A device for dynamically measuring capillary refill time (CRT)

Abstract

The invention relates to a portable device for dynamically measuring capillary refill time (CRT).

Description

[0001] A DEVICE FOR DYNAMICALLY MEASURING CAPILLARY REFILL TIME (CRT)

[0002] Technical Field

[0003] The invention relates to a portable device for dynamically measuring capillary refill time (CRT).

[0004] Background

[0005] In the nail bed located underneath our fingertips, there exists a vascular network comprising numerous arterioles and venules. Because the nail is relatively transparent, changes in the vascular circulation within the nail bed can be easily observed by examining the nails. In a healthy adult with normal blood circulation, body temperature, oxygenation level, and hemoglobin level, the nail bed typically exhibits a characteristic pinkish appearance. If the blood circulation in the nail bed is interrupted by applying brief pressure to the nail, the typical color of the nail bed fades, and upon removing the pressure, it gradually returns to its original color over time. This duration for returning to the normal color is defined as the capillary refill time (CRT).

[0006] In patent document numbered KR101459652B1, a system is defined where the user applies manual pressure. Pressure is applied via part number 120, light is directed to the area under pressure, and the amount of incoming light is measured to reach conclusions. In this document, it is observed that by rotating an outer bracelet (520), the inner bracelet (510) and the associated pulley (540) also rotate. In this way, pressure is applied to the finger by pulling the cable. When the button (530) on the device is pressed, the bracelets and pulleys return to their original position, releasing the force. The document does not address how the force is applied after the wire is pulled. Additionally, the absence of a force sensor in the system results in unknown force applied to the finger. Since different amounts of movement are required for children and adults, the application of the device described in this document is entirely based on experience. Excessive force application may lead to injuries to the patient's finger. In the known art described in document CN109589105 A, a system that automatically applies pressure to the finger and subsequently measures color change with an oxygen saturation probe has been outlined. The automatic pressure system operates through the airway. In the document, a pressurized membrane, along with pressurized air inlet and outlet valves, is utilized for applying and releasing pressure. Color measurements are again performed using sensors. In the document, compressed air is obtained using a compressor. This significantly affects the portability of the system. Additionally, the use of a compressor, which is quite noisy, may not be suitable for use in every location within a hospital. This limitation greatly restricts the portability and applicability of the system.

[0007] In patent document numbered CN116245784A, an artificial intelligence method for detecting color changes in the pressed finger is described. The document does not define a system that applies pressure or a color sensor. While there are no innovative elements in the mechanical components of the system in the document, the focus is more on processing data and early diagnosis systems.

[0008] In patent document CN109171658A, a system that applies pressure to the finger using gears and a motor is described. However, an infrared sensor is used for measurement. Evaluation is performed with an external computer. In the document, a lever mechanism for applying force and a gear system to actuate this mechanism are used. Since these systems still rely on a compressor for their operation, there are limitations in terms of portability and applicability. Additionally, the system utilizes pre-defined computer functions based on age and gender. While this expands the range of applications, it may be insufficient for determining the appropriate amount of force to apply for factors such as weight, illness, finger structural abnormalities, etc. And, the size of the system is quite large, making it impractical for continuous measurements in intensive care patients.

[0009] In the prior art document GB2596913A, a structure capable of applying pressure and subsequently measuring color change is described. The document describes reducing the device size to the dimensions of a pen, which involves significant innovations in the electronic components by changing the sensor systems. This enhances the portability of the system. Additionally, this innovation allows the device to be used not only on fingers but also on desired areas. The document does not specify the source of pressure application and does not focus on it. In the prior art document US2022039674A1, a device that applies pressure to the patient's body and then detects changes in skin color using an imaging sensor is described. While the document focuses on measuring skin complications such as skin cancer, it also measures capillary blood flow.

[0010] In the publication titled "Portable measurement device to quantitatively measure capillary refilling time" in the prior art, pressure applied manually by the user is measured instantly. When the correct pressure level is reached, feedback is provided, and then changes in skin color are measured using a color sensor.

[0011] Upon reviewing existing studies in the field, it is evident that there are numerous studies focusing on the application force and duration. However, regarding the removal of force, mechanisms such as gears or similar devices tend to result in slow force removal, thus affecting the capillary refill time (CRT). Additionally, existing studies are not operator-free and not suitable for dynamic measurements. Therefore, there is a need for the development of a portable device capable of dynamically measuring capillary refill time (CRT), which is addressed by the present invention.

[0012] Aim of the Invention

[0013] The aim of this invention is to develop a portable device capable of dynamically measuring capillary refill time (CRT).

[0014] Detailed Description of the Invention

[0015] The portable device capable of dynamically measuring capillary refill time (CRT) has been illustrated in the attached figures to achieve the aims of this invention.

[0016] These figures are;

[0017] Figure 1: The side view of the device subject to the invention.

[0018] Figure 2: The perspective view of the device subject to the invention.

[0019] Figure 3: The front view of the device subject to the invention.

[0020] Figure 4: The side view of the body II present in the device subject to the invention. Figure 5: The perspective view of the body II present in the device subject to the invention.

[0021] Figure 6: The side view of the components inside the body I present in the device subject to the invention.

[0022] Figure 7: The perspective view of the components inside the body I present in the device subject to the invention.

[0023] Figure 8: The perspective view of the components inside the body I present in the device subject to the invention with a different angle.

[0024] Figure 9: The perspective view of the components inside the body I present in the device subject to the invention with a different angle.

[0025] Figure 10: The view of the sensors and the soft pad in the device subject to the invention.

[0026] Figure 11 : Another view of the sensors and the soft pad in the device subj ect to the invention.

[0027] Figure 12: The body I present in the device subject to the invention.

[0028] Figure 13: The body I present in the device subject to the invention with a different angle.

[0029] The parts shown in the figures are individually numbered, and their corresponding numbers are given below.

[0030] 1. Body I

[0031] 2. Color Sensor

[0032] 3. Color Sensor Mold

[0033] 4. Soft Pads

[0034] 5. Force Sensor

[0035] 6. Force Sensor Mold

[0036] 7. Motor

[0037] 8. Force Transmission Part

[0038] 9. Pusher

[0039] 10. Return Springs

[0040] 11. Finger Entry Area

[0041] 12. Fixing Body 13. Connection Protrusions

[0042] 14. Back Cover

[0043] 15. Body II

[0044] 16. Screen

[0045] 17. Control Card

[0046] 18. Trigger Mechanism

[0047] 19. Battery

[0048] The invention relates to a portable device for dynamically measuring capillary refill time (CRT), comprising:

[0049] A body 1 (1),

[0050] A color sensor (2) located within the Body I (1) for measuring color changes on the user's finger,

[0051] A color sensor mold (3) for securing the color sensor (2) in place within the body I (1),

[0052] Soft pads (4) located within the Body I (1) to prevent injury of the user's finger and provide a comfortable usage area,

[0053] A force sensor (5) located within the Body I (1) to determine the applied force on the finger,

[0054] A force sensor mold (6) for securing the force sensor (5) in place within the Body I (1),

[0055] A motor (7) located within the Body 1 (1),

[0056] A force transmission part (8) connected to the motor (7) and transmitting motion to the color sensor mold (3) via a pusher (9),

[0057] - Return springs (10) positioned on the Body I (1) to quickly return the system when force is released,

[0058] A finger entry area (11) on the Body I (1),

[0059] A fixing body (12) within the Body I (1) to secure the color sensor mold (3),

[0060] Connection protrusions (13) located on the Body I (1),

[0061] A back cover (14) to be closed on the Body I (1) and to protect the internal components of the Body 1 (1), A body II (15),

[0062] A screen (16) on the Body II (15) for displaying the measured values, A control card (17) on the Body II (15) for controlling the motor (7), color sensor (2), and force sensor (5) components,

[0063] A trigger mechanism (18) on the Body II (15) for starting or stopping the measurement process,

[0064] A battery compartment (19) on the Body II (15) for housing the battery to power the system.

[0065] In the device according to the invention, there are primarily a force sensor (5) for measuring force and a color sensor (2) for measuring color located within the Body I (1). To bring these sensors together and keep them fixed, there are provided a color sensor mold (3) and a force sensor mold (6). The geometry of these molds may vary depending on the sensor used. In the operation method of the system, firstly, motion is imparted to the motor (7). This motion is directed using the force transfer component (8). The force transfer component (8) could be a rack and pinion mechanism or different gear mechanisms or force transfer systems. After the force is directed by the actuator (9), the color sensor mold (3) and the color sensor (2) are pushed downwards to apply pressure to the finger. This force value is transmitted to the force sensor (5) using the force sensor mold (6). When the force reaches the desired value, the motion of the motor (7) is stopped. The force value is held constant at the desired level for the desired duration. Then, the motor (7) is released. Thanks to the return springs (10), the color sensor mold (3) is quickly pulled upwards. Meanwhile, the color sensor (2) is activated and provides feedback by calculating the color change time in the finger, that is, the capillary refill time.

[0066] The device of the invention can be used both for long periods and in an ergonomic and portable manner. The back cover (14) can be removed from the body I (1), and then it is connected to the body II (15) via the connection protrusions (13) located on it. The device can be used in any part of the hospital, in ambulances, or in any place where urgent measurements may be required. An electronic or mechanical trigger mechanism (18) is used to activate the device. After the trigger mechanism (18) is pressed, the measurement starts, and the measurement is performed using the components in the system, with the read value reflected on the screen (16) for the user to read. For the completion of these electronic processes, a control card (17) and a battery are added to the device. The device can protect the battery by shutting itself off when not in use for measurements, thus significantly extending its lifespan. In an alternative application of the device, the finger inserted through the finger entry area (11) can be secured on the hand, especially for intensive care unit patients. The body II (15) secured with the connection protrusions (13) on body I (1) can be separated from the device, and body 1 (1) can be connected to a computer or an external power source for measurements. In this case, a different system is obtained. The read data can be directly transferred to the doctor's computer, phone, or any reporting area. This allows for dynamic measurements to assist in early diagnosis.

[0067] The invention aims to prepare electronic components that allow for the application of pressure in very short time intervals and sudden release for CRT measurements, ensuring accurate color values are measured. The sudden removal of the load enables a more accurate measurement of the CRT time.

Claims

CLAIMS1. A portable device for dynamically measuring capillary refill time (CRT), comprising:A body 1 (1),A color sensor (2) located within the Body I (1) for measuring color changes on the user's finger,A color sensor mold (3) for securing the color sensor (2) in place within the body 1 (1),Soft pads (4) located within the Body I (1) to prevent injury of the user's finger and provide a comfortable usage area,A force sensor (5) located within the Body I (1) to determine the applied force on the finger,A force sensor mold (6) for securing the force sensor (5) in place within the Body I (1),A motor (7) located within the Body I (1),A force transmission part (8) connected to the motor (7),A pusher (9) to transmit the motion taken from the motor (7) via the force transmission part (8), to the color sensor mold (3),- Return springs (10) positioned on the Body I (1) to quickly return the system when force is released, A body II (15),A screen (16) on the Body II (15) for displaying the measured values,A control card (17) on the Body II (15) for controlling the motor (7), color sensor (2), and force sensor (5) components,A trigger mechanism (18) on the Body II (15) for starting or stopping the measurement process.

2. The invention relates to a device according to claim 1, characterized by comprising a finger entry region (11) opened on the body I (1).

3. The invention relates to a device according to claim 1, characterized by comprising a fixing body (12) located within the body 1 (1) and enabling the fixation of the color sensor mold (3).

4. The invention relates to a device according to claim 1, characterized by comprising connection protrusions (13) located on the body I (1).

5. The invention relates to a device according to claim 1, characterized by comprising a back cover (14) that is placed on the body I (1) and protects the components inside the body I (1).

6. The invention relates to a device according to claim 1, characterized by comprising a battery compartment (19) located on the body II (15) and designed to accommodate the battery providing power to the system.

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