Artery and vein identification device, artery and vein identification method, program, and recording medium

Abstract

An artery and vein identification device (10) according to the present disclosure comprises: a first oxygen saturation acquisition unit (60) that acquires a first oxygen saturation, which is the oxygen saturation of blood flowing into a needle hub (16) from a blood vessel (BV) of a patient through a needle body (14) inserted into the blood vessel; a second oxygen saturation acquisition unit (62) that acquires a second oxygen saturation, which is the oxygen saturation of the arterial blood of the patient; and a determination unit (68) that determines whether the blood vessel is an artery on the basis of the difference between the first oxygen saturation and the second oxygen saturation.

Description

Artery and vein identification device, artery and vein identification method, program, and recording medium

[0001] The present disclosure relates to an artery and vein identifying device, an artery and vein identifying method, a program, and a recording medium.

[0002] Japanese Patent No. 5032653 discloses a blood type determination set that determines whether collected blood is arterial blood or venous blood.

[0003] Patent No. 5032653

[0004] Recently, there has been a demand for a better artery / vein identifying device, artery / vein identifying method, program, and recording medium.

[0005] (1) A first aspect of the present disclosure is an arteriovenous identification device comprising: a first oxygen saturation acquisition unit that acquires a first oxygen saturation, which is the oxygen saturation of blood flowing from a patient's blood vessel into a needle hub via a needle body that is inserted into the blood vessel; a second oxygen saturation acquisition unit that acquires a second oxygen saturation, which is the oxygen saturation of the patient's arterial blood; and a determination unit that determines whether the blood vessel is an artery based on the difference between the first oxygen saturation and the second oxygen saturation.

[0006] The determination unit provided in the artery / vein identification device can accurately determine whether the blood vessel punctured by the needle is an artery or not based on the difference between the first oxygen saturation level and the second oxygen saturation level.

[0007] (2) In the artery / vein identification device described in the above item (1), the determination unit may determine that the blood vessel is the artery when the difference is smaller than a predetermined difference threshold value.

[0008] This improves the accuracy of the determination by the determination unit.

[0009] (3) The artery and vein identification device described in item (2) above may further include a vital data acquisition unit that acquires vital data of the patient, wherein the difference threshold is set based on the vital data and a trained model, and the trained model may be a machine learning model that has been trained by machine learning to output the difference threshold in response to input of the vital data.

[0010] The determination unit uses a difference threshold value that is set based on vital data of the patient, thereby improving the accuracy of the determination by the determination unit.

[0011] (4) In the artery and vein identification device described in any one of items (1) to (3) above, the first oxygen saturation acquisition unit may acquire the first oxygen saturation based on a first output signal, which is a signal output from a first oximeter probe disposed in the needle hub.

[0012] This allows the first oxygen saturation level acquirer to acquire the first oxygen saturation level with high accuracy.

[0013] (5) In the artery and vein identification device described in the above item (4), the first oximeter probe may include a light-projecting unit that projects light toward the needle hub, and a sensor unit that receives the light that has passed through the needle hub and outputs the first output signal according to the amount of light received.

[0014] This allows the first oxygen saturation level acquirer to acquire the first oxygen saturation level with high accuracy.

[0015] (6) In the artery and vein identifying device described in the above item (4) or (5), the first oximeter probe may be detachable from the needle hub.

[0016] This allows the first oximeter probe to be reused.

[0017] (7) In the artery and vein identification device described in any one of items (1) to (6) above, the second oxygen saturation acquisition unit may acquire the second oxygen saturation based on a second output signal, which is a signal output from a second oximeter probe attached to the patient.

[0018] This allows the second oxygen saturation level acquirer to acquire the second oxygen saturation level with high accuracy.

[0019] (8) In the artery and vein identification device described in any one of items (1) to (6) above, the second oxygen saturation level acquisition unit may acquire the second oxygen saturation level based on a value input by a user via an operation unit.

[0020] This allows the user to cause the second oxygen saturation level acquirer to acquire the input value as the second oxygen saturation level.

[0021] (9) A second aspect of the present disclosure is an artery / vein identification method, comprising: a first oxygen saturation acquisition step of acquiring a first oxygen saturation, which is the oxygen saturation of blood flowing from a patient's blood vessel into a needle hub through a needle body inserted into the blood vessel; a second oxygen saturation acquisition step of acquiring a second oxygen saturation, which is the oxygen saturation of the patient's arterial blood; and a determination step of determining whether the blood vessel is an artery based on the difference between the first oxygen saturation and the second oxygen saturation.

[0022] In the determination step, it is possible to accurately determine whether the blood vessel punctured by the needle is an artery or not based on the difference between the first oxygen saturation level and the second oxygen saturation level.

[0023] (10) A third aspect of the present disclosure is a program for causing a computer to execute the artery / vein identifying method described in the above item (9).

[0024] This allows the computer to execute the artery / vein identifying method, and the computer can accurately determine whether the blood vessel punctured by the needle is an artery or not.

[0025] (11) A fourth aspect of the present disclosure is a computer-readable, non-transitory recording medium storing the program described in item (10) above.

[0026] This allows the computer to execute the artery / vein identifying method, and the computer can accurately determine whether the blood vessel punctured by the needle is an artery or not.

[0027] The present invention can accurately determine whether the blood vessel punctured by the needle is an artery or not.

[0028] Fig. 1 is a schematic diagram showing an artery and vein identification device and an indwelling needle according to one embodiment. Fig. 2 is a schematic diagram showing an indwelling needle and a part of the artery and vein identification device. Fig. 3 is a block diagram showing the configuration of a detector. Fig. 4 is a block diagram showing the configuration of a determiner. Fig. 5 is a flowchart showing the flow of an artery and vein identification method according to one embodiment. Fig. 6 is a flowchart showing the flow of a determination step. Fig. 7 is a flowchart showing the flow of an artery and vein identification method according to Modification 8. Fig. 8 is a flowchart showing the flow of an artery and vein identification method according to Modification 9.

[0029] A medical device (instrument) is known that includes a needle body and a needle hub. The needle body is inserted into a patient's blood vessel. The needle hub holds the needle body. Blood in the blood vessel flows (flashback) into the needle hub through the needle body. When the needle body is inserted into a vein, venous blood flows into the needle hub. When the needle body is inserted into an artery, arterial blood flows into the needle hub. The above-mentioned device is, for example, but not limited to, an indwelling needle used for intravenous drip infusion.

[0030] Arterial blood is a brighter red than venous blood. Conventionally, surgeons have judged whether a blood vessel punctured by a needle is an artery or not based on the color of the blood flowing into the needle hub. However, the accuracy of this judgment is largely dependent on the surgeon's level of skill (subjective). In addition, oxygen saturation (SpO ２ The color of arterial blood, which has a relatively low β-amyloid ratio, is a color (dark red) that is relatively similar to that of venous blood. Therefore, in the past, even experienced surgeons were unable to accurately determine whether the blood vessel punctured by the needle was an artery.

[0031] Based on the above preliminary explanation, one embodiment will be described below.

[0032] (One embodiment) Fig. 1 is a schematic diagram showing an artery and vein identification device 10 according to one embodiment and an indwelling needle 12. Fig. 2 is a schematic diagram showing the indwelling needle 12 and a part of the artery and vein identification device 10.

[0033] The indwelling needle 12 is a type of instrument having a needle body 14 and a needle hub 16. The needle body 14 is a tubular member that is inserted into a patient's blood vessel BV (FIG. 2). The needle body 14 has sufficient rigidity to be inserted into the patient's skin SK (FIG. 2). The needle hub 16 is located at the base end 14b of the needle body 14 and is a member that holds the needle body 14. The patient's blood flows into the needle hub 16 via the needle body 14. More specifically, the patient's blood flows into the lumen of the needle hub 16 via the needle body 14, as will be described later. The needle hub 16 also has an attachment portion 36. The attachment portion 36 is a portion to which a first oximeter probe 30 is attached. The first oximeter probe 30 will be described later. The attachment portion 36 is translucent. It is preferable that the attachment portion 36 is transparent. The entire needle hub 16 may be translucent (transparent).

[0034] As shown in Figure 1, the indwelling needle 12 further includes a catheter shaft 18 and a catheter hub 20. The catheter shaft 18 is a component that is inserted into the patient's blood vessel BV. The catheter hub 20 is located at the proximal end 18b of the catheter shaft 18 and is a component that holds the catheter shaft 18. The catheter shaft 18 is provided so as to protrude from the catheter hub 20. The needle body 14 is inserted through the lumen of the catheter hub 20 and the lumen of the catheter shaft 18, and is provided so as to protrude from the distal end 18t of the catheter shaft 18.

[0035] The catheter shaft 18 is a tubular member. The catheter hub 20 is a cylindrical member. Therefore, the catheter shaft 18 and the catheter hub 20 each have a lumen, and the lumen communicates with each other. The needle 14 is inserted through the lumen of the catheter shaft 18 and the lumen of the catheter hub 20, which communicate with each other.

[0036] The artery and vein identification device 10 is a device that identifies (determines) whether a blood vessel BV punctured by a needle 14 is an artery or not. As shown in Fig. 1, the artery and vein identification device 10 has a first measuring device 22, a second measuring device 24, a detector 26, and a determiner 28.

[0037] The first measuring device 22 and the detector 26 are capable of communication. The communication format between the first measuring device 22 and the detector 26 is, for example, wired communication, but may also be wireless communication. The second measuring device 24 and the detector 26 are capable of communication. The communication format between the second measuring device 24 and the detector 26 is, for example, wired communication, but may also be wireless communication. Furthermore, the detector 26 and the determiner 28 are capable of communication. The communication format between the detector 26 and the determiner 28 is, for example, wired communication, but may also be wireless communication.

[0038] The first measuring device 22 has a first oximeter probe 30. The first oximeter probe 30 is disposed on the needle hub 16. The first oximeter probe 30 has a first light-emitting unit (light-emitting unit) 32 and a first light-receiving unit (sensor unit) 34. The first light-emitting unit 32 and the first light-receiving unit 34 are disposed on the outer periphery of an attachment unit 36 ​​of the needle hub 16. The first light-emitting unit 32 and the first light-receiving unit 34 face each other with the attachment unit 36 ​​in between.

[0039] The first light-projecting unit 32 has, for example, a plurality of light-emitting elements (not shown). Each of the plurality of light-emitting elements is, for example, an LED (Light Emitting Diode). The first light-projecting unit 32 projects light emitted by the plurality of light-emitting elements toward the inside of the needle hub 16. The light projected by the first light-projecting unit 32 includes red light and infrared light. Therefore, the plurality of light-emitting elements that can be provided in the first light-projecting unit 32 can include an LED that emits red light and an LED that emits infrared light.

[0040] The light emitted by the first light-emitting unit 32 passes through the translucent attachment unit 36 ​​(needle hub 16) and the intra-hub blood BL (FIG. 2). The intra-hub blood BL is the blood inside the needle hub 16 (the lumen of the needle hub 16). In other words, the intra-hub blood BL is blood that has flowed into the needle hub 16 from the patient via the needle body 14. The light that has passed through the intra-hub blood BL can reach the first light-receiving unit 34.

[0041] The first light receiving unit 34 receives light that has passed through the blood BL in the hub. The first light receiving unit 34 also has a light intensity sensor that outputs a first output signal corresponding to the amount of light received. The light intensity sensor is not shown. The first light receiving unit 34 outputs a first output signal corresponding to the red light component of the light that has passed through the blood BL in the hub and the infrared light component of the light. The first light receiving unit 34 outputs the first output signal to the detector 26.

[0042] Generally, needle hubs 16 (indwelling needles 12) used for medical purposes are not reusable. In light of this, it is preferable that the first oximeter probe 30 is detachable from the needle hub 16. This allows a user of the first measuring device (arteriovenous identification device 10) to attach the first oximeter probe 30 removed from a used needle hub 16 (discarded) to another needle hub 16 (new). In other words, the first oximeter probe 30 is reusable.

[0043] The second measuring device 24 has a second oximeter probe 38. As shown in FIG. 1 , the second oximeter probe 38 has a second light-emitting unit 40 and a second light-receiving unit 42. The second light-emitting unit 40 and the second light-receiving unit 42 face each other. The second light-emitting unit 40 and the second light-receiving unit 42 are disposed with a distance therebetween that allows a human finger (finger of a hand) to be inserted therebetween. The second oximeter probe 38 is attached to the patient by inserting the patient's finger between the second light-emitting unit 40 and the second light-receiving unit 42. The arrangement direction of the second light-emitting unit 40 and the second light-receiving unit 42 is not limited to that shown in FIG. 1 .

[0044] The second light-projecting unit 40 has a plurality of light-emitting elements (not shown). Each of the plurality of light-emitting elements is, for example, an LED. The second light-projecting unit 40 projects light in a direction toward the second light-receiving unit 42. The light includes red light and infrared light. Therefore, the plurality of light-emitting elements that can be provided in the second light-projecting unit 40 can include an LED that emits red light and an LED that emits infrared light.

[0045] The light projected by the second light-projecting unit 40 passes through the patient's finger placed between the second light-projecting unit 40 and the second light-receiving unit 42. More specifically, the light projected by the second light-projecting unit 40 passes through the artery (arterial blood) in the patient's finger.

[0046] The second light receiving unit 42 receives light that has passed through the patient's finger (arterial blood). The second light receiving unit 42 has a light intensity sensor that outputs a second output signal corresponding to the amount of light received. The light intensity sensor is not shown. The second light receiving unit 42 outputs a second output signal corresponding to the red light component of the light that has passed through the patient's arterial blood and the infrared light component of the light. The second light receiving unit 42 outputs the second output signal to the detector 26.

[0047] The first measuring device 22 and the second measuring device 24 described above can supply the first output signal and the second output signal to the detector 26 .

[0048] FIG. 3 is a block diagram showing the configuration of the detector 26.

[0049] The detector 26 is an electronic device having a calculation unit 44 and a storage unit 46. The electronic device includes, for example, a computer. The computer is, for example, a smartphone, a tablet terminal, a PC (Personal Computer), etc., but is not limited to these.

[0050] The calculation unit 44 has a processing circuitry. The processing circuitry has, for example, one or more processors. The processors are, for example, a central processing unit (CPU) or a graphics processing unit (GPU). The processing circuitry may have a predetermined integrated circuit such as an application specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). The processing circuitry may also have discrete devices.

[0051] The storage unit 46 has a non-transitory tangible storage medium. The storage medium includes, for example, a volatile memory (not shown) and a non-volatile memory (not shown). The volatile memory is, for example, a random access memory (RAM). The non-volatile memory is, for example, a read only memory (ROM), a flash memory, or the like. The storage unit 46 (non-transitory tangible storage medium) may include a portable storage medium.

[0052] As shown in FIG. 3 , the calculation unit 44 includes a first oxygen saturation calculation unit 48 and a second oxygen saturation calculation unit 50 .

[0053] The first oxygen saturation calculator 48 and the second oxygen saturation calculator 50 may be realized by a processing circuit of the calculation unit 44. For example, the first oxygen saturation calculator 48 and the second oxygen saturation calculator 50 are realized by the calculation unit 44 (processor) executing a program stored in the storage unit 46 (memory). At least a portion of the first oxygen saturation calculator 48 and the second oxygen saturation calculator 50 may be realized by the above-mentioned predetermined integrated circuit, discrete device, or the like.

[0054] The first oxygen saturation calculator 48 calculates a first oxygen saturation based on the first output signal. The first oxygen saturation is the oxygen saturation (SpO ２ In other words, the first oxygen saturation level is the oxygen saturation level of the blood BL in the hub. The first oxygen saturation level calculator 48 outputs information indicating the first oxygen saturation level to the determiner 28.

[0055] The reason why the oxygen saturation of the blood BL in the hub can be calculated based on the first output signal is as follows.

[0056] The amount of red light transmitted through blood varies depending on the color of the blood. On the other hand, the amount of infrared light transmitted through blood does not vary substantially depending on the color of the blood. Therefore, it is possible to evaluate the color of the blood based on the ratio of the red light component of the light transmitted through the blood to the infrared light component of the light. Furthermore, the color of blood varies depending on the oxygen saturation of the blood. Therefore, it is possible to calculate the oxygen saturation of the blood based on this ratio.

[0057] In this regard, the first light receiving unit 34 outputs a first output signal corresponding to the red light component of the light transmitted through the blood in the hub BL and the infrared light component of that light. Therefore, the first output signal indicates the ratio between the red light component of the light transmitted through the blood in the hub BL and the infrared light component of that light. Therefore, the first oxygen saturation calculation unit 48 can calculate the oxygen saturation of the blood in the hub BL based on the first output signal (this ratio).

[0058] The second oxygen saturation calculator 50 calculates a second oxygen saturation level based on the second output signal. The second oxygen saturation level is the oxygen saturation level of the patient's arterial blood. The second oxygen saturation calculator 50 outputs information indicating the second oxygen saturation level to the determiner 28.

[0059] The reason why the oxygen saturation of the patient's arterial blood can be calculated based on the second output signal is as follows. That is, as described above, the oxygen saturation of the blood can be calculated based on the ratio between the red light component of the light transmitted through the blood and the infrared light component of the light. In this regard, the second light-receiving unit 42 outputs a second output signal corresponding to the red light component of the light transmitted through the patient's arterial blood and the infrared light component of the light. Therefore, the second output signal indicates the ratio between the red light component of the light transmitted through the patient's arterial blood and the infrared light component of the light. Therefore, the second oxygen saturation calculator 50 can calculate the oxygen saturation of the patient's arterial blood based on the second output signal (the ratio).

[0060] According to the detector 26 described above, information indicating the first oxygen saturation level and information indicating the second oxygen saturation level can be supplied to the determiner 28 .

[0061] FIG. 4 is a block diagram showing the configuration of the determiner 28.

[0062] The determiner 28 is an electronic device having a display unit 52, an operation unit 54, a calculation unit 56, and a storage unit 58. The electronic device includes, for example, a computer. The computer is, for example, a smartphone, a tablet terminal, a PC, or the like, but is not limited to these.

[0063] The display unit 52 includes a display element, a display panel, etc. (not shown) that can appropriately display information to the user. The display unit 52 is, for example, a liquid crystal display, but is not limited to this. The display unit 52 functions as an informing device that can inform the user of the result of the determination by the determination unit 68 (described later). Note that the display unit 52 (informing device) may be provided outside the determiner 28. For example, a smartphone, a tablet terminal, etc. that is separate from the determiner 28 and can communicate with the determiner 28 may be used as the display unit 52.

[0064] The operation unit 54 includes an input device (not shown) that enables a user to provide information, instructions, and the like to the determiner 28. The input device may include a keyboard, a mouse, and the like. The input device may include a pointing device such as a touch panel that is provided integrally with the display unit 52. The operation unit 54 may be provided outside the determiner 28. For example, a smartphone, a tablet terminal, or the like that is separate from the determiner 28 may be used as the operation unit 54. In this case, the determiner 28 is remotely controlled via the smartphone or tablet terminal that is separate from the determiner 28.

[0065] The calculation unit 56 has a processing circuit. The processing circuit has, for example, one or more processors. The processor is, for example, a CPU, a GPU, or the like. The processing circuit of the calculation unit 56 may have a predetermined integrated circuit such as an ASIC or an FPGA. The processing circuit of the calculation unit 56 may also have a discrete device.

[0066] The storage unit 58 has a non-transitory tangible storage medium. The storage medium includes, for example, a volatile memory (not shown) and a non-volatile memory (not shown). The volatile memory is, for example, a RAM. The non-volatile memory is, for example, a ROM, a flash memory, or the like. The storage unit 58 (non-transitory tangible storage medium) may include a portable storage medium.

[0067] As shown in Figure 4, the calculation unit 56 has a first oxygen saturation acquisition unit 60, a second oxygen saturation acquisition unit 62, a vital data acquisition unit 64, a threshold setting unit 66, a judgment unit 68, an alarm control unit (display control unit) 70, and a machine learning unit 72.

[0068] The first oxygen saturation acquisition unit 60, the second oxygen saturation acquisition unit 62, the vital data acquisition unit 64, the threshold setting unit 66, the determination unit 68, the notification control unit 70, and the machine learning unit 72 may be realized by a processing circuit of the calculation unit 56. For example, the first oxygen saturation acquisition unit 60, the second oxygen saturation acquisition unit 62, the vital data acquisition unit 64, the threshold setting unit 66, the determination unit 68, the notification control unit 70, and the machine learning unit 72 may be realized by the calculation unit 56 (processor) executing a program stored in the storage unit 58 (memory). A predetermined integrated circuit, discrete device, or the like included in the calculation unit 56 may realize at least a portion of the first oxygen saturation acquisition unit 60, the second oxygen saturation acquisition unit 62, the vital data acquisition unit 64, the threshold setting unit 66, the determination unit 68, the notification control unit 70, and the machine learning unit 72.

[0069] The first oxygen saturation level acquiring unit 60 acquires information indicating the first oxygen saturation level from the detector 26. The second oxygen saturation level acquiring unit 62 acquires information indicating the second oxygen saturation level from the detector 26.

[0070] The vital data acquiring unit 64 acquires vital data of the patient. The vital data is data indicating various vital signs such as blood pressure and blood oxygen saturation. The vital data of the patient may be measured by a device separate from the artery and vein identification device 10. In this case, the vital data acquiring unit 64 can acquire the vital data of the patient from the separate device. The vital data of the patient may be input to the determiner 28 by the surgeon using the operation unit 54. The surgeon is, for example, a medical professional who administers an intravenous drip to the patient.

[0071] The threshold setting unit 66 sets a difference threshold. The difference threshold is a threshold used by the determination unit 68. The threshold setting unit 66 can set the difference threshold using a trained model, which will be described later. The determination unit 68 and the trained model will be described in more detail later.

[0072] The determination unit 68 determines whether the blood vessel BV punctured by the needle body 14 is an artery or not based on the difference between the first oxygen saturation level and the second oxygen saturation level. More specifically, the determination unit 68 performs a first determination and a second determination, which will be described next, as necessary.

[0073] (First Determination) The determination unit 68 derives the difference between the first oxygen saturation acquired by the first oxygen saturation acquisition unit 60 and the second oxygen saturation acquired by the second oxygen saturation acquisition unit 62. The determination unit 68 derives this difference, for example, but not limited to, by subtracting the first oxygen saturation from the second oxygen saturation. Next, the determination unit 68 compares the difference (the absolute value of the difference) with a difference threshold. If the difference is equal to or less than the difference threshold, the determination unit 68 determines that the blood vessel BV punctured by the needle body 14 is an artery. If the difference is greater than the difference threshold, the determination unit 68 starts the next second determination.

[0074] (Second Determination) The determination unit 68 compares the first oxygen saturation acquired by the first oxygen saturation acquisition unit 60 with the second oxygen saturation acquired by the second oxygen saturation acquisition unit 62. If the first oxygen saturation is lower than the second oxygen saturation, the determination unit 68 determines that the blood vessel BV punctured by the needle body 14 is a vein. If the first oxygen saturation is equal to or higher than the second oxygen saturation, the determination unit 68 determines that the blood vessel BV cannot be identified. In other words, if the first oxygen saturation is equal to or higher than the second oxygen saturation, the determination unit 68 determines that it is difficult to identify whether the blood vessel BV punctured by the needle body 14 is an artery.

[0075] The reason why it is possible to determine whether the blood vessel BV punctured by the needle body 14 is an artery or not based on the difference between the first oxygen saturation level and the second oxygen saturation level is as follows.

[0076] The first oxygen saturation level is the oxygen saturation level of the blood BL in the hub. In contrast, the second oxygen saturation level is the oxygen saturation level of the patient's arterial blood. The blood BL in the hub is blood that has flowed into the needle hub 16 from the blood vessel BV punctured by the needle body 14. If the blood vessel BV punctured by the needle body 14 is an artery, the first oxygen saturation level indicates the oxygen saturation level of the patient's arterial blood.

[0077] In this case, the difference between the first oxygen saturation level and the second oxygen saturation level should be relatively small. For example, the oxygen saturation level of typical arterial blood is 95% to 98%. Therefore, if the blood vessel BV punctured by the needle body 14 is an artery, the difference between the first oxygen saturation level and the second oxygen saturation level should often fall within the range of approximately 0% to 3%.

[0078] On the other hand, if the blood vessel BV punctured by the needle body 14 is a vein, the first oxygen saturation level indicates the oxygen saturation level of the patient's venous blood. Generally, the oxygen saturation level of venous blood is lower than the oxygen saturation level of arterial blood. Therefore, if the blood vessel BV punctured by the needle body 14 is a vein, the difference between the first oxygen saturation level and the second oxygen saturation level should be relatively large. For example, the oxygen saturation level of typical venous blood is 60% to 80%. Therefore, if the blood vessel BV punctured by the needle body 14 is a vein, the difference between the first oxygen saturation level and the second oxygen saturation level will be, for example, approximately 15% to 38%.

[0079] For the above reasons, the determination unit 68 can determine whether the blood vessel BV punctured by the needle body 14 is an artery based on the difference between the first oxygen saturation level and the second oxygen saturation level. The difference threshold set by the threshold setting unit 66 is set to evaluate the difference between the first oxygen saturation level and the second oxygen saturation level, taking into account the difference between the oxygen saturation level of arterial blood and the oxygen saturation level of venous blood described above.

[0080] The notification control unit 70 executes notification processing. The notification processing is processing for notifying the user of the result of the determination by the determination unit 68. For example, the notification control unit 70 causes the display unit 52, which is a notification device, to display the result of the determination by the determination unit 68. In this case, the notification control unit 70 functions as a display control unit that controls the display unit 52. This allows the user to know whether the blood vessel BV punctured by the needle body 14 is an artery or not.

[0081] The machine learning unit 72 generates a trained model through machine learning. The trained model is a machine learning model that outputs a difference threshold in response to input of the patient's vital data. The generated trained model is stored in the storage unit 58. The machine learning unit 72 generates the trained model through machine learning using, for example, information indicating the accuracy of the determination by the determination unit 68. The information indicating the accuracy of the determination by the determination unit 68 is input to the determiner 28 by the user via, for example, the operation unit 54.

[0082] As described above, the oxygen saturation of typical arterial blood and the oxygen saturation of typical venous blood are known. However, the oxygen saturation of a patient's arterial blood and the oxygen saturation of the patient's venous blood may change depending on the patient's physical condition (vital signs). Therefore, a difference threshold appropriate for evaluating the difference between a first oxygen saturation and a second oxygen saturation obtained from a patient may not necessarily be appropriate for evaluating the difference between the first oxygen saturation and the second oxygen saturation obtained from another patient. In this regard, according to the present embodiment, the trained model outputs a difference threshold appropriate to the patient's vital data. This allows the threshold setting unit 66 to set an appropriate difference threshold appropriate to the patient (vital data). As a result, the accuracy of the determination by the determination unit 68 may be improved.

[0083] FIG. 5 is a flowchart showing the flow of an artery and vein identifying method according to one embodiment.

[0084] 5, the artery-vein identification method includes a first oxygen saturation level acquisition step S1, a second oxygen saturation level acquisition step S2, a vital data acquisition step S3, a threshold value setting step S4, a determination step S5, and a result notification step S6. The artery-vein identification method can be performed, for example, by having a processor (computing unit 56) included in the determiner 28 read and execute a program stored in a memory (storage unit 58) included in the determiner 28.

[0085] In the first oxygen saturation level acquisition step S1, the first oxygen saturation level acquisition unit 60 acquires the first oxygen saturation level. In the second oxygen saturation level acquisition step S2, the second oxygen saturation level acquisition unit 62 acquires the second oxygen saturation level.

[0086] The first oxygen saturation level acquisition step S1 and the second oxygen saturation level acquisition step S2 may be performed in any order, or may be performed in parallel.

[0087] In a vital data acquisition step S3, the vital data acquisition unit 64 acquires vital data of the patient. In a threshold setting step S4, the threshold setting unit 66 sets a difference threshold. The threshold setting unit 66 can set the difference threshold using the trained model and the vital data acquired in the vital data acquisition step S3.

[0088] The vital data acquisition step S3 and the threshold setting step S4 are performed in no particular order relative to the first oxygen saturation acquisition step S1. The vital data acquisition step S3 and the threshold setting step S4 are also performed in no particular order relative to the second oxygen saturation acquisition step S2.

[0089] FIG. 6 is a flowchart showing the flow of the determination step S5.

[0090] In the determination step S5, the determination unit 68 determines whether the blood vessel BV punctured by the needle body 14 is an artery based on the difference between the first oxygen saturation level and the second oxygen saturation level. As shown in Fig. 6, the determination step S5 includes a difference deriving step S51, a first determination step S52, and a second determination step S53.

[0091] In the difference deriving step S51, the determination unit 68 derives the difference between the first oxygen saturation level and the second oxygen saturation level.

[0092] In the first determination step S52, the determination unit 68 performs the first determination described above. That is, in the first determination step S52, the determination unit 68 compares the difference between the first oxygen saturation level and the second oxygen saturation level with a difference threshold. If the difference is equal to or less than the difference threshold (S52: YES), the determination unit 68 determines that the blood vessel BV punctured by the needle body 14 is an artery (RETURN 1). If the difference is greater than the difference threshold (S52: NO), the determination unit 68 proceeds to the second determination step S53.

[0093] In the second determination step S53, the determination unit 68 compares the first oxygen saturation level with the second oxygen saturation level. If the first oxygen saturation level is lower than the second oxygen saturation level (S53: YES), the determination unit 68 determines that the blood vessel BV punctured by the needle body 14 is a vein (RETURN 2). If the first oxygen saturation level is equal to or higher than the second oxygen saturation level (S53: NO), the determination unit 68 determines that the blood vessel BV is indistinguishable (RETURN 3).

[0094] In the result notification step S6, the result of the determination step S5 is notified to the user. In the result notification step S6, for example, the notification control unit 70 controls the display unit 52 to display information indicating the result of the determination step S5 on the display unit 52. In this way, the notification control unit 70 can notify the user of the result of the determination step S5.

[0095] According to this embodiment, the artery / vein identification device 10 (artery / vein identification method) can accurately determine whether the blood vessel BV punctured by the needle 14 is an artery or not.

[0096] One embodiment may be modified as follows. In the following modifications, explanations that overlap with the embodiment will be omitted. In addition, in the drawings used in the following modifications, the same reference numerals are used for the same components as those described in the embodiment.

[0097] (Variation 1) As described above, the instrument including the needle body 14 and the needle hub 16 is not limited to the indwelling needle 12. Therefore, the instrument to which the arteriovenous identification device 10 (first oximeter probe 30) is attached is not limited to the indwelling needle 12. The first oximeter probe 30 may be attached to, for example, an introducer needle. The introducer needle is an instrument that can be used to introduce a wire guide into a patient's blood vessel.

[0098] (Modification 2) The detector 26 and the determiner 28 may be integrated together. For example, the detector 26 and the determiner 28 may be realized by a single computer (electronic device).

[0099] (Variation 3) The detector 26 may be realized by a plurality of computers. For example, the calculation unit 44 and a part of the storage unit 46 may be provided on the cloud. Furthermore, the determiner 28 may be realized by a plurality of computers. For example, the calculation unit 56 and a part of the storage unit 58 may be provided on the cloud.

[0100] (Modification 4) At least one of the first oxygen saturation level and the second oxygen saturation level may be input to the determiner 28 by the user via the operation unit 54.

[0101] For example, the second oxygen saturation level may be measured using a known pulse oximeter equipped with a function for calculating oxygen saturation levels. If the pulse oximeter has a communication function, the second oxygen saturation level calculated by the pulse oximeter may be transferred to the determiner 28. If the pulse oximeter does not have a communication function, the user may input the second oxygen saturation level displayed on the display screen of the pulse oximeter to the determiner 28 via the operation unit 54.

[0102] (Variation 5) The machine learning unit 72 may be provided outside the determinator 28. For example, a learning device (learning server) (not shown) that can communicate with the determinator 28 may include the machine learning unit 72. In this case, the machine learning unit 72 of the determinator 28 may be omitted. In this case, the learned model is provided to the determinator 28 by a learning device (not shown).

[0103] (Variation 6) In the embodiment, the case where the result notification step S6 is performed regardless of the result of the determination step S5 has been described, but the artery and vein identification method is not limited to this. For example, the result notification step S6 may be performed only when it is determined that the needle 14 has mistakenly punctured an artery during a procedure in which the needle 14 should have punctured a vein.

[0104] (Variation 7) The notification device controlled by the notification control unit 70 is not limited to the display unit 52. For example, the notification device may include a lamp, a buzzer, or the like. In this case, the notification control unit 70 may, for example, turn on a lamp to notify the user of the result of the determination by the determination unit 68. The notification control unit 70 may also, for example, sound a buzzer to notify the user of the result of the determination by the determination unit 68.

[0105] (Modification 8) The threshold setting unit 66 may set a value input by the user via the operation unit 54 as the difference threshold.

[0106] FIG. 7 is a flowchart showing the flow of an artery-vein identifying method according to the eighth modification.

[0107] The artery and vein identification device 10 according to this modification can execute the artery and vein identification method shown in Fig. 7. The artery and vein identification method in Fig. 7 differs from the artery and vein identification method of the embodiment (Fig. 5) in that the vital data acquisition step S3 is omitted. In the threshold setting step S4 in Fig. 7, the threshold setting unit 66 sets a value input by the user via the operation unit 54 as the difference threshold.

[0108] According to this modification, the threshold setting unit 66 can set the difference threshold without using a learning model. In this case, the vital data acquisition unit 64 and the machine learning unit 72 may be omitted from the artery and vein identification device 10.

[0109] The artery and vein identification device 10, which includes the vital data acquisition unit 64 and the machine learning unit 72, may selectively execute the artery and vein identification method of Fig. 5 or the artery and vein identification method of Fig. 7. In this case, the artery and vein identification device 10 may select one of the artery and vein identification method of Fig. 5 or the artery and vein identification method of Fig. 7 based on an instruction from a user given via the operation unit 54, for example.

[0110] (Modification 9) The difference threshold may be a fixed value. The fixed value may be determined in advance based on, for example, experiments. The fixed value may be stored in, for example, the storage unit 58 of the artery and vein identification apparatus 10.

[0111] FIG. 8 is a flowchart showing the flow of an artery-vein identifying method according to the ninth modification.

[0112] The artery-vein identification device 10 according to this modification can execute the artery-vein identification method shown in Fig. 8. The artery-vein identification method in Fig. 8 differs from the artery-vein identification method of the first embodiment (Fig. 5) in that the vital data acquisition step S3 and the threshold setting step S4 are omitted. In the determination step S5 in Fig. 8, the determination unit 68 can use the difference threshold stored in the storage unit 58.

[0113] In this modification, the vital data acquisition unit 64 , the threshold setting unit 66 , and the machine learning unit 72 may be omitted from the artery and vein identification device 10 .

[0114] The artery and vein identification device 10, which includes the vital data acquisition unit 64, the threshold setting unit 66, and the machine learning unit 72, may selectively execute the artery and vein identification method of Fig. 5 or the artery and vein identification method of Fig. 8. In this case, the artery and vein identification device 10 may select one of the artery and vein identification method of Fig. 5 or the artery and vein identification method of Fig. 8 based on an instruction from a user given via the operation unit 54, for example.

[0115] (Combination of Multiple Modifications) The multiple modifications described above may be combined as appropriate within a range that does not cause inconsistency.

[0116] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present disclosure.

Claims

1. An arteriovenous identification device comprising: a first oxygen saturation acquisition unit that acquires a first oxygen saturation, which is the oxygen saturation of blood that flows from a patient's blood vessel into a needle hub through a needle body that is inserted into the blood vessel; a second oxygen saturation acquisition unit that acquires a second oxygen saturation, which is the oxygen saturation of the patient's arterial blood; and a determination unit that determines whether the blood vessel is an artery based on the difference between the first oxygen saturation and the second oxygen saturation.

2. An artery / vein identification device according to claim 1, wherein the determination unit determines that the blood vessel is an artery when the difference is smaller than a predetermined difference threshold value.

3. An artery and vein identification device as described in claim 2, further comprising a vital data acquisition unit that acquires vital data of the patient, wherein the difference threshold is set based on the vital data and a trained model, and the trained model is a machine learning model that has been trained by machine learning to output the difference threshold in response to input of the vital data.

4. An artery and vein identification device according to any one of claims 1 to 3, wherein the first oxygen saturation acquisition unit acquires the first oxygen saturation based on a first output signal, which is a signal output from a first oximeter probe disposed in the needle hub.

5. An artery and vein identification device according to claim 4, wherein the first oximeter probe comprises: a light projecting unit that projects light toward the needle hub; and a sensor unit that receives the light that has passed through the needle hub and outputs the first output signal according to the amount of light received.

6. An artery and vein identification device according to claim 4, wherein the first oximeter probe is detachable from the needle hub.

7. An artery and vein identification device according to any one of claims 1 to 3, wherein the second oxygen saturation acquisition unit acquires the second oxygen saturation based on a second output signal, which is a signal output from a second oximeter probe attached to the patient.

8. An artery and vein identification device according to any one of claims 1 to 3, wherein the second oxygen saturation level acquisition unit acquires the second oxygen saturation level based on a value input by a user via an operation unit.

9. A method for identifying arteries and veins, comprising: a first oxygen saturation acquisition step of acquiring a first oxygen saturation, which is the oxygen saturation of blood flowing from a patient's blood vessel into a needle hub through a needle body that is inserted into the blood vessel; a second oxygen saturation acquisition step of acquiring a second oxygen saturation, which is the oxygen saturation of the patient's arterial blood; and a determination step of determining whether the blood vessel is an artery based on the difference between the first oxygen saturation and the second oxygen saturation.

10. A program for causing a computer to execute the artery / vein identifying method according to claim 9.

11. A computer-readable, non-transitory recording medium storing the program according to claim 10.

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