KR20160030428A - Laser speckle interferometric system and method for mobile devices - Google Patents

Abstract

Disclosed are a laser speckle interferometric system for a mobile device monitoring one or more parameters of an object, and a method proper to monitor one or more parameters of the object using the system. The disclosed system comprises: a data input part detecting a speckle pattern; a memory part to store one or more models connecting a measurement result of a correction parameter; and a process part stabilizing the speckle pattern by controlling an optimal condition of the speckle pattern detection, processing a time-varying functional showing temporal variation of the speckle pattern by the parameters of the speckle pattern and the object, and forming data representing one or more tested parameters.

Description

[0001] The present invention relates to a laser speckle interferometric system and method for mobile devices,

This disclosure relates to a laser speckle interferometer system and method, and more particularly to a laser speckle interferometer system and method for use in monitoring a parameter of a biological object using a mobile device.

Laser speckle interferometry is based on detecting and processing a second-order interference ("speckle") pattern formed by coherent radiation scattering from a rough surface. These laser speckle interferometry methods are widely used to monitor various parameters of engineering and biological objects. Various parameters of biological objects include parameters such as human body's blood pressure, pulse rate, blood flow, and skin. One of the most important advantages of laser speckle interferometry is non-contact, non-invasive, high sensitivity and ease of implementation.

However, existing laser speckle interferometry systems have limitations in studying biological parameters as the system is exposed to the effects of vibration. In laboratory conditions, vibration can be overcome by firmly fixing the object. However, this approach is often not applicable when it is necessary to monitor human parameters. Recently, there is an example in which a laser speckle interference method is used to extract information on pulse and pulse pressure (see Non-Patent Document 1 below). However, in order to implement this method, It is required to fix it.

Patent Document 1 describes a system and a method for tracking one or more parameters of a human body. The system includes an input port for receiving image data, a memory section, and a control section including a processor. The graphic data represents information collected by a detector consisting of an array of individual pixels and is given as a sequence of speckle patterns formed by scattering in one region of the human body of coherent radiation being irradiated at predetermined intervals. The memory unit stores one or more predetermined models and the model includes data indicative of a relationship between one or more measurable parameters and one or more parameters of the human body. The processor processes the image data and calculates a spatial correlation function between neighboring speckle patterns through a series of time-sequential calculations of the spatial correlation function in the form of a time-varying function of at least one parameter of the correlation function; Where the time-varying spatial correlation function represents the temporal variation of the speckle pattern; Selecting at least one parameter of a time-varying spatial correlation function to determine one or more corresponding parameters of the human body and generating output data corresponding to one or more parameters of the human organism to be studied, To perform the operations of. The system and method according to Patent Document 1 have a disadvantage in that it is difficult to apply to a mobile device due to the absence of a vibration reduction mechanism.

Patent Document 2 describes a system and a method for measuring biological tissue perfusion. The method includes the steps of: recording an image of a tissue illuminated by a laser beam; Providing a plurality of contrast images of the tissue; Determining a power spectrum of the scattered radiation in tissue from a plurality of contrast images; And determining perfusion of the power spectrum. The system controls a digital video camera, a laser light source, and a camera to form a plurality of images having different exposure times, to obtain a plurality of images from a camera, to process the image data to determine a power spectrum of the radiation, And a processor for determining the perfusion values of the fluid. This method is intended to measure tissue blood flow in the human body, but it is not sufficient to make accurate pressure measurement. Another disadvantage is that it is difficult to apply this method to mobile devices due to the absence of a vibration reduction mechanism.

Patent Document 3 describes a system and method for a medical instrument that non-invasively measures at least one parameter or state of the human body in a specific region of the body, which is a scattering medium. The measurement system includes an illumination system, a detection system, and a control system. The illumination system includes at least one light source capable of forming partial or complete coherent light that illuminates a region of the body to produce a response in the form of an optical signal from the illumination region. The recording system includes at least one radiation detector for recording the time-varying intensity variation of the light response, and produces data on the measurement results of the dynamic light scattering. The control system is designed to receive and analyze the results of dynamic light scattering measurements to determine at least one desired parameter and to generate output data. The disadvantage of this method is that it is difficult to apply this method to a mobile device due to the absence of a vibration reduction mechanism.

1. U.S. Patent Publication No. 20130144137 entitled " METHOD AND SYSTEM FOR NON-INVASIVELY MONITORING BIOLOGICAL OR BIOCHEMICAL PARAMETERS OF INDIVIDUAL ", University of Valencia, University of Valencia (2012) 2. US Patent Application Publication No. 20110013002 entitled LASER SPECKLE IMAGING SYSTEMS AND METHODS, Industrial Research Ltd., Oliver Ben-Deix Thompson, Michael Kenneth Andrews (2009) 3. U.S. Patent No. 7,925,056 entitled OPTICAL SPECKLE PATTERN INVESTIGATION, Coninclicke Philips Electronics Envy 2011,

1. Yevgeny Beiderman, Israel Horovitz et al., Remote estimation of blood pulse pressure via temporal tracking of reflected secondary speckles pattern / Journal of Biomedical Optics, 2010, 15 (6) 061707

This disclosure provides a laser speckle interferometry system and method for mobile devices that overcomes the above-identified problems in the art. The technical problem to be solved is not limited to the technical problems as described above, and other technical problems may exist.

A laser speckle interferometer system for a mobile device according to one aspect is for monitoring one or more parameters of an object,

An input unit including a laser light source and a detector for detecting a speckle pattern formed by scattering laser radiation from an object;

A memory unit storing a measurement result of the correction parameter and at least one predetermined pattern for connecting the processing result of the speckle pattern to the parameter of the object; And

By processing the speckle pattern, it is possible to stabilize the speckle pattern to be detected by controlling the optimum condition of the detection of the speckle pattern in real time, to process the stable speckle pattern, and to control the temporal change of the speckle pattern And a processor unit for determining the time varying function to represent and forming data representing one or more tested parameters.

The optimal condition for the detection of the speckle pattern may be that the statistical parameter distribution of the light intensity in the detected speckle pattern satisfies I _av / I _max > 0, 15. Where I _max is the maximum value of the detected light intensity and I _av is the average value of the detected light intensity. The distribution of the light intensity can be controlled through feedback between the laser light source and the detector and control of the output power of the subsequent laser light source.

The optimal condition for the detection of the speckle pattern may be that the radius of the detected speckle satisfies R0 / 3 < R < R0. Here, R0 denotes the radius of the detected speckles within 80% of the detected light intensity.

The optimal size of the detected speckle pattern can be controlled by monitoring the center (x _c , y _c ) of the detected speckle pattern. Here, x _c and y _{c, which} are the coordinates of the center of the speckle pattern,

및

And

Where x and y are the coordinates on the detection surface of the detector, n is the total number of pixels on the detection surface of the detector, and I represents the value of the light intensity.

The laser speckle interferometer system for a mobile device according to one aspect may further include an output unit performing at least one of a function of outputting data generated in the processor unit to a display and a function of transmitting the data to another apparatus. The other device may be a display device or a device for further processing.

In one example, the time-varying function may represent a temporal change in the speckle pattern as a sequence of values of the correlation coefficients between respective light intensity distributions of two neighboring speckle patterns.

In another example, the time-varying function may represent a temporal change in the speckle pattern as a sequence of values of the correlation coefficient between the reference and the light intensity distribution in the speckle pattern.

In another example, the time-varying function may represent a temporal change in the speckle pattern as a sum of the Fourier series expansion of each speckle pattern.

In yet another example, the time-varying function may represent a temporal change in the speckle speckle pattern of the wavelet transform coefficient values applied to each speckle pattern.

A mobile device implementing a laser speckle interferometry system according to one aspect may be a mobile phone or a smart phone, or a tablet computer, a personal digital assistant (PDA), or a laptop computer. In one embodiment, the mobile device may be a wristwatch or head-mounted display, or a portable media player.

The laser light source and detector may be integrated into one housing of the mobile device. Alternatively, the detector may be mounted to the body of the mobile device and the laser light source may be connected to the mobile device, with the light source positioned in the detachable housing.

The output unit may display data on a display of the mobile device. The output unit may output the data to the sound device of the mobile device.

A method of tracking one or more parameters of an object along another aspect is a method using a laser speckle interferometer system for a mobile device,

A step of irradiating a laser beam to an object to be examined and recording a speckle pattern formed by scattering a laser beam on an object to be examined as an image; And

And processing the speckle pattern,

The step of processing the speckle pattern comprises:

Controlling the optimum condition of the speckle pattern detection in real time to stabilize the detected speckle pattern;

Processing a stable speckle pattern and determining a time-varying function indicative of a temporal change in the speckle pattern with a change in an object parameter;

And forming data representing at least one of the tested parameters.

The optimal condition for the detection of the speckle pattern may be to make the statistical parameter of the intensity of the light in the detected speckle pattern I _av / I _max > 0, 15, where I _max is the maximum value of the detected light intensity , And I _av is an average value of the detected light intensities. The distribution of the light intensity can be controlled through feedback between the laser light source and the detector and control of the output power of the subsequent laser light source.

The optimal condition for the detection of the speckle pattern may be that the radius of the detected speckle is R0 / 3 < R < R0, where R0 is the radius of the detected speckles within 80% .

Optimum detected speckle pattern size can be controlled by monitoring the center of a detected speckle pattern, to the equation of the coordinates of x _c and y _c of the speckle pattern

, 및

, And

Where x and y are the coordinates on the detection surface of the detector, n is the total number of pixels on the detection surface of the detector, and I represents the value of the light intensity.

The method may further include at least one of outputting the data received in the processed speckle pattern to the display and transmitting the data to another device.

In the step of detecting a speckle pattern, the detected speckle pattern may be stored in a data file.

Stabilizing the detected speckle pattern comprises: receiving data at a mobile device; And excluding a speckle pattern obtained at an unoptimized position of the mobile device with respect to the object to be processed.

In one example, the time-varying function may represent a temporal change in the speckle pattern as a sequence of values of the correlation coefficients between respective light intensity distributions of two neighboring speckle patterns.

In another example, the time-varying function may represent a temporal change in the speckle pattern as a sequence of values of the correlation coefficient between the reference and the light intensity distribution in the speckle pattern.

In another example, the time-varying function may represent a temporal change in the speckle pattern as a sum of the Fourier series expansion of each speckle pattern.

In yet another example, the time-varying function may represent a temporal change in the speckle speckle pattern of the wavelet transform coefficient values applied to each speckle pattern.

According to another aspect, a computer-readable recording medium includes a recording medium on which a program for causing a computer to execute the above-described method is recorded.

As described above, the present disclosure can monitor various parameters of an object, such as heart rate and blood pressure, using a method of laser speckle interference with portable and mobile devices. Here, the portable and mobile devices may be, for example, but are not limited to, a portable telephone, a smart phone, a wrist watch, a personal digital assistant (PDA), a tablet computer, a portable computer (netbook, notebook)

The present disclosure addresses the problem of vibrations in order to realize a laser speckle interference system based on a mobile device and can be achieved by means of hardware, that is, by constructing feedback between the laser light source and the detector, That is, by ensuring that the size, shape and position of the speckle pattern for detecting the speckle pattern on the detector plane are controlled to be constant, by stabilizing the speckle pattern on the detector plane.

Further, the present disclosure provides a method of processing a speckle pattern that results in a higher signal-to-noise ratio than conventional solutions.

Figure 1 schematically illustrates a laser speckle interference system for a mobile device in accordance with one embodiment.
2 is a flow chart illustrating a method of laser speckle interferometry for a mobile device.
3 is a schematic diagram of a laser speckle interferometry system configured to measure blood pressure and heart rate.
Figure 4 shows an exemplary speckle pattern to detect for use in a laser speckle interference system for a mobile device.
5 is a graph illustrating pulsation detected by a laser speckle interference system in a mobile device according to a method in accordance with an embodiment.
FIG. 6 is a graph showing pulsation detected by a laser speckle contrast interference (LASCA) method for a mobile device using a laser speckle contrast analysis (LASCA) method.
7 is a graph showing the pulsation detected in the laser speckle interference system using Fourier transform.
8 schematically shows a laser speckle interference system for a mobile device according to another embodiment.
9 schematically shows a laser speckle interference system for a mobile device according to another embodiment.
FIG. 10 schematically shows a laser speckle interference system for a mobile device according to another embodiment.
11 is a side view of the laser speckle interferometry system for the mobile device of Fig.
12 schematically shows a laser speckle interference system for a mobile device according to another embodiment.

Brief Description of the Drawings The advantages and features of the present disclosure, and how to accomplish them, will become apparent with reference to the embodiments described below with reference to the accompanying drawings. It should be understood, however, that the present disclosure is not limited to the embodiments disclosed herein but may be embodied in many different forms and should not be construed as limited to the embodiments in which this disclosure is known to be complete and that those of ordinary skill in the art to which this disclosure belongs To fully disclose the scope of the invention, and this disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification, and the size and thickness of each element in the drawings may be exaggerated for clarity of explanation.

The disclosed laser speckle interferometry system includes an information input section including a laser light source and a detector, a memory section including research model data, correction data and measurement results, and a processor section for performing speckle stabilization and speckle processing. Also, in one embodiment, there may be further provided an output for displaying the measurement results to the user and / or transmitting the received data to another device. Human blood pressure and pulse rate can be obtained using the laser speckle interference method as follows.

The laser beam generated by the laser light source is scattered on the surface of the skin of the wrist area of the human body and the speckle pattern formed by the scattering of the incoherent light beam is detected and recorded by the detector. Pulsation of blood in the arteries causes movement of the skin, which affects the detected speckle pattern. In order to detect a pulsation having a signal / noise ratio sufficient to implement an accurate measurement, it is necessary to eliminate the influence of vibration due to the relative displacement between the mobile device and the object to be irradiated. This can be achieved by monitoring the parameters in real time so that the so-called optimum condition detection can be observed [ For the speckle processing of signals from a short-fiber multimode interferometer using charge coupled devices, as well as the use of charge coupled devices, as described in US patent application Ser. Correlation method for processing signals from single-fiber multimode interferometers by using charge-coupled devices, Quantum Electron, (2006), 36 (4), 339-342]. These parameters may be: Statistical parameter distribution of the light intensity of the detected speckle pattern satisfying I _av / I _max > 0, 15, where I _max is the maximum value of the detected light intensity and I _av is an average value of detected light intensities); The radius of the detected speckles within the range of R0 / 3 < R < R0, where R0 refers to the radius of the detected speckles within 80% of the total detected light intensity; The distribution of the light intensity is controlled through feedback between the laser light source and the detector and subsequent adjustment of the output power of the laser light source; The optimum size of the detected speckle pattern is controlled by monitoring the center (x _c , y _c ) of the detected speckle pattern, and the center coordinates x _c and y _c of the speckle pattern are expressed by the following equations (1) and .

Here, x and y are coordinates on the detection surface of the detector, n is the total number of pixels on the detection surface of the detector, and I represents the value of the light intensity.

The stabilized speckle pattern can be used to determine the time-varying function, which is represented by the sum of all the components obtained from the Fourier series expansion applied to each of the detected speckle pattern images. This time-varying function represents the temporal variation of the speckle pattern, which may be useful information on the parameters of the object.

The measured time-varying function corresponds to the time dependence of the blood pressure on the arterial wall, and the repetition frequency of the maximum value of this function corresponds to the human heartbeat, and the shape of the envelope of this time- Lt; / RTI &gt; It is necessary to count the number of detected peaks of the time-varying function for a predetermined time, e.g., one minute, to determine the size of the pulsation. Calibrating or calibrating the entire system by recording pulse waves of several cycles before using the laser speckle interferometry system and method for mobile devices to determine the value of the blood pressure and storing this data in the memory May be required. It may be necessary to measure the blood pressure using a conventional blood pressure meter immediately before or immediately after such a procedure and record the result in the memory unit. Therefore, the memory unit can hold the shape of the pulse wave and the corresponding blood pressure value. The need to use a conventional blood pressure monitor after the calibration procedure disappears, and blood pressure can be measured at any time by a laser speckle interferometry system and method for mobile devices.

In this case, the current value of the blood pressure can be calculated as follows: The processor calculates a proportional coefficient that determines the difference between the current pulse shape and the pulse wave stored in the memory. The next step is the product of the obtained coefficients and the corrected blood pressure value in the memory. The obtained blood pressure value may be displayed to the user and optionally transmitted wirelessly to another device.

Figure 1 schematically illustrates a laser speckle interference system for a mobile device in accordance with one embodiment. The laser speckle interferometer system for a mobile device shown in Fig. 1 includes a laser light source 1, a detector 2, a processor unit 13, and a memory unit 14.

The laser light source 1 illuminates laser light having coherence. The laser light source 1 may be, for example, a semiconductor laser diode. The detector 2, which is capable of capturing a speckle pattern image, may be, for example, a camera including an image sensor or an image sensor. The processor unit 13 and the memory unit 14 may be integrated in the body 3 of the mobile device. This arrangement eliminates the vibration caused by the relative movement between the laser light source 1 and the detector 2.

In addition, the laser speckle interferometry system may further include a display that displays pulse rate or blood pressure (see FIG. 3). Such a display is an example of an output unit. As another example, the output of the laser speckle interferometry system may include a speaker for outputting a pulse rate or blood pressure as a sound or voice, or a communication unit for communicating data wired and / or wirelessly to another device.

The mobile device may be, for example, a mobile phone or a smart phone. Or the mobile device may be, for example, a tablet computer, a personal digital assistant (PDA), or a laptop computer. Or the mobile device may be a portable media player. Or the mobile device may be a wristwatch or a head mounted display.

2 is a flow chart illustrating a method of laser speckle interferometry for a mobile device. The laser speckle interferometer system has a configuration for performing a process using a laser speckle interference method, as described in the flowchart of Fig. A method of the laser speckle interference method for a mobile apparatus will be described with reference to Figs. 2 to 7. Fig.

3 is a schematic diagram of a laser speckle interferometry system configured to measure blood pressure and heart rate. Fig. 3 shows the initial position of the laser speckle interferometry system for measuring human body parameters, i.e., blood pressure and pulse. To minimize the impact of vibrations during the measurement, as shown in Figure 3, the mobile device is positioned on the surface of the object. The object to be studied shown in Fig. 3 is a human wrist.

First, the control of the laser light source 1 and the detector 2 is initialized (S10). After initialization, the laser light source of the laser speckle interferometry system begins to illuminate the region of interest of the object. The laser light is scattered in this region and detected by the detector.

Figure 4 shows an exemplary speckle pattern to detect for use in a laser speckle interference system for a mobile device. The processor unit 13 analyzes the illumination value on the detector and feeds back the laser light source so as to adjust the subsequent output power in an optimal condition for detecting the laser light. The optimal conditions for detection may be as follows: I statistic parameter distribution of light intensity of the detected speckle pattern satisfying I _av / I _max > 0, 15, where I _max is the maximum value of the detected light intensity And I _av is an average value of the detected light intensities), the radius of the detected speckle pattern within the range of R0 / 3 < R < R0 where R0 is an area including 80% The radius of the detected speckle pattern corresponding to the radius of the bounding circle). The transition of this optimal condition can guarantee the linear regime of the detected speckle pattern field. If the detection conditions are not optimized, the output of the laser light source 1 and the position of the mobile device are adjusted (S12).

After the initial setting, start the measurement that is performed simultaneously with the stabilization procedure of the speckle pattern. And captures an image of the light emitted from the laser light source 1 and scattered by the object to be examined (S13). Next, the center position of the speckle pattern is estimated from the captured image (S14). Also, an optimum processing area is estimated and selected (S15). Stabilization of the speckle pattern can be achieved by simultaneously monitoring in real time the optimum conditions for the detection and the position of the center of the recorded speckle pattern. The coordinate (x _c , y _c ) of the center position of the detected speckle pattern is calculated by the above-described equation (1).

The processor unit 13 is configured to perform image processing in real time, thereby eliminating the need to store each frame in the memory unit 14, which may be important for improving overall system performance. The processor unit 13 performs a Fourier transform of each frame and obtains a set of spatial frequencies in the image (S16). Each transformed image is characterized by a set of spatial frequencies, and the sum of all components at any given time is a time-varying function. This time-varying function represents the temporal change of the speckle pattern as the sum of the Fourier series expansion. The time-varying function is not limited to this. For example, a sequence of values of a correlation coefficient between a light intensity distribution in a reference and a speckle pattern, a speckle of a wavelet transform coefficient value applied to each speckle pattern, It may also represent a temporal change of the pattern.

Next, the noise is removed and filtered (S19).

The acquired values are stored in the memory unit 14 (S17). If the detection of the speckle pattern is not sufficient, the process returns to the image capture step S13 and the same operation is repeated (S18).

FIG. 6 is a graph showing pulsation detected by a laser speckle contrast interference (LASCA) method for a mobile device using a laser speckle contrast analysis (LASCA) method. Referring to FIG. 6, a rough time dependence obtained from a speckle pattern formed by scattering from the surface of the wrist skin can be seen. 7 is a graph showing the pulsation detected in the laser speckle interferometry system using an algorithm based on Fourier transform. Comparing FIG. 6 with FIG. 7, the results obtained using an algorithm based on the Fourier transform can be seen to have time dependency similar to the time dependence obtained using the method of the speckle pattern contrast analysis (LASCA). As can be seen from these results, the disclosed method makes it possible to obtain a series of peaks corresponding to a person's pulse rate with a large signal-to-noise ratio, which such a large signal-to- To bring the peak.

The next step involves the use of one or more specific models that are acquired during one cardiac cycle and that describe the relationship between a single pulse wave stored in the memory 14 and the blood pressure corresponding to that person's pulse wave (S20). 5 is a graph illustrating pulsation detected by a laser speckle interference system in a mobile device according to a method in accordance with an embodiment. The exemplary pulse wave shown in Fig. 5 is acquired during one cardiac cycle and stored in the memory unit 14 of the mobile device. The processor unit 13 can recover the current blood pressure value by comparing the pulse wave stored in the memory unit 14 with the measured pulse wave. The obtained blood pressure value may be displayed on the display of the mobile device (S21). The obtained blood pressure value may be stored in the memory unit 14 of the mobile device or transmitted to another device, for example, by radio or other means known in the art.

8 schematically shows a laser speckle interference system for a mobile device according to another embodiment. 8, the laser speckle interferometry system for a mobile device of the present embodiment includes a laser light source 1, a detector 2, a main body 3 of a mobile device, a detachable housing 4, and a diaphragm 5 . The laser light source 1 may be located in a detachable housing 4 removably connected to the mobile device. The detector 2 may be a camera of a mobile device. As another example, the detector 2 may be provided in the detachable housing 4. The diaphragm (5) is located in the detachable housing (4). The detector (2) detects scattered light having a speckle pattern through the diaphragm (5). The laser speckle interferometer system of the present embodiment can be provided in any mobile device that can be connected to the detachable housing 4. [ For example, the mobile device may be a mobile phone, a smart phone, a tablet computer, a personal digital assistant (PDA), a laptop computer, or a portable media player. Or the mobile device may be a wristwatch or a head mounted display.

9 schematically shows a laser speckle interference system for a mobile device according to another embodiment. 9, the laser speckle interference method system for a mobile device according to the present embodiment includes a laser light source 1, a detector 2, a main body 3 of a mobile device, a detachable housing 4, an iris 5, A mirror 6, a power device 7, and an actuation button 8. The laser light source (1) is located in a detachable housing (4) removably connected to the mobile device. The diaphragm (5) is located in the detachable housing (4). The prism mirror 6 is provided on one side of the diaphragm 5 and changes the optical path so that the laser light emitted from the laser light source 1 is directed to the object to be studied. The detector (2) detects scattered light having a speckle pattern through the diaphragm (5). The actuation button 8 switches the operation of the laser speckle interferometry system. The laser speckle interferometer system of the present embodiment can be provided in any mobile device that can be connected to the detachable housing 4. [ For example, the mobile device may be a mobile phone, a smart phone, a tablet computer, a personal digital assistant (PDA), a laptop computer, or a portable media player. Or the mobile device may be a wristwatch or a head mounted display.

FIG. 10 schematically shows a laser speckle interference system for a mobile device according to another embodiment, and FIG. 11 is a side view of the laser speckle interference system for a mobile device of FIG.

Referring to Figs. 10 and 11, the laser speckle interferometry system of this embodiment includes a laser light source 1, a detector 2, and a wrist strap 11 that is fixed to a user's arm. The laser speckle interferometry system of the present embodiment can be implemented using a mobile device, e.g., a watch, worn on the wearer's wrist, and can be useful for tracking time parameters of the human body, such as pulse, blood pressure, have.

12 schematically shows a laser speckle interference system for a mobile device according to another embodiment. 12, the laser speckle interference system of the present embodiment includes a laser light source 1, a detector 2, a strap fixing device 12, a processor unit 13, and a memory unit 14. The strap securing device 12 may be an arm strap wrapped around the arm. This laser speckle interferometry system can be applied to a mobile device in the form of a cuff wound on the arm. chamberlain. The laser speckle interferometry system of this embodiment can be used when the brachial artery is needed for measurement and correction.

 The disclosed laser speckle interferometry systems and methods can be applied to mobile devices that can be used to monitor biological parameters of human or animal objects. Those skilled in the art will appreciate that the disclosed laser speckle interferometry systems and methods described above are generally applicable in the security and medical systems field. The disclosed laser speckle interferometry systems and methods can have high mobility to track various human parameters without specially designed equipment.

The disclosed laser speckle interferometry systems and methods may be implemented using various combinations of hardware and software, firmware, integrated circuits, microprocessors, memory devices, computer readable media, and the like.

A method of monitoring one or more parameters of an object using the laser speckle interferometer system for a mobile device described above can be realized by a computer program that can be executed by a computer and is a general purpose computer that uses the computer- And can be implemented in a digital computer. In addition, the structure of the data used in the above-described method can be recorded on a computer-readable recording medium through various means. The computer readable recording medium may be a magnetic storage medium such as a ROM, a RAM, a USB, a floppy disk or a hard disk, an optical reading medium such as a CD-ROM or a DVD, ) (E.g., PCI, PCI-express, Wifi, etc.).

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed methods should be considered from an illustrative point of view, not from a restrictive point of view. The scope of the present disclosure is set forth in the appended claims rather than the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present disclosure.

1: laser light source 2: detector
3: Body of mobile device 4: Detachable housing
5: Aperture 6: Prism mirror
7: Power supply unit 8: Operation button
10: strap 11: strap fixing device
13: processor unit 14: memory unit

Claims (31)

A laser speckle interferometer system for a mobile device for monitoring one or more parameters of an object,
An input unit including a laser light source and a detector for detecting a speckle pattern formed by scattering laser light from an object;
A memory unit storing a measurement result of the correction parameter and at least one predetermined pattern for connecting the processing result of the speckle pattern to the parameter of the object;
By processing the speckle pattern, it is possible to stabilize the speckle pattern to be detected by controlling the optimum condition of the detection of the speckle pattern in real time, to process the stable speckle pattern, and to show the temporal change of the speckle pattern And a processor unit for determining a time-varying function and forming data representing at least one of the tested parameters. The method according to claim 1,
The optimal condition for the detection of the speckle pattern is that the statistical parameter distribution of the light intensity in the speckle pattern to be detected satisfies I _av / I _max > 0, 15, where I _max is the maximum value of the detected light intensity And I _av is an average value of detected light intensities. 3. The method of claim 2,
Wherein the distribution of light intensity is controlled through feedback between the laser light source and the detector and subsequent adjustment of the output power of the laser light source. 4. The method according to any one of claims 1 to 3,
The optimal condition for the detection of the speckle pattern is that the radius of the speckle to be detected satisfies R0 / 3 < R < R0 where R0 is the radius of the detected speckles within 80% System that means. 5. The method of claim 4,
The optimum size of the speckle pattern to be detected is controlled by monitoring the center (x _c , y _c ) of the speckle pattern to be detected, where x _c and y _{c, which} are the center coordinates of the speckle pattern,

And

Where x and y are the coordinates on the detection surface of the detector, n is the total number of pixels on the detection surface of the detector, and I is the value of the light intensity. The method according to claim 1,
Further comprising an output unit for performing at least one of a function of outputting data generated by the processor unit to a display and a function of transmitting the data to another apparatus. The method according to claim 1,
Wherein the time-varying function represents a temporal change in the speckle pattern with a sequence of values of correlation coefficients between respective light intensity distributions of two neighboring speckle patterns. The method according to claim 1,
Wherein the time-varying function represents a temporal change in a speckle pattern as a sequence of values of a correlation coefficient between a reference and a light intensity distribution in a speckle pattern. The method according to claim 1,
Wherein the time-varying function represents a temporal change in the speckle pattern as a sum of the Fourier series expansion of each speckle pattern. The method according to claim 1,
Wherein the time-varying function represents a temporal change of a speckle speckle pattern of wavelet transform coefficient values applied to each speckle pattern. The method according to claim 1,
Wherein the mobile device is a mobile phone or a smartphone. The method according to claim 1,
Wherein the mobile device is a tablet computer, a personal digital assistant (PDA), or a laptop computer. The method according to claim 1,
Wherein the mobile device is a wristwatch. The method according to claim 1,
Wherein the mobile device is a head mounted display. The method according to claim 1,
Wherein the mobile device is a portable media player. The method according to claim 1,
Wherein the laser light source and detector are coupled to a housing of the mobile device. The method according to claim 1,
Wherein the detector is mounted to a body of the mobile device and the laser light source is located in a detachable housing connected to the mobile device. The method according to claim 6,
Wherein the output unit outputs data to a display of the mobile device. The method according to claim 6,
And wherein the output unit outputs data to a sound device of the mobile device. A method of monitoring one or more parameters of an object using a laser speckle interferometry system for a mobile device,
Irradiating an object to be examined with laser light and detecting a speckle pattern formed by scattering laser light on the object, as an image; And
And processing the speckle pattern,
The step of processing the speckle pattern comprises:
Controlling the optimum condition of the speckle pattern detection in real time to stabilize the detected speckle pattern;
Processing a stable speckle pattern and determining a time-varying function indicative of a temporal change in the speckle pattern with a change in an object parameter;
And forming data representing at least one of the tested parameters. 21. The method of claim 20,
The optimal condition for the detection of the speckle pattern is to set the statistical parameter of the intensity of the light in the detected speckle pattern to I _av / I _max > 0, 15, where I _max is the maximum value of the detected light intensity, And I _av is an average value of the detected light intensities. 22. The method of claim 21,
Wherein the distribution of the light intensity is controlled through feedback between the laser light source and the detector and subsequent adjustment of the output power of the laser light source. 23. The method according to any one of claims 20 to 22,
The optimal condition for the detection of the speckle pattern is to set the radius of the speckle to be detected as R0 / 3 < R < R0, where R0 denotes the radius of the detected speckles within 80% How to. 24. The method of claim 23,
Optimum size of the speckle pattern which is detected is controlled by monitoring the center of the speckle pattern is detected, to the equation of the coordinates of x _c and y _c of the speckle pattern

And

Where x and y are the coordinates on the detection surface of the detector, n is the total number of pixels on the detection surface of the detector, and I is the value of the light intensity. 21. The method of claim 20,
Outputting the data received in the processed speckle pattern to a display, and transmitting the data to another device. 21. The method of claim 20,
A method of storing a speckle pattern to be detected as a data file in the step of detecting the speckle pattern. 21. The method of claim 20,
Wherein the step of stabilizing the speckle pattern to be detected comprises:
Receiving data at a mobile device; And
Excluding the speckle pattern obtained at an unoptimized location of the mobile device with respect to the object of interest. 21. The method of claim 20,
Wherein the time-varying function represents a temporal variation of the speckle pattern as a sequence of values of correlation coefficients between respective light intensity distributions of two neighboring speckle patterns. 21. The method of claim 20,
Wherein the time-varying function represents a temporal change of the speckle pattern with a sequence of values of correlation coefficients between a reference and a distribution of light intensities in a current speckle pattern. 21. The method of claim 20,
Wherein said function represents a temporal change of a speckle pattern with a sequence of sum of Fourier series expansion of each speckle pattern. 21. The method of claim 20,
Wherein the time-varying function represents a temporal change of a speckle pattern by a sequence of values of wavelet transform coefficients applied to each speckle pattern.

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