Handheld OCT probe

Abstract

The utility model relates to the technical field of OCT (Optical Coherence Tomography) imaging, and discloses a handheld OCT probe, which comprises a probe, a piezoelectric stack and a handheld shell, the moving assembly comprises a base and a moving part, the base is fixedly connected into the handheld shell, the moving part is arranged on the base, the probe is connected to the moving part through the piezoelectric stack, and the position of the probe is adjusted through the moving part; the control piece is arranged on the base, and the moving piece and the piezoelectric stack are respectively connected with the control piece; and the optical fiber is arranged on the base, is connected with an external optical fiber system and is used for emitting near-infrared light and receiving reflected light on the surface of an object to be detected. The in-vivo tissue testing device is simple to operate, convenient to carry and capable of flexibly testing in-vivo tissues.

Description

Technical Field

[0001] The utility model relates to the technical field of OCT imaging, in particular to a handheld OCT probe. Background Art

[0002] The mechanical properties of biological tissues are one of the most important indicators of their physiological health. Some tissues exhibit significant differences in mechanical properties between healthy and pathological states. For example, the elastic modulus of sclerotic skin tissue is greater than that of normal skin tissue. Therefore, quantitative assessment of tissue mechanical properties is crucial for disease prediction and diagnosis.

[0003] Currently, measurements of biological tissues are generally divided into in vitro and in vivo measurements. Although in vitro measurements can easily obtain the mechanical parameters of biological tissues, the experimental conditions of in vitro measurements are very different from the in vivo environment. Therefore, the measurement results cannot well represent the mechanical properties of in vivo biological tissues. In summary, it is of great significance to achieve the characterization of the mechanical properties of biological tissues in vivo.

[0004] Optical Coherence Tomography (OCT) is a new and promising tomographic imaging technology that has developed rapidly in recent years. It features low damage, high resolution, and non-invasive imaging. Mechanical waves are generated by exciting the surface of the object to be measured, and OCT is used to collect signals. The elastic modulus of the object to be measured can be obtained through relevant data processing. Currently, the excitation device of most OCT systems mainly includes instruments and components such as signal generators, power amplifiers, piezoelectric stacks, and probes. These make the excitation device complex to operate and inconvenient to carry during use. Furthermore, the device can only excite the object to be measured in a relatively fixed position, and cannot flexibly test in vivo tissues.

[0005] Therefore, there is an urgent need for a handheld OCT probe to solve the above problems. Utility Model Content

[0006] The purpose of the utility model is to provide a handheld OCT probe to solve the problems existing in the above-mentioned prior art.

[0007] To achieve the above objectives, the present invention provides the following solutions: The present invention provides a handheld OCT probe, comprising a probe, a piezoelectric stack, and:

[0008] Handheld housing;

[0009] A moving assembly comprising a base and a moving member, wherein the base is fixedly connected to the handheld housing, the moving member is disposed on the base, the probe is connected to the moving member via the piezoelectric stack, and the position of the probe is adjusted by the moving member;

[0010] A control member is provided on the base, and the moving member and the piezoelectric stack are respectively connected to the control member;

[0011] The optical fiber is arranged on the base and is connected to an external optical fiber system for emitting near-infrared light to the surface of the object to be measured and receiving reflected light.

[0012] Preferably, the movable part includes a linear guide rail fixedly connected in the base, a guide rail slider is slidably connected to the linear guide rail, a first lead screw is rotatably connected to the guide rail slider, a sleeve is threadedly connected to the first lead screw, a second lead screw is rotatably connected in the base, the second lead screw is arranged perpendicular to the first lead screw, the sleeve is threadedly connected to the second lead screw, and the probe is fixedly connected to the sleeve through the piezoelectric stack.

[0013] Preferably, the control component includes a circuit board, which is fixedly connected to the bottom end of the base, and the piezoelectric stack, the stepper motor on the first lead screw, and the stepper motor on the second lead screw are respectively connected to the circuit board through wires.

[0014] Preferably, a display screen is fixedly connected to a side of the handheld housing away from the probe, and the display screen is a touch screen.

[0015] Preferably, the handheld housing is provided with a power switch and a control button.

[0016] Preferably, the probe is a spherical metal probe, and the diameter of the probe is 1.5 mm.

[0017] Preferably, a metal protective sheath is provided on the optical fiber.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects:

[0019] The present invention provides a handheld OCT probe with a small size and compact structure, facilitated by a handheld housing. This makes the device suitable for handheld use in a variety of situations and is relatively flexible. Furthermore, the loading amplitude is small, preventing damage to the object being tested. The probe position is adjusted by a movable element. Testing is performed using the probe, piezoelectric stack, and optical fiber. Real-time data is collected from the generated mechanical waves, and the elastic modulus of the object under test is analyzed. This application is simple to operate, portable, and capable of flexible testing of in vivo tissues. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without inventive work:

[0021] Figure 1 This is a schematic diagram of the first internal structure of the handheld housing of the present invention;

[0022] Figure 2 This is a schematic diagram of the second internal structure of the handheld housing of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the moving part of the utility model;

[0024] Among them, 1. Probe; 2. Piezoelectric stack; 3. Handheld housing; 4. Base; 5. Display screen; 6. Linear guide; 7. Guide rail slider; 8. First lead screw; 9. Sleeve; 10. Second lead screw; 11. Circuit board; 12. Optical fiber; 13. Power switch; 14. Control button; 15. Tail end outlet. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0027] Reference Figure 1-Figure 3 The present invention provides a handheld OCT probe, comprising a probe 1, a piezoelectric stack 2, and further comprising:

[0028] Handheld housing 3;

[0029] The mobile assembly includes a base 4 and a moving part. The base 4 is fixedly connected to the handheld housing 3. The moving part is arranged on the base 4. The probe 1 is connected to the moving part through the piezoelectric stack 2. The position of the probe 1 is adjusted by the moving part.

[0030] A control member is provided on the base 4, and the moving member and the piezoelectric stack 2 are respectively connected to the control member;

[0031] The optical fiber 12 is provided on the base 4 and is connected to an external optical fiber system for emitting near-infrared light to the surface of the object to be measured and receiving reflected light.

[0032] A further optimized solution is that the moving part includes a linear guide rail 6 fixedly connected to the base 4, a guide rail slider 7 is slidably connected to the linear guide rail 6, a first lead screw 8 is rotatably connected to the guide rail slider 7, a sleeve 9 is threadedly connected to the first lead screw 8, a second lead screw 10 is rotatably connected to the base 4, the second lead screw 10 is vertically arranged to the first lead screw 8, the sleeve 9 is threadedly connected to the second lead screw 10, and the probe 1 is fixedly connected to the sleeve 9 through the piezoelectric stack 2.

[0033] In one embodiment of the present invention, the first lead screw 8 controls the movement of the probe 1 in the z direction, and the second lead screw 10 controls the movement of the probe 1 in the y direction.

[0034] According to a further optimized solution, the control component includes a circuit board 11, which is fixedly connected to the bottom end of the base 4. The piezoelectric stack 2, the stepper motor on the first lead screw 8, and the stepper motor on the second lead screw 10 are respectively connected to the circuit board 11 through wires.

[0035] In one embodiment of the present invention, the circuit board 11 can function as a signal generator, capable of outputting waveforms such as square waves, sine waves, and sawtooth waves during the experiment, and can output corresponding frequencies and amplitudes. Furthermore, the circuit board 11 can control a stepper motor, thereby enabling movement of the probe 1.

[0036] The specific circuit board 11 is preferably an stm32 circuit board. With the low-power stm32 circuit board as the main control device, a signal generator that can generate arbitrary waveforms is realized through circuit design and program writing. The waveform is generated by the stm32 single-chip microcomputer, which is characterized in that the waveform generated is relatively pure through software filtering, and its price is low, performance is high, stability is good within the range of low frequency, operation is simple, volume is small, and power consumption is low. For the generation of waveform, a touch screen is used as the operation interface, and the operator can determine the waveform parameters during the experiment on the touch screen. By a stepper motor control system based on the PWM subdivision technology of stm32, the steering of the stepper motor and the control of the wire collection and release can be realized by a control button.

[0037] The stm32 circuit board can realize the function of a signal generator, and can output waveforms such as square waves, sine waves, and sawtooth waves during the experiment, and can output corresponding frequencies and amplitudes. In addition, the stm32 circuit board can be used to control the stepper motor, thereby realizing the movement of the probe.

[0038] According to a further optimized solution, a display screen 5 is fixedly connected to a side of the handheld housing 3 away from the probe 1 , and the display screen 5 is a touchable display screen.

[0039] In one embodiment of the present invention, the display screen 5 adopts a touch screen to display the mechanical wave waveform, frequency, amplitude and displacement information of the probe during the experiment. The operator adjusts the mechanical wave waveform, frequency and amplitude information output during the experiment through touch screen operation. The touch screen is a prior art. The specific specifications and models are selected by technical personnel in this field according to actual needs. The specifications and models and principles are not described in detail here.

[0040] In a further optimized solution, the handheld housing 3 is provided with a power switch 13 and a control button 14 .

[0041] In one embodiment of the present invention, the power switch 13 is used to start the device, and there are three control buttons 14, namely a first button for controlling the movement of the probe 1 in the z direction, a second button for controlling the movement of the probe 1 in the y direction, and a third button for controlling the generation of excitation.

[0042] According to a further optimized solution, the probe 1 is a spherical metal probe with a diameter of 1.5 mm.

[0043] In one embodiment of the present invention, testing experiments with probes of varying diameters revealed that the waveform excited by a spherical probe was more stable than that of probes of other shapes. Furthermore, as the probe diameter decreased, the measured elastic modulus decreased. Further experimental results showed that when a 1.5mm spherical metal probe was used with a contact depth of 0-0.06mm with the object being measured, the measured elastic modulus was closer to the object's true elastic modulus.

[0044] As a further optimization solution, a metal protective sheath is provided on the optical fiber 12 .

[0045] In one embodiment of the present invention, the outside of the optical fiber 12 is wrapped with a hard metal protective sheath to protect the optical fiber 12 and prevent the optical fiber 12 from bending during the experiment, thereby causing its focal length to change. In addition, at least two through holes should be left on the base 4, which are used to fix the optical fiber 12 and position the optical fiber 12 on the one hand, and to allow other cables such as internal wires to pass through and be fixed well on the other hand. The optical fiber 12 is not in contact with the outside world, thereby protecting the optical fiber 12, preventing the optical fiber 12 from being damaged, and extending its service life. The optical fiber 12 is connected to the optical fiber system on the outside, and obtains optical coherence tomography signals by emitting near-infrared light and receiving reflected light. The optical fiber 12 can image tiny tissues, and an excitation device is added at the same time. Excitation and imaging can be performed simultaneously, and tiny integration is performed. This is a prior art and will not be described in detail here.

[0046] Specifically, optical fiber 12 can be either coreless or lensed. It is fixed in the same z and y planes as probe 1, ensuring that the light spot and probe are always aligned on the surface of the object being measured. Optical fiber 12 connects to the external fiber optic system through a cable outlet 15 at the end of the handheld portion of the handheld housing 3 (only a portion of the optical fiber inside the housing is shown here, not the entire fiber).

[0047] To use the handheld OCT probe, turn on the power switch 13 and the device enters operation. The external fiber optic system controls the handheld OCT probe to emit a beam of near-infrared light, allowing a light spot to be observed on the surface of the object to be tested. The manual adjustment control button 14 contacts the surface of the object to be tested at the appropriate position. The operator adjusts the mechanical wave waveform, frequency, and amplitude information used during the experiment by operating on the display screen 5. Once the information is determined, the probe 1 connected to the piezoelectric stack 2 will operate according to the set information, generating mechanical waves on the surface of the object to be tested. Generally, for human skin tissue, an excitation frequency of 800 Hz is preferred during the experiment. The mechanical wave generated at the excitation point on the surface of the object to be tested, where it contacts the probe 1, propagates through the detection point below the optical fiber, is identified, and converted by the detector into an electrical signal that is transmitted to a computer. By performing windowing and Fourier transform on the collected optical coherence tomography signal, image information of the detection point can be obtained. By observing the clarity of the image on the computer, the excitation depth and excitation position of the probe can be adjusted accordingly to ensure that the image quality meets expectations. Because mechanical waves have the characteristic of attenuation when propagating inside the object to be tested, the distance between the excitation point and the detection point of the sample to be tested should not be too far.

[0048] After collecting the phase signal at excitation point 1, the probe 1 is moved to excitation point 2, and the displacement information of the probe movement is recorded. Generally, by measuring the distance and time of the mechanical wave from the excitation point to the detection point, the propagation speed of the mechanical wave in the object to be measured is calculated, and then the elastic modulus of the object to be measured is calculated based on the relationship between the speed of the mechanical wave and the mechanical parameters of the object to be measured. Here, excitation is performed at excitation point 1 and excitation point 2 respectively, and the time difference information is obtained by performing correlation calculations on the signals identified at the detection point. The displacement difference is obtained by reading the data of the moving probe. The wave velocity is obtained by calculating the ratio of the displacement difference to the time difference. In particular, it should be noted that excitation point 1, excitation point 2 and the detection point should be on the same straight line, and the movement distance of probe 1 should not be too far to prevent excessive attenuation and the inability to detect relevant signals at the detection point.

[0049] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention.

[0050] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements to the technical solutions of the present invention made by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A handheld OCT probe, comprising a probe (1) and a piezoelectric stack (2), characterized in that: Also includes: Handheld housing (3); A moving assembly comprises a base (4) and a moving part, wherein the base (4) is fixedly connected to the handheld housing (3), the moving part is arranged on the base (4), the probe (1) is connected to the moving part via the piezoelectric stack (2), and the position of the probe (1) is adjusted via the moving part; A control member is arranged on the base (4), and the moving member and the piezoelectric stack (2) are respectively connected to the control member; An optical fiber (12) is arranged on the base (4), and the optical fiber (12) is connected to an external optical fiber system and is used for emitting near-infrared light to the surface of the object to be measured and receiving reflected light.

2. The handheld OCT probe according to claim 1, characterized in that: The movable part includes a linear guide rail (6) fixedly connected to the base (4), a guide rail slider (7) slidably connected to the linear guide rail (6), a first lead screw (8) rotatably connected to the guide rail slider (7), a sleeve (9) threadedly connected to the first lead screw (8), a second lead screw (10) rotatably connected to the base (4), the second lead screw (10) is vertically arranged with the first lead screw (8), the sleeve (9) is threadedly connected to the second lead screw (10), and the probe (1) is fixedly connected to the sleeve (9) through the piezoelectric stack (2).

3. The handheld OCT probe according to claim 2, characterized in that: The control component includes a circuit board (11), which is fixedly connected to the bottom end of the base (4), and the piezoelectric stack (2), the stepper motor on the first lead screw (8) and the stepper motor on the second lead screw (10) are respectively connected to the circuit board (11) through wires.

4. The handheld OCT probe according to claim 1, characterized in that: A display screen (5) is fixedly connected to a side of the handheld housing (3) away from the probe (1), and the display screen (5) is a touchable display screen.

5. The handheld OCT probe according to claim 1, characterized in that: The handheld housing (3) is provided with a power switch (13) and a control button (14).

6. The handheld OCT probe according to claim 1, characterized in that: The probe (1) is a spherical metal probe, and the diameter of the probe (1) is 1.5 mm.

7. The handheld OCT probe according to claim 1, characterized in that: A metal protective sheath is provided on the optical fiber (12).

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