JP3931080B2 - Fundus photographing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fundus imaging apparatus that determines the imaging timing of a fundus blood vessel using the timing of an electrocardiogram signal input from an electrocardiogram measurement apparatus.
[0002]
[Prior art]
It is well known that cardiovascular diseases such as angina pectoris, myocardial infarction, cerebral infarction, and cerebral hemorrhage are caused by arteriosclerosis. If there is a device that can objectively measure the state of arteriosclerosis, the necessary precautions can be taken. In particular, since arteriosclerosis progresses with aging, a device capable of measuring arteriosclerosis is considered to be highly important in an aging society such as Japan.
[0003]
International Patent Application Publication No. WO 01/30235 A1 discloses a technique for measuring arteriosclerosis by measuring the size of a fundus blood vessel from an image taken by a fundus camera. This measurement principle is intended to evaluate the deformation of the vein 2 accompanying the pulsation of the artery 1 in a region where the artery 1 and the vein 2 of the fundus intersect as shown in FIG.
[0004]
Specifically, based on the diameter A of the artery, the diameter V1 of the vein 2 at a distance A * 3 away from the intersection of the artery 1 and the vein 2 and the distance A / 10 away from the intersection to the distal side. The diameter V2 of the vein 2 at the selected position is measured, and the state of arteriosclerosis is evaluated from the ratio of V2 and V1. For example, it is determined that there is no arteriosclerosis when the ratio of V2 / V1 is close to 1, and higher arteriosclerosis when the ratio of V2 / V1 is close to 0. The measurement is not performed for only one measurement point, but is performed for a plurality of intersections of the fundus artery and vein that are one or more nipples away from the fundus papilla, and the average of the V2 / V1 ratio obtained at each is calculated. It is desirable to do so.
[0005]
[Problems to be solved by the invention]
The measurement method described in International Patent Application Publication No. WO 01/30235 A1 is based on the premise that measurement is performed in a state in which pulsation occurs in the fundus artery. It is disclosed that the imaging timing of a part is generated. The reason why the pulsation timing of the electrocardiogram signal is not directly used is that there is a time lag between the heart pulsation and the blood flow near the periphery, such as the fundus, and is not completely synchronized.
[0006]
However, this publication does not describe the details of the technique for generating the fundus camera shooting timing using the electrocardiogram signal, and accurately and reproducibly captures the fundus camera using each ECG signal. A technique for generating timing is desired.
[0007]
An object of the present invention is to solve the above-mentioned problems and to fundus photographing apparatus capable of photographing a fundus image including a fundus blood vessel with accuracy and good reproducibility in synchronism with an electrocardiogram signal for the purpose of measuring arteriosclerosis or the like. Is to provide.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problem, according to the present invention, in the fundus imaging apparatus that determines the imaging timing of the fundus image by the imaging unit using the timing of the electrocardiogram signal input from the electrocardiogram measurement apparatus, the electrocardiogram signal timing is delayed. Timing control means for adding time to generate photographing timing of the fundus image by the photographing means; A timing switch operated at the timing when the examiner observes the fundus image and recognizes the pulsation of the fundus blood vessel, Examine the delay time Depending on the operation of the timing switch Has setting means to set The setting means calculates the delay time value from the pulsation timing of the fundus blood vessel inputted through the timing switch while the fundus image is observed by the examiner and the timing of the electrocardiogram signal. Adopted the configuration.
[0013]
Alternatively, a shutter button for inputting a shutter operation signal for instructing photographing by the photographing means is provided, and the timing control means generates a fundus image photographing timing by the photographing means after the shutter operation signal becomes effective. The configuration is adopted.
[0014]
Or In the fundus imaging apparatus for determining the fundus image capturing timing by the imaging unit using the timing of the electrocardiogram signal input from the electrocardiogram measurement apparatus, a delay time is added to the electrocardiogram signal timing to generate the fundus image capturing timing by the imaging unit And a shutter button for inputting a shutter operation signal for instructing photographing by the photographing means, and The timing control means calculates a delay timing obtained by adding the delay time to the electrocardiogram signal timing. Regardless of the shutter operation, The signal processing means for generating is used, and the signal processing means generates the earliest delay timing after the shutter operation signal becomes effective as the fundus image photographing timing by the photographing means.
[0015]
Alternatively, a configuration having a supply unit that supplies a photographing timing signal of the fundus image by the photographing unit to an external device is adopted.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0017]
FIG. 1 shows the configuration of a measuring apparatus employing the present invention. In FIG. 1, reference numeral 10 denotes a fundus camera having a fundus camera optical system 11. In FIG. 1, only the main part of the photographing system is shown by blocks, and the illustration of the housing and the alignment mechanism of the fundus camera optical system 11 is omitted because it is the same as in the prior art.
[0018]
The fundus image by the fundus camera optical system 11 can be input by the CCD 13 and filed in the filing device 30.
[0019]
Although a shutter 12 is shown between the fundus camera optical system 11 and the CCD 13, the shutter 12 does not necessarily have to be a mechanical type, and may be configured purely electronically. That is, the shutter 12 only needs to be capable of controlling the image acquisition timing by the CCD 13.
[0020]
The filing device 30 is configured using PC (personal computer) hardware, and includes user interface means such as a monitor 40 including a keyboard 31, a mouse 32, a CRT display, and the like. Further, it has a network interface 33 (or a communication means such as a modem) for exchanging data such as photographed images and measurement results with an external device.
[0021]
The filing device 30 filings data such as a photographed image and a measurement result, and performs image processing on a fundus blood vessel image photographed by the CCD 13, and an arteriosclerosis measurement device (measures arteriosclerosis based on the result) It also functions as the main part). A program for data filing and arteriosclerosis measurement is stored in a hard disk or the like of the filing device 30 and executed by an OS (operating system) of the filing device 30. These programs can be shipped in a state of being stored in a hard disk in advance, can be supplied through a medium such as a flexible disk, MO, CD-ROM, or can be downloaded via the network interface 33.
[0022]
In this apparatus, using the measurement method described in the above-mentioned International Patent Application Publication WO 01/30235 A1, image processing is performed on the image of the fundus blood vessel photographed by the CCD 13 to measure (evaluate) the state of arteriosclerosis. To do. The measurement principle is as described in relation to FIG.
[0023]
According to the measurement method of FIG. 2, a target region of the fundus is imaged by the CCD 13 in a state where blood flow (pulsation) is present in the artery, image processing is performed on the captured image of the fundus blood vessel, and the vein 2 The diameters V1 and V2 must be measured.
[0024]
For this purpose, an electrocardiogram signal H output from the electrocardiogram measuring device 20 and a shutter operation signal S of the shutter button 14 operated by the examiner are input, and a shutter timing signal ST (imaging timing signal) for determining the drive timing of the shutter 12 is input. ) Is provided.
[0025]
Although it is desirable to use the original shutter button 14 for the fundus camera 10, depending on the specifications of the apparatus, an external switch dedicated to measuring arteriosclerosis (such as a pedal switch) may be used. In the fundus camera, the shutter operation must be performed while always adjusting the alignment between the camera and the eye to be inspected. Therefore, the shutter button 14 is indispensable for photographing for arteriosclerosis measurement as in the present invention.
[0026]
There are various types of electrocardiogram signals H that can be output from the electrocardiogram measuring apparatus 20, and signals suitable for arteriosclerosis measurement are used. As already recognized in International Patent Application Publication No. WO 01/30235 A1, there is a time lag between the electrocardiogram signal and the actual pulsation of the fundus blood vessel, so the shutter of the electrocardiogram signal H is used directly to release the shutter. I can't.
[0027]
Therefore, in the present embodiment, a shutter timing signal ST for driving the shutter 12 is generated by adding a delay time corresponding to the time lag of the pulsation of the electrocardiogram signal and the fundus blood vessel to the timing of the electrocardiogram signal H. In the present embodiment, the delay time applied to the electrocardiogram signal H can be set by the delay time setting unit 16. The configuration and operation of the delay time setting unit 16 will be described later.
[0028]
Further, as described above, since the shutter operation is performed while always adjusting the alignment between the camera and the eye to be examined, if the operation timing of the shutter button 14 is used to generate the shutter timing signal ST, a more accurate fundus range can be captured. it can.
[0029]
3 and 4 show a configuration example of the timing control circuit 15 for generating the shutter timing signal ST from the electrocardiogram signal H and the shutter operation signal S. FIG.
[0030]
FIGS. 3 and 4 schematically show different configurations and operations of the main part of the timing control circuit 15. The lower part of FIGS. 3 and 4 shows the circuit configuration of the timing control circuit 15, and the upper part shows the timing of signals in the circuit. Note that the configurations shown in FIGS. 3 and 4 are merely schematic, and it is a matter of course that similar functions can be configured by, for example, a DSP and its program.
[0031]
First, the configuration of FIG. 4 will be described. The configuration of FIG. 4 is a very simple configuration, and its design concept is to generate a shutter timing signal ST by adding a delay time to the edge of the logical product signal of the electrocardiogram signal H and the shutter operation signal S.
[0032]
Therefore, the circuit of FIG. 4 inputs the output of the gate 102 for inputting the electrocardiogram signal H and the output of the gate 101 for inputting the shutter operation signal S to the AND gate 103, and further outputs the electrocardiogram signal and the fundus blood vessel by the output of the AND gate 103. The delay time generation circuit 104 in which a delay time corresponding to the pulsation time lag is set is driven, the negative edge of the output of the delay time generation circuit 104 is taken out by the waveform shaping circuit 105 such as a flip-flop, and is used as the shutter timing signal ST. Output.
[0033]
The gates 101 and 102 are composed of a circuit such as a Schmitt trigger. The delay time generation circuit 104 is a mono multivibrator in the present embodiment, but can also be configured from a counter, a timer circuit, and the like.
[0034]
In the configuration of FIG. 4, the addition of the delay time corresponding to the time lag of the pulsation of the fundus blood vessel starts after the shutter operation signal S generated by the examiner's shutter operation is input. For this reason, depending on how the ECG signal H and the shutter operation timing are shifted, there is a possibility that the shutter 12 is driven considerably later than the timing intended by the examiner.
[0035]
Therefore, the shutter timing signal ST obtained by adding a delay time corresponding to the time lag of the pulsation of the fundus blood vessel to the electrocardiogram signal timing at the fastest timing after the shutter operation signal S becomes effective is shown in FIG. It is the composition.
[0036]
In FIG. 3, the waveform shaping circuit 105 configured by the delay time generation circuit 104 and the flip-flop of FIG. 4 is provided between the gate 102 and the AND gate 103. The reset terminal R of the flip-flop constituting the waveform shaping circuit 105 is wired so as to be reset by the low level of the output signal (shutter operation signal S) of the gate 101.
[0037]
That is, in the configuration of FIG. 3, the waveform shaping circuit 105 functions as a signal processing unit that always generates a delay timing (regardless of the shutter operation) obtained by adding the delay time to the electrocardiogram signal timing.
[0038]
Therefore, according to the configuration of FIG. 3, after the shutter operation signal S becomes valid, the pulsation of the fundus blood vessel is synchronized with the electrocardiogram signal timing in synchronization with the negative edge of the output signal of the delay time generation circuit 104 at the fastest timing. The shutter timing signal ST to which a delay time corresponding to the time lag is added can be output, the time lag with respect to the examiner's shutter operation can be further reduced, and photographing and measurement can be performed without greatly changing the alignment state of the fundus camera. Has the effect of being able to
[0039]
An image captured by the CCD 13 in synchronization with the shutter timing signal ST is input to the filing device 30, and a ratio of the vein diameter V2 / V1 is calculated at a plurality of intersections of the fundus artery and vein by the measurement method described above. Based on the results, the state of arteriosclerosis is evaluated. Evaluation of the arteriosclerosis state is performed for the same eye (or subject), and the calculation of the vein diameter ratio is performed at multiple locations as described above, and the average of the obtained values is calculated. It is desirable to do so.
[0040]
The filing device 30 automatically identifies the fundus vein and artery to be measured in the image, detects the vein portion to be measured for diameter, and measures the actual vein diameter as much as possible based on image data recognition. However, in some cases, some of these processes are performed manually (for example, using the mouse 32 to indicate a vein whose diameter should be measured in the fundus image displayed on the monitor 40). You may do it.
[0041]
When imaging, measurement, and evaluation are performed multiple times, for the same subject, the delay time corresponding to the time lag of the pulsation of the fundus blood vessel to be added to the electrocardiogram signal timing is the same as before the imaging, measurement, and evaluation are started. The setting may be performed only once, or the manual setting as described above or the setting method as described later may be used according to the situation (for example, the pulse of the subject monitored by the electrocardiogram measurement apparatus 20). The measurement accuracy can be improved.
[0042]
Note that the delay time set by the timing switch 163 or manual operation is stored in the delay time memory 152 and is stored as it is until it is updated next time. Therefore, if there is no change in the situation (the subject's pulse, etc.), 1 Shooting and measurement can be repeated simply by setting a delay time at the beginning of each measurement session.
[0043]
Furthermore, in this embodiment, a delay time corresponding to the time lag of the pulsation of the fundus blood vessel to be added to the ECG signal timing can be set by the delay time setting unit 16. FIG. 5 shows a configuration example of the timing control circuit 15 and the delay time setting unit 16.
[0044]
In FIG. 5 (or FIG. 6 described later), the examiner manually inputs the delay time, sets up / down, or manually inputs the pulsation timing of the fundus artery while observing the fundus. 1 shows a configuration for calculating and setting a delay time from the input timing and an electrocardiogram signal.
[0045]
The timing control circuit 15 in FIG. 5 includes a delay time control circuit 151, a delay time memory 152, and a delay time generation circuit 104.
[0046]
The delay time control circuit 151 includes the basic configuration shown in FIG. 3 or FIG. 4, and the delay time generation circuit 104 is specifically illustrated as a block in FIG. 3 or FIG.
[0047]
Then, the delay time control circuit 151 sets a delay time value in the delay time memory 152 according to the operation of each operation means of the right delay time setting unit 16.
[0048]
The delay time value of the delay time memory 152 determines the pulse length that the delay time generation circuit 104 should generate.
[0049]
The delay time setting unit 16 includes operation means 163 to 168 and a display 169 shown in FIG. 5, and a delay time value to be set in the delay time memory 152 can be input by these operation means 163 to 168. It is not necessary to provide all of the operation means 163 to 168, and an appropriate one according to the specifications of the apparatus is provided on the operation panel of the fundus camera 10 (or an operation panel configured as a unit externally attached to the fundus camera 10). Can be implemented. Of course, the delay time control circuit 151 receives operation information from the operation means 163 to 168 and incorporates a circuit for controlling the display of the display 169.
[0050]
The operation means 163 to 168 and the display 169 will be described below.
[0051]
Reference numeral 164 is a delay time input means, and this delay time input means 164 can be composed of, for example, a rotary switch or a variable resistor. The examiner can measure about 1 ms to 1000 ms (the unit of delay time handled by this apparatus is Any delay time value in the range of (not limited to ms) can be input. Alternatively, the delay time input means 164 may be constituted by a keyboard such as a numeric keypad.
[0052]
The current value of the delay time value set by the delay time input means 164 can be displayed on a display 169 constituted by an LCD or LED panel, and the examiner confirms the current value of the delay time value set by this display. it can.
[0053]
Further, if an up key 167 and a down key 168 are provided, the current delay time value can be adjusted up and down in an appropriate unit (about 1 to 10 ms) by one operation of these keys 167 and 168. If the clear key 166 is provided, the delay time value once set can be reset to an invalid value.
[0054]
As described above, by using the delay time setting unit 16, the examiner can set a desired delay time corresponding to the time lag of the pulsation of the fundus blood vessel to be added to the electrocardiogram signal timing.
[0055]
The operation means of the delay time setting unit 16 described above directly inputs a desired delay time corresponding to the time lag of the pulsation of the fundus blood vessel to be added to the ECG signal timing by the examiner by manual operation (numerical value input, up / down input) Setting).
[0056]
In the present embodiment, the examiner inputs the actual pulsation timing of the fundus blood vessel, and the delay time can be determined by using the pulsation timing input by the operation and the electrocardiogram signal H (the delay time is (It does not input directly, but is calculated.) For this reason, in this embodiment, a timing switch 163 and a setting key 165 are provided.
[0057]
The timing switch 163 and the setting key 165 are used as follows.
[0058]
For example, the examiner observes an eyepiece (not shown) included in the fundus camera optical system 11 or a part where the pulsation of the fundus blood vessel such as the fundus of the fundus can be visually recognized by a real-time captured image of the CCD 13 on the monitor 40. However, the timing switch 163 is operated at the timing when the pulsation of the fundus blood vessel is recognized.
[0059]
Then, a time value from a predetermined waveform portion of the electrocardiogram signal H immediately before the operation timing of the timing switch 163 (any portion representing one waveform such as a waveform peak) is input as a delay time.
[0060]
The timing switch 163 is not operated after visually confirming the pulsation of the fundus blood vessel, but the examiner predicts and presses the next pulsation while reading the tempo of the pulsation of the fundus blood vessel. However, it is desirable to recommend the above predictive operation in the instruction manual etc., considering the variation in the reaction time of the examiner, etc. It may be.
[0061]
In addition, it is possible to input the pulsation timing of the fundus blood vessel by the timing switch 163 not only once but a plurality of times. It can be used to determine the final delay time by performing a predetermined calculation (for example, arithmetic mean) on the delay time calculated by the operation of 163. Thus, by determining the delay time from the timing obtained by operating the timing switch 163, the delay time can be obtained more accurately.
[0062]
Further, the delay time setting using the timing switch 163 and the setting key 165 can be displayed as shown in FIG.
[0063]
FIG. 6 shows an example of display to be performed at the time of delay time setting or arteriosclerosis measurement on the monitor 40 of the filing device 30.
[0064]
In FIG. 6, reference numeral 400 is a display screen of the monitor 40, and a fundus image display unit 401, a bibliographic item display unit 402, and an electrocardiogram waveform display unit 404 are provided in the display screen 400.
[0065]
The fundus image display unit 401 displays the captured image of the CCD 13 in real time. The bibliographic item display unit 402 displays bibliographic items such as an ID number, date, subject's age, sex, measurement (imaging) method, filter type at the time of imaging, and the like for arteriosclerosis measurement. The delay time value 403 (the current value set in the delay time memory 152 in the same manner as the value displayed on the display 169) is displayed.
[0066]
The electrocardiogram waveform display unit 404 displays the current waveform of the electrocardiogram signal H in the same display format as that of an oscilloscope, and graphically displays the delay time width D input and set by the timing switch 163 on the waveform of the electrocardiogram signal H. Such a display allows the examiner to recognize a delay time corresponding to the time lag of the pulsation of the fundus blood vessel to be added to the ECG signal timing more visually.
[0067]
The method of displaying the delay time on the waveform of the electrocardiogram waveform display unit 404 can also be used to display the delay time set by the above-described manual setting.
[0068]
Alternatively, the delay time width D can be input intuitively and easily by dragging the mouse 32 from a suitable time range, for example, from the waveform representative portion T0 to the desired timing T1.
[0069]
In order to implement the user interface as shown in FIG. 6 on the monitor 40 of the filing device 30, it is natural that necessary information is provided between the filing device 30 and the timing control circuit 15 (or further, the delay time setting unit 16). A path that can be input and output (the dashed path in FIG. 1) is required. Such a path can be configured by providing an appropriate input / output interface (an arbitrary system such as a parallel port or USB) between the filing device 30 and the timing control circuit 15 (or further, the delay time setting unit 16). . Alternatively, all the functions of the timing control circuit 15 (or further the delay time setting unit 16) are hardware of a PC constituting the filing device 30 (part or all of it may be mounted on an expansion card). It can also be configured by software.
[0070]
As described above, the delay time corresponding to the time lag of the pulsation of the fundus blood vessel to be added to the electrocardiogram signal timing can be set for the measurement of arteriosclerosis.
[0071]
Among the above, especially in the configuration in which the delay time is set by manual setting, any delay time value can be set. For example, any delay time value suitable for the research use of the examiner or the medical use can be set. .
[0072]
Further, according to the method of setting the delay time using the timing switch 163 while observing the pulsation of the fundus blood vessel, the delay time can be set intuitively by a very easy operation.
[0073]
Further, in relation to the shutter operation, after the shutter operation signal S becomes effective as shown in FIG. 3, a delay time corresponding to the time lag of the fundus blood vessel pulse is added to the electrocardiogram signal timing at the fastest timing. The shutter timing signal ST can be output, the time lag with the examiner's shutter operation can be further reduced, and photographing and measurement can be performed without greatly changing the alignment state of the fundus camera. .
[0074]
The shutter timing signal ST may be provided not only with the fundus camera 10 and the filing device 30 but also with means (such as an external terminal) for supplying the shutter timing signal ST so that it can be used with other external devices.
[0075]
【The invention's effect】
As is apparent from the above description, according to the present invention, in the fundus imaging apparatus that determines the imaging timing of the fundus image by the imaging means using the timing of the electrocardiogram signal input from the electrocardiogram measurement apparatus, the electrocardiogram signal timing is determined. Timing control means for adding a delay time and generating photographing timing of the fundus image by the photographing means; A timing switch operated at the timing when the examiner observes the fundus image and recognizes the pulsation of the fundus blood vessel, Examine the delay time Depending on the operation of the timing switch Has setting means to set The setting means calculates the delay time value from the pulsation timing of the fundus blood vessel inputted through the timing switch while the fundus image is observed by the examiner and the timing of the electrocardiogram signal. Constitution Alternatively, in a fundus imaging apparatus that determines the timing of imaging of the fundus image by the imaging means using the timing of the electrocardiogram signal input from the electrocardiogram measurement apparatus, a delay time is added to the electrocardiogram signal timing and the imaging of the fundus image is performed by the imaging means A timing control means for generating timing; and a shutter button for inputting a shutter operation signal for instructing photographing by the photographing means; and the timing control means is a delay timing obtained by adding the delay time to the electrocardiogram signal timing. Signal processing means for always generating the image regardless of the shutter operation, and the signal processing means generates the earliest delay timing after the shutter operation signal becomes valid as the fundus image shooting timing by the imaging means. By adopting the configuration, it is possible to obtain an excellent effect that a fundus image can be photographed accurately and with good reproducibility of photographing conditions in synchronization with an electrocardiogram signal for the purpose of measuring arteriosclerosis.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an ophthalmologic measuring apparatus employing the present invention.
FIG. 2 is an explanatory diagram showing the principle of arteriosclerosis measurement of an ophthalmologic measuring apparatus adopting the present invention.
FIG. 3 is an explanatory diagram showing an example of the configuration of the timing control circuit of FIG. 1;
4 is an explanatory diagram showing an example of a different configuration of the timing control circuit of FIG. 1; FIG.
5 is a block diagram showing a configuration example of a timing control circuit and a delay time setting unit in FIG. 1. FIG.
6 is an explanatory diagram showing an example of a user interface using the monitor of FIG. 1. FIG.
[Explanation of symbols]
1 Arteries
2 Veins
10 Fundus camera
11 Fundus camera optical system
12 Shutter
13 CCD
14 Shutter button
15 Timing control circuit
16 Delay time setting section
20 ECG measurement device
30 Filing equipment
31 keyboard
32 mice
33 Network interface
40 monitors
101 gate
102 gate
103 AND gate
104 Delay time generation circuit
105 Waveform shaping circuit
151 Delay time control circuit
152 Delay time memory
163 Timing switch
164 Delay time input means
165 Setting key
166 Clear key
167 Up key
168 Down key
169 Display
400 display screen
401 Fundus image display unit
402 Bibliographic Information Display
403 Delay time value
404 ECG waveform display
D Delay time width
H ECG signal
S Shutter operation signal
ST Shutter timing signal

Claims (6)

In the fundus imaging apparatus for determining the imaging timing of the fundus image by the imaging means using the timing of the electrocardiogram signal input from the electrocardiogram measurement apparatus,
Timing control means for adding a delay time to the electrocardiogram signal timing and generating a fundus image photographing timing by the photographing means;
A timing switch operated at the timing when the examiner observes the fundus image and recognizes the pulsation of the fundus blood vessel,
Have a setting means for setting in accordance with the delay time in the operation of the timing switch examiner,
The setting means calculates and calculates the delay time value from the pulsation timing of the fundus blood vessel input through the timing switch while the fundus image is observed by the examiner and the timing of the electrocardiogram signal. Fundus photographing device.   A shutter button for inputting a shutter operation signal for instructing photographing by the photographing unit is provided, and the timing control unit generates a fundus image photographing timing by the photographing unit after the shutter operation signal becomes valid. The fundus imaging apparatus according to claim 1, characterized in that: In the fundus imaging apparatus for determining the imaging timing of the fundus image by the imaging means using the timing of the electrocardiogram signal input from the electrocardiogram measurement apparatus,
Timing control means for adding a delay time to the electrocardiogram signal timing and generating a fundus image photographing timing by the photographing means;
A shutter button for inputting a shutter operation signal for instructing photographing by the photographing means;
Further, the timing control means has signal processing means for always generating a delay timing obtained by adding the delay time to the electrocardiogram signal timing irrespective of a shutter operation, and the signal processing means is configured to make the shutter operation signal valid. The fundus photographing apparatus characterized in that the earliest delay timing is generated as a fundus image photographing timing by the photographing means.   The fundus photographing apparatus according to claim 1, further comprising a supply unit that supplies a photographing timing signal of a fundus image by the photographing unit to an external device. The fundus imaging apparatus according to claim 1, wherein the setting means inputs a time value from a predetermined waveform portion representing one waveform of the electrocardiogram signal immediately before the operation timing of the timing switch as a delay time. The setting means determines a final delay time by performing a predetermined calculation for each delay time calculated in response to a pulse timing input of the fundus blood vessel by the timing switch performed a plurality of times. The fundus imaging apparatus according to claim 1, characterized in that:

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