This application claims the priority benefit of Taiwan application serial no. 105207982, filed on May 30, 2016. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The invention relates to a physiological detection device and particularly relates to a physiological detection device for detecting a body circulation state.
Cardiovascular disease has become one of the major causes of death around the world. Therefore, the research and development of various detection methods for cardiovascular circulation have become more important than before. Among current detection methods, the method of detecting peripheral blood circulation based on photoplethysmography signals generated by a photoplethysmograph (PPG) is drawing more and more attention. The PPG is capable of obtaining an optical volume pulse of the blood in the detected portion of the human body so as to calculate a physiological state index by using a calculator according to the obtained optical volume pulse wave.
Specifically, a physiological detection device that uses the PPG to detect and measure the circulation state calculates the physiological state index based on information of feature points of the optical volume pulse wave signal obtained from the detected portion of the human body.
However, the way the conventional physiological detection device calculates the physiological state index has the following deficiency. Specifically, an optical volume pulse signal of a normal subject has a pulse wave with a transient rebound and rise during the process of descending, which is the above-mentioned diastolic wave. For subjects who are in poor health or aging, however, the optical volume pulse wave signal obtained by detecting the detected portion may not have the diastolic wave or the diastolic wave may not have an obvious diastolic peak. Consequently, the conventional physiological detection device may not be able to effectively obtain the physiological state index of the subject by the aforementioned calculation method. For the above reason, the physiological state index detection and calculation method of the conventional physiological detection device are not applicable to all subjects. Thus, it has become an important issue in this field to develop a physiological detection device that can easily and accurately detect body circulation for all subjects.
The invention provides a physiological detection device that detects and assesses a body circulation state of a subject in a noninvasive manner.
The physiological detection device of the invention includes a main body, a sensor pair, a signal processor, and a calculation module. The sensor pair is disposed in the main body and adapted to detect a detected portion of a human body to obtain a sensing signal. The signal processor is disposed in the main body and receives and processes the sensing signal to output a digital physiological signal. The calculation module receives the digital physiological signal and calculates to obtain first information and second information of a plurality of feature points of the digital physiological signal. The calculation module calculates a ratio of the second information to the first information to obtain a physiological state index. The digital physiological signal includes a plurality of pulse waves generated according to a time sequence. The feature points of the digital physiological signal include a pulse peak of each of the pulse waves and a foot point at a forepart of a rising edge of each of the pulse waves.
In an embodiment of the invention, the first information is an integral area of the pulse wave between the foot point and the pulse peak with respect to a time axis while the second information is an integral area of the pulse wave between adjacent two foot points with respect to the time axis.
In an embodiment of the invention, the first information is a time difference between the foot point and the pulse peak while the second information is a time difference between the adjacent two foot points.
In an embodiment of the invention, the sensor pair is a photoplethysmograph, including an optical emitter and an optical receiver. The optical emitter emits a light that passes through the detected portion of the human body. The optical receiver receives the light passing through the detected portion to obtain the sensing signal.
In an embodiment of the invention, the signal processor includes a filter, an amplifier, and an analog-to-digital converter. The filter performs filtering on the sensing signal. The amplifier amplifies the sensing signal. The analog-to-digital converter converts the sensing signal into the digital physiological signal.
In an embodiment of the invention, the calculation module includes a normalization processor and a physiological state index calculator. The normalization processor normalizes the digital physiological signal. The physiological state index calculator calculates the physiological state index according to the feature points of the normalized digital physiological signal.
In an embodiment of the invention, the physiological detection device further includes an alarm disposed in the main body and electrically connected with the calculation module.
In an embodiment of the invention, the physiological detection device further includes a display disposed on a surface of the main body and displaying the physiological state index.
In an embodiment of the invention, the physiological detection device further includes a power supply disposed in the main body. The power supply is electrically connected with the sensor pair, the signal processor, and the calculation module.
In an embodiment of the invention, the physiological detection device further includes a transmitter disposed in the main body and transmitting the physiological state index outside the physiological detection device.
Based on the above, the physiological detection device in the embodiments of the invention is capable of detecting the circulation state of the detected portion of the human body. Specifically, the sensor pair of the physiological detection device detects the detected portion of the human body to obtain the sensing signal of the detected portion. The sensing signal is further processed by the signal processor for the digital physiological signal to be outputted. Moreover, the calculation module calculates to obtain multiple feature points from the digital physiological signal and obtains the physiological state index according to the information of the feature points of the digital physiological signal. In the embodiments of the invention, the physiological state of the human body is assessed simply based on the physiological state index obtained by the physiological detection device. Thus, the time, procedure, equipment, and costs required for the general physiological detection are reduced.
To make the aforementioned and other features and advantages of the invention more comprehensible, several embodiments accompanied with drawings are described in detail as follows.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention.
Some other embodiments of the invention are provided as follows. It should be noted that the reference numerals and part of the contents of the previous embodiment are used in the following embodiments, in which identical reference numerals indicate identical or similar components, and repeated description of the same technical contents is omitted. Please refer to the description of the previous embodiment for the omitted contents, which will not be repeated hereinafter.
For instance, the detected portion 50 is a peripheral part of the human body, such as finger, toe, and earlobe. Referring to
In this embodiment, the optical emitter 122 and the optical receiver 124 are an infrared optical emitter and an infrared optical receiver capable of emitting and receiving an infrared light, for example. The emitted and received light has a wavelength in a range of 760 nm to 1 μm. However, this embodiment is not intended to limit the range of the wavelength of the light emitted and received by the sensor pair 120. In some other embodiments, the light of the optical emitter 122 and the optical receiver 124 may be a green light having a wavelength in a range of 495 nm to 570 nm. Alternatively, the light of the optical emitter 122 and the optical receiver 124 may be a red light having a wavelength in a range of 620 nm to 750 nm.
As shown in
As the above-mentioned, since the blood volume in the blood vessels of the human body increases and decreases periodically with systole and diastole, the amount of the spectral energy of the light absorbed by the blood also changes periodically with the heart beat. Thus, after the light is received by the optical receiver 124 of the sensor pair 120, the sensing signal S1 having a quasi-periodic change is generated.
Specifically, during systole, blood is pushed into the arteries from the ventricle. As the blood volume in the blood vessels increases, the amount of the spectral energy of the light absorbed by the blood increases and accordingly the sensing signal S1 of the sensor pair 120 changes. Therefore, the change of the sensing signal S1 of the sensor pair 120 and the blood volume (perfusion flow) in the blood vessels of the detected portion of the human body are correlated with each other.
Further, referring to
The amplifier of the signal processor 130 controls a gain of the sensing signal S1 to be appropriate automatically. Moreover, the analog-to-digital converter 136 converts the sensing signal S1, which is an analog signal, to a digital physiological signal S2 to facilitate the subsequent signal processing and related calculation.
In this embodiment, after signal gain control of the sensing signal S1 is performed by the amplifier 134, the sensing signal S1 is converted to the digital physiological signal S2 by the analog-to-digital converter 136. An order of processing the sensing signal S1 may be adjusted as appropriate according to the actual requirements. For example, the sensing signal S1 may be converted to the digital physiological signal S2 by the analog-to-digital converter 136 first, and then the signal is amplified by the amplifier 134.
The calculation module 140 is disposed in the main body 110 and coupled to the signal processor 130 to receive the digital physiological signal S2 processed by the signal processor 130. In this embodiment, the calculation module 140 performs calculation on the digital physiological signal S2 to obtain information of feature points of the digital physiological signal S2.
In this embodiment, the pulse waves of the digital physiological signal S2 have a foot point P1 at a forepart of a rising edge, a pulse peak P2, and a trough point P3, which are feature points of the digital physiological signal S2.
In this embodiment, the foot point P1 of the digital physiological signal S2 reflects changes of pressure and volume in the blood vessels when diastole ends and systole is to begin. The pulse peak P2 is the highest point of the pulse waves and reflects a maximum pulse wave amplitude caused by the blood pushed into the blood vessels from the ventricle during systole. In this embodiment, the rise from the foot point P1 to the pulse peak P2 indicates a process of rapid expansion of the vascular wall as the intravascular blood volume in the artery increases rapidly when the blood is rapidly injected from the heart ventricle. The drop after the pulse peak P2 reflects a process that the blood volume in the arteries gradually decreases and the blood vessel walls are gradually restored to the state before expansion.
Referring to
Specifically, referring to
Referring to
In this embodiment, the user of the physiological detection device 100 may assess the state of blood perfusion in the blood vessels of the detected portion and the condition of blood circulation of the whole human body based on the physiological state index obtained through calculation of the calculation module 140.
In comparison with the conventional technology shown in
In this embodiment, the second information is the pulse wave directly extracted between the adjacent two foot points P1 and P1′. That is, in this embodiment, the physiological detection device 100 obtains the second information directly from one complete cycle of pulse wave. Therefore, in addition to obtaining the second information from the pulse wave between the adjacent two foot points P1 and P1′, the physiological detection device of this embodiment may also obtain the second information from the pulse wave between any feature points (e.g., the trough point P3 in
Furthermore, as compared with the conventional technology of
The physiological detection device 100 of this embodiment may obtain the first information, the second information, and the physiological state index by the two methods described above, and compare the data obtained by the two methods to more accurately determine the condition of blood circulation of the human body.
Further, referring to
In this embodiment, the physiological detection device 100 includes a display 150 disposed on a surface of the main body 110 to display the physiological state index that the calculation module 140 obtains through calculation. The display 150 is, for example, a seven-segment display. Nevertheless, this embodiment is not limited thereto. The physiological detection device 100 may also use an organic light emitting diode (OLED) or other display elements as the display 150.
Then, referring to
The physiological detection device 100 includes a power supply 170, which includes a switch button 172 and a power supply module 174. In this embodiment, supply of power to the physiological detection device 100 is turned on or off by pressing the switch button 172. Moreover, the power supply module 174 of the physiological detection device 100 is electrically connected with the sensor pair 120, the signal processor 130, and the calculation module 140 to provide power for operation. Furthermore, the power supply module 174 may be a rechargeable battery or a disposable alkaline battery. This embodiment is not intended to limit the type of power supply of the power supply module 174.
In this embodiment, the physiological detection device 100 further includes a transmitter 180, e.g., Bluetooth, WiFi, or USB, disposed on the printed circuit board 117 for transmitting the physiological state index to an external device, such as a smart phone, a tablet computer, or a remote server, that is capable of displaying and recording data. Moreover, the physiological detection device 100 may be connected with other physiological detection devices 100 or electrically connected with an external power supply through the transmitter 180.
The physiological detection device 100 further includes a memory 190 disposed on the printed circuit board 117. The memory 190 is a data storage device, e.g., a flash memory, for storing the obtained sensing signal S1 and physiological state index.
Referring to
To sum up, the physiological detection device of the embodiments of the invention utilizes the optical emitter of the physiological detection device to emit light, which passes through the detected portion of the human body or is reflected to the optical receiver of the physiological detection device by the detected portion, so as to obtain the sensing signal. Moreover, the sensing signal is processed by the signal processor to obtain the digital physiological signal. The physiological detection device of the invention calculates the ratio of the integral area of the pulse wave of one full cycle with respect to the time axis to the integral area of the pulse wave from the foot point to the pulse peak with respect to the time axis based on the foot point and the pulse peak of the pulse wave of the digital physiological signal, so as to obtain the corresponding physiological state index. Moreover, the physiological detection device of the invention calculates the ratio of the time difference between two foot points (i.e., time of the full pulse wave cycle) to the time difference from the foot point to the pulse peak of the pulse wave, so as to obtain the corresponding physiological state index. Accordingly, the way the physiological detection device of the invention obtains the physiological state index is not limited by whether the pulse waves of the subject include diastolic waves and locations of the vertices of the diastolic waves, for the subject to easily and quickly obtain the physiological state index and thereby assess the condition of blood circulation.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of this invention. In view of the foregoing, it is intended that the invention covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.
Number | Date | Country | Kind |
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105207982 | May 2016 | TW | national |