Intelligent contact lens for monitoring intraocular pressure

Abstract

The invention discloses an intelligent contact lens for monitoring intraocular pressure, which relates to the technical field of intraocular pressure monitoring and comprises a cornea contact layer, a self-lubricating layer and a sensing layer, a plurality of bubble holes are uniformly distributed in the cornea contact layer close to the outer edge of the inner ring; a controller, a vibrator and a storage module are embedded in the cornea contact layer; the self-lubricating layer is arranged on the outer side of the cornea contact layer and forms a double-lens structure with the cornea contact layer; the sensing layer is embedded between the self-lubricating layer and the cornea contact layer, and the vibration sensor, the wireless transmission module and the power module are integrated on the sensing layer; the controller is connected with the wireless transmission module, the vibrator, the vibration sensor and the storage module through stretchable and interconnected wires, and the wireless transmission module is further connected with the power module through stretchable and interconnected wires. The intraocular pressure monitoring system can realize real-time dynamic intraocular pressure monitoring and has good biocompatibility.

Description

Technical Field

[0001] The present invention relates to the technical field of intraocular pressure monitoring, and in particular to an intelligent contact lens for monitoring intraocular pressure. Background Art

[0002] Glaucoma is one of the three major blinding eye diseases that cause blindness in humans, with an overall population incidence of 1% and 2% after the age of 45. Intraocular pressure monitoring is of great significance.

[0003] Traditional intraocular pressure monitoring needs to be carried out in a hospital, which is not only time-consuming for doctors and patients, but also difficult to achieve continuous 24-hour monitoring. It is impossible to accurately grasp the fluctuation law of intraocular pressure, and the currently commonly used intraocular pressure measurement and monitoring technologies have defects in terms of size, measurement accuracy, power consumption, and intelligence.

[0004] Most existing tonometers are point-type measurements, which are large in volume, high in cost, lack portability, and cannot achieve 24-hour real-time dynamic intraocular pressure monitoring; although invasive intraocular pressure sensors can directly obtain accurate values of intraocular pressure, they will inevitably cause trauma to patients during the implantation process; non-invasive intraocular pressure sensors are integrated through corneal contact lenses or other devices, and the sensor is attached to the corneal surface. For example, the sensor is based on principles such as capacitance, inductance, strain gauge, and microfluidics. Its essence is to monitor the intraocular pressure by monitoring the deformation and tension of the cornea under the change of intraocular pressure. It is strongly interfered by individual differences, the collected information is relatively single, and it is difficult to demodulate accurate intraocular pressure values.

[0005] Therefore, it is an urgent problem for those skilled in the art to propose an intelligent contact lens for monitoring intraocular pressure to solve the difficulties existing in the prior art. Summary of the Invention

[0006] In view of this, the present invention provides an intelligent contact lens for monitoring intraocular pressure, which can achieve real-time dynamic intraocular pressure monitoring and has good biocompatibility.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An intelligent contact lens for monitoring intraocular pressure, comprising: a corneal contact layer, a self-lubricating layer, and a sensing layer;

[0009] A number of air bubble holes are evenly distributed near the outer edge of the inner circle of the corneal contact layer, and a controller, an oscillator, and a storage module are embedded in the corneal contact layer;

[0010] The self-lubricating layer is provided on the outside of the corneal contact layer and forms a double-lens structure with the corneal contact layer;

[0011] The sensing layer is embedded between the self-lubricating layer and the corneal contact layer, and a vibration sensor, a wireless transmission module, and a power supply module are integrated in the sensing layer;

[0012] The controller is connected to the wireless transmission module, the oscillator, the vibration sensor, and the storage module through stretchable interconnected wires. The wireless transmission module is also connected to the power module through stretchable interconnected wires. The wires are in a horseshoe structure;

[0013] The controller controls the oscillator to apply vibrations to the cornea. The vibration sensor collects vibration signals at different positions of the cornea and transmits them to the controller for signal processing to obtain intraocular pressure data;

[0014] The wireless transmission module is used for the communication of the controller and the transmission of intraocular pressure data;

[0015] The power module is used to provide a regulated voltage and current power supply for the wireless transmission module and the controller;

[0016] The storage module is used to store vibration signals and intraocular pressure data.

[0017] Preferably, an optical correction area is provided at the central position of the corneal contact layer. The controller, the oscillator, the vibration sensor, the wireless transmission module, the storage module, and the power module are all provided outside the optical correction area.

[0018] Preferably, the vibration sensor and the oscillator are evenly distributed around the optical correction area. The controller applies excitation signals with different frequencies to the oscillator, and the oscillator generates vibrations and applies them to the cornea; the frequency of the excitation signal is 1 Hz to 1 kHz.

[0019] Preferably, the vibration sensor is a piezoelectric sensor, an electromagnetic sensor, a capacitive sensor, or a resistive sensor. The number of vibration sensors is ≥2, and they are symmetrically distributed in the sensor layer.

[0020] Preferably, the oscillator and the vibration sensor work in combination. The excitation signal of the oscillator and the received signal of the vibration sensor are subjected to a discrete Fourier transform. The transformation formula is:

[0021]

[0022] In the formula, x(n) represents the time-domain signal, and X(k) represents the frequency-domain signal;

[0023] In the frequency-domain signal of the excitation signal, a peak search algorithm is used to identify the frequency with the maximum intensity, and the center frequency, intensity, and full width at half maximum are recorded;

[0024] The discrete Fourier transform is performed on the vibration sensor signal, and the center frequency, intensity, and full width at half maximum are recorded;

[0025] The center frequencies, intensities, and full widths at half maximum of the two are compared to construct the correlation with the intraocular pressure;

[0026] Compare the vibration sensor signals at different positions, and extract the time delay, frequency drift, and amplitude loss information between the sensor signals at different positions.

[0027] Preferably, the controller performs signal processing based on the excitation signal and the vibration sensor signal:

[0028] Compare the excitation signal of the oscillator with the signals collected by a single vibration sensor respectively, and extract the waveform information between the sensor signal and the excitation signal;

[0029] Compare the signals collected by vibration sensors at different positions, and extract the waveform information between the signals collected by different sensors;

[0030] Introduce the spatial positions of each vibration sensor to construct the vector distribution of the characteristic signals on the cornea;

[0031] Combine the signals of each vibration sensor with the excitation signal to demodulate the mechanical properties of the cornea, and then obtain the intraocular pressure.

[0032] Preferably, the corneal contact layer is a lower lens made of a high molecular hydrophilic material, polyvinyl alcohol hydrogel.

[0033] Preferably, the self-lubricating layer includes: an upper lens made of a high molecular hydrophilic material, polyvinyl alcohol hydrogel, and a lubricating coating provided on the surface of the upper lens.

[0034] Through the above technical solutions, compared with the prior art, the present invention provides an intelligent contact lens for monitoring intraocular pressure, which has the following beneficial effects: The present invention uses vibration sensors to obtain the intensity, frequency, and time delay of vibrations, corresponding to the intrinsic mechanical properties of the cornea, and can exclude various interference factors caused by individual differences and user behaviors; The present invention designs multiple vibration sensors at different positions on the corneal contact layer to collect signals, with more information and stronger anti-interference ability, significantly improving the accuracy of intraocular pressure; The present invention has good biocompatibility. The bubble hole design of the corneal contact layer is beneficial to reducing the interference of surface friction on the sensing signal, has excellent oxygen permeability and wettability, alleviates the problem of corneal hypoxia, and avoids eye discomfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0036] Figure 1 It is a system structure diagram of an intelligent contact lens for monitoring intraocular pressure provided by the present invention;

[0037] Figure 2 Schematic waveform diagram of the oscillator excitation signal provided by the present invention;

[0038] Figure 3 Schematic waveform diagram of the vibration sensor signal provided by the present invention. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] In this application, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. The terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0041] Referring to Figure 1 As shown, the present invention discloses an intelligent contact lens for monitoring intraocular pressure, including: a corneal contact layer, a self-lubricating layer, and a sensing layer;

[0042] A number of air bubble holes are evenly distributed near the outer edge of the inner circle of the corneal contact layer, and a controller, an oscillator and a storage module are embedded in the corneal contact layer;

[0043] The self-lubricating layer is arranged on the outer side of the corneal contact layer and forms a double-lens structure with the corneal contact layer;

[0044] The sensing layer is embedded between the self-lubricating layer and the corneal contact layer, and a vibration sensor, a wireless transmission module and a power supply module are integrated in the sensing layer;

[0045] The controller is connected to the wireless transmission module, the oscillator, the vibration sensor and the storage module through stretchable interconnected wires, and the wireless transmission module is also connected to the power supply module through stretchable interconnected wires. The wires are in a horseshoe shape; the wires are in a horseshoe shape, so that the electronic components embedded in the lens allow the device to be bent as needed to insert or remove it.

[0046] The controller controls the oscillator to apply vibrations to the cornea. The vibration sensor collects vibration signals at different positions of the cornea and transmits them to the controller for signal processing to obtain intraocular pressure data;

[0047] The wireless transmission module is used for the communication of the controller and the transmission of intraocular pressure data;

[0048] The power supply module is used to provide a regulated voltage and current power supply for the wireless transmission module and the controller;

[0049] The storage module is used to store vibration signals and intraocular pressure data.

[0050] Furthermore, an optical correction area is provided at the central position of the corneal contact layer, and the controller, oscillator, vibration sensor, wireless transmission module, storage module, and power supply module are all arranged outside the optical correction area.

[0051] Specifically, the corneal contact layer fits effectively with the eye cornea. The optical correction area is a transparent optical window, which does not block the line of sight and provides the function of vision correction; the controller is powered by the power supply module and realizes the functions of communication, signal acquisition and processing, and frequency conversion signal source; the wireless transmission module is used to communicate with an external radio frequency reader and transmit information such as intraocular pressure, vibration data, and battery status;

[0052] Even further, the vibration sensors and oscillators are evenly distributed around the optical correction area. The controller applies excitation signals with different frequencies to the oscillators, and the oscillators generate vibrations and apply them to the cornea; the frequency of the excitation signal is 1 Hz to 1 kHz, and this frequency range is consistent with the natural oscillation frequency of the cornea. Using this frequency range as the excitation signal frequency, the characteristic information collected by the sensor has a greater correlation with the intraocular pressure, making the intraocular pressure measurement more accurate.

[0053] Furthermore, the vibration sensor is a piezoelectric sensor, electromagnetic sensor, capacitive sensor, or resistive sensor, and the number of vibration sensors ≥ 2, which are symmetrically distributed in the sensor layer.

[0054] Even further, multiple vibration sensors can be placed, which is beneficial for overcoming individual differences (corneal thickness, thickness distribution). The vibration sensors and oscillators are evenly distributed around the optical correction area. For example, two vibration sensors and one oscillator are distributed outside the optical correction area at intervals of 120° centered on the optical correction area.

[0055] Even further, referring to Figure 2 and Figure 3 as shown, the oscillator and the vibration sensor work in combination. The excitation signal of the oscillator and the received signal of the vibration sensor are subjected to discrete Fourier transform, and the transformation formula is:

[0056]

[0057] Wherein, x(n) represents the time-domain signal, and X(k) represents the frequency-domain signal;

[0058] In the frequency-domain signal of the excitation signal, a peak-seeking algorithm is used to identify the frequency with the maximum intensity, and the central frequency, intensity, and full-width at half maximum are recorded;

[0059] Perform discrete Fourier transform on the vibration sensor signal, and record the central frequency, intensity, and full-width at half maximum;

[0060] Compare the central frequency, intensity, and full-width at half maximum of the two, and construct the correlation with the intraocular pressure;

[0061] Compare the vibration sensor signals at different positions, and extract the time delay, frequency drift, and amplitude loss information between the sensor signals at different positions.

[0062] Furthermore, the controller performs signal processing based on the excitation signal and the vibration sensor signal:

[0063] Compare the excitation signal of the oscillator with the signals collected by a single vibration sensor respectively, and extract the waveform information between the sensor signal and the excitation signal;

[0064] Compare the signals collected by vibration sensors at different positions, and extract the waveform information between the signals collected by different sensors;

[0065] Introduce the spatial positions of each vibration sensor, and construct the vector distribution of the characteristic signals on the cornea;

[0066] Combine the signals of each vibration sensor with the excitation signal to demodulate the mechanical properties of the cornea, and then obtain the intraocular pressure.

[0067] Furthermore, the corneal contact layer is a lower lens made of a high-molecular hydrophilic material, polyvinyl alcohol hydrogel; this design is beneficial to the biocompatibility with the eye, and at the same time has a bubble hole design, which is beneficial to reducing the interference of surface friction on the sensing signal, has excellent oxygen permeability and wettability, alleviates the problem of corneal hypoxia, and avoids eye discomfort.

[0068] Furthermore, the self-lubricating layer includes: an upper lens made of a high-molecular hydrophilic material, polyvinyl alcohol hydrogel, and a lubricating coating disposed on the surface of the upper lens; the lubricating coating has the characteristics of low friction and wear resistance, high bonding strength, and is not easy to fall off.

[0069] In a specific embodiment, an oscillator and two vibration sensors are employed, and the vibration sensors are located in the outer annular region of the optical correction area. To further improve the measurement accuracy of intraocular pressure, the oscillator and the two vibration sensors are centered on the optical correction area and are distributed at intervals of 120° pairwise on the outside of the optical correction area. The smart contact lens transmits data to an external reader through a wireless transmission module and then to the user's mobile terminal, such as a mobile phone or a personal computer. The application in the mobile terminal can save user data, record the dynamic changes of the user's intraocular pressure, and display it in real time. And the application can construct a personal medical model based on the data of the user's smart contact lens and supplementary reference data (such as gender, height, weight, corneal parameters detected by medical institutions), making the dynamic intraocular pressure monitoring results more accurate; the application also includes intraocular pressure early warning and other medical services. When in use, the user wears the smart contact lens on the surface of the eyeball. The smart contact lens communicates with the reader through a wireless transmission module and starts to work.

[0070] In the working state, it controls and processes the working states and signals of each built-in module. The digital-to-analog converter (DAC) is used to modulate digital signals into analog signals. After power amplification, the oscillator generates stable vibrations with digital signal modulation. The sensing signal processing module is used to perform preliminary filtering and amplification on the signals collected by the sensors based on principles such as Fourier transform, wavelet, and adaptive, and is collected and demodulated by the analog-to-digital converter (ADC). The power module and the wireless transmission module are connected by stretchable interconnected wires. The power module is used to provide a regulated power supply with stable voltage and current for the wireless transmission module and the controller; the storage module is used to store vibration signals and intraocular pressure data.

[0071] This embodiment specifically describes one preferred method for extracting delay signals: The excitation signal is synchronized with the vibration sensor signal in time. The peak search algorithm is used for the excitation signal, preferably the peak search algorithm based on the dynamic threshold method, to find the time position of the first peak. After low-pass filtering the collected sensor signals, the peak search algorithm is used to find the time positions of the first peak and the highest peak in the same pulse, and the differences are made with the time position of the first peak of the excitation signal respectively to calculate the delay information, and then the correlation between the delay information and the intraocular pressure is constructed. This method is simple to implement and has a low computational load. The delay signal has a strong correlation with the corneal modulus. Combining the sensor signals at multiple spatial positions makes the intraocular pressure measurement more accurate.

[0072] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for a system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for the relevant parts, reference can be made to the partial description of the method embodiment. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative efforts.

[0073] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A smart contact lens for monitoring intraocular pressure, characterized in that: include: Corneal contact layer, self-lubricating layer, sensing layer; A number of air bubble holes are evenly distributed near the outer edge of the inner circle of the corneal contact layer, and a controller, a vibrator and a storage module are embedded in the corneal contact layer; A self-lubricating layer is arranged on the outer side of the corneal contact layer and forms a double lens structure with the corneal contact layer; The sensing layer is embedded between the self-lubricating layer and the corneal contact layer, and the vibration sensor, the wireless transmission module and the power module are integrated in the sensing layer; The controller is connected to the wireless transmission module, the vibrator, the vibration sensor and the storage module through a stretchable interconnected wire, and the wireless transmission module is also connected to the power module through a stretchable interconnected wire, and the wire is a horseshoe-shaped structure; The controller controls the vibrator to apply vibration to the cornea, and the vibration sensor collects vibration signals at different positions of the cornea and transmits them to the controller for signal processing to obtain intraocular pressure data; The wireless transmission module is used for controller communication and intraocular pressure data transmission; The power module is used to provide a stable voltage and current power supply for the wireless transmission module and the controller; The storage module is used to store vibration signals and intraocular pressure data.

2. The smart contact lens for monitoring intraocular pressure according to claim 1, characterized in that: An optical correction area is arranged at the center of the corneal contact layer, and a controller, a vibrator, a vibration sensor, a wireless transmission module, a storage module and a power supply module are arranged outside the optical correction area.

3. The smart contact lens for monitoring intraocular pressure according to claim 2, characterized in that: The vibration sensor and the vibrator are evenly distributed around the optical correction area. The controller applies excitation signals of different frequencies to the vibrator, and the vibrator generates vibrations that are applied to the cornea. The frequency of the excitation signal is 1 Hz to 1 KHz.

4. The smart contact lens for monitoring intraocular pressure according to claim 3, characterized in that: The vibration sensor is a piezoelectric sensor, an electromagnetic sensor, a capacitive sensor or a resistive sensor. The number of the vibration sensors is ≥2 and they are symmetrically distributed on the sensor layer.

5. The smart contact lens for monitoring intraocular pressure according to claim 3, characterized in that: The vibrator and the vibration sensor work together to perform discrete Fourier transform on the excitation signal of the vibrator and the receiving signal of the vibration sensor. The transformation formula is: In the formula, x(n) represents the time domain signal, and X(k) represents the frequency domain signal; In the frequency domain signal of the excitation signal, the peak-finding algorithm is used to identify the frequency with the largest intensity, and the center frequency, intensity, and half-peak width are recorded; Perform discrete Fourier transform on the vibration sensor signal and record the center frequency, intensity, and half-peak width; The center frequency, intensity, and half-peak width of the two were compared to construct a correlation with intraocular pressure; Compare the vibration sensor signals at different locations and extract the time delay, frequency drift, and amplitude loss information between the sensor signals at different locations.

6. The smart contact lens for monitoring intraocular pressure according to claim 5, characterized in that: The controller performs signal processing based on the excitation signal and the vibration sensor signal: The excitation signal of the vibrator is compared with the signal collected by a single vibration sensor, and the waveform information between the sensor signal and the excitation signal is extracted; Compare the collected signals of vibration sensors at different positions and extract the waveform information between the collected signals of different sensors; The spatial position of each vibration sensor is introduced to construct the vector distribution of characteristic signals on the cornea; The signals of each vibration sensor are combined with the excitation signal to demodulate the mechanical properties of the cornea and obtain the intraocular pressure.

7. The smart contact lens for monitoring intraocular pressure according to claim 1, characterized in that: The corneal contact layer is a lower lens made of high molecular weight hydrophilic material polyvinyl alcohol hydrogel.

8. The smart contact lens for monitoring intraocular pressure according to claim 1, characterized in that: The self-lubricating layer comprises: an upper lens made of a high molecular hydrophilic material polyvinyl alcohol hydrogel and a lubricating coating arranged on the surface of the upper lens.

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