Exemplary embodiments of the present invention are explained in detail below with reference to the accompanying drawings.
As shown in
The skin temperature acquiring unit 100 continuously acquires skin temperature from the temperature sensor 20. The ripple detecting unit 102 detects a cyclic variation, a ripple, in the skin temperature acquired by the skin temperature acquiring unit 100. The term “ripple” as used herein refers to variation in skin temperature in the form of ripples, and the cycle is of relatively short duration. Specifically, a ripple with a cycle of not less than 30 seconds and not more than 180 seconds is detected by frequency analysis based on Fourier transform. The thermal sensation analyzing unit 104 analyzes person's thermal sensation based on ripples detected by the ripple detecting unit 102 and the skin temperature. The output unit 106 outputs a result of the thermal sensation analysis by the thermal sensation analyzing unit 104. Processes performed by the thermal sensation analyzing unit 104 and the output unit 106 are described later.
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The thermal sensation analyzing system 1 can also be attached to the tip of a finger, or attached to a nail in the same manner as a false nail. That is, the thermal sensation analyzing system 1 can be attached to any part of a human body if able to measure skin temperature of a peripheral part where arteriovenous anastomoses exist. For example, the thermal sensation analyzing system 1 can be attached to a foot.
In another variation, the thermal sensation analyzing device 10 and the temperature sensor 20 can be separated. For example, the temperature sensor 20 can be in a ring form so that a person can wear it on his/her finger, while the thermal sensation analyzing device 10 can be in the form of a wristband so that a person can wear it on his/her forearm or above. It is assumed herein that the temperature sensor such as thermocouple, thermistor touches the skin. However, the use of a thermopile or thermography enables measurement of skin temperature without touching the skin.
Next is an explanation of a relationship between ripples and thermal sensation. Arteriovenous anastomoses exist in peripheral parts of the body such as hands and feet. Arteriovenous anastomoses directly link small arteries to venous plexus without through capillaries. Arteriovenous anastomoses are surrounded by muscular tissues, and when a person feels hot, the arteriovenous anastomoses dilate and increase blood flow to release heat from the body. Conversely, when the person feels cold, the arteriovenous anastomoses contract, and reduce blood flow to retain heat in the body.
When the temperature is within an appropriate range, body temperature is finely controlled by fine adjustment of blood flow through repetition of dilation and contraction of arteriovenous anastomoses. Thus, the temperature of peripheral parts changes in short duration in the vicinity of comfortable temperature along with changes in blood flow related to adjustment of body temperature.
In
Temperature during the experiment is maintained at 25° C. The person starts feeling cold at a point of 35 minutes, i.e., a little later after ripples are no more detected. This is because, change in feeling occurs after change in the body.
Having obtained skin temperatures as shown in
A trend other than ripples is likely to be detected in a frequency range not higher than 0.0056 Hz. Therefore, it is preferable to extract frequencies from a range higher than 0.0056 Hz. The frequency of 0.0056 Hz corresponds to a 180 second cycle. In other words, it is desirable to detect cyclic variations of 180 seconds or less as ripples.
It is also desirable to extract frequencies from a range not higher than 0.033 Hz. The frequency of 0.033 Hz corresponds to a 30 second cycle. When temperature change was visually checked on several data samples as shown in
As another example, in place of comparing a peak with a threshold value, an integrated value of the extracted frequencies of 0.0056 Hz to 0.033 Hz can be compared with a predetermined threshold value, and when the integrated value is equal to or larger than the threshold value, it is determined that there is a ripple.
In still another example, the ripple detection unit 102 can be a band-pass filter. In this case, frequencies from 0.0056 Hz to 0.033 Hz are used as cut-off frequencies. Amplitude of ripples derived from a filter output value is compared with a predetermined threshold value. If the amplitude is larger than the threshold value, it is determined that there is a ripple.
As shown in
If ripples are not detected, temperature is not appropriate. The thermal sensation analyzing unit 104 compares the skin temperature with a predetermined threshold value. For example, the threshold value is set to 2° C. When the skin temperature is equal to or lower than the threshold value (Yes at step S108), the thermal sensation analyzing unit 104 determines that the person feels cold, i.e., temperature is cold (step S110). On the other hand, if the skin temperature exceeds the threshold value (No at S108), the thermal sensation analyzing unit 104 determines that the person feels hot, i.e., temperature is hot (step S112).
When the thermal sensation analyzing process ends, the output unit 106 outputs a thermal sensation analysis result (step S114). Thus, the thermal sensation analyzing process is completed.
As described above, according to the first embodiment, appropriateness of the temperature is determined based on the presence of ripples. Further, the skin temperature of a person is compared to a threshold value to determine whether the person feels cold or hot. Thus, it is possible to analyze thermal sensation correctly with a simple device without any hindrance in activities in daily life.
The thermal sensation analyzing program can be stored in a computer-readable recording medium, such as a compact disk-read only memory (CD-ROM), a flexible disk (FD), and a digital versatile disk (DVD), in a form of a file that can be installed on and executed by a computer.
In this case, the thermal sensation analyzing device 10 loads the thermal sensation analyzing program from the recording medium into a main memory and executes it to implement thereon each unit explained above as software.
The thermal sensation analyzing program can also be stored in a computer that is connected to a network such as the Internet, and downloaded through the network.
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When ripples are detected (Yes at step S122), the temperature is determined to be appropriate (step S124). If ripples are not detected, in other words, if the temperature is not appropriate, whether the person feels hot or cold is determined based on the gradient. When the gradient is equal to or less than a threshold value (Yes at step S128), it is determined that the person feels cold, i.e., temperature is cold (step S130). When the gradient is higher than the threshold value (No at step S128), it is determined that the person feels hot, i.e., temperature is hot (step S132). The result of the thermal sensation analysis is output (step S134). Thus, the thermal sensation analyzing process is completed.
Otherwise, the thermal sensation analyzing system 1 according to the second embodiment is of essentially the same configuration and operates in the same manner as that of the first embodiment.
As shown in
The thermal sensation analyzing device according to the third embodiment checks whether there is a gradient if ripples are not detected. An arbitrary reference value is fixed, and if the gradient is more than the reference value, it is determined that there is a gradient. The reference value is smaller than a threshold value to be described later.
If there is a gradient (Yes at step S140), and the gradient is equal to or less than the threshold value (Yes at step S142), it is determined that the person feels cold, i.e., temperature is cold (step S144). On the other hand, if the gradient is higher than the threshold value (No at step S142), it is determined that the person feels hot, i.e., temperature is hot (step S146).
When there is no gradient, (No at step S140), skin temperature and a threshold value is compared. The threshold value is set to, for example, 28° C. The average value of skin temperature, acquired by the skin temperature acquiring unit 100 in a predetermined short time, is compared with the threshold value.
If the skin temperature is equal to or higher than the threshold value (Yes at step S150), it is determined that the person feels hot, i.e., temperature is hot (step S146). On the other hand, if the skin temperature is less than the threshold value (No at step S150), it is determined that the person feels cold, i.e., temperature is cold (step S144). The analysis result is output (step S152), and the thermal sensation analyzing process is completed.
Otherwise, a thermal sensation analyzing system according to the third embodiment is of essentially the same configuration and operates in the same manner as that of the second embodiment.
As shown in
The air-conditioning control unit 300 controls air-conditioning by a heater or a cooler based on whether ripples are detected by the ripple detecting unit 102. Specifically, the air-conditioning device 40 is remotely controlled to turn on or off the cooler or the heater. It is also possible to remotely control the speed of a fan, a direction of the fan, in addition to turning on or off the cooler or the heater.
The process performed by the skin temperature acquiring unit 100 and the ripple detecting unit 102 is the same as previously described for the thermal sensation analyzing device 10.
As shown in
At step S102, if ripples are not detected (No at step S104), it is checked whether the air-conditioning is on or off. If the air-conditioning is not on (No at step S204), the air-conditioning is turned on (step S206). If ripples are not detected, the person is not feeling comfortable. Therefore, the air-conditioning is turned on to adjust the room temperature to be appropriate. The process described above is repeated until an instruction to end the air-conditioning process is issued (step S210). Thus, the air-conditioning process is completed.
As described above, according to the fourth embodiment, the air-conditioning control device 30 controls turning on or off of the air-conditioning based on the presence of ripples. Therefore, it is possible to achieve effective air-conditioning. Further, minimizing operation of air conditioning contributes to saving energy.
Otherwise, the air-conditioning control system 2 is of essentially the same configuration and operates in the same manner as the thermal sensation analyzing system 1 according to the above embodiments.
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Specifically, if it is determined that the person feels the temperature is appropriate (appropriate at step S222), it is checked whether the heater or the cooler is on. If the heater or the cooler is on (Yes at step S224), it is turned off (step S226).
If it is determined that the person feels cold (cold at step 222), it is checked whether the heater is on. If the heater is not on (No at step S228), the heater is turned on (step S230). If the cooler is on, the cooler is turned off and the heater is turned on.
As other examples, when it is determined that the person feels cold and the cooler is on, the cooler can just be turned off. If the heater and the cooler as well are off, the heater can be turned on.
When it is determined that the person feels hot (hot at step S222), it is checked whether the cooler is on. If the cooler is not on (No at step S232), the cooler is turned on (step S234). If the heater is on, the heater is turned off and the cooler is turned on.
As other examples, when it is determined that the person feels hot and the heater is on, the heater can just be turned off. If the heater and the cooler are off, the cooler can be turned on.
Otherwise, the air-conditioning control system 5 is of essentially the same configuration and operates in the same manner as the thermal sensation analyzing system 1 or the air-conditioning control system 2 according to the above embodiments.
Next is an explanation regarding an air-conditioning control system 6 according to a sixth embodiment of the present invention. The air-conditioning control system 6 is basically similar to the air-conditioning control system 5 except for an air-conditioning control device 60. The air-conditioning control device 60 analyzes thermal sensation based on ripples and gradient, and controls air-conditioning based on the result of the thermal sensation analysis.
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In an air-conditioning process, the air-conditioning control device 60 first performs the thermal sensation analyzing process as explained in the second embodiment in connection with
As another example, it is possible to replace the thermal sensation analyzing process of
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
Number | Date | Country | Kind |
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2006-256271 | Sep 2006 | JP | national |