Photodynamic therapy device with cooling water circulation for blood

Abstract

To provide a photodynamic therapy device capable of suppressing temperature rise of blood in PDT therapy.SOLUTION: Provided is a photodynamic therapy device for radiating a light beam from a light source to blood which is extracted to outside of the body of a patient, flows in a blood tube, and absorbs a photoreaction agent, and breaking an undesired component in the blood or applying an affection to the component. The photodynamic therapy device comprises: a radiation unit comprising a light source, and radiating the light beam to the blood in the blood tube; and a circuit cooling block for cooling the blood in the blood tube. The circuit cooling block is coupled to a pump for circulating cooling water into the circuit cooling block, a reservoir tank, and a cooling part for cooling water, by a water channel for flowing the cooling water.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present disclosure relates to a photodynamic therapy device with a cooling water circuit for blood. [Background technology]

[0002] In photodynamic therapy (PDT), blood that has absorbed a photoreactive agent with a characteristic light absorption band is temporarily removed from the patient's body and irradiated with light corresponding to the characteristic light absorption band, thereby destroying or affecting undesirable components in the blood. For example, an LED is used as a light source for the irradiating light.

[0003] However, when the LED light used in the PDT treatment is irradiated onto blood removed from the patient's body, the blood generates heat and its temperature rises. This increase in blood temperature can place a strain on the patient's body when the blood is returned. Furthermore, the increase in temperature can have a negative effect on the blood itself. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 164202 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a photodynamic therapy device that suppresses blood temperature rise during PDT therapy. [Means for solving the problem]

[0006] The photodynamic therapy device disclosed herein is a photodynamic therapy device that irradiates light from a light source onto blood that has absorbed a photoreactive agent and is flowing outside the patient's body in a blood tube, thereby destroying or affecting undesirable components in the blood. an irradiation unit including a light source for irradiating light onto the blood in the blood tube; and a circuit cooling block for cooling the blood in the blood tube. The circuit cooling block is connected to a pump for circulating cooling water within the circuit cooling block, a reservoir tank, and a cooling unit for cooling the water, by a water flow path through which the cooling water flows. [Effects of the Invention]

[0007] The photodynamic therapy device of the present disclosure suppresses temperature rise caused by heat generation in the blood due to absorption of irradiated light. [Brief explanation of the drawings]

[0008] [Figure 1A] FIG. 1 is a front view of a photodynamic therapy device according to an embodiment of the present disclosure. [Figure 1B] 1 is a rear perspective view of a photodynamic therapy device according to an embodiment. FIG. [Figure 2A] 1 is a perspective view of a circuit holder, a circuit cooling block, and an irradiation unit in a photodynamic therapy device according to an embodiment, in which the arrangement of the irradiation unit, the circuit holder, and the circuit cooling block is that when light intensity is monitored. [Figure 2B] 1 is a perspective view of a circuit holder, a circuit cooling block, and an irradiation unit in a photodynamic therapy device according to an embodiment, in which the irradiation unit, the circuit holder, and the circuit cooling block are arranged as they are during treatment. [Figure 3A] 1 is a perspective view of a circuit holder and a circuit cooling block in a photodynamic therapy device according to an embodiment, viewed from approximately the front. [Figure 3B] 1 is a perspective view of a circuit holder and a circuit cooling block in a photodynamic therapy device according to an embodiment. FIG. [Figure 4A] 1 is a perspective view of a circuit holder in a photodynamic therapy device according to an embodiment. FIG. [Figure 4B] 1 is a bottom perspective view of a circuit holder in a photodynamic therapy device according to an embodiment. FIG. [Figure 4C] 1 is an exploded perspective view of a circuit holder in a photodynamic therapy device according to an embodiment. FIG. [Figure 5] 1 is a perspective view of a photodynamic therapy device according to an embodiment, showing a state in which a blood tube is wound around inside a circuit holder. FIG. [Figure 6A] 1 is a perspective view of a circuit cooling block in a photodynamic therapy device according to an embodiment. FIG. [Figure 6B] 6B is a partial cross-sectional view of the circuit cooling block taken along a horizontal plane including line IB-IB in FIG. 6A. [Figure 7] FIG. 1 is a perspective view of a circuit cooling sub-block that constitutes a circuit cooling block in a photodynamic therapy device according to an embodiment, showing pipes through which cooling water flows. [Figure 8] 1 is a schematic diagram of a cooling water circulator connected to a photodynamic therapy device according to an embodiment, in which the cooling water circulator is in a state ready for treatment. [Figure 9] 1 is a schematic diagram of a cooling water circulator connected to a photodynamic therapy device according to an embodiment, in which the cooling water circulator is in a state during treatment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of well-known matters or redundant explanation of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0010] The inventor(s) provide the accompanying drawings and the following description to enable those skilled in the art to fully understand the present disclosure, and do not intend for them to limit the subject matter described in the claims.

[0011] 1. [Background to this disclosure] Photodynamic therapy (PDT) is a treatment method that involves administering a photosensitive substance or its precursor, allowing it to accumulate in affected areas such as tumor tissue, neovascularization, or the skin surface, and then irradiating it with light corresponding to the absorption band wavelength of the photosensitive substance as excitation light, thereby utilizing the cell-killing effects of reactive oxygen species, including singlet oxygen, generated by the excitation.

[0012] For example, in photodynamic therapy, a patient with hematological cancer is first administered orally absorbed 5-aminolevulinic acid (5-ALA). During heme biosynthesis in intracellular mitochondria, 5-ALA is metabolized into the photosensitizer protoporphyrin IX (PpIX). Because PpIX accumulates specifically in mitochondria, it accumulates in the patient's tumor cells.

[0013] Next, in photodynamic therapy, the patient's circulatory system is connected to an irradiation device for photodynamic therapy via a blood circuit for blood flow. The patient's blood contains tumor cells in which protoporphyrin IX has accumulated, and the blood flows into the irradiation device via the blood circuit by the action of a circulation pump connected to the blood circuit for blood flow. When the irradiation device irradiates the blood with light in a wavelength range that protoporphyrin IX can absorb (e.g., around 410 nm, around 500 to 650 nm), the protoporphyrin IX contained in the blood enters an excited singlet state. Protoporphyrin IX returns from the excited singlet state to the excited triplet state and then to the ground state. Oxygen absorbing the energy becomes singlet oxygen, which can destroy or affect tumor cells in the blood. The light-irradiated blood is returned to the patient's circulatory system via the blood circuit for blood flow by the action of the circulation pump.

[0014] The blood circuit is connected to a translucent blood tube made of a specific resin in the irradiation device. The blood tube, through which blood flows, is irradiated with light corresponding to the absorption band wavelength of the photosensitizer protoporphyrin IX, for example, from an LED light source. The inventors realized that the blood may heat up due to absorption of the irradiated light, thereby increasing its temperature. To achieve sufficient effectiveness of photodynamic therapy, particularly within a treatment time (e.g., three hours) that does not significantly impact the patient's physical strength, the light source's illuminance must be increased accordingly. In this case, the inventors' calculations and experiments indicated that the blood temperature could reach 60°C. An increase in blood temperature places a strain on the patient's body due to the high temperature to which the blood is returned. Furthermore, the increase in temperature adversely affects the blood itself.

[0015] The inventors have found through numerous trials and calculations that it is desirable that the temperature of the blood that can be increased by the irradiation device be at most 40° C. or less.

[0016] The present disclosure overcomes these problems and provides a photodynamic therapy device that suppresses the rise in blood temperature caused by irradiated light during photodynamic therapy.

[0017] 2. [Embodiment] Preferred embodiments of the present disclosure will now be described with reference to the accompanying drawings.

[0018] 2.1. [Configuration of photodynamic therapy device] First, the configuration of a photodynamic therapy device according to an embodiment will be described.

[0019] 2.1.1. [Outline of photodynamic therapy device] Figure 1A is a front view of a photodynamic therapy device 2 according to an embodiment, and Figure 1B is a rear perspective view of the photodynamic therapy device 2 according to the same embodiment.

[0020] As shown in FIG. 1A, the photodynamic therapy device 2 includes a circuit cooling block 6 and an irradiation unit 4.

[0021] The circuit cooling block 6 is made of a predetermined material and, as will be described later, is inserted into the circuit holder 22 (see FIGS. 3A, 3B, etc.) containing the blood tube 34 (see FIGS. 5 and 9) that connects to (i.e., forms part of) the blood circuit for blood flow. The circuit cooling block 6 comes into contact with the inner surface of the circuit holder 22 to cool the blood tube 34 and the blood. The material forming the circuit cooling block 6 is preferably a metal with high thermal conductivity, such as aluminum. The irradiation unit 4 irradiates the blood tube and blood in the circuit holder 22 with light corresponding to a characteristic light absorption band. The irradiation unit 4 includes a light source (not shown) comprised of multiple light-emitting elements (e.g., LEDs) and a light detection unit (not shown) comprised of photodetectors. The multiple light-emitting elements that make up the light source are arranged, for example, in a matrix pattern on the inside of a pair of opposing, wider side surfaces (see FIGS. 2A and 2B) of the irradiation unit 4. The light detection units are arranged, for example, on the inside of the top surface and the inside of the bottom surface of the irradiation unit 4.

[0022] The photodynamic therapy device 2 shown in Fig. 1A is further provided with a lower housing 8. The lower housing 8 houses a cooling unit 16, a first valve 14a, a second valve 14b, a reservoir tank 18, and a pump 20, which constitute a cooling water circulation unit described later with reference to Figs.

[0023] In the photodynamic therapy device 2 shown in FIGS. 1A and 1B, valve opening and closing operations, which will be described later, are performed via operations on an operating unit 5 provided on the top.

[0024] 2.1.2. [Configuration of the circuit holder, circuit cooling block, and irradiation unit] 2A is a perspective view of the circuit holder 22, the circuit cooling block 6, and the irradiation unit 4 in the photodynamic therapy device 2 according to the embodiment. As shown in FIG. 2A, the circuit cooling block 6 is inserted into the circuit holder 22. The irradiation unit 4 is configured to be movable relative to the circuit holder 22 and the circuit cooling block 6. In the configuration shown in FIGS. 2A and 2B, the irradiation unit 4 can move relative to the fixed circuit cooling block 6. When the circuit holder 22 and the circuit cooling block 6 are separated from the irradiation unit 4, the irradiation unit 4 monitors the light intensity using a light source and a light detection unit.

[0025] 2B is also a perspective view of the circuit holder 22, the circuit cooling block 6, and the irradiation unit 4. The irradiation unit 4 moves relative to the circuit holder 22 and the circuit cooling block 6, so that the circuit holder 22 and the circuit cooling block 6 are housed inside the irradiation unit 4. At this time, the pair of left and right light sources inside the irradiation unit 4 are arranged opposite to a pair of side surfaces of the circuit holder 22. The pair of left and right light sources of the irradiation unit 4 are arranged opposite to a pair of side surfaces of the circuit holder 22, and treatment is performed by light irradiation from the irradiation unit 4.

[0026] 2.1.3. [Circuit holder and circuit cooling block configuration] Fig. 3A is a perspective view, seen from approximately the front, of the circuit holder 22 and the circuit cooling block 6 in the photodynamic therapy device 2 according to the embodiment, in a separated state. Fig. 3B is also a perspective view of the circuit holder 22 and the circuit cooling block 6 in the photodynamic therapy device 2 according to the embodiment, in a separated state.

[0027] 4A is a perspective view of the circuit holder 22 in the photodynamic therapy device 2 according to the embodiment, and FIG. 4B is a perspective view from the bottom of the circuit holder 22 in the photodynamic therapy device 2 according to the embodiment. In particular, as shown in FIG. 4B, the inside of the circuit holder 22 is hollow, and the circuit cooling block 6 is inserted into this hollow portion and comes into contact with the inner surface of the circuit holder 22.

[0028] 4C is a perspective view of the circuit holder 22 in the photodynamic therapy device 2 according to the embodiment in an exploded state. As shown in FIG. 4C, the circuit holder 22 has a combined structure of four types of molded parts and two aluminum metal sheets 24. The four types of molded parts are a circuit holder center part 30, two circuit holder end parts 28, two circuit holder side parts 26, and a circuit holder top part 32.

[0029] 4C omits blood tube 34, which is connected to (i.e., forms part of) the blood circuit for flowing blood. Inside circuit holder 22, blood tube 34 is wound around winding core 33, which is composed of two aluminum metal sheets 24, circuit holder center 30, two circuit holder end portions 28, and circuit holder upper surface portion 32 (see FIG. 5). To ensure that blood tube 34 is wound around winding core 33 in an orderly manner, aluminum metal sheets 24, circuit holder center 30, and circuit holder end portions 28 are appropriately provided with guides for winding blood tube 34.

[0030] The two circuit holder side portions 26 are formed from a thin plate of transparent resin, for example, a thin plate of polycarbonate, so that the light emitted from the light source of the irradiation unit 4 can reach the blood tube 34 and the blood flowing therein. As shown in the circuit holder side portion 26 in Fig. 4C, lateral guides 25 for circulating the blood tube 34 are also appropriately provided on the inside of the circuit holder side portion 26.

[0031] Additionally, many thin vertical ribs 27 are provided on the inside of the circuit holder side surface 26. These many vertical ribs 27 improve the adhesion of the blood tube 34 to the aluminum sheet metal 24.

[0032] Most of blood tube 34 wound around winding core 33 of circuit holder 22 is sandwiched between circuit holder side surface 26, which transmits the light irradiated from the light source of irradiation unit 4, and aluminum sheet metal 24, which is cooled by direct contact with circuit cooling block 6. Fig. 5 is a perspective view of blood tube 34 wound around winding core 33 in circuit holder 22 of photodynamic therapy device 2 according to the embodiment.

[0033] A transparent thin film cover may be provided between circuit holder side surface portion 26 and blood tube 34, or circuit holder side surface portion 26 and blood tube 34 may be in direct contact with each other without anything sandwiched between them. A transparent thin film cover may also be provided between aluminum sheet metal 24 and blood tube 34, or aluminum sheet metal 24 and blood tube 34 may be in direct contact with each other without anything sandwiched between them.

[0034] 2.1.4. [Circuit cooling block configuration] FIG. 6A is a perspective view of the circuit cooling block 6 in the photodynamic therapy device 2 according to the embodiment. The circuit cooling block 6 is composed of four circuit cooling sub-blocks (6f, 6s) and a base portion 6b on which the circuit cooling sub-blocks (6f, 6s) are mounted. The four circuit cooling sub-blocks (6f, 6s) are composed of two fixed circuit cooling sub-blocks 6f and two sliding circuit cooling sub-blocks 6s. The terms "fixed" and "sliding" will be explained later. The four circuit cooling sub-blocks (6f, 6s) may have substantially the same structure. Furthermore, it is preferable that the circuit cooling sub-blocks (6f, 6s) are made of aluminum. The number of circuit cooling sub-blocks (6f, 6s) may be more than four.

[0035] 7 is a perspective view of the circuit cooling sub-blocks (6f, 6s) constituting the circuit cooling block 6 in the photodynamic therapy device 2 according to the embodiment, showing the pipes 40 through which the cooling water flows. The cooling water flows in from the base 6b, flows through the pipes 40 arranged vertically and horizontally inside the circuit cooling sub-blocks (6f, 6s), and flows out to the base 6b. The pipes 40 inside the circuit cooling sub-blocks (6f, 6s) and the base 6b form part of the water flow path 12 (see FIGS. 8 and 9) of the cooling water circulation unit, which will be described later.

[0036] FIG. 6B is a partial cross-sectional view of the circuit cooling block 6 taken along a horizontal plane including line IB-IB in FIG. 6A. One of the circuit cooling sub-blocks constituting the circuit cooling block 6 is a fixed type (fixed circuit cooling sub-block 6f). The other circuit cooling sub-block is a sliding type (sliding circuit cooling sub-block 6s). As shown in FIG. 6B, an elastic body 10 is sandwiched between the fixed circuit cooling sub-block 6f and the sliding circuit cooling sub-block 6s, which are arranged opposite each other, and engages with each recess. In the circuit cooling block 6 shown in FIG. 6B, a spring is used as an example of the elastic body 10.

[0037] A shaft 11 passes through the elastic body 10. This shaft 11 is configured to be fixed to the sliding circuit cooling sub-block 6s and to be slidable relative to the fixed circuit cooling sub-block 6f. This allows the sliding circuit cooling sub-block 6s to slide relative to the fixed circuit cooling sub-block 6f while accurately maintaining a parallel positional relationship between the fixed circuit cooling sub-block 6f and the sliding circuit cooling sub-block 6s. The shaft 11 may be configured to be fixed to the fixed circuit cooling sub-block 6f and to be slidable relative to the sliding circuit cooling sub-block 6s.

[0038] A plurality of elastic bodies 10, for example, four elastic bodies 10 are provided in a pair of fixed circuit cooling sub-block 6f and sliding circuit cooling sub-block 6s facing each other.

[0039] As described above, by sandwiching and setting multiple elastic bodies 10, the sliding type circuit cooling sub-block 6s is biased in the direction of arrow A shown in Fig. 6B, i.e., outward. By biasing the sliding type circuit cooling sub-block 6s outward by the elastic bodies 10, when the circuit cooling block 6 is inserted into the circuit holder 22, the circuit cooling sub-blocks (6s, 6f) come into stronger contact with the inner surface of the aluminum sheet metal 24 of the circuit holder 22.

[0040] That is, of the two circuit cooling sub-blocks (6s, 6f) facing each other, one is fixed, and the other is held in a state where a reaction force is applied in the facing direction by an elastic mechanism. This is to improve the adhesion of the circuit cooling sub-blocks (6s, 6f) to the aluminum metal plate 24 of the circuit holder 22. This enhances the cooling effect of the circuit cooling block 6 on the aluminum metal plate 24 of the circuit holder 22, the blood tube 34, and ultimately on the blood in the blood tube 34.

[0041] That is, the temperature of the blood is transferred and exchanged through the blood tube 34, the aluminum metal plate 24, and the circuit cooling block 6, thereby suppressing an increase in the blood temperature.

[0042] In addition, the circuit cooling block 6 may be configured so that both of the two facing circuit cooling sub-blocks are sliding type circuit cooling sub-blocks 6s, and both of these sliding type circuit cooling sub-blocks 6s are biased outward by an elastic mechanism.

[0043] 2.1.5. [Configuration of the cooling water circulation section] 8 and 9 are schematic diagrams showing the configuration of the circuit holder 22 with the blood tube 34 connected to (i.e., forming part of) the blood circuit for blood flow, the circuit cooling block 6, and the cooling water circulator. The cooling water circulator in Fig. 8 is in a state when preparing for treatment. The cooling water circulator in Fig. 9 is in a state when treatment is being performed.

[0044] 8 and 9, the cooling water circulation unit includes a cooling unit 16, a first valve 14a, a second valve 14b, a reservoir tank 18, and a pump 20. The cooling unit 16, the first valve 14a, the circuit cooling block 6, the second valve 14b, the reservoir tank 18, and the pump 20 are connected by a water flow path 12 through which the cooling water flows.

[0045] Although shown at the forefront in Figures 8 and 9 for convenience of drawing and display, the water flow paths 12 are also provided vertically and horizontally inside the circuit cooling block 6 (see Figure 7). The first valve 14a is provided between the cooling section 16 and the circuit cooling block 6, on the upstream side of the circuit cooling block 6. The second valve 14b is provided between the cooling section 16 and the reservoir tank 18, on the upstream side of the reservoir tank 18.

[0046] As shown in Fig. 8, during preparation for treatment, the first valve 14a is closed and the second valve 14b is opened, and the cooling water is short-circuited among the cooling unit 16, the reservoir tank 18, and the pump 20, and does not flow to the circuit cooling block 6. On the other hand, as shown in Fig. 9, during treatment, the first valve 14a is opened and the second valve 14b is closed, and the cooling water circulates through the cooling unit 16, the circuit cooling block 6, the reservoir tank 18, and the pump 20. The opening and closing operations of the first valve 14a and the second valve 14b are performed in accordance with the operation of the operation unit 5.

[0047] The cooling unit 16 is configured to cool the water circulating to the circuit cooling block 6. The cooling unit 16 is configured, for example, by a Peltier element. The cooling unit 16 may be configured as a heat exchanger that cools water, for example, a radiator. The cooling unit 16 may also be a refrigerator such as a circulating constant temperature water bath with a compressor using chlorofluorocarbon gas as a refrigerant. In this case, the cooling unit 16, the reservoir tank 18, and the pump 20 may be configured to be provided in a housing separate from the photodynamic therapy device 2 including the circuit cooling block 6 and the irradiation unit 4. Note that antifreeze may be used as the cooling water to prevent freezing.

[0048] In this embodiment, the cooling unit 16, the first valve 14a and the second valve 14b, the reservoir tank 18, and the pump 20, which constitute the cooling water circulation unit, are housed in the lower housing 8 of the photodynamic therapy device 2 shown in Figures 1A and 1B.

[0049] 2.2. [Operation of the cooling water circulation unit connected to the photodynamic therapy device] Next, the operation of the cooling water circulator connected to the photodynamic therapy device according to the embodiment will be described.

[0050] Referring again to Figure 8, the cooling water circulation unit shown in Figure 8 is in a state during preparation for treatment. During preparation for treatment, the first valve 14a is closed and the second valve 14b is opened by operating the operation unit 5. The cooling water is short-circuited within the cooling unit 16, reservoir tank 18, and pump 20, and does not flow to the circuit cooling block 6.

[0051] In this way, during preparation for treatment, the cooling water is not circulated to the circuit cooling block 6 side, but is short-circuited within the cooling section 16, reservoir tank 18, and pump 20, thereby cooling the cooling water to the target temperature.

[0052] This has two main purposes. The first is to prevent cooled saline from being sent into the patient's body immediately after the start of treatment. In other words, before treatment begins, the blood circuit is initially filled with saline. If the circuit holder 22 including the blood circuit is placed on a sufficiently cooled circuit cooling block 6 at that time, the temperature of the saline in the blood circuit will not increase even when exposed to irradiated light, but will be lowered by the circuit cooling block 6. This prevents the lowered temperature saline from being sent into the patient's body.

[0053] Another purpose is to allow the short circuit to efficiently cool the water during treatment preparation.

[0054] 9, the cooling water circulation unit shown in FIG. 9 is in a state during treatment. During treatment, the first valve 14a is opened and the second valve 14b is closed by operating the operation unit 5. The cooling water circulates through the cooling unit 16, the circuit cooling block 6, the reservoir tank 18, and the pump 20. This suppresses the rise in blood temperature caused by heat generation in the blood due to absorption of irradiated light.

[0055] 2.3. [Summary] The photodynamic therapy device 2 according to this embodiment is a photodynamic therapy device that irradiates light from a light source onto blood that has absorbed a photoreactive agent and is flowing outside the patient's body and inside a blood tube 34, destroying or affecting undesirable components in the blood. The photodynamic therapy device 2 includes an irradiation unit 4 that has a light source and irradiates the blood inside the blood tube 34 with light, and a circuit cooling block 6 that cools the blood inside the blood tube 34. The circuit cooling block 6 is connected to a pump 20 for circulating cooling water inside the circuit cooling block 6, a reservoir tank 18, and a cooling unit 16 that cools the water, via a water flow path 12 through which the cooling water flows.

[0056] By configuring the photodynamic therapy device 2 in this way, a temperature rise caused by heat generation in the blood due to absorption of irradiated light during photodynamic therapy is suppressed.

[0057] 3. [Other embodiments] As described above, the embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to these, and can be applied to embodiments in which appropriate changes, substitutions, additions, omissions, etc. are made.

[0058] As described above, it is required that the temperature of the blood, which may be increased by the irradiation unit 4, be kept below 40°C. Therefore, for example, in the blood circuit, a temperature sensor that detects the temperature of the blood inside the blood tube 34 in real time immediately before returning to the patient's circulatory system may be provided, and a controller that controls the cooling capacity of the cooling unit 16 based on the detected value of the temperature sensor may be provided. That is, if the temperature sensor detects a temperature close to 40°C (e.g., 39°C), the controller that receives the detected value may be configured to increase the current and / or voltage flowing through the Peltier element of the cooling unit 16 to further enhance the cooling capacity. Also, if the temperature sensor detects a temperature lower than normal body temperature (e.g., 34°C), the controller that receives the detected value may be configured to decrease the current and / or voltage flowing through the Peltier element of the cooling unit 16 to further reduce the cooling capacity.

[0059] Furthermore, the accompanying drawings and detailed description are provided to explain the embodiments. Therefore, the components described in the accompanying drawings and detailed description may include not only components essential for solving the problem, but also components that are not essential for solving the problem in order to illustrate the above technology. Therefore, the fact that these non-essential components are described in the accompanying drawings or detailed description should not be interpreted as immediately indicating that these non-essential components are essential.

[0060] Furthermore, since the above-described embodiments are intended to illustrate the technology of the present disclosure, various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents. [Explanation of symbols]

[0061] 2 Photodynamic therapy device, 4 Irradiation unit, 6 Circuit cooling block, 6b Base, 6f Fixed circuit cooling sub-block, 6s Sliding circuit cooling sub-block, 8 Lower housing, 10 Elastic body, 11 Shaft, 12 Water flow path, 14a First valve, 14b Second valve, 16 Cooling section, 18 Reservoir tank, 20 Pump, 22 Circuit holder, 24 Aluminum sheet metal, 25 Guide, 26 Side section of circuit holder, 27 Rib, 28 End section of circuit holder, 30 Center section of circuit holder, 32 Top section of circuit holder, 34 Blood tube, 40 Tube.

Claims

1. A photodynamic therapy device that irradiates light from a light source onto blood that has absorbed a photoreactive agent and is flowing outside a patient's body in a blood tube, thereby destroying or affecting undesirable components in the blood, an irradiation unit that includes the light source and irradiates the blood in the blood tube with light; and a circuit cooling block that cools the blood in the blood tube, The circuit cooling block is connected to a pump for circulating cooling water through the circuit cooling block, a reservoir tank, and a cooling unit for cooling water by a water flow path through which the cooling water flows, Furthermore, a first valve is provided between the cooling unit and the circuit cooling block on the upstream side of the circuit cooling block, and a second valve is provided between the cooling unit and the reservoir tank on the upstream side of the reservoir tank, When preparing for treatment, the first valve is closed and the second valve is opened to short-circuit water in the cooling unit, the reservoir tank, and the pump, During treatment, the first valve is opened and the second valve is closed, thereby circulating water through the cooling unit, the circuit cooling block, the reservoir tank, and the pump. Photodynamic therapy device.

2. Furthermore, 2. The photodynamic therapy device of claim 1, further comprising a circuit holder including the blood tube and a winding core around which the blood tube is arranged, wherein the circuit cooling block cools the blood in the blood tube by contacting an inner surface of the circuit holder.

3. The photodynamic therapy device according to claim 2 , wherein the irradiation unit is configured to be movable relative to the circuit holder and the circuit cooling block.

4. 3. The photodynamic therapy device of claim 2, wherein the circuit cooling block is composed of a plurality of circuit cooling sub-blocks, and one or more elastic bodies are sandwiched between pairs of opposing circuit cooling sub-blocks, and the circuit cooling block is configured to come into stronger contact with the inner surface of the circuit holder by being biased by the one or more elastic bodies.

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