Flexible wearable array probe and intracranial imaging system

Abstract

The application belongs to the technical field of intracranial imaging, and specifically discloses a flexible wearable array probe and an intracranial imaging system, wherein the probe comprises a flexible sensing array composed of a plurality of array-arranged sensing units, a hemispherical supporting shell and a fixing belt; the flexible sensing array is fixedly arranged in the supporting shell and is used for transmitting ultrasonic signals to a biological tissue to be measured and receiving ultrasonic signals returned by the biological tissue to be measured; each sensing unit comprises a receiving module and M emitting modules arranged around the receiving module, and the receiving module is flexibly connected with each emitting module; one emitting module is shared by two adjacent sensing units; the fixing belt is connected with the supporting shell and is used for fixing the supporting shell on the biological tissue to be measured. The probe can be closely attached to the curved surface of the biological tissue to be measured, effectively reduces the attenuation and reflection of ultrasonic waves in air and bones, and can perform efficient, safe and non-invasive ultrasonic imaging on the biological intracranial brain and other biological tissues to be measured.

Description

Technical Field

[0001] This invention discloses a flexible wearable array probe and an intracranial imaging system, belonging to the field of intracranial imaging technology. Background Technology

[0002] Intracranial imaging is a technique that utilizes modern scientific technologies such as physics, electronics, and computers to observe and analyze the structure and function of the brain. It has significant applications and value in neuroscience, medicine, psychology, and other fields. The development of intracranial imaging technology can help us gain a deeper understanding of how the brain works, reveal the neural basis of cognitive, emotional, and behavioral processes, and diagnose and treat various neurological diseases. The development of intracranial imaging technology can also drive innovation and breakthroughs in emerging fields such as artificial intelligence, brain-computer interfaces, and neuromorphic computing, contributing to the progress and development of human society. Currently, intracranial imaging technology has developed into various imaging methods, each with its own advantages and limitations. Examples include electroencephalography (EEG), magnetoencephalography (MEG), functional near-infrared spectroscopy (FIR), positron emission tomography (PET), and magnetic resonance imaging (MRI). Current intracranial imaging commonly uses PET and MRI methods. Both methods can be applied to human experiments and can provide whole-brain images, but they require expensive, complex, and bulky equipment, limiting their widespread adoption and comprehensive application.

[0003] In recent years, researchers have proposed a method for intracranial functional ultrasound imaging, a non-invasive neuroscience imaging method that features high temporal / spatial resolution, high contrast, portability, and non-invasiveness, providing clear and detailed imaging of brain structure and function.

[0004] The primary method for intracranial functional ultrasound imaging in current technology is transcranial Doppler (TCD). However, current TCD methods mainly observe changes in cerebral blood flow or blood volume, rather than neuronal activity, thus requiring the inference of brain functional activity through neurovascular coupling mechanisms. TCD examination is also affected by operator skill; its main drawback is that the operator cannot visualize the course of intracranial vessels and the angle between the vessels and the ultrasound beam, reducing the accuracy of repeated blood flow velocity measurements. Overall, the failure rate of transcranial Doppler ultrasound is 2.7%–5%, due to factors such as skull thickening, arterial tortuosity, and arterial displacement in some patients. In summary, the main limitation of traditional ultrasound Doppler blood flow imaging is its insufficient sensitivity, failing to detect low-velocity blood flow in small vessels, which are the primary sites of hemodynamic responses. Summary of the Invention

[0005] The purpose of this application is to provide a flexible wearable array probe and intracranial imaging system to solve the technical problem of low sensitivity of transcranial Doppler ultrasound in the prior art, which makes it unable to detect low-speed blood flow in small blood vessels and thus results in inaccurate intracranial imaging results.

[0006] A first aspect of the present invention provides a flexible wearable array probe, comprising a flexible sensing array composed of multiple arrayed sensing units, a hemispherical support shell, and a fixing strap;

[0007] The flexible sensor array is fixedly installed inside the supporting shell and is used to send ultrasonic signals to the biological tissue under test and receive ultrasonic signals returned by the biological tissue under test.

[0008] Each of the sensing units includes a receiving module and M transmitting modules arranged around the receiving module, wherein the receiving module is flexibly connected to each of the transmitting modules;

[0009] Two adjacent sensing units share a single transmitting module;

[0010] The fixing strap is connected to the supporting shell and is used to fix the supporting shell onto the biological tissue to be tested.

[0011] Preferably, the receiving module includes a sensitive layer and an optical fiber sensing unit;

[0012] The sensitive layer is disposed on the port of the optical fiber sensing unit and is used to receive the ultrasonic signal returned by the biological tissue under test. The ultrasonic signal modulates the refractive index of the laser transmitted in the optical fiber sensing unit through the photoelastic effect of the sensitive layer.

[0013] Preferably, it also includes a connector, which includes a wire mating head and an optical fiber interface;

[0014] The wire connector is connected to the transmitting module;

[0015] The fiber optic interface is connected to the fiber optic sensing unit.

[0016] Preferably, it also includes a buffer layer;

[0017] The buffer layer is disposed between the supporting shell and the flexible sensing array.

[0018] Preferably, it also includes a hose clamp;

[0019] The hose clamp body is connected to the buffer layer, and the hose clamp screw is located on the outside of the supporting shell.

[0020] A second aspect of the present invention provides an intracranial imaging system, comprising a signal generator, a light source generator, an optical signal demodulator imaging unit, and the aforementioned flexible wearable array probe;

[0021] The signal generator is connected to the transmitting module and is used to generate an excitation electrical signal, which causes the transmitting module to generate an ultrasonic signal.

[0022] The light source generator is connected to the receiving module and is used to provide laser to the receiving module. The laser is modulated by the ultrasonic signal returned by the head under test.

[0023] The optical signal demodulator is connected to the receiving module and is used to demodulate the refractive index change from the laser to obtain the electrical signal corresponding to the ultrasonic signal returned by the head under test.

[0024] The imaging unit is connected to the optical signal demodulator and is used to generate intracranial images based on the electrical signals.

[0025] Preferably, the imaging unit includes a control device and a display;

[0026] The control device is connected to the optical signal demodulator and is used to generate intracranial images based on the electrical signals.

[0027] The display is connected to the control device and is used to display the intracranial images.

[0028] Preferably, it also includes a power amplifier;

[0029] The power amplifier is located between the signal generator and the transmitting module to amplify the excitation electrical signal and transmit it to the transmitting module.

[0030] Preferably, the light source generator and the receiving module are connected via multimode optical fiber.

[0031] Preferably, the light source generator is a semiconductor laser, and the wavelength of the laser emitted by the semiconductor laser is 1550nm.

[0032] The flexible wearable array probe and intracranial imaging system of the present invention have the following advantages compared with the prior art:

[0033] The flexible sensing array of this invention can closely fit the curved surface of the biological tissue to be tested, effectively reducing the attenuation and reflection of ultrasound in air and bone, improving the utilization rate and signal-to-noise ratio of ultrasound energy, realizing efficient excitation, transmission and high-sensitivity reception of ultrasound, improving imaging quality and resolution, and enabling efficient, safe and non-invasive ultrasound imaging of biological tissues such as the brain. Taking brain imaging as an example, it can realize the visualization of brain structure and function, such as cerebral blood flow, brain oxygen saturation, neuronal activity, etc., providing new means for studying brain cognitive mechanisms, diagnosing neurodegenerative diseases and assessing the degree of brain injury. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the flexible wearable array probe in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of a sensing unit in an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the structure of the transmitting module in an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the receiving module in an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the intracranial imaging system in an embodiment of the present invention.

[0039] In the figure, 1 is a flexible sensing array; 11 is a receiving module; 111 is a second backing; 112 is a micro / nano fiber; 113 is a sensitive layer; 114 is a matching layer; 12 is a transmitting module; 121 is a piezoelectric film; 122 is an upper electrode; 123 is a lower electrode; 124 is a first backing; 13 is a flexible circuit; 14 is a flexible substrate; 2 is a supporting shell; 31 is a strap; 32 is a buckle; 4 is a connector; 5 is a buffer layer; 6 is a hose clamp; 7 is a screw thread; 8 is a signal generator; 9 is a light source generator; 10 is an optical signal demodulator; 11 is a control device; 12 is a display; 13 is a power amplifier; 14 is a data line; 15 is an optical signal line; 16 is a composite cable; 17 is a flexible wearable array probe; and 18 is a movable vertical platform. Detailed Implementation

[0040] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0041] A first aspect of the present invention provides a flexible wearable array probe 17, such as Figure 1 As shown, it includes a flexible sensing array 1 composed of multiple arrayed sensing units, a hemispherical supporting shell 2, and a fixing strap;

[0042] The flexible sensor array 1 is fixedly installed inside the supporting shell 2 and is used to send ultrasonic signals to the biological tissue under test and receive ultrasonic signals returned by the biological tissue under test.

[0043] Each sensing unit includes a receiving module 11 and M transmitting modules 12 arranged around the receiving module 11. The receiving module 11 is flexibly connected to each transmitting module 12, such as... Figure 2 As shown;

[0044] Two adjacent sensing units share a single transmitting module 12;

[0045] The fixing strap is connected to the support shell 2 and is used to fix the support shell 2 onto the biological tissue to be tested.

[0046] In this embodiment of the invention, the number of transmitting modules 12 in each sensing unit can be multiple. For example, Figure 2 It includes four transmitting modules 12, each of which is connected to the receiving module 11 via a flexible component, wherein the flexible component includes a flexible substrate 14 and a flexible circuit 13 disposed on the flexible substrate 14.

[0047] The flexible sensing array 1 of this invention can closely fit the curved surface of the biological tissue to be tested, effectively reducing the attenuation and reflection of ultrasound in air and bone, improving the utilization rate and signal-to-noise ratio of ultrasound energy, realizing efficient excitation, transmission and high-sensitivity reception of ultrasound, improving imaging quality and resolution, and enabling efficient, safe and non-invasive ultrasound imaging of biological tissues such as the brain. Taking intracranial imaging as an example, it can realize the visualization of brain structure and function, such as cerebral blood flow, brain oxygen saturation, neuronal activity, etc., providing new means for studying brain cognitive mechanisms, diagnosing neurodegenerative diseases and assessing the degree of brain injury.

[0048] This invention allows for the adjustment of parameters such as the shape, size, and arrangement of the array probes to adapt to the imaging needs of different individuals' head shapes and body parts, increasing the system's flexibility and adaptability. It boasts advantages such as simple structure, low cost, portability, and ease of use.

[0049] By way of example, the structure of the transmitting module 12 of the present invention is as follows: Figure 3As shown, it includes a piezoelectric film 121, a first backing 124, an upper electrode 122, and a lower electrode 123; the piezoelectric film 121 is disposed on the first backing 124 and is used to generate ultrasonic signals; the upper electrode 122 and the lower electrode 123 are respectively disposed on the two sides of the piezoelectric film 121.

[0050] The first backing 124 is a flexible backing, which can be made of polyimide.

[0051] The excitation electrical signal of the piezoelectric film 121 of the present invention comes from an external signal generator. The signal generator is connected to the piezoelectric film 121 through an upper electrode 122 and a lower electrode 123. The piezoelectric film 121 is used to generate an ultrasonic signal emitted towards the biological tissue to be tested under the action of the excitation electrical signal.

[0052] The piezoelectric film 121 is made of polyvinylidene fluoride (PVDF). PVDF has good biocompatibility and can be directly adhered to the biological tissue to be tested without the need for a coupling agent. Furthermore, PVDF has an acoustic impedance similar to that of human tissue, a wide operating bandwidth, and a high piezoelectric coefficient, thus maximizing the achievement of high-efficiency ultrasonic emission.

[0053] The receiving module 11 of the present invention is as follows Figure 4 As shown, it includes a sensitive layer 113 and an optical fiber sensing unit;

[0054] The sensitive layer 113 is disposed on the port of the fiber optic sensing unit and is used to receive the ultrasonic signal returned by the biological tissue under test and to modulate the laser transmitted in the fiber optic sensing unit.

[0055] The fiber optic sensing unit includes a second backing 111, a micro / nano fiber 112, and a matching layer 114.

[0056] The sensitive layer 113 is disposed on the port of the micro-nano fiber 112 and is used to receive the ultrasonic signal returned by the biological tissue under test. The laser transmitted on the micro-nano fiber 112 is caused to change the refractive index through the photoelastic effect.

[0057] A micro / nano optical fiber 112 with a sensitive layer 113 is disposed on a second backing 111;

[0058] A matching layer 114 is disposed on the micro / nano optical fiber 112 with a sensitive layer 113 and is connected to the second backing 111, thereby encapsulating the micro / nano optical fiber 112 with the sensitive layer 113 on the second backing 111.

[0059] The sensitive layer 113 and matching layer 114 of this invention are both polydimethylsiloxane elastic films. Polydimethylsiloxane has advantages such as low Young's modulus, excellent air permeability, chemical stability, thermal stability, low-temperature flexibility (excellent performance at -60 to 200°C), full transparency, and biocompatibility. It can accurately receive the ultrasonic signals returned by the biological tissue under test and modulate the laser transmitted in the micro-nano fiber 112. The micro-nano fiber 112 has a strong evanescent field, and the receiving module made from it has a large response range and high sensitivity. Therefore, the flexible wearable array probe 17 made using it has advantages such as high sensitivity, high resolution, resistance to electromagnetic interference, and simple structure.

[0060] The preparation method of the second backing 111 is as follows:

[0061] Step 1: Obtain the backing material, which includes epoxy resin adhesive and tungsten powder. The volume of tungsten powder accounts for 13-40% of the volume of the backing material, and the volume of epoxy resin adhesive accounts for 60-87% of the volume of the backing material.

[0062] Step 2: Add tungsten powder to the epoxy resin adhesive and stir to obtain tungsten powder particles coated with epoxy resin. The epoxy resin has a temperature resistance range of -45℃ to 245℃.

[0063] The density of the epoxy resin on the outer surface of the tungsten powder particles is 2.5–3.5 g / cm³. 3 .

[0064] Step 3: Load the composite particles into the mold, and use a hot press to hot press the composite particles in the mold at 40-80℃ to obtain the second backing 111.

[0065] The second backing 111 of the present invention is a rigid backing with high acoustic impedance and acoustic attenuation. The acoustic impedance can reach 15-17 MRayls and the acoustic attenuation can reach 83-93 dB / cm / MHz. It also has a wide operating temperature range, which can improve the accuracy of the receiving module 11 in receiving ultrasonic signals.

[0066] The flexible wearable array probe 17 of the present invention also includes a connector 4, which includes a wire connector and an optical fiber interface; the wire connector is connected to the transmitting module 12 and an external signal generator; the optical fiber interface is connected to the optical fiber sensing unit and an external optical signal demodulator and light source generator.

[0067] For example, connector 4 is disposed on top of supporting housing 2. To prevent collision damage to the flexible sensing array 1, the flexible wearable array probe 17 of the present invention also includes a buffer layer 5;

[0068] The buffer layer 5 is disposed between the supporting shell 2 and the flexible sensing array 1, and the material of the buffer layer 5 can be silicone.

[0069] To secure the buffer layer 5, the present invention also includes a hose clamp 6;

[0070] The hose clamp 6 is connected to the buffer layer 5, and the screw thread of the hose clamp 6 is aligned with the screw hole 7 on the support housing 2, and is set on the outside of the support housing 2. The tightness of the hose clamp 6 can be adjusted by adjusting the screw thread on the outside of the support housing 2.

[0071] The fixing strap of the present invention includes a strap body 31 and a buckle 32. The strap body 31 is made of polyester, and the buckle 32 is a polyethylene buckle. The length of the strap body is adjusted and fixed by means of the buckle 32.

[0072] A second aspect of the present invention provides an intracranial imaging system, such as Figure 5 As shown, it includes a signal generator 8, a light source generator 9, an optical signal demodulator 10, an imaging unit, and the aforementioned flexible wearable array probe 17;

[0073] The signal generator 8 is connected to the transmitting module 12 via the data line 14 in the composite cable 16 and the wire pair of the connector 4 to generate an excitation electrical signal, which causes the transmitting module 12 to generate an ultrasonic signal.

[0074] The light source generator 9 is connected to the receiving module 11 via the optical signal line 15 in the composite cable 16, and is used to provide laser to the receiving module 11. The laser is modulated by the ultrasonic signal returned by the head under test.

[0075] The optical signal demodulator 10 is connected to the receiving module 11 via the composite cable 16, and is used to demodulate the refractive index change from the laser to obtain the electrical signal corresponding to the ultrasonic signal returned by the head under test.

[0076] The imaging unit is connected to the optical signal demodulator 10 and is used to generate intracranial images based on electrical signals.

[0077] The imaging unit of the intracranial imaging system of the present invention includes a control device 11 and a display 12;

[0078] Control device 11 is connected to optical signal demodulator 10 and is used to generate intracranial images based on electrical signals;

[0079] The display 12 is connected to the control device 11 and is used to display intracranial images.

[0080] This invention connects the data processing and imaging software within the optical signal demodulator 10 and control device 11 to convert ultrasound signals into optical signals for intracranial imaging and display, facilitating observation and analysis by the operator. These features make this invention valuable for applications in neuroscience and the diagnosis and treatment of intracranial diseases.

[0081] The intracranial imaging system of the present invention also includes a power amplifier 13;

[0082] The power amplifier 13 is located between the signal generator 8 and the transmitting module 12 to amplify the excitation electrical signal and transmit it to the transmitting module 12.

[0083] In this embodiment of the invention, the optical signal line 15 includes multiple multimode optical fibers, and the light source generator 9 is connected to each receiving module 11 through multiple multimode optical fibers.

[0084] In this embodiment of the invention, the light source generator 9 is a semiconductor laser, and the wavelength of the laser emitted by the semiconductor laser is 1550nm. This wavelength of laser can improve the transmission accuracy of micro-nano optical fibers.

[0085] The intracranial imaging system of the present invention is mounted on a movable vertical platform 18 for ease of use.

[0086] The working process of the intracranial imaging system of this invention is as follows:

[0087] First, the signal generator 8 and power amplifier 13 select the mode and intensity of the electrical signal that excites the flexible wearable array probe 17. The array probe responds by emitting a corresponding ultrasonic signal into the intracranial cavity. Simultaneously, the light source generator 9 transmits a 1550nm wavelength laser through an optical signal line to the optical fiber in the flexible wearable array probe 17. The receiving module 11 of the flexible wearable array probe 17 then receives the ultrasonic signal. Through the elastic optical effect, the refractive index of the laser transmitted in the optical fiber changes, and the optical signal demodulator 10 demodulates and converts it into an electrical signal. The electrical signal is then transmitted to the host (control device 11) via the data line 14. The data processing and imaging software installed on the host completes the intracranial imaging and finally displays it on the display 12.

[0088] The intracranial imaging system of the present invention has the advantages of good imaging quality and high resolution.

[0089] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A flexible wearable array probe, characterized in that, It includes a flexible sensing array consisting of multiple arrayed sensing units, a hemispherical support shell, and a fixing strap; The flexible sensor array is fixedly installed inside the supporting shell and is used to send ultrasonic signals to the biological tissue under test and receive ultrasonic signals returned by the biological tissue under test. Each of the sensing units includes a receiving module and M transmitting modules arranged around the receiving module, wherein the receiving module is flexibly connected to each of the transmitting modules; Two adjacent sensing units share a single transmitting module; The receiving module includes a sensitive layer and an optical fiber sensing unit. The sensitive layer is disposed on the port of the optical fiber sensing unit and is used to receive the ultrasonic signal returned by the biological tissue under test. The ultrasonic signal modulates the refractive index of the laser transmitted in the optical fiber sensing unit through the photoelastic effect of the sensitive layer. The fixing strap is connected to the supporting shell and is used to fix the supporting shell onto the biological tissue to be tested.

2. The flexible wearable array probe according to claim 1, characterized in that, It also includes a connector, which includes a wire mating head and an optical fiber interface; The wire connector is connected to the transmitting module; The fiber optic interface is connected to the fiber optic sensing unit.

3. The flexible wearable array probe according to claim 1, characterized in that, It also includes a buffer layer; The buffer layer is disposed between the supporting shell and the flexible sensing array.

4. The flexible wearable array probe according to claim 3, characterized in that, It also includes hose clamps; The hose clamp body is connected to the buffer layer, and the hose clamp screw is located on the outside of the supporting shell.

5. An intracranial imaging system, characterized in that, Includes a signal generator, a light source generator, an optical signal demodulator, an imaging unit, and the flexible wearable array probe as described in any one of claims 1-4; The signal generator is connected to the transmitting module and is used to generate an excitation electrical signal, which causes the transmitting module to generate an ultrasonic signal. The light source generator is connected to the receiving module and is used to provide laser to the receiving module. The laser is modulated by the ultrasonic signal returned by the head under test. The optical signal demodulator is connected to the receiving module and is used to demodulate the refractive index change from the laser to obtain the electrical signal corresponding to the ultrasonic signal returned by the head under test. The imaging unit is connected to the optical signal demodulator and is used to generate intracranial images based on the electrical signals.

6. The intracranial imaging system according to claim 5, characterized in that, The imaging unit includes a control device and a display; The control device is connected to the optical signal demodulator and is used to generate intracranial images based on the electrical signals. The display is connected to the control device and is used to display the intracranial images.

7. The intracranial imaging system according to claim 5, characterized in that, It also includes power amplifiers; The power amplifier is located between the signal generator and the transmitting module to amplify the excitation electrical signal and transmit it to the transmitting module.

8. The intracranial imaging system according to claim 5, characterized in that, The light source generator and the receiving module are connected via multimode optical fiber.

9. The intracranial imaging system according to claim 5, characterized in that, The light source generator is a semiconductor laser.

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