Endoscope system

Abstract

This endoscope system 1 comprises: an LED 45 provided inside an operation unit 11 of an endoscope 2; a liquid feeding channel 27 disposed around the LED 45 inside the operation unit 11; and a CPU 7 that controls the output of the LED 45 on the basis of the flow rate of a liquid flowing through the liquid feeding channel 27.

Description

Endoscope system

[0001] The present invention relates to an endoscope system in which a light source is disposed inside an operation unit.

[0002] Generally, a single-use endoscope that is discarded after a single use requires an inexpensive structure. In response to such a requirement, a light source built-in type endoscope in which a light source such as an LED is mounted inside the operation unit has been proposed. The light source built-in type endoscope can simplify structures such as a universal cord and an endoscope connector as compared with an endoscope to which illumination light is supplied from an external device such as a light source device. Therefore, the light source built-in type endoscope can simplify an assembly process and the like and can be manufactured at low cost.

[0003] By the way, a light source such as an LED used in a light source built-in type endoscope generates heat. Also, the amount of light emitted by a light source such as an LED decreases as the temperature of the light source increases. In contrast to these, for example, Patent Document 1 discloses a technique for correcting a drive current according to the temperature of a light source.

[0004] International Publication No. 2017 / 216908

[0005] However, increasing the drive current in response to an increase in the temperature of the light source may cause a further increase in the temperature of the light source. On the other hand, in a light source built-in type endoscope, it is necessary to suppress an increase in the temperature of the outer surface of the operation unit that is gripped by an operator or the like, and thus there is a limit to increasing the drive current for the light source.

[0006] Here, when the amount of light emitted by the light source cannot be sufficiently ensured, it is also possible to adjust the brightness of the image by setting a high gain for the imaging signal. However, when the gain is set high, there is a risk of image quality deterioration due to the occurrence of noise or the like.

[0007] An object of the present invention is to provide an endoscope system that can ensure the amount of light necessary for illuminating a subject without excessively increasing the temperature of the light source.

[0008] An endoscope system according to one aspect of the present invention comprises a light source provided inside the operating section of an endoscope, a fluid conduit arranged around the light source inside the operating section, and a processor that controls the output of the light source based on the flow rate of fluid flowing through the fluid conduit.

[0009] Schematic diagram of the endoscope system Functional block diagram showing the main parts of the endoscope system Perspective view showing the tip Perspective view showing the internal structure of the control unit Perspective view showing the internal structure of the control unit with the base plate removed Cross-sectional view showing the internal structure of the control unit around the light source Characteristic diagram showing the relationship between the drive current to the light source and the maximum surface temperature of the control unit Flowchart showing the light source control routine Timing chart showing the relationship between the fluid delivery state and the drive current to the light source Flowchart showing the endoscope reprocessing method A variation of the first characteristic diagram showing the relationship between the drive current to the light source and the maximum surface temperature of the control unit A variation of the first flowchart showing the light source control routine A variation of the first timing chart showing the relationship between the fluid delivery state and the drive current to the light source at each drive voltage This relates to a modified version of the functional block diagram 2 showing the main parts of the endoscope system, a modified version of the characteristic diagram 2 showing the relationship between the drive current for the light source and the maximum temperature of the outer surface of the operating unit, a modified version of the flowchart 3 showing the light source control routine, a modified version of the functional block diagram 3 showing the main parts of the endoscope system, a modified version of the characteristic diagram 3 showing the relationship between the drive current for the light source and the maximum temperature of the outer surface of the operating unit, a modified version of the flowchart 4 showing the light source control routine, a modified version of the functional block diagram 4 showing the main parts of the endoscope system, a modified version of the flowchart 5 showing the light source control routine, a modified version of the functional block diagram 6 showing the main parts of the endoscope system, and a functional block diagram showing the main parts of the endoscope system.

[0010] The embodiments of the present invention will be described below with reference to the drawings. Figures 1 to 10 relate to one embodiment of the present invention, where Figure 1 is a schematic diagram of the endoscope system and Figure 2 is a functional block diagram showing the main parts of the endoscope system.

[0011] As shown in Figures 1 and 2, the endoscope system 1 includes an endoscope 2, a fluid delivery device 3, a suction device 4, and an endoscope processor 5.

[0012] Endoscope 2 is, for example, an endoscope for the renal pelvis and ureter. In this embodiment, endoscope 2 is a single-use endoscope that is discarded after a single use. However, endoscope 2 may also be a reusable endoscope that is disinfected and sterilized after use and reused.

[0013] The endoscope 2 includes an insertion section 10, an operating section 11, a universal cable 12, and an endoscope connector 13.

[0014] The insertion portion 10 has, in order from the tip side, a tip portion 15, a curved portion 16, and a flexible tube portion 17.

[0015] As shown in Figures 2 and 3, the tip portion 15 has an imaging unit 20, an illumination unit 21, a fluid delivery port 22, a suction port 23, and a treatment tool port 24. Note that the suction port 23 and the treatment tool port 24 may be a single common port.

[0016] As shown in Figure 2, the imaging unit 20 includes a lens unit 20a and an image sensor unit 20b.

[0017] The lens unit 20a is composed of a laminate of multiple optical elements, such as objective lenses. The plan view of the lens unit 20a is rectangular. The optical element located at the very front of the lens unit 20a forms an observation window at the tip portion 15.

[0018] The image sensor unit 20b includes an image sensor and a circuit board (neither of which are shown). The image sensor unit 20b is fixed to the lens unit 20a. The lens unit 20a forms an image of the subject on the image sensor. The image sensor receives the optical image (image of the subject) focused by the lens unit 20a and converts it into an electrical signal. The electrical signal of the optical image is transmitted to a signal cable 25 connected to the circuit board.

[0019] The illumination unit 21 is composed of multiple optical components, such as light distribution lenses. The optical component located at the very front of the illumination unit 21 forms an illumination window at its tip 15. A light guide bundle 26 is optically connected to the base end of the illumination unit 21. Alternatively, instead of the light guide bundle 26, a light guide consisting of, for example, a single optical fiber can be optically connected to the base end of the illumination unit 21.

[0020] The fluid delivery port 22 is composed of a through-hole that penetrates the tip portion 15. A fluid delivery channel 27, which serves as a fluid conduit, is connected to the base end of the fluid delivery port 22. The fluid delivery channel 27 is a delivery conduit for delivering liquid (such as physiological saline) into the subject.

[0021] The suction port 23 is composed of a through-hole that penetrates the tip portion 15. A suction channel 28, which serves as a fluid conduit, is connected to the base end of the suction port 23. The suction channel 28 is a suction conduit for drawing fluid from within the subject.

[0022] The treatment tool hole 24 is composed of a through hole that penetrates the tip portion 15. A treatment tool channel 29 is connected to the base end of the treatment tool hole 24. The treatment tool channel 29 is a tube for guiding treatment tools into the subject. If the suction hole 23 and the treatment tool hole 24 are composed of a single common hole, for example, the suction channel 28 will merge with the treatment tool channel 29 inside the operating section 11.

[0023] The curved portion 16 has a configuration that allows the insertion portion 10 to be actively bent in two directions, vertically. The curved portion 16 may also have a configuration that allows it to be actively bent in four directions, vertically, horizontally, and to the right. In this embodiment, the vertical, horizontal, and to the left directions of the insertion portion 10 are defined in correspondence with the vertical, horizontal, and to the left directions of the subject image captured by the imaging unit 20.

[0024] The flexible tube section 17 is composed of a tubular member that passively bends in response to external forces. A signal cable 25, a light guide bundle 26, a fluid delivery channel 27, a suction channel 28, and a treatment tool channel 29 are inserted inside this flexible tube section 17.

[0025] As shown in Figure 1, the operating unit 11 has a housing 30 as the main body of the operating unit. The housing 30 is divided into left and right sections by, for example, a first housing body 31 and a second housing body 32. Although not shown, the housing 30 may also be divided front and back by, for example, the first housing body and the second housing body. In this case, the left-right direction and front-back direction of the operating unit 11 (housing 30) are the directions as viewed from the operator or the like who is holding the operating unit 11. These first and second housing bodies 31 and 32 are formed by, for example, resin molding. The first housing body 31 and the second housing body 32 are joined together using an adhesive or the like to form a hollow housing 30. The first housing body 31 and the second housing body 32 may also be joined together using screws or the like.

[0026] A gripping portion 35 for the operator or other person to grasp by hand is provided approximately in the center of the longitudinal direction of the housing 30.

[0027] Further forward than the gripping portion 35, a channel opening 36 for inserting a treatment instrument is attached to the housing 30. Inside the housing 30, the base end of the treatment instrument channel 29 is connected to the channel opening 36.

[0028] Furthermore, a bending operation lever 37 is rotatably mounted on the housing 30 at the base end of the gripping portion 35. Inside the housing 30, the bending operation lever 37 is connected to a pulley 38 (see Figures 4 and 5). The pulley 38 rotates integrally with the bending operation lever 37. This rotation of the pulley 38 causes a pair of bending operation wires 39 connected to the pulley 38 to be pulled or released. This pulling or releasing of the bending operation wires 39 causes the bending portion 16 to bend.

[0029] Furthermore, as shown in Figures 5 and 6, a light-emitting diode (LED) 45 is provided inside the housing 30 as a light source. The LED 45 is mounted on an LED substrate 46. In addition, as shown in Figures 4 and 6, the LED substrate 46 is screwed to the first housing body 31 while sandwiched between the heat dissipation block 47 and the base plate 48.

[0030] As shown in Figure 6, a cavity-shaped LED housing chamber 47a is formed in the middle of the longitudinal direction of the heat dissipation block 47. An LED 45 mounted on an LED substrate 46 is housed in this LED housing chamber 47a. Furthermore, the heat dissipation block 47 is provided with a light guide insertion hole 47b that communicates with the LED housing chamber 47a. The base end of a light guide bundle 26 is inserted through the light guide insertion hole 47b. As a result, the base end of the light guide bundle 26 is optically connected to the LED 45 within the LED housing chamber 47a. The light guide bundle 26 inserted through the light guide insertion hole 47b is fixed to the heat dissipation block 47 using an adhesive 49 or the like.

[0031] Furthermore, as shown in Figures 5 and 6, the middle of the liquid supply channel 27 is located near the LED 45. Specifically, inside the housing 30, the liquid supply channel 27 is piped to reach the universal cable 12 via the periphery of the heat dissipation block 47. In addition, a portion of the liquid supply channel 27 is in contact with the heat dissipation block 47 in a manner that allows for heat exchange. This makes it possible to dissipate the heat transferred from the LED 45 to the heat dissipation block 47 to the liquid flowing inside the liquid supply channel 27. In other words, the LED 45 can be cooled by the liquid flowing inside the liquid supply channel 27.

[0032] As shown in Figure 1, the universal cable 12 extends, for example, from the tip side of the operating section 11. Also, as shown in Figure 2, signal cables 25, 50, a fluid delivery channel 27, and a suction channel 28 are inserted through the universal cable 12.

[0033] The endoscope connector 13 is connected to the extended end of the universal cable 12. The endoscope connector 13 has a plug portion 51, a fluid supply port 52, and a suction port 53.

[0034] The plug portion 51 is located at the end of the endoscope connector 13. The plug portion 51 can be connected to a receptacle (not shown) of the endoscope processor 5. Multiple electrical contacts 51a are provided inside the plug portion 51. Signal cables 25, 50, etc., are connected to each electrical contact 51a. This allows each electrical contact 51a to electrically connect the signal cables 25, 50, etc., to the endoscope processor 5.

[0035] The liquid supply port 52 is located on the side of the endoscope connector 13. Inside the endoscope connector 13, a liquid supply channel 27 is connected to the liquid supply port 52. This liquid supply port 52 can be connected to the liquid supply device 3 via a conduit 54.

[0036] The suction port 53 is located on the side of the endoscope connector 13. Inside the endoscope connector 13, a suction channel 28 is connected to the suction port 53. This suction port 53 can be connected to a suction device 4 via a conduit 55.

[0037] The fluid delivery device 3 comprises a fluid delivery pump 3a and a fluid delivery tank 3b. The fluid delivery tank 3b stores a liquid such as physiological saline. The liquid in the fluid delivery tank 3b is supplied to the fluid delivery channel 27 by the drive of the fluid delivery pump 3a. The liquid supplied to the fluid delivery channel 27 is ejected into the subject from the fluid delivery hole 22. In this way, the fluid delivery device 3 achieves fluid delivery into the inside of the subject.

[0038] The suction device 4 comprises a suction pump 4a and a suction tank 4b. The operation of the suction pump 4a generates negative pressure within the suction channel 28. This negative pressure draws fluid (liquid) from within the subject into the suction channel 28 through the suction hole 23. The liquid drawn into the suction channel 28 is then stored in the suction tank 4b. Thus, the suction device 4 achieves the suction of fluid from within the subject.

[0039] The endoscope processor 5 is composed of a well-known microcomputer equipped with a CPU (Central Processing Unit) 7 as a processor, RAM 8, ROM 9 as a memory unit, and peripheral devices thereof. The ROM 9, which is a non-temporary memory medium, has fixed data such as programs executed by the CPU and data tables pre-stored in it. In addition, all or part of the functions of the processor may be composed of logic circuits or analog circuits, and the processing of various programs may be realized by electronic circuits such as FPGAs.

[0040] The endoscope processor 5 configured in this way functionally includes a pump control unit 5a, a light source control unit 5b, and an image control unit 5c.

[0041] The pump control unit 5a controls the drive of the fluid delivery pump 3a and the suction pump 4a. This drive control is achieved, for example, by controlling the respective drive voltages V1 and V2 for the fluid delivery pump 3a and the suction pump 4a. Here, the pump control unit 5a can perform fluid perfusion into the subject by simultaneously driving the fluid delivery pump 3a and the suction pump 4a. When the endoscope 2 is used in the ureter or the like, perfusion is performed not only when performing various procedures on the subject, but also when inserting the insertion section 10 into the subject and when observing the inside of the subject, in order to secure a field of view inside the subject.

[0042] The light source control unit 5b controls the emission of light from the LED 45. This emission control is achieved, for example, by controlling the drive current I supplied to the LED 45. In controlling the emission of light from the LED 45, the light source control unit 5b varies the upper limit Imax of the current that can be supplied to the LED 45 depending on the on / off state of the liquid supply pump 3a.

[0043] For example, as shown in Figure 7, if Tmax is the maximum temperature that can be allowed on the outer surface of the operating unit 11, the current value that raises the outer surface temperature to the maximum temperature Tmax (i.e., the upper limit of the current Imax) is different when the liquid transfer pump 3a is on and when the liquid transfer pump 3a is off.

[0044] That is, in the example shown in FIG. 7, when the liquid feed pump 3a is turned off, unless the drive current I for the LED 45 is controlled to be I0 or less, the outer surface temperature of the operation unit 11 cannot be suppressed to be equal to or less than the maximum temperature Tmax. On the other hand, when the liquid feed pump 3a is turned on, if the drive current I for the LED 45 is controlled to be I1 (I1 > I0) or less, the outer surface temperature of the operation unit 11 can be suppressed to be equal to or less than the maximum temperature Tmax. This is because when the liquid feed pump 3a is turned on, the liquid flows in the liquid feed channel 27, improving the heat exchange efficiency between the liquid feed channel 27 and the heat radiation block 47. The relationship shown in FIG. 7 is obtained in advance by experiments or the like and recorded in a storage unit such as the ROM 9. However, in the relationship shown in FIG. 7, it is assumed that the drive voltage V1 when the liquid feed pump 3a is turned on is a preset fixed value.

[0045] Based on such a relationship, when the liquid feed pump 3a is off, the light source control unit 5b basically sets the drive current I to I0. However, when an operator or the like operates a control panel (not shown) of the endoscope processor 5 to adjust the brightness of the illumination light, the light source control unit 5b controls the drive current I within a range not exceeding I0.

[0046] Also, when the liquid feed pump 3a is on, the light source control unit 5b basically sets the drive current I to I1. However, when an operator or the like operates a control panel (not shown) of the endoscope processor 5 to adjust the brightness of the illumination light, the light source control unit 5b controls the drive current I within a range not exceeding I1.

[0047] The image control unit 5c processes an electrical signal (imaging signal) transmitted from the imaging unit 20 via the signal cable 25 and generates an image for display on a monitor (not shown). At that time, when the amount of illumination light irradiated on the subject is insufficient, the image control unit 5c increases the gain for the imaging signal as necessary. However, when the liquid feed pump 3a is on, since a drive current I capable of ensuring a sufficient amount of light is supplied to the LED 45, the gain for the imaging signal can be kept sufficiently low.

[0048] Next, the light source control performed by the CPU 7 of the endoscope processor 5 will be described according to the flowchart of the light source control routine shown in FIG. 8. This routine is repeatedly executed every set time.

[0049] When the routine starts, the CPU 7 checks, in step S101, whether the liquid feeding pump 3a is turned on.

[0050] And if it is determined in step S101 that the liquid feeding pump 3a is turned off (step S101: NO), the CPU 7 proceeds to step S102. In step S102, the CPU 7 sets the upper limit value Imax of the current for the LED 45 to I0.

[0051] On the other hand, if it is determined in step S101 that the liquid feeding pump 3a is turned on (step S101: YES), the CPU 7 proceeds to step S103. In step S103, the CPU 7 sets the upper limit value Imax of the current for the LED 45 to I1 (I1 > I0).

[0052] When proceeding from step S102 or step S103 to step S104, the CPU 7 checks whether the brightness of the illumination light has been adjusted by the operator or the like.

[0053] And if it is determined in step S104 that the brightness adjustment has not been performed (step S104: NO), the CPU 7 proceeds to step S105. In step S105, after setting the drive current I for the LED 45 to Imax, the CPU 7 exits the routine.

[0054] On the other hand, if it is determined in step S104 that the brightness adjustment has been performed (step S104: YES), the CPU 7 proceeds to step S106. In step S106, after controlling the drive current I for the LED 45 to a current value corresponding to the adjusted brightness (within the range up to the upper limit value Imax), the CPU 7 exits the routine.

[0055] Through this control, for example, as shown in Figure 9, the drive current I for the LED 45 fluctuates according to the on / off state of the fluid delivery pump 3a. However, Figure 9 shows the change in drive current I when the brightness is not adjusted by the operator or other personnel.

[0056] According to this embodiment, the endoscope system 1 includes an LED 45 provided inside the operating unit 11 of the endoscope 2, a fluid delivery channel 27 arranged around the LED 45 inside the operating unit 11, and a CPU 7 that controls the output of the LED 45 based on the flow rate of the fluid flowing through the fluid delivery channel 27. This makes it possible to secure the amount of light necessary for illuminating the inside of the subject without excessively raising the temperature of the LED 45.

[0057] In other words, the endoscope 2 of this embodiment employs a configuration in which a liquid delivery channel 27 is arranged around an LED 45 located inside the operating unit 11. This allows the heat generated when the LED 45 is driven to be dissipated into the liquid in the liquid delivery channel 27. This heat dissipation suppresses the decrease in luminous efficiency due to the temperature rise of the LED 45, and also suppresses the temperature rise of the outer surface of the operating unit 11. In addition, the CPU 7 controls the output of the LED 45 based on the flow rate of the liquid flowing through the liquid delivery channel 27. Specifically, the CPU 7 makes the output of the LED 45 greater when the liquid delivery pump 3a is on and liquid is flowing through the liquid delivery channel 27 than the output of the LED 45 when the liquid delivery pump 3a is off. In other words, the CPU 7 makes the drive current I for the LED 45 greater when the liquid delivery pump 3a is on than the drive current I for the LED 45 when the liquid delivery pump 3a is off. By doing so, it is possible to ensure the amount of light necessary for illuminating the inside of the subject while suppressing the temperature rise of the LED 45.

[0058] In particular, with the endoscope 2 for the renal pelvis and ureter, it is necessary to ensure visibility into the narrow lumen of the ureter and other tubular structures filled with bodily fluids. For this reason, perfusion of saline solution and other fluids into the subject is performed not only when various procedures are being performed on the subject, but also when the insertion section 10 is inserted into the subject and when observing the inside of the subject. Such perfusion involves supplying fluid into the subject using the fluid delivery channel 27. Therefore, from the time the operator starts inserting the insertion section 10 into the subject until the insertion section 10 is removed, the supply of fluid into the subject using the fluid delivery channel 27 is performed almost continuously. Consequently, in particular with the endoscope 2 for the renal pelvis and ureter, the amount of light necessary for illuminating the inside of the subject can be ensured while suppressing the temperature rise of the LED 45 (and the temperature rise of the control section 11) for almost the entire period that the operator uses the endoscope 2.

[0059] Furthermore, by ensuring sufficient illumination light intensity, the gain for the imaging signal can be set low, effectively suppressing image quality degradation when displayed on a monitor or the like.

[0060] Here, the reprocessing of the endoscope 2 that constitutes the endoscope system 1 can be carried out, for example, using the following reprocessing method. The endoscope 2 described above may be discarded after a single use, or it may be used repeatedly multiple times.

[0061] For configurations that are used repeatedly multiple times, a reprocessing method such as the one shown in Figure 6 may be necessary.

[0062] In this reprocessing method, the worker collects and receives used endoscopes 2 after they have been used for treatment, and then transports, ships, and delivers them to factories, etc. (Step S1). At this time, the used endoscopes 2 can be transported in a special container to prevent contamination from the endoscopes 2.

[0063] Next, the operator can perform pre-cleaning such as washing and sterilization on the collected and transported used endoscope 2 (Step S2). Specifically, in washing the endoscope, the operator removes any attached substances from the endoscope 2 using a brush or the like. After that, the operator washes the endoscope 2 with any washing solution such as an isopropanol-containing washing agent, a proteolytic enzyme washing agent, or alcohol to remove pathogenic microorganisms derived from blood or bodily fluids. Note that the washing solution is not limited to the washing solutions mentioned above, and other washing solutions may be used. Furthermore, in sterilizing the endoscope 2, one of the following methods is used to sterilize pathogenic microorganisms: autoclaving, ethylene oxide gas sterilization, gamma ray sterilization, or hydrogen peroxide sterilization.

[0064] Next, the operator performs an acceptance inspection of the used endoscope 2 (step S3). Specifically, the operator checks whether the used endoscope 2 has any serious defects or whether the used endoscope 2 has exceeded the maximum number of reprocessing cycles.

[0065] Next, the worker may disassemble the used endoscope 2 (step S4).

[0066] Furthermore, the worker replaces some of the parts of the used endoscope 2 with new parts as needed (step S5).

[0067] The worker can then assemble the new endoscope 2 (step S6). In some examples, the worker may add an identifier to the reassembly of the endoscope 2 to indicate that the endoscope 2 has been modified from its original state, for example, by adding a label or other marking that designates the endoscope 2 as a reworked, refurbished, or remanufactured item.

[0068] Next, the worker can inspect and test the newly formed endoscope 2 (step S7). Specifically, the worker confirms through various functional tests that the newly formed endoscope 2 has the same effectiveness and safety as the original product.

[0069] Next, the worker may sequentially perform sterilization and storage (step S8) and shipment (step S9) of the new endoscope 2. In step S8, the new endoscope 2 is sterilized using a sterilization gas such as ethylene oxide gas or propylene oxide gas, and stored in a storage container until use.

[0070] By performing steps S1 to S9 described above, the endoscope 2 is reprocessed. In this embodiment, where the light source, such as the LED 45, is located inside the operating unit 11, the length of the light guide bundle 26 can be significantly reduced compared to a configuration in which illumination light is supplied from an external light source device or the like. In particular, with the light source located inside the operating unit 11, it is not necessary to insert the light guide bundle 26 through the universal cable 12. Therefore, replacing components related to the optical system for supplying illumination light to the tip 15 becomes significantly easier. Although specific order of terms is used above, one or more steps in this method may be performed in any order depending on the situation.

[0071] (First Modification) Next, a first modification of the above-described embodiment will be explained with reference to Figures 11 to 13. In this modification, when the drive voltages V1 and V2 of the liquid transfer pump 3a and the suction pump 4a are controlled in steps, the upper limit value Imax of the current to the LED 45 is changed in steps.

[0072] In other words, when the drive voltage V1 of the liquid transfer pump 3a is controlled in steps, the flow rate of the liquid supplied from the liquid transfer pump 3a to the liquid transfer channel 27 changes in steps. More specifically, the more the drive voltage V1 of the liquid transfer pump 3a increases, the more the flow rate of the liquid supplied from the liquid transfer pump 3a to the liquid transfer channel 27 increases. As a result, the more the drive voltage V1 of the liquid transfer pump 3a increases, the better the heat exchange efficiency between the heat dissipation block 47 and the liquid transfer channel 27 becomes, and the upper limit value Imax of the current for the LED 45, which suppresses the external surface temperature of the operating unit 11 to below the maximum temperature Tmax, becomes larger. In the example shown in Figure 11, when the liquid transfer pump 3a is off, the upper limit value Imax is the lowest at I0, and as the drive voltage V1 of the liquid transfer pump 3a increases from 1 [V] to 2 [V] to 3 [V], the upper limit value Imax increases to I1, I2, and I3. Such relationships are determined in advance through experiments and stored in a memory unit such as ROM 9.

[0073] Next, the light source control performed by the CPU 7 of the endoscope processor 5 will be explained according to the flowchart of the light source control routine shown in Figure 12. This routine is executed repeatedly at set intervals.

[0074] When the routine starts, CPU 7 checks in step S201 whether the liquid transfer pump 3a is turned on or not.

[0075] Then, if it is determined in step S201 that the liquid transfer pump 3a is turned off (step S201: NO), the CPU 7 proceeds to step S202. In step S202, the CPU 7 sets the upper limit value Imax of the current to the LED 45 to I0.

[0076] On the other hand, if it is determined in step S201 that the liquid transfer pump 3a is turned on (step S201: YES), the CPU 7 proceeds to step S203. In step S203, the CPU 7 reads the drive voltage V1 of the liquid transfer pump 3a.

[0077] In the following step S204, the CPU 7 sets the upper limit value Imax of the current to the LED 45 to a value (I1 to I3) corresponding to the drive voltage V1. That is, for example, the CPU 7 sets the upper limit value Imax to I1 when the drive voltage V1 is 1 [V] or less, sets the upper limit value Imax to I2 when the drive voltage V1 is 2 [V] or less, and sets the upper limit value Imax to I3 when the drive voltage V1 is 3 [V] or less.

[0078] Note that the processes in steps S205 to S207 correspond to steps S104 to S106 shown in Figure 8, so their explanation will be omitted.

[0079] With this control, for example, as shown in Figure 13, the drive current I for the LED 45 fluctuates according to the on / off state of the fluid delivery pump 3a. Furthermore, when the fluid delivery pump 3a is turned on, the drive current I for the LED 45 fluctuates according to the drive voltage V1 of the fluid delivery pump 3a. However, Figure 13 shows the change in drive current I when the brightness is not adjusted by the operator or other personnel.

[0080] According to this modified configuration, the upper limit Imax of the current to the LED 45 can be precisely set according to the drive voltage V1, based on the correlation between the drive voltage V1 for the liquid delivery pump 3a and the flow rate of the liquid flowing through the liquid delivery channel 27.

[0081] (Second Modification) Next, a second modification of the above-described embodiment will be explained with reference to Figures 14 to 16. In this modification, the flow rate of the liquid flowing through the liquid delivery channel 27 is measured, and the upper limit value Imax of the current to the LED 45 is changed in steps according to the measured flow rate.

[0082] To achieve this type of control, for example, as shown in Figure 14, a flow sensor 60 is provided in the pipeline 54. The liquid flow rate detected by the flow sensor 60 is input to the endoscope processor 5 via a signal cable (not shown).

[0083] Furthermore, as shown in Figure 15, for example, the relationship between the flow rate of the liquid flowing through the liquid delivery channel 27 and the upper limit of the current, Imax, has been determined in advance through experiments or other means. In the example shown in Figure 15, when the liquid delivery pump 3a is turned off and the flow rate is "0", the upper limit Imax is the lowest at I0, and as the liquid delivery pump 3a is turned on and the flow rate increases to 10 [ml / min], 20 [ml / min], and 30 [ml / min], the upper limit Imax increases to I1, I2, and I3. Such relationships are stored in a memory unit such as ROM 9.

[0084] Next, the light source control performed by the CPU 7 of the endoscope processor 5 will be explained according to the flowchart of the light source control routine shown in Figure 16. This routine is executed repeatedly at set intervals.

[0085] When the routine starts, CPU 7 checks in step S301 whether the liquid transfer pump 3a is turned on or not.

[0086] Then, if it is determined in step S301 that the liquid transfer pump 3a is turned off (step S301: NO), the CPU 7 proceeds to step S302. In step S302, the CPU 7 sets the upper limit value Imax of the current to the LED 45 to I0.

[0087] On the other hand, if it is determined in step S301 that the liquid transfer pump 3a is turned on (step S301: YES), the CPU 7 proceeds to step S303. In step S303, the CPU 7 reads the flow rate from the flow sensor 60.

[0088] In the following step S304, the CPU 7 sets the upper limit Imax of the current to the LED 45 to a value (I1 to I3) corresponding to the flow rate of the liquid delivery channel 27. That is, for example, the CPU 7 sets the upper limit Imax to I1 when the flow rate is 10 [ml / min] or less, sets the upper limit Imax to I2 when the flow rate is 20 [ml / min] or less, and sets the upper limit Imax to I3 when the flow rate is 30 [ml / min] or less.

[0089] Note that the processes in steps S305 to S307 correspond to steps S104 to S106 shown in Figure 8, so their explanation will be omitted.

[0090] With this modified configuration, the flow rate of the liquid flowing through the liquid delivery channel 27 can be directly measured by the flow sensor 60, allowing for precise setting of the upper limit Imax of the current supplied to the LED 45.

[0091] (Third Modification) Next, a third modification of the above-described embodiment will be explained with reference to Figures 17 to 19. In this modification, the pressure in the liquid supply channel 27 is measured, and the upper limit value Imax of the current to the LED 45 is changed in steps according to the measured pressure.

[0092] To achieve this type of control, for example, as shown in Figure 17, a pressure sensor 61 is provided in the pipeline 54. The liquid pressure (pipe pressure) detected by the pressure sensor 61 is input to the endoscope processor 5 via a signal cable (not shown).

[0093] Furthermore, as shown in Figure 18, for example, the relationship between the pipeline pressure in the liquid delivery channel 27 and the upper limit of the current, Imax, has been determined in advance through experiments or other means. In the example shown in Figure 18, when the liquid delivery pump 3a is turned off and the pressure in the liquid delivery channel 27 is low, the upper limit Imax is the lowest at I0. As the liquid delivery pump 3a is driven and the pressure in the liquid delivery channel 27 increases to 100 [kPa], 200 [kPa], and 300 [kPa], the upper limit Imax changes to I1, I2, and I3. Such relationships are stored in a memory unit such as ROM 9.

[0094] Next, the light source control performed by the CPU 7 of the endoscope processor 5 will be explained according to the flowchart of the light source control routine shown in Figure 19. This routine is executed repeatedly at set intervals.

[0095] When the routine starts, CPU 7 checks in step S401 whether the liquid transfer pump 3a is turned on or not.

[0096] Then, if it is determined in step S401 that the liquid transfer pump 3a is turned off (step S401: NO), the CPU 7 proceeds to step S402. In step S402, the CPU 7 sets the upper limit value Imax of the current to the LED 45 to I0.

[0097] On the other hand, if in step S401 it is determined that the liquid transfer pump 3a is turned on (step S401: YES), the CPU 7 proceeds to step S403. In step S403, the CPU 7 reads the flow rate from the pressure sensor 61.

[0098] In the following step S404, the CPU 7 sets the upper limit Imax of the current to the LED 45 to a value (I1 to I3) corresponding to the pipeline pressure in the liquid delivery channel 27. That is, for example, the CPU 7 sets the upper limit Imax to I1 when the pipeline pressure is 100 [MPa] or less, sets the upper limit Imax to I2 when the flow rate is 200 [MPa] or less, and sets the upper limit Imax to I3 when the flow rate is 300 [MPa] or less.

[0099] Note that the processes in steps S405 to S407 correspond to steps S104 to S106 shown in Figure 8, so their explanation will be omitted.

[0100] According to this modified configuration, the upper limit Imax of the current to the LED 45 can be precisely set based on the correlation between the pipeline pressure measured by the pressure sensor 61 and the flow rate of the liquid flowing through the liquid delivery channel 27.

[0101] (Fourth Modification) Next, a fourth modification of the above-described embodiment will be explained with reference to Figures 20 to 21. In this modification, the drive current I of the LED 45 is appropriately corrected based on the temperature of the LED 45.

[0102] For this reason, a temperature sensor 62 is provided near the LED 45. The temperature of the LED 45 detected by the temperature sensor 62 is input to the endoscope processor 5 via a signal cable.

[0103] Next, the light source control performed by the CPU 7 of the endoscope processor 5 will be explained according to the flowchart of the light source control routine shown in Figure 21. This routine is executed repeatedly at set intervals.

[0104] When the routine starts, the CPU 7 performs the processes corresponding to steps S101 to S103 shown in Figure 8 in steps S501 to S503.

[0105] When the system proceeds from step S502 or step S503 to step S504, the CPU 7 reads the temperature of the LED 45 detected by the temperature sensor 62.

[0106] In the following step S505, the CPU 7 checks whether the temperature of the LED 45 is greater than a preset threshold Tth. Here, the threshold Tth is set to a temperature that can raise the external surface temperature of the operating unit 11 to Tmax or higher.

[0107] Then, in step S505, if it is determined that the temperature T of the LED 45 is greater than the threshold Tth (step S505: YES), the CPU 7 proceeds to step S508.

[0108] On the other hand, if in step S505 it is determined that the temperature of the LED 45 is below the threshold Tth (step S505: NO), the CPU 7 proceeds to step S506.

[0109] In step S506, the CPU 7 checks whether the brightness of the illumination light has been adjusted by the operator or other personnel.

[0110] Then, if it is determined in step S506 that brightness adjustment has not been performed (step S506: NO), the CPU 7 proceeds to step S507. In step S507, the CPU 7 sets the drive current I for the LED 45 to Imax and then exits the routine.

[0111] On the other hand, if it is determined in step S506 that brightness adjustment has been performed (step S506: YES), the CPU 7 proceeds to step S508.

[0112] When the process proceeds from step S505 or step S506 to step S508, the CPU 7 controls the drive current I for the LED 45 to a predetermined current value and then exits the routine. For example, if the temperature T of the LED 45 is higher than the threshold Tth, the CPU 7 controls the drive current I for the LED 45 to a value less than the upper limit Imax. Also, for example, if brightness adjustment is being performed, the CPU 7 controls the drive current I for the LED 45 to a current value corresponding to the adjusted brightness (however, within the range up to the upper limit Imax).

[0113] With this modified configuration, the temperature of the LED 45 can be adjusted more precisely, and the surface temperature of the operating unit 11 can be kept lower than the maximum temperature Tmax.

[0114] (Sixth Modification) Next, a sixth modification of the above-described embodiment will be explained with reference to Figure 22. In this modification, in addition to the liquid supply channel 27, the suction channel 28 is also piped to reach the universal cable 12 via the periphery of the heat dissipation block 47. Furthermore, a portion of the suction channel 28 is in contact with the heat dissipation block 47 in a state where heat exchange is possible. This makes it possible to dissipate the heat transferred from the LED 45 to the heat dissipation block 47 to the liquid flowing inside the suction channel 28. In other words, it is possible to cool the LED 45 with the liquid flowing inside the liquid supply channel 27.

[0115] According to this modified example, the cooling efficiency for the LED 45 can be more effectively improved.

[0116] (Seventh Modification) Next, a seventh modification of the above-described embodiment will be explained with reference to Figure 23. In this modification, a suction channel 28 is placed near the LED 45 instead of the liquid supply channel 27. For this reason, inside the housing 30, the suction channel 28 is piped to reach the universal cable 12 via the periphery of the heat dissipation block 47. Furthermore, a part of the suction channel 28 is in contact with the heat dissipation block 47 in a state where heat exchange is possible. This makes it possible to dissipate the heat transferred from the LED 45 to the heat dissipation block 47 to the liquid flowing inside the suction channel 28. In other words, it is possible to cool the LED 45 with the liquid flowing inside the liquid supply channel 27.

[0117] Such modifications can achieve substantially the same effects as the embodiments described above.

[0118] It should be noted that the present invention is not limited to the embodiments described above, and various modifications and changes are possible, all of which fall within the technical scope of the present invention. For example, the fluid perfused in the endoscope system 1 is not limited to a liquid, but may be a gas. Furthermore, the configurations of the above embodiments and their respective modifications may be combined as appropriate.

Claims

1. An endoscope system characterized by comprising: a light source provided inside the operating section of an endoscope; a fluid conduit arranged around the light source inside the operating section; and a processor that controls the output of the light source based on the flow rate of fluid flowing through the fluid conduit.

2. The endoscopic system according to claim 1, characterized in that the processor sets the drive current of the light source based on the flow rate.

3. The endoscopic system according to claim 2, characterized in that the processor sets the drive current to be larger as the flow rate increases.

4. The endoscope system according to claim 3, further comprising a pump connected to the fluid conduit for circulating the fluid through the fluid conduit.

5. The endoscopic system according to claim 4, characterized in that the processor sets the drive current based on the on / off state of the pump.

6. The endoscopic system according to claim 4, characterized in that the processor sets the drive current based on the drive voltage of the pump.

7. The endoscope system according to claim 6, further comprising a storage unit which stores in advance an upper limit value of the current that can be supplied to the light source according to the drive voltage of the pump, wherein the processor sets the drive current based on the drive voltage of the pump and the upper limit value recorded in the storage unit.

8. The endoscope system according to claim 3, further comprising a flow sensor for detecting the flow rate of the fluid flowing through the fluid conduit, wherein the processor sets the drive current based on the detection result of the flow sensor.

9. The endoscope system according to claim 8, further comprising a storage unit which stores in advance an upper limit value of the current that can be supplied to the light source according to the flow rate of the fluid flowing through the fluid conduit, wherein the processor sets the drive current based on the flow rate of the fluid flowing through the fluid conduit and the upper limit value stored in the storage unit.

10. The endoscope system according to claim 3, characterized in that the processor sets the drive current based on the pressure of the fluid flowing through the fluid conduit.

11. The endoscope system according to claim 10, further comprising a pressure sensor for detecting the pressure of the fluid flowing through the fluid conduit, wherein the processor sets the drive current based on the detection result of the pressure sensor.

12. The endoscope system according to claim 11, further comprising a storage unit which stores in advance an upper limit value of the current that can be supplied to the light source according to the pressure inside the fluid conduit, wherein the processor sets the drive current based on the pressure inside the fluid conduit and the upper limit value stored in the storage unit.

13. The endoscope system according to claim 3, further comprising a temperature sensor for detecting the temperature of the light source, wherein the processor reduces the drive current to a current value based on the flow rate when the temperature of the light source is higher than a threshold.

Images