JP2013017770A - Endoscope cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the flow rate of a refrigerant and to perform appropriate feedback to a pump so as to cool an endoscope distal end part.SOLUTION: The endoscope cooling device has an operation part, a shaft part, a distal end part, and an external device. The endoscope cooling device includes: a heat exchange mechanism for performing heat exchange at the distal end part; a pump for feeding the refrigerant; a first flow path for making the refrigerant flow toward the heat exchange mechanism from the pump; a second flow path for making the refrigerant flow toward the pump from the heat exchange mechanism; a flow rate measuring mechanism which is provided at any position in the second flow path between the heat exchange mechanism and the pump; and a control means for controlling the pump in accordance with the output of the flow rate measuring mechanism. A refrigerant circulation type cooling mechanism is configured such that the refrigerant circulates and flows in the first flow path and the second flow path, and thus the distal end part is cooled.

Description

  The present invention relates to an endoscope cooling apparatus.

  In a conventional endoscope apparatus, a liquid cooling system is used for cooling the distal end portion of the endoscope. For example, in Patent Document 1, focusing on the temperature of the water supply system, the Peltier element is driven to cool.

Japanese Laid-Open Patent Publication No. 2006-14925

  Patent Document 1 discloses a configuration in which a cooling mechanism is driven by paying attention only to a temperature change in a water supply system. Here, the behavior of the refrigerant is not monitored. For this reason, even if an abnormality occurs in the mechanism of the water supply system, for example, the refrigerant leaks, the abnormality cannot be detected and only the driving condition of the Peltier element is changed. In such a case, there is a problem that the object to be cooled, for example, the distal end portion of the endoscope is overheated.

  The present invention has been made in view of the above, and provides an endoscope cooling apparatus capable of appropriately cooling the distal end portion of an endoscope by measuring the flow rate of the refrigerant and applying accurate feedback to the pump. The purpose is to do.

In order to solve the above-described problems and achieve the object, the present invention provides:
An endoscope cooling device having an operation part, a shaft part, a tip part, and an external device,
A heat exchange mechanism for exchanging heat at the tip,
A pump for delivering refrigerant;
A first flow path for flowing the refrigerant from the pump toward the heat exchange mechanism;
A second flow path for flowing the refrigerant from the heat exchange mechanism toward the pump;
A flow rate measuring mechanism that is provided at any position of the second flow path between the heat exchange mechanism and the pump and measures the flow rate of the refrigerant;
Control means for controlling the pump according to the output of the flow rate measuring mechanism;
Have
An endoscope cooling apparatus comprising a refrigerant circulation type cooling mechanism that cools the tip portion by circulating the refrigerant through the first flow path and the second flow path. Can be provided.

According to a preferred aspect of the present invention, the pump is disposed in the operation unit,
It is desirable that the flow rate measuring mechanism is the internal circulation type heat exchange mechanism disposed in the shaft portion.

According to a preferred aspect of the present invention, the pump is disposed in the external device section,
It is desirable that the flow rate measurement mechanism is the external circulation type heat exchange mechanism disposed in the external device, the operation unit, or the shaft unit.

According to a preferred aspect of the present invention, the first flow path and the second flow path are constituted by tubes,
Further, the flow rate measuring mechanism is coupled at a hollow heat transfer block, a heater coupled to the heat transfer block, a thermocouple coupled to the heat transfer block, and a hollow portion of the heat transfer block. It is desirable that the tube to be configured is thermally coupled.

  According to a preferred aspect of the present invention, the control means drives the pump so that the refrigerant has a desired flow rate based on the flow rate of the refrigerant measured by the internal circulation type heat exchange mechanism. It is desirable to change the conditions.

  According to a preferred aspect of the present invention, the control means stops driving the pump in response to detection of a state where the flow rate of the refrigerant measured by the flow rate measurement mechanism is substantially zero, and the tip portion It is desirable to drive the image sensor provided in the apparatus with low power.

  The endoscope cooling apparatus according to the present invention monitors the state of the cooling mechanism using the flow rate of the refrigerant and feeds back to the pump, so that it is possible to stably control the cooling of the endoscope distal end member.

It is a figure showing a schematic structure of an endoscope system provided with an endoscope cooling device concerning a 1st embodiment. It is a figure which shows the structure of the endoscope cooling device which concerns on 1st Embodiment. It is a figure which shows the structure of the flow volume measuring mechanism in 1st Embodiment. It is a functional block diagram explaining a flow measurement mechanism. It is a figure explaining control of a pump. It is a figure explaining operation | movement of an endoscope cooling device. It is a figure explaining the structure of a control mechanism. It is a figure which shows the structure of the endoscope cooling device which concerns on 2nd Embodiment.

  Hereinafter, the effect by the structure of the endoscope cooling device of embodiment is demonstrated. In addition, this invention is not limited by this embodiment. That is, in describing the embodiment, a lot of specific details are included for the purpose of illustration, but various variations and modifications may be added to these details without exceeding the scope of the present invention. Accordingly, the exemplary embodiments of the present invention described below are set forth without loss of generality or limitation to the claimed invention.

(First embodiment)
FIG. 1 is a diagram showing a configuration of an endoscope cooling apparatus according to the first embodiment of the present invention. The entire endoscope system will be described with reference to FIG. An endoscope system is an observation apparatus that observes the inside of a subject.

  The endoscope 1 is a device having means for entering the body of a subject and acquiring in-vivo images, living cells, and treatment. The endoscope operation unit 2 is a member in which a mechanism that is held by a user of an endoscope and operates the direction of the endoscope tip is arranged.

  The universal cord 3, the light source device 4, the video processor 5, and the monitor 6 are electrically and mechanically connected to the endoscope 1 and play various roles. The universal cord 3 is a cord for connecting the endoscope operation unit 2 and the light source device 4. The universal cord 3 is a member in which a large number of wirings for electrical and mechanical connection are arranged. The light source device 4 is a device that drives light emitted from the endoscope tip. The video processor 5 performs processing of images sent from the endoscope 1 and synchronization and processing of each circuit. The monitor 6 outputs and displays an image from the endoscope 1.

  FIG. 2 is a diagram illustrating a configuration of an endoscope cooling device in the endoscope system. The refrigerant circulation cooling mechanism 7 of the endoscope according to the present embodiment will be described with reference to FIG. The endoscope 1 includes a rigid distal end portion 8, a shaft portion 9, an operation portion 10, and an external device 11 (details not shown). The distal end portion 8 is the most advanced portion when introduced into the body, and an electrical member such as an image sensor is incorporated therein. The member in which the electric member is disposed is referred to as an endoscope tip member 12.

  The endoscope distal end member 12 is thermally joined to the electric member. For this reason, when heat is generated with the driving of the electric member, heat transfer occurs and the temperature of the endoscope distal end member 12 rises. In this embodiment, it has the structure which cools the endoscope front end member 12 whose temperature rose. The heat exchange mechanism 13 is fitted to the endoscope distal end member 12 and has a hollow structure through which the refrigerant passes.

  The heat exchange mechanism 13 is made of a material having high thermal conductivity such as metal. When the refrigerant 14 passes through the heat exchange mechanism 13, heat exchange occurs between the endoscope tip member 12 and the refrigerant 14, and the temperature of the endoscope tip member 12 decreases. At this time, it is desirable that the refrigerant 14 is a liquid from the viewpoint of heat exchange efficiency, that is, the refrigerant is a coolant. Hereinafter, the refrigerant 14 will be described by taking a liquid as an example.

  Next, the circulation of the refrigerant 14 will be described. The refrigerant 14 is filled and sealed in the refrigerant circulation cooling mechanism 7. The pump 50 has a role of applying pressure to the refrigerant 14 and sending it out.

  The refrigerant 14 sent out by the pump 50 includes a pump 50, a first tube (first flow path) 15, a heat exchange mechanism 13, a tube (second flow path) 16, a flow rate measurement mechanism 18, a tube (first flow path). 2) and the pump 50 circulate in this order.

  In this order, the refrigerant 14 circulates, the heat is exchanged, and the temperature of the refrigerant 14 whose temperature has risen is measured before the pump 50 and returns to the pump 50 again.

In other words, the endoscope cooling apparatus includes the operation unit 10, the shaft unit 9, the distal end unit 8, and the external device 11.
The tip 8 is provided with a heat exchange mechanism 13 that performs heat exchange.
A tube 15 that is a first flow path for flowing the refrigerant from the pump 50 toward the heat exchange mechanism 13;
Tubes 16 and 17 that are second flow paths for flowing the refrigerant from the heat exchange mechanism 13 toward the pump 50 are provided.
The flow rate measuring mechanism 18 is provided at any position of the tubes 16 and 17 which are the second flow paths between the heat exchange mechanism 13 and the pump 50, and measures the flow rate of the refrigerant.
The control means described later controls the pump 50 according to the output of the flow rate measuring mechanism 18.
In this way, a refrigerant circulation type cooling mechanism for cooling the tip 8 is obtained by circulating the refrigerant through the tube 15 as the first flow path and the tubes 16 and 17 as the second flow paths. Configure.

  The tubes 16 and 17 are tubes having an inner diameter of about several hundred μm. When the refrigerant 14 passes through the tubes 16 and 17, heat exchange with air outside the tubes is performed. Therefore, the refrigerant 14 whose temperature has been raised by the heat exchange mechanism 13 is heat-exchanged with the air outside the tubes 16 and 17 before returning to the pump 50, and the temperature is lowered to the environmental temperature. The refrigerant 14 is sent out from the pump 50 to cool the endoscope distal end member 12 and the temperature rises. However, in the cycle of liquid cooling in which the temperature reaches the environmental temperature during the course of flowing through the tubes 16 and 17 and returns to the pump 50. is there.

  FIG. 3 is a diagram showing a schematic configuration of the flow rate measuring mechanism 18. The flow rate measuring mechanism 18 will be described with reference to FIG. The flow rate measuring mechanism 18 includes a tube 16, a tube 17, a heat transfer block 19, a heater 20, and a thermocouple 21. The heat transfer block 19 can be composed of a metal block.

  Two electric wires are connected to each of the heater 20 and the thermocouple 21. The two electric wires are a heater electric wire 22, a heater electric wire 23, a thermocouple electric wire 24, and a thermocouple electric wire 25. The flow rate is measured by measuring the temperature of the heat transfer block 19 with the thermocouple 21.

  Details of the flow rate measurement will be described below. The heater 20, the thermocouple 21, the tube 16, and the tube 17 are in contact with and bonded to the heat transfer block 19, respectively. The heater 20 is, for example, a resistance heating type heater.

  When power is turned on, the heater 20 generates heat and transfers heat to the heat transfer block 19. Both the heat transfer block 19 and the heater 20 are formed of members having a size of about several mm. When the temperature of the heater 20 rises and the temperature is saturated, the heat transfer block 19 and the members connected to the heat transfer block 19 are almost free from temperature gradient and saturated at a constant temperature.

  When the refrigerant 14 passes through the heat transfer block 19 in this state, heat exchange occurs. Thereby, the temperature of the heat transfer block 19 is lowered. At this time, the flow rate can be calculated from the input power to the heater 20 and the temperature drop of the heat transfer block 19. The heat transfer block 19 is preferably made of a metal having a high thermal conductivity.

  The calculation formula of the refrigerant flow rate is shown below. With the refrigerant 14 flowing, the heat generation amount P of the heater 20 is controlled so that the temperature difference between the environmental temperature and the heat transfer block 19 becomes a predetermined value. The flow rate F is uniquely determined by the calorific value P.

The flow rate F and the calorific value P can be approximated by the following equations within a practical range.
F = a × P ² + b × P + c (a, b, and c are constants)

The constants a, b, and c do not change if the environment is the same. Once a, b, and c are calculated once in the endoscope environment, the calculation formula can be used without change thereafter.
It is desirable that the flow rate measuring mechanism 18 is disposed immediately behind the operation unit 10 behind the shaft portion 9 in the longitudinal direction of the endoscope. As described above, the refrigerant 14 reaches the ambient temperature as it circulates, but immediately after passing through the flow rate measuring mechanism 18, the temperature rises. If it passes through the endoscope distal end member 12 in this state, the temperature of the endoscope distal end member 12 may be increased. Therefore, it is desirable to arrange the flow rate measuring mechanism 18 in the shaft portion 9 and at a position away from the endoscope distal end member 12.

  This configuration has two advantages. The first advantage is that since the flow rate measuring mechanism 18 can be introduced into a portion having a relatively large space such as the shaft portion 9 and the operation portion 10, an increase in the size of the endoscope tip can be avoided. The second advantage is that the airtightness of the cooling system can be maintained.

  The first advantage will be described. In the refrigerant circulation type cooling mechanism 7, the refrigerant 14 is sealed. For this reason, the state of the internal refrigerant 14 cannot be confirmed. In order to know the state of the refrigerant 14, it is necessary to introduce a pressure sensor and measure the pressure, or measure the temperature of the endoscope tip member 12 to predict the flow rate.

  However, the introduction of the pressure sensor increases the size of the endoscope itself due to the large size of the sensor. A number of members are arranged at the distal end of the endoscope in the portion where the refrigerant circulation type cooling mechanism 7 is arranged. For this reason, since introduction of a temperature measuring mechanism is likely to lead to an increase in size, it is not desirable.

  In the configuration of the present embodiment, the position where the flow rate measurement mechanism 18 is disposed is not limited to the distal end of the endoscope. Therefore, it becomes possible to arrange the flow rate measuring mechanism 18 in the shaft portion 9 or the operation portion 10 having a sufficient space. As a result, an increase in the size of the endoscope tip can be avoided.

  The configuration of the refrigerant circulation cooling mechanism 7 described above can be referred to as an internal circulation cooling mechanism 26. In this configuration, since the circulation type configuration of the refrigerant is all disposed closer to the endoscope tip side than the operation unit 10, the flow path is not exposed to the environment in the human body, and there is no need for disinfection and sterilization. Therefore, the maintenance of the refrigerant circulation type cooling mechanism 7 becomes free and the burden on the user can be reduced.

  The second advantage will be described. In the refrigerant circulation type cooling mechanism 7, the refrigerant 14 is enclosed inside, but the refrigerant 14 may leak or volatilize over time. What is important is to reduce the number of members constituting the refrigerant circulation type cooling mechanism 7 and its connecting portions and prevent the refrigerant 14 from decreasing. Therefore, it is not desirable to provide a mechanism for measuring the flow rate in the middle of the flow path of the refrigerant circulation type cooling mechanism 7. In the configuration of the present application, since a flow rate measuring mechanism is attached to the outer periphery of the flow path, the state of the refrigerant 14 can be confirmed without increasing the number of connecting portions. That is, the flow rate measuring mechanism 18 can prevent the refrigerant 14 from decreasing.

  With the above configuration, the flow rate of the refrigerant 14 can be measured, the flow rate is controlled, and it is possible to avoid applying an excessive pressure. As a result, the life of the refrigerant circulation cooling mechanism 7 can be extended. Further, it is possible to prevent overheating of the endoscope tip by detecting an abnormality in the refrigerant circulation cooling mechanism 7 and stopping the pump drive and driving the electric element in the endoscope tip member with low power.

  FIG. 4 shows a functional block diagram of the flow rate measuring mechanism. The data measured with the thermocouple 21 is a voltage value. For this reason, in order to calculate as temperature, the measurement temperature calculation part 28 calculates. The temperature comparison unit 29 compares the temperature calculated here with the temperature of the target temperature storage unit (memory) 30. The comparison result at this time determines whether the heater power is to be increased, decreased or made constant.

  For example, when the calculated temperature is lower than the target temperature, the heater power control unit 31 determines to increase the power, and the heater power generation unit 32 sets the power higher to generate the power. The flow rate calculation unit 33 calculates the flow rate from the power value generated by the heater power generation unit 32. The greater the flow rate, the greater the input power.

  The pump drive feedback will be described with reference to FIG. The flow rate comparison unit 34 compares the flow rate measured by the flow rate measurement mechanism 18 with the value stored in the target flow rate storage unit 35. Whether to change the driving condition of the pump 50 is determined based on the comparison result at this time.

For example, when the flow rate measured by the flow rate measurement mechanism 18 is smaller than the value stored in the target flow rate storage unit 35, the pump voltage control unit 36 determines to increase the pump voltage. Then, the pump voltage generator 37 sets a high voltage to generate the voltage to drive the pump 50.
The flow rate comparison unit 34, the target flow rate storage unit 35, the pump voltage control unit 36, and the pump voltage generation unit 37 constitute a control means 41.

  When the pump 50 is driven for a long time, the flow rate increases and decreases, and the actual flow rate may differ from the desired flow rate. In the present embodiment, since the flow rate is measured, the necessary flow rate can be flowed.

  Further, when the flow rate increases or decreases, the pressure also increases or decreases, and an excessive pressure may be applied to the flow path. If excessive pressure is applied with respect to the flow rate, the circulation mechanism may be damaged, and the life of the circulation mechanism may be shortened.

  According to this embodiment, it is possible to control the flow rate of the refrigerant 14 and avoid applying more pressure than necessary. For this reason, the lifetime of the refrigerant circulation cooling mechanism 7 can be extended.

  FIG. 6 is a flowchart illustrating the flow of operation control according to this embodiment. An image sensor driving condition change when the refrigerant circulation cooling mechanism 7 of the embodiment fails will be described with reference to FIGS. 5 and 6.

  If the pump 50 fails for some reason, it is conceivable that the flow rate of the refrigerant 14 becomes zero. At this time, if the driving of the pump 50 is continued in a state where the flow rate of the refrigerant 14 becomes zero, there is a possibility that another pump abnormality or a failure of peripheral devices may be caused. Therefore, in such a case, the pump 50 is stopped by the following procedure.

First, the operation of the refrigerant circulation cooling mechanism 7 is started.
In step S71, the pump 50 is driven.
In step S72, the flow rate measuring mechanism 18 determines whether or not the flow rate is zero.
When the determination result in step S72 is negative (No), that is, when the flow rate is not 0, the flow rate determination is performed again in step S72 in the next cycle.
When the determination result of step S72 is affirmative (Yes), that is, when the flow rate is 0, the process proceeds to step S73.

In step S73, the driving of the pump 50 is completely stopped. Thereby, it can prevent that the pump 50 and its peripheral member deteriorate further.
In step S74, the image sensor 40 is further driven under low power conditions. When driving of the pump 50 stops, cooling of the endoscope tip stops. For this reason, the temperature of the tip rises. By driving the image sensor 40 under a low power condition, the endoscope tip is prevented from becoming high temperature.

  In this manner, when the flow rate of the refrigerant 14 becomes 0, appropriate control of the pump 50 and the image sensor 40 is performed, so that overheating of the endoscope tip can be prevented.

  FIG. 7 is a functional block diagram for explaining the control mechanism for the flow rate measuring mechanism 18, the pump 50, and the image sensor 40. In order to change the driving conditions of the image sensor 40, first, the image sensor voltage adjustment unit 38 determines the input power value for driving the image sensor 40 at low power. Next, the voltage generated by the image sensor voltage generator 39 is applied to the image sensor 40. In addition, when the driving of the pump 50 is changed, first, the voltage to be applied to the pump 50 is determined by the pump voltage control unit 36. Then, a voltage is applied to the pump 50 via the pump voltage generator 37.

(Second Embodiment)
Next, an endoscope cooling apparatus according to the second embodiment will be described. FIG. 8 is a diagram illustrating a schematic configuration of the endoscope cooling apparatus according to the present embodiment. This embodiment differs from the first embodiment described above in that the pump 50 is arranged in an external device.

  The external circulation type refrigerant circulation cooling mechanism 27 will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. In particular, the description of the shaft portion 9 and the operation portion 10 among the tip portion 8, the shaft portion 9, the operation portion 10, and the external device 11 is omitted.

  An advantage of configuring the refrigerant circulation type cooling mechanism 27 as an external circulation type is that the pump 50 can be disposed in the optical device 4 where there is a space with a sufficient space. Thereby, a large pump with a high discharge pressure can be arranged as the pump 50. As a result, the cooling performance can be improved.

  At this time, the flow rate measuring mechanism 18 can be disposed in a place other than the tip 8 and in the tubes 16 and 17 which are the second flow paths.

  Although not shown, a mechanism for storing the refrigerant 14 such as a pump / reservoir may be provided. When the pump / reservoir is provided, a large amount of the refrigerant 14 can be stored. For this reason, it becomes possible to select a refrigerant having relatively high volatility and high cooling performance. For this reason, cooling performance can be improved.

  With the above configuration, the flow rate in the refrigerant circulation cooling mechanism 27 can be measured and controlled, and a large cooling performance can be obtained. Therefore, it becomes possible to use a high-performance electric element that requires high power at the distal end of the endoscope, and the function of the endoscope can be enhanced.

  As described above, the endoscope cooling apparatus according to the present invention is useful for stable control of the refrigerant circulation type cooling mechanism, and is particularly suitable for an endoscope cooling apparatus that is required to be downsized.

DESCRIPTION OF SYMBOLS 1 Endoscope 2 Endoscope operation part 3 Universal code 4 Light source device 5 Video processor 6 Monitor 7 Refrigerant circulation type cooling device 8 Tip part 9 Shaft part 10 Operation part 11 External apparatus 12 End-of-endoscope part 13 Heat exchange mechanism 14 Refrigerant 15, 16, 17 Tube 18 Flow rate measuring mechanism 19 Heat transfer block 20 Heater 21 Thermocouple 22, 23 Heater electrical wiring 24, 25 Thermocouple electrical wiring 26 Internal circulation cooling mechanism 27 External circulation cooling mechanism 28 Actual temperature calculation unit DESCRIPTION OF SYMBOLS 29 Temperature comparison part 30 Target temperature storage part 31 Heater power control part 32 Heater power generation part 33 Flow rate calculation part 34 Flow rate comparison part 35 Target flow rate storage part 36 Pump voltage control part 37 Pump voltage generation part 38 Image pick-up element voltage adjustment part 39 Imaging Element voltage generator 40 Image sensor 41 Control means 50 Pump

Claims (6)

An endoscope cooling device having an operation part, a shaft part, a tip part, and an external device,
A heat exchange mechanism for exchanging heat at the tip,
A pump for delivering refrigerant;
A first flow path for flowing the refrigerant from the pump toward the heat exchange mechanism;
A second flow path for flowing the refrigerant from the heat exchange mechanism toward the pump;
A flow rate measuring mechanism that is provided at any position of the second flow path between the heat exchange mechanism and the pump and measures the flow rate of the refrigerant;
Control means for controlling the pump according to the output of the flow rate measuring mechanism;
Have
An endoscope cooling apparatus comprising a refrigerant circulation type cooling mechanism that cools the tip portion by circulating the refrigerant through the first flow path and the second flow path. The pump is disposed in the operation unit,
The endoscope cooling apparatus according to claim 1, wherein the flow rate measurement mechanism is an internal circulation type heat exchange mechanism disposed in the shaft portion. The pump is disposed in the external device unit,
The endoscope cooling apparatus according to claim 1, wherein the flow rate measuring mechanism is the external circulation type heat exchange mechanism disposed in the external device, the operation unit, or the shaft portion. The first flow path and the second flow path are configured by tubes,
Further, the flow rate measuring mechanism is coupled at a hollow heat transfer block, a heater coupled to the heat transfer block, a thermocouple coupled to the heat transfer block, and a hollow portion of the heat transfer block. The endoscope cooling apparatus according to any one of claims 1 to 3, wherein the tube is configured to be thermally coupled.   The said control means changes the drive condition of the said pump so that the said refrigerant | coolant may become a desired flow volume based on the flow volume of the said refrigerant | coolant measured with the said internal circulation type heat exchange mechanism. 4. The endoscope cooling apparatus according to 4. The control means stops driving the pump in response to detection of a state in which the flow rate of the refrigerant measured by the flow rate measurement mechanism is substantially zero, and causes the imaging device provided at the tip end portion to operate at low power The endoscope cooling apparatus according to claim 5, wherein the endoscope cooling apparatus is driven.

Images