to be obtained and is based on using indicators that require the subsequent insufficiently formal multiple-factor analysis of the indicators in combination with additional data that can be analyzed by the physician only when the data are being generated, so the analysis is possible only in hospital conditions.
- the mandatory measurement of one the physiological parameters of the patient that is required for confirming the critical position of the patient limits the range of possible critical positions that can be detected, specifically in the conditions when the physical state of a healthy invalid is monitored. In this case, the critical position of the patient may not be accompanied with cardiac problems.
- the maximum values of the output signal of each of the accelerometers may correspond to different movements of the parts of the human being body and objects on the body, including movements that are possible in the falling of the human being. Such movements may be caused by that the body parts and the objects on the body compose an insufficiently rigid system and have some degrees of freedom.
- the method does not allow the falling of the human being to be detected reliably as the maximum values of the output signals of the accelerometers and the coincidence of the maximal signal values may be caused by uncritical independent movements of the parts of the human being body or objects on the body.
- the uncritical movements that can be confused with the movements that correspond to the falling of the human being include, for example, uncoordinated movements of an aged human being or an invalid, which are caused by the collision of the aged human being or invalid with an obstacle, unsuccessful settling of the aged human being or invalid in a chair, or another event. These movements induce changes in the output signal of the accelerometer that can be taken for the changes corresponding to the falling.
- the output signal of the accelerometer may have maximum values that do not correspond to the critical positions of the human being body but exceed the difference of the values of the constant component of the output signal of the accelerometer that are measured at two positions of the accelerometer differing by
- the critical positions of the human being body that may be considered as the uncritical ones when analyzing the maximum values of the output signal of the accelerometer include, for example, the position that is possible in the hindered falling of the human being or when the human being attempts to remain on his feet in collision with an obstacle.
- the maximum values of the output signal of the accelerometer may be induced by the movements of the accelerometer relative to the human being body that are possible because the accelerometer is attached to the body without sufficient rigidity.
- the proposed method for detecting the critical position in orientation and indicating the change of the position of a human being body is distinctive by using new, empirically supported combinations of the output signals of accelerometers.
- the use of such signal combinations makes it possible to increase the accuracy of the detection due to reducing the effect of the nonlinear characteristics of the accelerometers and the nonuniform accelerations of the human being body or parts of the body as a result of movements of the human being with varying velocity, change of the direction of movement, collision of the human being with obstacles, unsuccessful settling of the human being in a chair, or another event.
- the method is based on using two accelerometers as sensors for detecting the critical position of the human being body.
- the method consists in attaching the accelerometers to the human being body, monitoring the position of the human being body by analyzing the output signals of the accelerometers, and detecting the specified maximum value of the output signal of each of the accelerometer followed by the value of the signal that is constant over the specified time interval.
- the method is distinctive by performing the following operations: determining the difference of the values of the constant component of the output signal of each of two accelerometers to be used that are measured at two positions of the accelerometer differing by 90 degrees; attaching the aforesaid accelerometers, as the first accelerometer and the second accelerometer, to the human being body; monitoring the output signal of the first accelerometer for detecting two sequential time intervals, each of length no less than 2 s, within which the signal value is constant or varies by a value that does not exceed the noise signal level; determining the amplitude of the alternating component of the output signal between the aforesaid time intervals of 2 s; determining the value of the change of the constant component of the output signal between the aforesaid time intervals of 2 s; analyzing, over a time interval of length 5 ...
- the output signal of the second accelerometer if the amplitude of the alternating component of the output signal of the first accelerometer between the aforesaid time intervals of 2 s exceeds the double difference of the values of the constant component of the output signal of the first accelerometer that are measured at two positions of the first accelerometer differing by 90 degrees and if the value of the change of the constant component of the output signal of the first accelerometer between the aforesaid time intervals of 2 s exceeds the noise signal level more than two times, by performing, for the purpose of the analysis, the following operations: monitoring the output signal of the second accelerometer for detecting two sequential time intervals, each of length no less than 2 s, within which the signal value is constant or varies by a value that does not exceed the noise signal level, and determining the amplitude of the alternating component of the output signal between the aforesaid time intervals; indicating the falling of the human being if the amplitude of the alternating component of the output signal of the second accelerometer between the
- the use of the output signals of two accelerometers attached to different parts of the human being body provides a possibility to additionally increase the accuracy in detecting the critical position of the human being body due to the increase of the amount of information on the movements of the human being body that result in the critical position of the body.
- the increased amount of such information allows the use of new parameters in analyzing the output signals of the accelerometers that significantly increase the reliability of the detection of the falling of the human being resulting in the critical position of the human being body or other consequences.
- the data obtained according to the method are less dependent on nonuniform accelerations of the human being body or parts of the body as a result of movements of the human being with varying velocity, change of the direction of movement, collision of the human being with obstacles, unsuccessful settling of the human being in a chair, or another event.
- the following operations are performed: monitoring the output signals of both the accelerometers attached to the human being body; indicating the noncritical position of the human being body if the output signal of the second accelerometer is a sine signal, over a time interval of length 20 ... 6O s, with an amplitude that exceeds the noise signal level; indicating the critical position of the human being body if the output signals of both the accelerometers are constant signals, over a time interval of length 20 ...
- the first accelerometer is attached to the foot of the human being.
- the output signal of the accelerometer attached to the foot of the human being allows the accuracy in detecting the critical position of the human being body to be significantly increased, as the movement patterns of the foot in the critical state of the human being less differ from each other.
- the output signal of the accelerometer is characterized by the more distinct constant component, increased amplitude, and shorter time interval between the adjacent signal sections within which the signal value is constant.
- the first accelerometer is attached to the ankle of the human being.
- the use of the output signal of the accelerometer attached to the ankle of the human being allows the accuracy in detecting the critical position of the human being body to be additionally increased, as the movement patterns of the ankle in the critical state of the human being still less differ from each other.
- the output signal of the accelerometer is characterized by the more distinct constant component, increased amplitude, and shorter time interval between the adjacent signal sections within which the signal value is constant.
- a further embodiment of the method is distinctive by: connecting the accelerometers by a radio link; automatically starting the processing of the output signal and reading the measurement data corresponding to the output signal of the second accelerometer in response to a remote control signal transmitted from the first accelerometer to the second one via the radio link.
- connection of two accelerometers via a radio link provides a possibility to start the processing of the output signal of the second accelerometer only after the detection of the falling of the human being by the first accelerometer. As a result, the power consumed by the second accelerometer can be reduced.
- Figure 1 shows the time charts of the output signals of the accelerometers when detecting the critical position of the human being body according to the proposed method.
- Figures 2 through 4 show the time charts of the output signals of the accelerometers according to the corresponding embodiments of the proposed method that are characterized by performing the additional analysis of the output signals of the accelerometers after detecting the falling of the human being.
- the operations required for the embodiments of the proposed method can be performed manually by an operator, which reads out the output signals of the accelerometers, analyses the signals, and determines the results of the monitoring of the position of the human being body, or automatically by a microprocessor or another control device, which allows the resulting output data of the device to be shared by many users.
- the method according to this embodiment is distinctive from the method according to Embodiment 1 by performing the following operations: 1. Monitoring, after the indication of the falling of the human being, the output signal of the second accelerometer attached to the human being body.
- the method according to this embodiment is distinctive from the method according to Embodiment 1 by performing the following operations:
- the method according to this embodiment is distinctive from the method according to Embodiment 1 by performing the following operations: 1. Monitoring, after the indication of the falling of the human being, the output signals of both the accelerometers attached to the human being body.
- the falling of the human being in certain unpredicted conditions would be associated with unique time and amplitude characteristics of the output signals of the accelerometers, so the signals do not correspond to the signals that allow the critical position of the human body to be detected.
- the unique time and amplitude characteristics of the output signals may be in the conditions of the falling that are caused by movements of the human being, collision of the human being with an obstacle, unsuccessful settling of the human being in a chair, or another event. In such conditions, the reliable detection of the critical position of the human body after the falling would be difficult.
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Abstract
A method for indicating the fall of a person. It uses two accelerometers which may be placed on different parts of the body. The method is characterized in that before attaching the accelerometers to the body, the signal of both accelerometers is measured at two stable positions differing by 90 degrees. The fall event is flagged after both accelerometers detected a maximum signal which is higher than twice the difference in the signal measured between the two stable positions differing by 90 degrees and when the time interval between the two maximum signals does not exceed 100 ms.
Description
METHOD FOR DETECTING THE CRITICAL POSITION IN
ORIENTATION AND INDICATING THE CHANGE OF THE POSITION OF A HUMAN BEING BODY
The proposed method can be used in control systems designed for detecting the critical position and indicating the change of the position of a human being body over a short time interval, within which the physiological state of the human being may significantly change so that substantial medical assistance would be required. The method provides a possibility to monitor the state of solitary aged people or invalids that live in isolated rooms or in remote areas without attendance.
It is known the method for detecting the critical position of a human being body by using an accelerometer as a sensor for monitoring the position of the human being body (WO 2007057692; G08B 21/04, G08B 21/22, G08B 21/00; May 24, 2005) that consists in performing the following operations: attaching the accelerometer to the human being body; establishing a data base for storing the data corresponding to the specified waveforms of the output signal of the accelerometer that characterize the potential critical positions of the human being body; monitoring the position of the human being body by analyzing the output signal of the accelerometer; comparing the current waveform of the output signal with the specified waveforms represented by the corresponding data read out from the data base; indicating the falling of the human being if the current waveform of the output signal coincides with the specified waveform at a certain instant of time; and confirming the conclusion that the falling is associated with the critical position of the human being body by measuring the temperature of the human being body. This method has disadvantages that are discussed below.
First, it is necessary to establish, for each controlled human being, a data base for storing the data corresponding to the specified waveforms of the output signal of
the accelerometer that characterize the potential critical positions of the human being body. This disadvantage makes it difficult to introduce the method. Access to the data base, search of data in the data base, and comparison of the current waveform of the output signal of the accelerometer with the specified waveforms require the availability of complex equipment.
Additionally, it is possible that the falling of the human being in certain unpredicted conditions is associated with the unique time and amplitude characteristics of the output signal of the accelerometer, so the waveforms of the signal are not represented by the corresponding data in the data base. The unique time and amplitude characteristics of the output signal may be in the conditions of the falling that are caused by movements of the human being, collision of the human being with an obstacle, unsuccessful settling of the human being in a chair, or another event. In such conditions, the no-coincidence state detected when comparing the waveform of the output signal of the accelerometer with the specified waveforms represented by the corresponding data in the data base would be considered as the absence of the critical position of the human being body. Second, the temperature measurement may increase the probability of detection only in the event when a temperature sensor is attached to the human being body, so the proposed method is limited due to the necessity to use additional equipment. Additionally, the critical change, specifically the decrease, of the human being body temperature is possible only within a certain period of time. As a result, the alarm signal that indicates the critical position of the human being body might be generated too late, that is, when medical assistance is unnecessary. It is known the method for monitoring the physical state of a patient in a hospital by using an accelerometer as a sensor for monitoring the position of the patient (US 6160478; A61B 5/11, G08B 5/22, G08B 21/04, A61B 5/00, A61B 5/021, A61B 5/024; December 12, 2007) that consists in performing the following operations: attaching the accelerometer to the patient body;
monitoring the position of the patient body by analyzing the output signal of the accelerometer; detecting the vertical, horizontal, or intermediate position of the human being body; detecting the specified acceleration of the patient body; measuring, additionally, one of the physiological parameters of the patient, such as, for example, cardiac arrhythmia; and determining the critical position of the patient by using the obtained data in combination with other indicators of the falling of the patient. This method does not allow the reliable proofs of the falling of the patient to be obtained and is based on using indicators that require the subsequent insufficiently formal multiple-factor analysis of the indicators in combination with additional data that can be analyzed by the physician only when the data are being generated, so the analysis is possible only in hospital conditions. The mandatory measurement of one the physiological parameters of the patient that is required for confirming the critical position of the patient limits the range of possible critical positions that can be detected, specifically in the conditions when the physical state of a healthy invalid is monitored. In this case, the critical position of the patient may not be accompanied with cardiac problems. It is known the method for detecting the critical position of a human being body by using three accelerometers, each of which is designed for measuring the acceleration of the human being body at a certain point of the body in one of three coordinate planes, (WO 2006101587; G08B 23/00; September 28, 2006) that consists in performing the following operations: attaching the aforesaid accelerometers to the human being body; monitoring the position of the human being body by analyzing the output signals of the accelerometers corresponding to the movements of the human being in three coordinate planes;
determining the sum of squares of the current maximum values of the output signals of all the accelerometers that coincide in time; and indicating the falling of the human being if the aforesaid sum of squares of the maximum values is equal to or exceeds the specified threshold value. This method has the disadvantage that is discussed below.
It is evident, that the maximum values of the output signal of each of the accelerometers may correspond to different movements of the parts of the human being body and objects on the body, including movements that are possible in the falling of the human being. Such movements may be caused by that the body parts and the objects on the body compose an insufficiently rigid system and have some degrees of freedom.
For this reason, the method does not allow the falling of the human being to be detected reliably as the maximum values of the output signals of the accelerometers and the coincidence of the maximal signal values may be caused by uncritical independent movements of the parts of the human being body or objects on the body.
It is also known the method for detecting the critical position of a human being body by using an accelerometer as a sensor for monitoring the position of the human being body (US 6433690; A61B 5/11, G08B 5/22, G08B 21/04; August 13, 2002) that consists in performing the following operations: attaching the accelerometer to the human being body; monitoring the output signal of the accelerometer for detecting a section of the signal with a constant value over a specified time interval of length no less than 2 s; and indicating the falling of the human being if the aforesaid time interval of 2 s is preceded by the change of the output signal value over a time interval of length no more than 0,335 s, provided that the position of the human being body within the aforesaid time interval of 0,335 s is changed by no less than 50 degrees.
This method does not ensure sufficient accuracy in detecting the critical position of a human being body because some movements of the body are not associated with the falling of the human being.
In most cases, falling of a human beings occurs not on a plane surface but in a room or another premise with various obstacles. In these conditions, the uncritical movements that can be confused with the movements that correspond to the falling of the human being include, for example, uncoordinated movements of an aged human being or an invalid, which are caused by the collision of the aged human being or invalid with an obstacle, unsuccessful settling of the aged human being or invalid in a chair, or another event. These movements induce changes in the output signal of the accelerometer that can be taken for the changes corresponding to the falling.
Due to the nonlinearity of the gain-transfer characteristic of the accelerometer, the output signal of the accelerometer may have maximum values that do not correspond to the critical positions of the human being body but exceed the difference of the values of the constant component of the output signal of the accelerometer that are measured at two positions of the accelerometer differing by
90 degrees.
The critical positions of the human being body that may be considered as the uncritical ones when analyzing the maximum values of the output signal of the accelerometer include, for example, the position that is possible in the hindered falling of the human being or when the human being attempts to remain on his feet in collision with an obstacle.
The maximum values of the output signal of the accelerometer may be induced by the movements of the accelerometer relative to the human being body that are possible because the accelerometer is attached to the body without sufficient rigidity.
The proposed method for detecting the critical position in orientation and indicating the change of the position of a human being body is distinctive by using
new, empirically supported combinations of the output signals of accelerometers. The use of such signal combinations makes it possible to increase the accuracy of the detection due to reducing the effect of the nonlinear characteristics of the accelerometers and the nonuniform accelerations of the human being body or parts of the body as a result of movements of the human being with varying velocity, change of the direction of movement, collision of the human being with obstacles, unsuccessful settling of the human being in a chair, or another event. The method is based on using two accelerometers as sensors for detecting the critical position of the human being body. The method consists in attaching the accelerometers to the human being body, monitoring the position of the human being body by analyzing the output signals of the accelerometers, and detecting the specified maximum value of the output signal of each of the accelerometer followed by the value of the signal that is constant over the specified time interval. The method is distinctive by performing the following operations: determining the difference of the values of the constant component of the output signal of each of two accelerometers to be used that are measured at two positions of the accelerometer differing by 90 degrees; attaching the aforesaid accelerometers, as the first accelerometer and the second accelerometer, to the human being body; monitoring the output signal of the first accelerometer for detecting two sequential time intervals, each of length no less than 2 s, within which the signal value is constant or varies by a value that does not exceed the noise signal level; determining the amplitude of the alternating component of the output signal between the aforesaid time intervals of 2 s; determining the value of the change of the constant component of the output signal between the aforesaid time intervals of 2 s; analyzing, over a time interval of length 5 ... 10 s, the output signal of the second accelerometer, if the amplitude of the alternating component of the output signal of
the first accelerometer between the aforesaid time intervals of 2 s exceeds the double difference of the values of the constant component of the output signal of the first accelerometer that are measured at two positions of the first accelerometer differing by 90 degrees and if the value of the change of the constant component of the output signal of the first accelerometer between the aforesaid time intervals of 2 s exceeds the noise signal level more than two times, by performing, for the purpose of the analysis, the following operations: monitoring the output signal of the second accelerometer for detecting two sequential time intervals, each of length no less than 2 s, within which the signal value is constant or varies by a value that does not exceed the noise signal level, and determining the amplitude of the alternating component of the output signal between the aforesaid time intervals; indicating the falling of the human being if the amplitude of the alternating component of the output signal of the second accelerometer between the aforesaid time intervals of 2 s exceeds the double difference of the values of the constant component of the output signal of the second accelerometer that are measured at two positions of the second accelerometer differing by 90 degrees, and if the time interval between the maximum values of the alternating components of the output signal of the first accelerometer and the output signal of the second accelerometer does not exceed 100 ms.
The use of the output signals of two accelerometers attached to different parts of the human being body provides a possibility to additionally increase the accuracy in detecting the critical position of the human being body due to the increase of the amount of information on the movements of the human being body that result in the critical position of the body. The increased amount of such information allows the use of new parameters in analyzing the output signals of the accelerometers that significantly increase the reliability of the detection of the falling of the human
being resulting in the critical position of the human being body or other consequences.
The data obtained according to the method are less dependent on nonuniform accelerations of the human being body or parts of the body as a result of movements of the human being with varying velocity, change of the direction of movement, collision of the human being with obstacles, unsuccessful settling of the human being in a chair, or another event.
According to one of the embodiments of the method, after the indication of the falling of the human being, the following operations are performed: monitoring the output signals of both the accelerometers attached to the human being body; indicating the noncritical position of the human being body if the output signal of the second accelerometer is a sine signal, over a time interval of length 20 ... 6O s, with an amplitude that exceeds the noise signal level; indicating the critical position of the human being body if the output signals of both the accelerometers are constant signals, over a time interval of length 20 ...
60 s, with fluctuations that do not exceed the noise signal level; and indicating the critical position of the human being body if, over a time interval of length 20 ... 60 s, the value of the output signal of one of the accelerometers does not exceed the noise signal level, and the value of the fluctuation of the output signal of the other accelerometer exceeds the noise signal level.
According to another embodiment of the method, the first accelerometer is attached to the foot of the human being.
The use of the output signal of the accelerometer attached to the foot of the human being allows the accuracy in detecting the critical position of the human being body to be significantly increased, as the movement patterns of the foot in the critical state of the human being less differ from each other. As a result, the output signal of the accelerometer is characterized by the more distinct constant
component, increased amplitude, and shorter time interval between the adjacent signal sections within which the signal value is constant.
According to yet another embodiment of the method, the first accelerometer is attached to the ankle of the human being. The use of the output signal of the accelerometer attached to the ankle of the human being allows the accuracy in detecting the critical position of the human being body to be additionally increased, as the movement patterns of the ankle in the critical state of the human being still less differ from each other. As a result, the output signal of the accelerometer is characterized by the more distinct constant component, increased amplitude, and shorter time interval between the adjacent signal sections within which the signal value is constant.
A further embodiment of the method is distinctive by: connecting the accelerometers by a radio link; automatically starting the processing of the output signal and reading the measurement data corresponding to the output signal of the second accelerometer in response to a remote control signal transmitted from the first accelerometer to the second one via the radio link.
The connection of two accelerometers via a radio link provides a possibility to start the processing of the output signal of the second accelerometer only after the detection of the falling of the human being by the first accelerometer. As a result, the power consumed by the second accelerometer can be reduced.
The proposed method is illustrated by Figures 1 through 4.
Figure 1 shows the time charts of the output signals of the accelerometers when detecting the critical position of the human being body according to the proposed method. Figures 2 through 4 show the time charts of the output signals of the accelerometers according to the corresponding embodiments of the proposed method that are characterized by performing the additional analysis of the output signals of the accelerometers after detecting the falling of the human being.
The operations required for the embodiments of the proposed method can be performed manually by an operator, which reads out the output signals of the accelerometers, analyses the signals, and determines the results of the monitoring of the position of the human being body, or automatically by a microprocessor or another control device, which allows the resulting output data of the device to be shared by many users.
Embodiment 1
This embodiment of the proposed method is illustrated by the time charts shown in Figure 1. According to the embodiment, the following operations are performed: 1. Determining the difference of the values of the constant component of the output signal of each of two accelerometers to be used that are measured at two positions of the accelerometer differing by 90 degrees (parameter a = 90° in Figure 1). 2. Specifying the threshold value of the constant component of the output signal of each of two accelerometers, which is determined as the double value of the difference of the values of the constant component of the output signal of each of two accelerometers that are measured at two positions of the accelerometer differing by 90 degrees. 3. Attaching the aforesaid accelerometers, as the first accelerometer and the second accelerometer, to the human being body at different points.
4. Monitoring the output signal of the first accelerometer for detecting two sequential time intervals, each of length no less than 2 s, (sections "2 s" of the time chart shown in Figure 1) within which the signal value is constant or varies by a value that does not exceed the noise signal level.
5. Determining the amplitude of the alternating component of the output signal between the aforesaid time intervals of 2 s.
6. Determining the value of the change of the constant component of the output signal between the aforesaid time intervals of 2 s.
7. Analyzing, over a time interval of length 5 ... 10 s, the output signal of the second accelerometer, if the amplitude of the alternating component of the output signal of the first accelerometer between the aforesaid time intervals of 2 s exceeds the double difference of the values of the constant component of the output signal of the first accelerometer that are measured at two positions of the first accelerometer differing by 90 degrees and if the value of the change of the constant component of the output signal of the first accelerometer between the aforesaid time intervals of 2 s exceeds the noise signal level more than two times, by performing, for the purpose of the analysis, the following operations: monitoring the output signal of the second accelerometer for detecting two sequential time intervals, each of length no less than 2 s, within which the signal value is constant or varies by a value that does not exceed the noise signal level, and determining the amplitude of the alternating component of the output signal between the aforesaid time intervals of 2 s.
8. Indicating the falling of the human being if the amplitude of the alternating component of the output signal of the second accelerometer between the aforesaid time intervals of 2 s exceeds the double difference of the values of the constant component of the output signal of the second accelerometer that are measured at two positions of the second accelerometer differing by 90 degrees (amplitude b > 2a on the time chart shown in Figure 1), and if the time interval between the maximum values of the alternating components of the output signal of the first accelerometer and the output signal of the second accelerometer does not exceed 100 ms.
Embodiment 2
The method according to this embodiment is distinctive from the method according to Embodiment 1 by performing the following operations:
1. Monitoring, after the indication of the falling of the human being, the output signal of the second accelerometer attached to the human being body.
2. Indicating the noncritical position of the human being body if the output signal of the second accelerometer is a sine signal, over a time interval of length 20 ... 60 s, with an amplitude that exceeds the noise signal level. The presence of this sine signal indicates that the human being has recovered the normal state and does not need assistance.
Embodiment 3
The method according to this embodiment is distinctive from the method according to Embodiment 1 by performing the following operations:
1. Monitoring, after the indication of the falling of the human being, the output signals of both the accelerometers attached to the human being body. 2. Indicating the critical position of the human being body if the output signals of both the accelerometers are constant signals, over a time interval of length 20 ... 60 s, with fluctuations that do not exceed the noise signal level. The presence of these signals indicates that the human being has not recovered the normal state and needs assistance.
Embodiment 4
The method according to this embodiment is distinctive from the method according to Embodiment 1 by performing the following operations: 1. Monitoring, after the indication of the falling of the human being, the output signals of both the accelerometers attached to the human being body.
2. Indicating the critical position of the human being body if, over a time interval of length 20 ... 60 s, the value of the output signal of one of the accelerometers does not exceed the noise signal level, and the value of the fluctuation of the output
signal of the other accelerometer exceeds the noise signal level. The presence of these signals indicates that the human being has not recovered the normal state and needs assistance.
It is possible that the falling of the human being in certain unpredicted conditions would be associated with unique time and amplitude characteristics of the output signals of the accelerometers, so the signals do not correspond to the signals that allow the critical position of the human body to be detected. The unique time and amplitude characteristics of the output signals may be in the conditions of the falling that are caused by movements of the human being, collision of the human being with an obstacle, unsuccessful settling of the human being in a chair, or another event. In such conditions, the reliable detection of the critical position of the human body after the falling would be difficult.
Claims
1. The method for detecting the critical position in orientation and indicating the change of the position of a human being body by using an accelerometer attached to the human being body as a sensor for detecting the critical position that consists in monitoring the position of the human being body by analyzing the output signal of the accelerometer and detecting the specified maximum value of the output signal of the accelerometer followed by the value of the signal that is constant over the specified time interval, which is distinctive by performing the following operations: determining the difference of the values of the constant component of the output signal of each of two accelerometers to be used that are measured at two positions of the accelerometer differing by 90 degrees; attaching the aforesaid accelerometers, as the first accelerometer and the second accelerometer, to the human being body; monitoring the output signal of the first accelerometer for detecting two sequential time intervals, each of length no less than 2 s, within which the signal value is constant or varies by a value that does not exceed the noise signal level; determining the amplitude of the alternating component of the output signal between the aforesaid time intervals of 2 s; determining the value of the change of the constant component of the output signal between the aforesaid time intervals of 2 s; analyzing, over a time interval of length 5 ... 10 s, the output signal of the second accelerometer, if the amplitude of the alternating component of the output signal of the first accelerometer between the aforesaid time intervals of 2 s exceeds the double difference of the values of the constant component of the output signal of the first accelerometer that are measured at two positions of the first accelerometer differing by 90 degrees and if the value of the change of the constant component of the output signal of the first accelerometer between the aforesaid time intervals of 2 s exceeds the noise signal level more than two times, by performing, for the purpose of the analysis, the following operations: monitoring the output signal of the second accelerometer for detecting two sequential time intervals, each of length no less than 2 s, within which the signal value is constant or varies by a value that does not exceed the noise signal level, and determining the amplitude of the alternating component of the output signal between the aforesaid time intervals of 2 s; indicating the falling of the human being if the amplitude of the alternating component of the output signal of the second accelerometer between the aforesaid time intervals of 2 s exceeds the double difference of the values of the constant component of the output signal of the second accelerometer that are measured at two positions of the second accelerometer differing by 90 degrees and if the time interval between the maximum values of the alternating components of the output signal of the first accelerometer and the output signal of the second accelerometer does not exceed 100 ms.
2. The method according to Paragraph 1 that is distinctive by performing the following operations: monitoring, after the indication of the falling of the human being, the output signals of both the accelerometers attached to the human being body; indicating the noncritical position of the human being body if the output signal of the second accelerometer is a sine signal, over a time interval of length 20 ... 6O s, with an amplitude that exceeds the noise signal level; indicating the critical position of the human being body if the output signals of both the accelerometers are constant signals, over a time interval of length 20 ...
60 s, with fluctuations that do not exceed the noise signal level; and indicating the critical position of the human being body if, over a time interval of length 20 ... 60 s, the value of the output signal of one of the accelerometers does not exceed the noise signal level, and the value of the fluctuation of the output signal of the other accelerometer exceeds the noise signal level.
3. The method according to Paragraph 1 that is distinctive by that the first accelerometer is attached to the foot of the human being.
4. The method according to Paragraph 1 that is distinctive by that the first accelerometer is attached to the ankle of the human being.
5. The method according to Paragraph 1 that is distinctive by: connecting the accelerometers by a radio link; automatically starting the processing of the output signals and reading the measurement data corresponding to the output signals of the second accelerometer in response to a remote control signal transmitted from the first accelerometer to the second one via the radio link.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| UAU200807964U UA38088U (en) | 2008-06-12 | 2008-06-12 | Method for indication of critical situation in orientation of position of human body coming to existence and signaling on its change |
| UAU200807964 | 2008-06-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2009151411A1 true WO2009151411A1 (en) | 2009-12-17 |
Family
ID=40984746
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/UA2009/000016 Ceased WO2009151411A1 (en) | 2008-06-12 | 2009-04-29 | Method for detecting the critical position in orientation and indicating the change of the position of a human being body |
Country Status (2)
| Country | Link |
|---|---|
| UA (1) | UA38088U (en) |
| WO (1) | WO2009151411A1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6160478A (en) * | 1998-10-27 | 2000-12-12 | Sarcos Lc | Wireless health monitoring system |
| US20050110648A1 (en) * | 1999-09-15 | 2005-05-26 | Ilife Systems, Inc. | System and method for detecting motion of a body |
| US20070277586A1 (en) * | 2006-06-02 | 2007-12-06 | Oki Electric Industry Co., Ltd. | Three-axial acceleration sensor inspection device and method of inspecting three-axial acceleration sensor |
-
2008
- 2008-06-12 UA UAU200807964U patent/UA38088U/en unknown
-
2009
- 2009-04-29 WO PCT/UA2009/000016 patent/WO2009151411A1/en not_active Ceased
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6160478A (en) * | 1998-10-27 | 2000-12-12 | Sarcos Lc | Wireless health monitoring system |
| US20050110648A1 (en) * | 1999-09-15 | 2005-05-26 | Ilife Systems, Inc. | System and method for detecting motion of a body |
| US20070277586A1 (en) * | 2006-06-02 | 2007-12-06 | Oki Electric Industry Co., Ltd. | Three-axial acceleration sensor inspection device and method of inspecting three-axial acceleration sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| UA38088U (en) | 2008-12-25 |
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