CN112263233A

CN112263233A - Human body internal pressure sensing array based on catheter

Info

Publication number: CN112263233A
Application number: CN202010672291.4A
Authority: CN
Inventors: 李儒雅; 樊瑜波; 王雅馨
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2020-07-14
Filing date: 2020-07-14
Publication date: 2021-01-26

Abstract

The invention discloses a catheter-based human body internal pressure sensing array, which comprises a carrier catheter and a pressure sensor array. The pressure sensor array includes at least one pressure sensor, the pressure sensor includes a pressure sensitive layer, an electrical signal conducting layer, and a wire, wherein the electrical signal conducting layer includes at least one electrode. The pressure-sensitive layer can sense pressure and convert the pressure into an electrical signal, and the electrical signal conducting layer can collect the electrical signal and conduct the electrical signal through the electrodes and wires. One or more of the pressure sensors are distributed outside the carrier conduit to form a pressure sensor array.

Description

Human body internal pressure sensing array based on catheter

Technical Field

The invention relates to the technical field of sensors. In particular, the present invention relates to a catheter-based internal body pressure sensing array.

Background

The muscle activity inside the human body, the interaction of the tissues and the interaction of the medical apparatus and the human body are very complex, and different activities and actions can also generate different pressure information inside the human body. As food enters the stomach from the mouth, such as during swallowing, pressure on the esophagus occurs at various locations; when the enteroscope enters the intestinal tract, the enteroscope and the inner wall of the intestinal tract act to generate pressure; when the airway collapses to generate breath pause, the pressure generated at the collapse part. The knowledge of the pressure information is of great significance to the judgment of the patient's condition or the performance of the doctor's operation. However, most of the existing measurements of mechanical information in the body of a patient depend on indirect measurement or doctor experience estimation, and the reliability of final data needs to be further improved. If the equipment capable of directly measuring the pressure change in the human body is provided, more comprehensive information can be provided, so that the condition of a patient can be more comprehensively known.

Take the Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) as an example. Partial or complete obstruction of an upper respiratory tract can repeatedly occur when a patient with obstructive sleep apnea hypopnea syndrome sleeps, so that apnea or hypopnea is caused, blood oxygen saturation is lowered frequently, sleep structure disorder is caused, and then multiple organ tissues such as blood vessels, heart, brain and the like are damaged. The "gold standard" tool currently and generally used in the clinic for diagnosing OSAHS is the Polysomnography (PSG), and portable sleep monitors have also started to be used in recent years. The above system allows for overall monitoring and diagnosis of apnea, hypopnea and hypoxemia, i.e., macroscopically assessing the severity of the obstruction and obstruction, but has two disadvantages. One is the indirection of the evaluation. PSG indirectly reflects the obstruction and low ventilation change of a respiratory channel through the obtained air flow thoracic motion outside the mouth and the nose, and cannot directly reflect the most important pathological change of a specific pathogenic link in the pathogenic process of the disease, namely the specific collapse and blockage change of an upper respiratory tract. Secondly, PSG can only qualitatively and quantitatively determine the upper respiratory tract macroscopically, and cannot determine a specific occlusion plane, i.e., cannot accurately analyze, monitor and diagnose specific occlusion sites and the degree of occlusion at each occlusion site.

The method for removing the blockage of the anatomical part through the surgical operation is one of important ways for treating the OSAHS, and the accurate obtaining of the information of the blocked part before the operation and the accurate operation of the blocked area are the keys for improving the curative effect, so that the method has important clinical significance for the blockage positioning diagnosis of the OSAHS patient. Currently available sleep apnea blocking systems are apneagraph and flextube. The principle of the apneagraph is that the air pressure sensor is used for collecting the air pressure at different positions of a breathing passage and calculating the difference of the air pressure to perform blocking positioning; flextube is somewhat more complex, and sound transmission is affected by sound conduction in a duct at different pressures, and the pressure changes around the duct are obtained by indirectly measuring the sound transmission changes to locate the breathing obstruction. At present, there is no related introduction of domestic products and independent intellectual property designs owned by China.

In addition, some medical devices have no objective standard for judging the contact pressure with the internal tissues of the human body after entering the human body, such as enteroscopy. Clinically, patients with lower abdominal pain, abdominal mass, etc. of unknown origin often require an enteroscopy. Enteroscopy is a kind of endoscope, and is a medical device which is long and flexible and has a diameter of about 1cm, enters the large intestine through the anus and rectum, can observe the internal conditions of the large intestine and the colon, and is a common method for examining the large intestine and the colon. Clinically, one of the risks of enteroscopy is the occurrence of perforation of the intestine, a common cause of which is the mechanical stress exerted by the enteroscope on the intestine, especially at the enteroscope head and the intestine bend. At present, excessive mechanical pressure can only be avoided according to the experience of doctors and the visual field of the enteroscope, so that an objective method for directly measuring the contact pressure between the enteroscope and the inner wall of the intestinal canal is lacked.

As described above, although pressure information in the human body is of great significance for clinical diagnosis and the like, there is no objective and direct method for obtaining pressure information, and thus a device capable of directly measuring the contact pressure in the human body is urgently needed to solve the problem.

Disclosure of Invention

The invention provides a catheter-based human body internal pressure sensing array, which can provide a brand-new solution for the problems, and adopts the following technical scheme for achieving the purpose:

a catheter-based internal body pressure sensing array, comprising: a carrier conduit; an array of pressure sensors comprising at least one pressure sensor; wherein the conduit is used for a mounting carrier of the pressure sensor; the pressure sensor may convert a pressure signal into an electrical signal.

In a further embodiment the pressure sensor comprises: a pressure sensitive layer; an electrical signal conducting layer comprising at least one electrode therein; connecting wires; wherein the pressure sensitive layer is capable of sensing pressure and converting the pressure into an electrical signal; the electric signal conducting layer can collect the electric signal and conduct the electric signal through the electrode; the connecting wire is connected out through the electrode and can conduct the electric signal conducted by the electrode.

In a further embodiment, the pressure sensitive layer and the electrical signal conducting layer are attached together, either directly or through an insulating layer, to form a film-like whole that can be tightly attached to the outside of the carrier conduit.

In a further embodiment, the pressure sensitive layer, the electrical signal conducting layer and the insulating layer enclose a closed or non-closed chamber.

In a further embodiment, the pressure sensor, wherein the pressure sensitive layer is one or more of a resistive pressure sensitive layer, a capacitive pressure sensitive layer, a piezoelectric pressure sensitive layer, a triboelectric pressure sensitive layer, and an ionic pressure sensitive layer.

In a further embodiment, the ionic pressure sensitive layer comprises: a layer of ionic material; an electrode layer including at least two electrodes; the ion material layer or the electrode layer can be deformed under the action of external pressure, so that the capacitance formed by the electrode is influenced.

In further embodiments, the carrier catheter may be a stand-alone catheter or may be a catheter portion of an existing medical device.

In a further embodiment, the sensor array and the wiring are connected by individual wiring or grouped wiring.

In a further embodiment, the wiring is routed from the outside of the carrier catheter to the inside thereof and out of the inside thereof by perforating the carrier catheter.

In further embodiments, the pressure sensor array may include any number of the pressure sensors.

In a further embodiment, each of the pressure sensors in the array of pressure sensors may independently measure pressure signals simultaneously.

From the above, the invention provides a catheter-based human body internal pressure sensing array, and the sensitivity and the measuring range of the array can be flexibly adapted. Advantages of the present invention include, but are not limited to, the ability to measure contact pressure inside the human body. The device according to the invention is particularly suitable for assisting the diagnosis of diseases and the use of other implantable medical devices by measuring the internal pressure of the human body.

The details of some exemplary embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the accompanying drawings and from the description of the embodiments and from the claims.

Drawings

FIG. 1 illustrates a schematic diagram of a catheter-based internal body pressure sensing array in accordance with an embodiment of the present invention;

FIG. 2 illustrates a schematic diagram of an ionic pressure sensor in accordance with an embodiment of the present invention;

FIG. 3 illustrates a schematic diagram of a wrap-around wrapping method for a sensor in accordance with an embodiment of the present invention;

FIG. 4 illustrates a spring-loaded winding method of a sensor according to an embodiment of the invention;

FIG. 5 illustrates a wire routing manner according to an embodiment of the present invention;

FIG. 6 illustrates an obstruction locating device for obstructive sleep apnea hypopnea syndrome in accordance with an embodiment of the present invention;

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is clear that the described embodiments are only some of the exemplary embodiments of the present application, and are not exhaustive of all embodiments. Based on the embodiments in the present application, a person skilled in the art will easily make other combinations of technical features and means in these embodiments and the prior art, and all other embodiments obtained thereby are within the spirit and scope of the present application and are within the scope of protection intended by the present application.

The invention may be implemented in numerous ways, such as being implemented as an apparatus, a method, a computer program product. In general, the order of the steps of disclosed processes may be altered within the scope of the invention unless otherwise indicated or logically necessary.

A detailed description of embodiments of the invention is provided below along with accompanying figures that illustrate the principles of the invention. While the invention will be described in conjunction with such embodiments, the invention is not limited to any embodiment. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. The details are provided for the purpose of example and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, techniques known in the art to which the invention relates have not been described in detail so as not to obscure the invention.

The invention discloses a human body internal pressure sensing array based on a catheter. As shown in fig. 1, the invention includes a carrier catheter, a pressure sensor array, wherein the pressure sensor array includes at least one pressure sensor. The pressure sensor comprises a pressure sensitive layer, an electrical signal conducting layer, a wire, wherein the electrical signal conducting layer comprises at least one electrode. The pressure sensitive layer can convert a pressure signal into an electric signal, the electric signal conducting layer can collect the electric signal and conduct the electric signal through the electrode, and the connecting wire is connected out through the electrode and can conduct the electric signal conducted by the electrode. The pressure sensor is attached to the outside of the carrier conduit, and is directly contacted with a site to be measured in work, and the connecting wire enters the conduit through the opening on the carrier conduit and is connected out of the conduit.

In the human body, the pressure change of specific parts in the human body can be generated along with the change of the body position, different physiological activities and the like, which has important significance for the diagnosis of some diseases. For example, in sleep apnea caused by obstructive sleep apnea-hypopnea syndrome, partial or total obstruction of the upper airway occurs, and the corresponding pressure changes. In addition, some implantable medical devices also generate contact pressure after entering a human body, and the knowledge of the pressure information can provide help for a doctor to perform the operation of the device or to check the condition of the device. For example, during enteroscopy, the enteroscope may generate excessive mechanical pressure on the intestinal wall due to improper operation, so that the contact pressure is known to be beneficial to avoid the situation. The pressure sensor array arranged on the catheter enters a human body along with the catheter, and the contact pressure of a specific part can be directly detected. Preferably, the pressure sensor is a thin film monolith that is conveniently attached to the catheter surface. Preferably, the pressure sensitive layer and the electric signal conducting layer of the pressure sensor are both made of flexible materials so as to satisfy good adhesion to the curved surface of the conduit. The pressure sensitive layer may be a solid, liquid, or composite material. The material of the pressure sensitive layer is subjected to micro displacement under the pressure action of the part to be detected, so that the physical and chemical properties of the pressure sensitive material are changed, and further, electrical signal change is generated, the electrical signal of the conducting layer is changed, and the electrical signal is further transmitted by the conducting layer. The electrical signal conducting layer may be a solid, liquid, or composite material, such as a metal, a conductive liquid, a conductive film, a conductive fabric, graphene, or the like. The electric signal conducting layer can be formed by insulating materials around the electric signal conducting layer or attaching a conducting medium on an insulating substance. The electrical signal conducting layer may be a conductive surface of a layer. The conductive surface can be implemented in a variety of ways, such as an electrically conductive active conductive surface and various conductive materials, such as thin film Indium Tin Oxide (ITO), and can also be electrically conductive by doping the proton with different oxidation states of the active material. The electric signal conducting layer can also be made of metal materials (such as gold, aluminum, silver, copper, iron and the like, and alloys thereof, liquid metal mercury, gallium alloys and other metals); nanostructures (e.g., monoatomic conductors, nanotubes, nanoparticles, nanowires, and the like); non-metallic particles (e.g., carbon black, graphene, carbon nanotubes, zinc oxide nanowires of carbon fullerene, indium oxide, silicon germanium, gallium arsenide, etc.); the insulating layer material can be a variety of non-conductive materials including SU-8 glue, glass, polymer, Avatrel, double sided glue, plastic, BCB PPA (benzocyclobutene), polyimide, silicone rubber (PDMS), polymethylmethacrylate.

In some examples, the pressure sensitive layer is one or more of a resistive pressure sensitive layer, a capacitive pressure sensitive layer, a piezoelectric pressure sensitive layer, a triboelectric pressure sensitive layer, an ionic pressure sensitive layer.

In a further example, the pressure sensitive layer of the pressure sensor and the electric signal conducting layer are directly attached or attached through insulating glue to form a film whole without a cavity or with a cavity.

Taking an ionic thin film pressure sensor as an example, the pressure sensitive layer of the ionic thin film pressure sensor is an ionic pressure sensitive layer, and the sensor realizes a pressure sensing function based on an Electrical Double Layer (EDL). The interface between the electrode material and the electrolyte forms an electric double layer, under the action of static electricity, the positive and negative electrodes attract ions with opposite charges in the electrolyte respectively, and finally, coacervates are formed on two sides of the electrode-electrolyte interface. The charge cannot be neutralized across the interface because of the potential barrier present between the electrode-electrolyte, so a stable capacitance is formed on both sides of the electrode-electrolyte contact interface. The capacitance of the electrical double layer is given by the following equation:

C_H＝ε₀ε_rA/d

wherein, C_HIs an electric double layer capacitance of epsilon₀Is a vacuum dielectric constant of ∈_rIn terms of relative dielectric constant, a is the specific surface area of the electrode layer in contact with the ion functional material layer, and d is the electric double layer thickness. When the device is pressed, the contact area A between the electrode layer and the functional material layer is generatedThe change causes the change of the electric double-layer capacitance, and the pressure signal is converted into an electric signal. The electric double layer thickness d is a nano-scale constant, and thus an output higher than that of the conventional capacitive pressure sensor can be obtained. The ionic thin film pressure sensor is designed based on the EDL principle, and has a structure that the contact area of an electrode and an ionic functional material can be changed along with the pressure applied to a device, so that a pressure signal is detected. As shown in fig. 2, a structure of an ionic flexible membrane pressure sensor is shown. The two layers of the sensor are combined through the insulating layer, and the sensor is provided with a cavity structure. Under the action of pressure, the electrode is in contact with the pressure sensitive layer, the contact area changes along with the pressure, the formed EDL capacitance value changes, and the pressure signal is converted into an electric signal.

In a further embodiment, the carrier catheter is preferably made of a biocompatible material to ensure that it is not harmful to the human body. Preferably, the carrier catheter is a flexible catheter to meet the need to conform to the physiological curvature of the interior of the human body. For example, the silica gel hose has good biocompatibility and is soft, so that the safety can be ensured, and the silica gel hose can be properly bent along with the internal structure of a human body. In operation, the carrier catheter is placed into the region of interest inside the human body. The size and the length of the carrier hose can be adjusted according to the detection target. The inside of the carrier catheter can be added with a guide wire, so that the catheter keeps a certain shape after entering a human body and does not bend or move along with tissue motion, body position change and the like.

In a further example, since the film-type pressure sensor has flexibility and can be attached to the carrier hose, the pressure sensor can be optionally mounted outside the carrier conduit by winding, and the winding can be changed according to the characteristics of the device. For example, as shown in fig. 3, the length of the pressure sensor can be matched with the section perimeter of the carrier conduit, and the pressure sensor can be wrapped outside the carrier hose by winding. For example, as shown in FIG. 4, the pressure sensor may be angled during the wrapping process, such as by spring-like wrapping around the outside of the carrier conduit.

In a further example, as shown in FIG. 5, the sensor wires are routed through openings in the carrier hose, from outside the hose into the interior thereof, and out one end of the hose.

Under the configuration of the pressure sensor array based on the catheter, the acquisition of various human body internal pressure signals can be realized under different scenes.

For example, as shown in fig. 6, there is shown the application of the present invention to the location of an obstruction in obstructive sleep apnea hypopnea syndrome. A plurality of pressure sensors are distributed on the carrier catheter according to the anatomical characteristics of the upper respiratory tract of the human body aiming at the interested area, and then are placed into the hypopharynx through the nostril. After reaching the location, the array of pressure sensors may monitor the contact pressure generated when an object contacts the sensors. When the soft tissues of the respiratory tract collapse to cause the blockage of the lumen, the mucosa can contact the pressure sensor to generate a certain extrusion pressure P1, the extrusion pressure of the mucosa on the pressure sensor is gradually increased along with the increase of the negative pressure of the respiratory tract, the peak value is P2, then the blockage is relieved along with the occurrence of arousal, high-frequency mucosa vibration caused by forced inspiration is accompanied during the relief, the high-frequency vibration can continuously beat the pressure sensor at a certain frequency, and then the snoring period beating pressure P3 is obtained. The sensors are arranged according to the anatomical features of human bodies, such as the arrangement of the pressure sensors aiming at the good hair parts of the soft palate, the posterior tongue root and the like. Therefore, the pressure level and the pressure change mode of the upper respiratory tract of the OSAHS patient in different physiological states (unobstructed, blocked and open with snoring) during sleeping can be accurately obtained in real time, and the obstruction condition of the sleeping respiratory tract can be directly reflected to diagnose diseases; and the specific occlusion plane can be judged, so that the formulation of an operation scheme is assisted and the treatment effect is improved. In specific use, the pressure sensor can also be matched with a data analysis module, a user display module and the like to process and analyze the acquired pressure signals to obtain related information such as the blocking position, the blocking degree and the like.

Claims

1. A catheter-based internal body pressure sensing array, comprising:

a carrier conduit;

an array of pressure sensors comprising at least one pressure sensor;

wherein the conduit is used for a mounting carrier of the pressure sensor; the pressure sensor may convert a pressure signal into an electrical signal.

2. The pressure sensor of claim 1, comprising:

a pressure sensitive layer;

an electrical signal conducting layer comprising at least one electrode therein;

connecting wires;

wherein the pressure sensitive layer is capable of sensing pressure and converting the pressure into an electrical signal; the electric signal conducting layer can collect the electric signal and conduct the electric signal through the electrode; the connecting wire is connected out through the electrode and can conduct the electric signal conducted by the electrode.

3. A pressure sensor according to claim 1 or 2, wherein the pressure sensitive layer and the electrical signal conducting layer are attached together, either directly or through an insulating layer, to form a film-like whole that can be tightly attached to the outside of the carrier conduit.

4. The pressure sensor of claim 3, wherein the pressure sensitive layer, the electrical signal conducting layer and the insulating layer enclose a closed or non-closed chamber.

5. The pressure sensor of any preceding claim, wherein the pressure sensitive layer is one or more of a resistive pressure sensitive layer, a capacitive pressure sensitive layer, a piezoelectric pressure sensitive layer, a triboelectric pressure sensitive layer, an ionic pressure sensitive layer.

6. The pressure sensor of claim 5, wherein the ionic pressure sensitive layer comprises:

a layer of ionic material;

an electrode layer including at least two electrodes;

the ion material layer and/or the electrode layer can be deformed under the action of external pressure, so that the capacitance formed by the electrode is influenced.

7. The carrier catheter of claim 1, wherein one or more of the pressure sensors are conformable thereto.

8. The carrier catheter of claim 1 or 7, which may be a stand-alone catheter or a catheter portion of an existing medical device.

9. The sensor array and wiring of claim 1 wired out individually or in groups.

10. The wiring of claim 1, passing from outside to inside of said carrier conduit and exiting inside thereof by perforating said carrier conduit.

11. The pressure sensor array of claim 1, comprising any number of said pressure sensors.

12. The array of pressure sensors of claims 1, 2, wherein each of said pressure sensors is capable of independently measuring pressure signals at the same time.