Design of flexible implantable miniature ultrasonic stimulation system for nerve regulation and control

Abstract

The invention relates to a flexible implantable miniature ultrasonic stimulation system, and aims to solve the problems of insufficient minimally invasive property, poor tissue compatibility and equipment miniaturization in the existing nerve regulation and control technology. According to the system, the miniature ultrasonic transducer is combined with the flexible electronic technology, efficient and accurate regulation and control of a complex neural network are achieved, and the system is particularly suitable for treatment of nervous system diseases. The system comprises a flexible substrate, a miniature ultrasonic transducer, a driving and control module, a packaging layer, an integrated circuit and data interface, an implantation fixing structure and a power module. The system has the advantages of miniaturization, minimally invasive property and high efficiency, can be widely applied to treatment of nervous system diseases, and particularly has wide application prospects in the fields of deep nerve regulation and control, nerve stimulation and recovery and the like.

Description

Technical Field

[0001] The present invention relates to the design and application of a flexible implantable micro-ultrasound stimulation system, aiming to provide an efficient, minimally invasive and precise solution for the treatment of nervous system diseases, and belongs to the fields of biomedical engineering and neuroscience. Background Art

[0002] Neuromodulation technology is an important means of treating a variety of neurological diseases, including epilepsy, Parkinson's disease and chronic pain. However, traditional electrical stimulation methods have significant limitations. For example, the rigid structure of the stimulation electrode can easily cause mechanical damage to the tissue, thereby inducing inflammation and fibrosis. At the same time, due to the limited range of electrical stimulation, it is difficult to achieve precise stimulation of deep tissues, which greatly limits its widespread clinical application. Therefore, finding a more flexible, minimally invasive and efficient neuromodulation technology has become the focus of current research.

[0003] In recent years, ultrasound stimulation technology has received widespread attention as an emerging means of neuroregulation. Studies have shown that ultrasound can affect the membrane potential of neurons through its unique mechanical vibration, acoustic cavitation effect, and thermal effect, thereby regulating neural activity. Compared with traditional electrical stimulation, ultrasound stimulation has stronger tissue penetration and high spatial resolution, and can achieve non-contact deep tissue regulation. Despite this, most of the ultrasound stimulation devices on the market are large laboratory instruments that are difficult to meet the needs of implantable applications. How to achieve the miniaturization and precision of ultrasound stimulation equipment is still a key issue in the current technological development.

[0004] The rapid development of flexible electronic technology has provided new possibilities for implantable neural regulation devices. Flexible materials such as polyimide (PI), polydimethylsiloxane (PDMS) and liquid metals have been widely used in the research and development of flexible sensors and stimulators due to their excellent mechanical flexibility, biocompatibility and electrical properties. These materials can not only significantly reduce the mechanical stimulation of implants on neural tissues, but also enhance the fit of the device to complex biological tissues. However, in the development of flexible electronic devices, there are still many challenges in organically combining flexible materials with ultrasonic stimulation functions, while achieving structural miniaturization and functional efficiency.

[0005] The research and development of flexible implantable ultrasound stimulation systems requires overcoming multiple obstacles in materials science and engineering design. First, the miniaturized design of ultrasonic transducers is key. Most existing ultrasonic transducers use hard ceramic materials, such as piezoelectric ceramics, and the rigid structures of these materials are difficult to be compatible with flexible devices. In addition, how to integrate efficient ultrasonic transducers on flexible substrates and ensure their long-term stability and durability in complex biological environments is an important issue that needs to be addressed. Secondly, the reliability of device packaging is also a technical bottleneck. Flexible ultrasound devices need to work in a humid and corrosive in vivo environment. Therefore, their packaging materials must have excellent barrier properties and mechanical strength to ensure the stable operation of the device.

[0006] At present, research on flexible implantable ultrasound stimulation systems is still in its early stages. Some laboratories have successfully developed small ultrasonic transducers based on flexible materials, but the energy output efficiency and stability of these devices still need to be improved. In addition, how to accurately connect flexible ultrasound stimulation devices to the complex neural network of the human body and achieve efficient neural regulation through optimized design is also an important research direction. Therefore, the development of a flexible, miniaturized and efficient implantable ultrasound stimulation system will provide a new solution for the application and promotion of neural regulation technology. Summary of the invention

[0007] The present invention provides a flexible implantable micro-ultrasound stimulation system, which aims to solve the problems of insufficient minimal invasiveness, poor tissue compatibility and equipment miniaturization in existing neural regulation technologies. The system combines micro-ultrasound transducers with flexible electronic technology to achieve efficient and precise regulation of complex neural networks.

[0008] The system of the present invention mainly includes the following components:

[0009] Flexible Substrate:

[0010] The flexible substrate is the core carrier of the entire system, which is made of polyimide (PI), polydimethylsiloxane (PDMS) or liquid metal-like materials. The flexible substrate has excellent mechanical flexibility and biocompatibility, and can fit tightly with the surface of complex biological tissues. In the design of the substrate, its thickness and mechanical properties are specially optimized to ensure that the device can withstand mechanical deformation in the in vivo environment while reducing stimulation to surrounding tissues.

[0011] Micro ultrasonic transducer:

[0012] The micro-ultrasonic transducer is the core component for achieving neural regulation. The transducer is made of piezoelectric thin film materials (such as lithium niobate or lead zirconate titanate), and its thickness is controlled within 5 mm to take into account both transduction efficiency and flexibility requirements. The surface of the transducer is formed with platinum or metal indium electrodes through photolithography technology to ensure its efficient electrical signal transmission capability. The transducer also integrates multiple layers of acoustic matching layers to optimize the efficiency of sound wave output and reduce energy loss in the body.

[0013] Drive and control module:

[0014] The drive and control module includes a signal generator, a power amplifier, and a frequency adjustment circuit. The signal generator generates an electrical signal of a specific frequency and waveform, and drives the micro-ultrasonic transducer to work through the power amplifier. The frequency adjustment circuit is used to dynamically adjust the frequency and intensity of the ultrasound to meet different neural regulation needs. The drive module adopts a system-on-chip (SoC) design, which greatly reduces the size and power consumption of the circuit.

[0015] Encapsulation layer:

[0016] To ensure the long-term stability of the system, the encapsulation layer uses a multi-layer barrier material, the outer layer is polydimethylsiloxane (PDMS) with excellent wear resistance and biocompatibility, the middle layer is a polymer barrier film, and the inner layer is a conductive shielding layer. The encapsulation layer can not only isolate the infiltration of body fluids, but also enhance the mechanical strength of the device and prevent the performance of the device from deteriorating due to changes in the biological environment.

[0017] Integrated circuits and data interfaces:

[0018] The system is equipped with miniaturized integrated circuits for signal acquisition and data processing. Through the built-in wireless communication module, the device can transmit working status and real-time data to external devices for easy clinical monitoring and debugging. The data interface adopts a low-power design to extend the working life of the device.

[0019] Implantation of fixation structures:

[0020] To ensure the stability of the system in vivo, the present invention designs an implant fixation structure. The structure is combined with the surrounding tissues through flexible arms and micro-fixation hooks to ensure that the device will not shift during physiological activities. At the same time, the structure also has a certain degree of elasticity and can change with the movement of biological tissues. It was tested by implantation in the CA3b area and M1 area of ​​the hippocampus.

[0021] Power module:

[0022] The system has a built-in micro lithium battery or rechargeable capacitor to keep the device running for a long time. The power module is optimized to meet the high power requirements of the ultrasonic transducer and supports external wireless charging, reducing the complexity of maintenance after implantation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of the flexible implantable micro-ultrasound stimulation system of the present invention;

[0024] Figure 2 Schematic diagram of the position of the device after implantation in the body. DETAILED DESCRIPTION

[0025] The present invention provides a flexible implantable micro-ultrasonic stimulation system, which combines a micro-ultrasonic transducer with flexible electronic technology to achieve precise control of neural networks. The system includes a flexible substrate, a micro-ultrasonic transducer, a drive and control module, a packaging layer, an integrated circuit, an implant fixing structure and a power module. The flexible substrate is made of polyimide or polydimethylsiloxane, which has good mechanical flexibility and biocompatibility. The micro-transducer uses piezoelectric film material to optimize the efficiency of sound wave output. The drive module adopts a low-power design, and the system is equipped with a wireless communication module and a built-in power supply to achieve efficient and long-term neural control.

Claims

1. A design of a flexible implantable micro-ultrasound stimulation system for neural regulation, characterized in that: include: A flexible substrate, a micro-ultrasonic transducer, a drive and control module, a packaging layer, an integrated circuit and a data interface, an implant fixation structure, and a power module, wherein the flexible substrate is made of polyimide, polydimethylsiloxane, and a liquid metal-like material, has excellent mechanical flexibility and biocompatibility, can fit closely with biological tissues, and its thickness and mechanical properties are optimized during design to ensure that it can adapt to mechanical deformation in the in vivo environment and reduce stimulation to surrounding tissues; the micro-ultrasonic transducer is made of piezoelectric film materials, such as lithium niobate or lead zirconate titanate, and its thickness is controlled within 5 microns. Electrodes are formed on the surface of the transducer by photolithography technology, and a multi-layer acoustic matching layer is integrated to improve the output efficiency of ultrasound and reduce energy loss; the drive and control module includes a signal generator, a power amplifier, and a frequency adjustment circuit. The micro-ultrasonic transducer is driven to work by the power amplifier, and the frequency adjustment circuit can adjust the ultrasound according to the needs of neural regulation. frequency and intensity, the module adopts a system-on-chip design to reduce the circuit volume and power consumption; the packaging layer is composed of a multi-layer barrier material, the outer layer adopts polydimethylsiloxane to provide good wear resistance and biocompatibility, the middle layer is a polymer barrier film, and the inner layer is a conductive shielding layer, which can effectively prevent the infiltration of body fluids and enhance the mechanical strength of the equipment; the integrated circuit and data interface can realize signal acquisition and data processing, and transmit the working status and real-time data to external equipment through the wireless communication module, which is convenient for clinical monitoring and debugging; the implant fixation structure stably fixes the system in the biological tissue through flexible arms and micro fixation hooks to ensure that the equipment does not shift during physiological activities, and at the same time has a certain degree of elasticity to adapt to the movement changes of biological tissues; the power module adopts a micro lithium battery or a rechargeable capacitor, which can meet the high power requirements of the micro ultrasonic transducer and support external wireless charging function, reducing the complexity of maintenance after implantation.

2. A design of a flexible implantable micro-ultrasound stimulation system for neural regulation according to claim 1, characterized in that: The thickness of the micro ultrasonic transducer material is controlled within 5 mm to ensure that the transducer has sufficient flexibility and high ultrasonic conversion efficiency.

3. The design of a flexible implantable micro-ultrasound stimulation system for neural regulation according to claim 1, characterized in that: The outer layer of the packaging layer is made of polydimethylsiloxane material, which has excellent corrosion resistance and biocompatibility. It can effectively prevent the equipment from being corroded by body fluids in the human body, ensuring the long-term stable operation of the system; the middle layer is a polymer barrier film, which can further improve the water-proof and chemical resistance of the packaging layer. The inner layer is a conductive shielding layer, which effectively prevents the influence of external electromagnetic interference on the system and ensures the normal operation of the ultrasonic transducer.

4. A design of a flexible implantable micro-ultrasound stimulation system for neural regulation according to claim 1, characterized in that: The driving and control module can dynamically adjust the frequency, intensity and waveform of ultrasound according to the neural regulation requirements of actual applications to achieve neural activity regulation in the CA3b and M1 regions of the hippocampus.

5. The design of a flexible implantable micro-ultrasound stimulation system for neural regulation according to claim 1, characterized in that: The integrated circuit and data interface include a signal acquisition circuit, a data storage module and a wireless communication module, which can collect relevant data during the neural stimulation process in real time and transmit the data to an external device via wireless communication for real-time monitoring by clinicians. The system also supports remote debugging and data analysis to optimize the neural regulation effect.

6. A flexible implantable micro-ultrasound stimulation system for neural regulation according to claim 1, characterized in that: Through optimized design, the power module can effectively meet the high power requirements of the ultrasonic transducer during operation, while supporting external wireless charging function, reducing the difficulty of maintaining the implanted device, and has the ability to work stably for a long time, so that the system can continue to provide stable ultrasonic stimulation effects during use.

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