Gastrointestinal motility capsule

Abstract

According to the gastrointestinal motility capsule, a bidirectional ultrasonic probe pair is adopted to synchronously obtain the distance from the capsule to the opposite side of a digestive tract part, and a directional cavity diameter is obtained by adding the distance between the probe pair, so that a data fusion error caused by capsule movement can be eliminated; cavity diameters in multiple directions are synchronously obtained, the largest direction is the main shaft direction of the part, and the average value of the cavity diameters in all the directions orthogonal to the largest direction is taken as the average inner diameter; extracting morphological characteristics such as curvature, inner diameter, volume and anatomical position; on the basis of the feature sequence, alimentary canal power parameters such as peristalsis frequency and strength and the movement track and emptying time of the capsule are obtained; the device can be used for digestive tract motility routine examination and disease diagnosis, and examinees do not need to clean the stomach and intestine, can be matched with different diets, and can conveniently perform self-examination at home or go to hospitals for examination.

Description

Technical Field

[0001] The present invention relates to the field of bioinformatics technology, and in particular to a digestive tract detection method, a capsule, and a system. Background Art

[0002] There is a close relationship between digestive tract motility and human physiology and pathology. The existing detection means for digestive tract motility are mainly based on the tracking of radioactive markers, as disclosed in US Patent Application No. 15881671. Since radioactive examinations are harmful to organisms, there is an urgent need for a non-destructive detection scheme for living bodies in the basic research and clinical applications of digestive tract motility. Light, sound, and magnetism are commonly used non-destructive detection means. 3D cameras and digestive tract video capsule robots with magnetic positioning, such as Olympus' EndoCapsule 10 and endoscopic ultrasounds, have been commercially applied. For the implementation technology of the general gastrointestinal capsule system adopted in the present invention, reference can be made to Chinese Patent Application Nos. CN202011339489.7, CN202010260190.6, and US Patent US10932690B2. A capsule robot generally may include sensors, a controller, and an intelligent processor. The sensors and at least part of the controller are usually located inside the capsule, and the intelligent processor is usually located in a control terminal outside the body. The sensors, the controller, and the intelligent processor are usually connected by a wired or wireless communication link. Due to the widespread commercial application of capsule robots, the present invention regards the implementation means well-known to those of ordinary skill in the art in this field as the prior art and will not elaborate on them in the following description of the invention. Summary of the Invention

[0003] The present invention provides a first digestive tract motility detection system, including a data acquisition module, a system control and processing module, and a capsule. The data acquisition module and the system control and processing module are connected by a wired or wireless communication link; the data acquisition module is disposed inside the capsule and is used to acquire one or more of the depth, morphology, and image data of the inner wall of the digestive tract; the system control and processing module is used to receive the data and extract the morphological features of the digestive tract from the data, including one or more of the curvature, inner diameter, and volume of the digestive tract, as parameters for evaluating digestive tract motility.

[0004] The present invention provides a first digestive tract motility detection method corresponding to the above system, including the following steps: acquiring the morphological features of the digestive tract, including one or more of the curvature, inner diameter, and volume, as parameters for evaluating digestive tract motility.

[0005] 5. The present invention provides an ultrasonic capsule for gastrointestinal tract detection, which is internally provided with a plurality of ultrasonic probe pairs. The probes are used to obtain data of the gastrointestinal tract part. The capsule or a device or a processor communicatively connected to the capsule extracts morphological features of the part based on the data, including one or more of curvature, inner diameter, and volume. The morphological features are identified with reference to the corresponding relationship between gastrointestinal tract parts to determine the anatomical position features of the part. Gastrointestinal motility parameters are calculated based on the morphological features, including one or more of the frequency, amplitude, movement trajectory of the capsule, and movement time of the capsule between gastrointestinal tract parts obtained from the data sequence based on the features. The anatomical position features are set as the first position, and one or more of matching, alignment, registration, and fusion are performed on the first position and the second position data of the capsule in any coordinate system outside the gastrointestinal tract collected by magnetic positioning. Among them, probe 1 of any probe pair is used to obtain the first distance from the first direction to one side of the inner wall of the part, and probe 2 is used to obtain the second distance from the second direction to the other side of the inner wall. The included angle between the first direction and the opposite direction of the second direction is less than 38°. The sum of the first distance, the second distance, and the distance between probes 1 and 2 is calculated to obtain a directional lumen diameter. Obtaining the inner diameter may include dividing the longest directional lumen diameter among the directional lumen diameters obtained by the plurality of probe pairs by the shortest directional lumen diameter to obtain a length-to-short ratio. When the length-to-short ratio is greater than or equal to a threshold, the direction of the longest directional lumen diameter is taken as the main channel direction of the part, and the mean value of one or more directional lumen diameters orthogonal to the main channel direction is taken as the inner diameter of the part. When the length-to-short ratio is less than the threshold, the shortest directional lumen diameter is taken as the inner diameter of the part. The threshold can be determined with reference to the gastrointestinal tract anatomical position and is equal to 2 when the position is uncertain. When the number of probe pairs is equal to 2 or 3, the ranging directions of the probe pairs are orthogonal to each other in pairs. When the number of probe pairs is greater than 3, at least 3 of them are orthogonal to each other in pairs. The orthogonality includes a tolerance of 38°. Obtaining the volume may include taking the product of three mutually orthogonal directional lumen diameters as the equivalent volume of the gastrointestinal tract part. The orthogonality includes a tolerance of 38°. The ranging of the probe pairs can be synchronous. The shell of the capsule includes an axisymmetric body, and the number of probe pairs with the ranging direction perpendicular to the longest axis of symmetry is greater than the number of probe pairs with the ranging direction parallel to the axis.

[0006] The present invention provides a second gastrointestinal motility detection system, including: a system control and processing module, a magnetic drive module, and a capsule. The capsule is provided with at least one magnet and is used to be driven by the magnetic field generated by the magnetic drive module to move the capsule in the gastrointestinal tract. The system control and processing module obtains the data of the movement and estimates the gastrointestinal motility according to the data and the driving magnetic force.

[0007] The present invention provides a second gastrointestinal motility detection method corresponding to the above-mentioned second gastrointestinal motility detection system, comprising the following steps: obtaining the movement data of a capsule with a magnet in the gastrointestinal tract under the action of a magnetic field; estimating the motility of the gastrointestinal tract according to the data and the magnetic field force. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic diagram of gastric peristalsis; Figure 2 is a schematic diagram of an embodiment of an ultrasonic capsule and the calculation of the gastrointestinal tract inner diameter; Figure 3 is a schematic diagram of the architecture of the first gastrointestinal motility detection system; Figure 4 is a schematic diagram of the structure of the ultrasonic capsule, and the housing is an ellipsoid rotating around the major axis of the ellipse; Figure 5 is another schematic diagram of the structure of the ultrasonic capsule, and the housing is a combination of two hemispheres and a frustum of a cone; An ultrasonic capsule with a shape similar to that of a capsule endoscope, the upper and lower parts of the capsule are hemispheres, and the middle part is a cylinder. Tv1, Tv2 (Vertical) are ultrasonic ranging probe pairs located at the ends of the major axis of the capsule, and Tm (Middle) is a probe pair perpendicular to the page. Tu1, Tu2 (Upper) are upper probe pairs, and Tl1, Tl2 (Lower) are lower probe pairs. The major axis direction is the same as the ranging direction of Tv, and is orthogonal to the ranging directions of other probe pairs. Figure 6 is a schematic diagram of the architecture of the second gastrointestinal motility detection system; Figure 7 is a schematic diagram of obtaining the lumen diameter and inner diameter of the gastrointestinal tract part; Figure 8 is a schematic diagram of extracting gastrointestinal motility parameters based on time series data.

[0009] Specific implementation solution: The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments for the purpose of explaining the present invention, but not limiting the present invention.

[0010] Gastrointestinal motility generally refers to the force and frequency of contraction, relaxation, and peristalsis of the gastrointestinal tract under the action of the gastrointestinal muscles. Its function is to make food move and be transported for digestion, absorption, and evacuation. Intuitively, the relationship between the morphological characteristics of the gastrointestinal tract and gastrointestinal motility is that under the action of the gastrointestinal muscles, gastrointestinal peristalsis first causes deformation, including changes in the curvature of the gastrointestinal tract and the inner diameter of the gastrointestinal tract; the deformation then transmits the force of the gastrointestinal muscles to the gastrointestinal contents such as chyme, causing the gastrointestinal contents to move. Secondly, like most other tissues in the human body, the gastrointestinal tract can have elastic properties. It is well known that the force on an elastic object is proportional to the deformation of the object under the action of the force. Therefore, there is a close correlation between the magnitude of the change in the morphology of the inner wall of the gastrointestinal tract and the magnitude of gastrointestinal motility. In particular, as Figure 1 shown, the changes in the inner diameter and curvature of the gastrointestinal tract, including the frequency of jumps in the convexity and concavity of the curvature of the gastrointestinal surface, are directly related to the frequency, strength, and weakness of gastrointestinal peristalsis. Thus, the frequency and intensity of gastrointestinal peristalsis can be obtained based on the changes in the inner diameter and curvature. On the other hand, there are also significant morphological differences in the physiology and pathology of gastrointestinal peristalsis. For example, when stenosis, dilation, or obstruction occurs, the normal rhythm of contraction and relaxation will change. By statistically analyzing the data on the morphological characteristics of the focus points in different parts of the gastrointestinal tract, the data on the changes in the morphological characteristics, and the data on the frequency of the changes, a model of the morphology and motility of the focus points in different parts of the gastrointestinal tract can be obtained as parameters for evaluating gastrointestinal motility. Like curvature and inner diameter, the morphological characteristics of the gastrointestinal tract also include data on the changes in the lumen volume of different parts of the gastrointestinal tract during peristalsis. The change in volume reflects the evacuation volume generated by gastrointestinal peristaltic force, and is related to the work done by the gastrointestinal muscles and the energy generated.

[0011] The above-mentioned gastrointestinal motility parameters can preferably be obtained by first acquiring one or more of the depth, morphology, and image data of the inner wall of the gastrointestinal tract to obtain the data of the curved surface of the inner wall surface of the gastrointestinal tract; then extracting the morphological characteristics. Specifically, an ultrasonic ranging device can preferably be set in a capsule. After the capsule enters the body, the ultrasonic ranging device is activated to obtain the distance from the capsule to the inner wall surface of the gastrointestinal tract. The ultrasonic detection device can also collect the distances from the capsule to multiple tissue structures of the inner wall of the gastrointestinal tract. Ultrasonic ranging mainly uses the time-difference ranging method. The ultrasonic probe emits directional ultrasonic waves and starts timing at the moment of emission. The same ultrasonic probe stops timing after receiving the reflected wave. Let the propagation speed of ultrasonic waves in the medium be V, the time difference T recorded by the timer for the emission and reception of the return wave, and the distance S from the emission point to the reflection point. Its expression formula is: S = V ×T / 2 【1】 Let the capsule be a sphere with its center of the sphere located at any point within the digestive tract. The sum of the distance from the said arbitrary point to a point on the inner wall of the digestive tract in any direction and the distance from the same point to a point on the inner wall on the other side of the digestive tract in the opposite direction is a measure of the shape of the digestive tract, which is defined in the present invention as the directional lumen diameter for measuring the inner diameter of the digestive tract and includes a pair of depth data of the inner wall of the digestive tract at the same time. There can be multiple directional lumen diameters passing through any point of the capsule. The directional lumen diameter is a direct measure of the shape of the digestive tract, eliminating the error caused by the movement of the capsule in the digestive tract in the one-way measurement of the prior art. Further, assume that the relative positions of at least two probes in the capsule are fixed during measurement. Corresponding to any pose of the capsule, the pose includes the coordinates of the position of the capsule in the digestive tract in the world spherical coordinate system outside the body and the angular difference between the spherical coordinate system inside the capsule and the world spherical coordinate system outside the body. Probe 1 of the probe pair measures the first distance from probe 1 to one side of the digestive tract in the direction α0 from probe 2 to probe 1, and its actual measurement direction is α1; probe 2 measures the second distance from probe 2 to the other side of the digestive tract in the direction -α0 from probe 1 to probe 2, and its actual measurement direction is α2; the sum of the first distance, the second distance and the third distance between the two probes is the directional lumen diameter obtained by the capsule in any of the above poses and corresponding to the above pose. Due to the design or actual manufacturing errors of the capsule and the probes, an error threshold for the measurement direction can be set.

[0012] |α1 - α0| < Tα; 【2】 |α2 + α0| < Tα; 【3】 where Tα = 19°.

[0013] The sampling interval determines the spatial resolution of the depth map or point cloud, as well as the curved surface of the inner wall of the digestive tract, conforming to the relationship of the Nyquist law. Multiple ultrasonic ranging probe pairs can be preferably arranged inside the capsule to form an ultrasonic ranging probe array platform including mechanical, circuit, and control software structures. The probes can be located on the outer surface of a centrosymmetric body including an ellipsoid. The outer surface of the centrosymmetric body includes the shell of the capsule, which is used to isotropically obtain multi-directional depth and / or morphological data. Obviously, the denser the probe array, the more sampling points there are, and the corresponding cost and power consumption of the circuit are also higher. When the number of probe pairs is equal to 2 or 3, the probe pair matrix can preferably adopt an orthogonal arrangement to synchronously obtain the cavity diameters in multiple directions. Considering manufacturing and measurement errors, a tolerance threshold for the orthogonal direction, such as 38°, can be set as shown in Formulas [2] and [3]. Or a platform mechanical rotation device can be set on the sparse probe array platform. After one sampling, the system controls the platform to rotate by an angle and then conducts the next sampling. The minimum cavity diameter obtained from multiple measurements is taken as the inner diameter of this part. When the platform realizes one measurement, the following features can be preferably achieved. First, multiple probes are located on the outer surface of a centrosymmetric body including an ellipsoid, which is used to isotropically obtain multi-directional depth and / or morphological data. Second, the ranging directions of the two probes of any probe pair are opposite; and the ranging of the two probes of any probe pair is synchronous, and the data obtained by the two probes are correlated; Third, the ranging of multiple probes can be simultaneous, or synchronous with a time interval. Among them, the additional measurement error generated by the time interval can preferably be less than the measurement error of a single probe. Since the capsule is always moving with the peristalsis of the digestive tract, the depths or morphologies obtained from multiple samplings can be matched, registered, and fused.

[0014] In addition to the ultrasonic ranging device, a 3D camera based on infrared or visible light sensors can also be used to obtain a panoramic depth map or point cloud.

[0015] The movement of the capsule in the digestive tract with the peristalsis of the digestive tract is passive and random, and it is finally excreted from the body. In a preferred implementation of the present invention, a magnetic control device can be used to generate a magnetic field to drive the capsule with a magnet to move to, or stay at, one or more concerned parts in the digestive tract to achieve fixed-point detection.

[0016] Figure 2is an embodiment of an ultrasonic capsule containing a probe pair. The probe pair includes probe 1 and probe 2, which are used to bidirectionally obtain the depth and / or morphological data of the opposite side related to the inner wall of the digestive tract. When the capsule sphere enters the subject's body, it can first reach the position of Pa. The distance from probe 1 located outside the capsule to a point on the gastric wall along any direction (θ, φ) of the spherical coordinate system with Pa as the coordinate origin is represented by |A210, A21|; at the same time, the distance from another sensor probe 2 located on the opposite side of the capsule to another point on the gastric wall along the opposite direction (-θ, -φ) of the any direction is represented by |A200, A20|. The distance |A210, A21| + |A200, A20| + |A200, A210| is a direction diameter D passing through point Pa. Among them, A200 and A210 are the coordinates of the two ultrasonic probes respectively. The coordinates (θ, φ, |A210, A21| + 1 / 2 * |A200, A210|) and (-θ, -φ, |A200, A20| + 1 / 2 * |A200, A210|) are a pair of depth data obtained with the capsule center located at point Pa. The set of depth data of all points on the gastric wall collected by the capsule at point Pa is the depth map at point Pa. The depth maps obtained at different points, such as Pb, Pc... can be matched and fused into a single depth map, and then the depth map can be converted into a point cloud, or each depth map can be converted into a point cloud first, and then the point clouds can be matched and fused. The fusion of the depth map and the point cloud can preferably refer to the pose data of the capsule. The present invention preferably uses a magnetic positioning system to obtain the pose of the capsule. The implementation of magnetic positioning includes a first positioning method, where the system control and processing module obtains the data of the magnetic field signal generated by the magnet provided inside the capsule received by the magnetic field sensor provided outside the body, and then uses a positioning algorithm to process the data to obtain the pose of the capsule; and a second positioning method, where the magnetic sensor inside the capsule obtains the data of the magnetic field signal of the positioning magnet provided outside the body, and then wirelessly transmits the data to the system control and processing module, and the system control and processing module uses a positioning algorithm to process the data to obtain the pose of the capsule. The system control and processing module can switch between the above two positioning methods according to needs. By processing the time series of the above pose data, the motion data of the capsule can be obtained, including position, displacement (including selection angle), and velocity (including angular velocity), acceleration (including angular acceleration), and frequency characteristics. The pose positioning of the capsule can not only be used for data fusion to obtain a panoramic view of the digestive tract, but also be used to obtain the position of the digestive tract part in the body relative to the body surface, such as detecting the position of the capsule at the pylorus as a detection means for gastroptosis.

[0017] The point cloud can be regarded as a sampling of the inner wall surface of the digestive tract. The sparse point cloud can be smoothed and denoised through surface fitting to obtain surface data. As the capsule moves with the peristalsis of the digestive tract, the surface data of the entire inner wall surface of the digestive tract can be accumulated. Due to the unique morphological characteristics and corresponding relationships of different parts of the human digestive tract, the system control and processing module or the detection program of the capsule can identify the morphological characteristics of the digestive tract parts from the collected digestive tract data. When it is necessary to detect a specific area of concern, such as Figure 2 the Pc point in Figure 5 , if the current position of the capsule is at the Pa point, the magnetic control device can be activated to drive the capsule from Pa to the Pc point. When the magnetic positioning device confirms that the capsule has reached the Pc point, the system control and processing module or the detection program of the capsule activates the ultrasonic ranging device of the capsule to start collecting data. Further, the system control and processing module or the detection program of the capsule will match and register the current pose information of the capsule collected by magnetic positioning with the part features extracted from the data of the inner wall of the digestive tract collected from the capsule. In order to minimize the disturbance of the test to the surrounding physiological environment, a capsule design with a small volume and the same density as chyme can be adopted. During the test without intervention, the driving force of the magnetic control device can usually be in the zero state. During the test with intervention, a specific intervention force can be applied to keep the capsule staying around the area of concern or to antagonistically interfere with the movement of the capsule to measure the motility of the digestive tract. As an example, the capsule can be observed at the Pc point near the pylorus, for example. The magnetic control device can apply an interference magnetic field to the movement of the capsule with a magnet. When the magnetic field force reaches the first threshold, the evacuation time of the capsule can be seen to increase; when the magnetic field force reaches the second threshold, the capsule cannot be evacuated. The peristaltic force acting on the capsule can be estimated based on the magnitude and direction of the magnetic field force, the evacuation time of the capsule, the physical properties of the capsule, and the physical properties of the gastric contents. Since the main function of the digestive tract is centered around the movement of food, the movement direction of the food can be used as the main axis direction or the main channel direction of the digestive tract. The statistical average of the diameters in multiple directions perpendicular to the main axis through any area of concern in the digestive tract can be set as the main direction diameter or inner diameter of the digestive tract at that area of concern. The following is combined with 6, 7 further illustrates the process of obtaining the average inner diameter. Tij is the j-th probe of the i-th pair of probes (j = 1, 2). When the capsule passes through the probe pairs T1j and T2j at point A, two orthogonal cavity diameters, Ha1Ha2 and Va1Va2, are synchronously obtained. Among them, the longer Ha1Ha2 is the measurement value of the main channel direction at point A. Due to the random movement of the capsule, the attitude of the capsule is arbitrary. At a large part of the digestive tract cavity such as point A in the middle of the stomach, the measurement value of the main channel direction is not necessarily the actual main channel direction. However, at a part with a smaller inner diameter, especially when the length of the capsule's shell is close to or greater than the actual inner diameter of this part, such as point B in the figure, there is a high probability that the long axis direction of the capsule is close to or coincides with the main channel direction of this part. Therefore, multiple probe pairs can be set in one or more planes perpendicular to the long axis of the capsule, and the average value of the cavity diameters measured by all probe pairs is taken as the inner diameter of this part. Further, reasonable configuration can be made in terms of external dimensions, density center of gravity, etc., so that the long axis of the capsule is consistent with the main channel of the digestive tract with a high probability. Further, the cavity diameters can be synchronously obtained along the long axis and short axis directions respectively, and the lengths of the two are compared to judge the pose of the symmetry axis of the capsule relative to the main channel direction at the measurement moment. If the length ratio is greater than or equal to a threshold, the direction of the longest cavity diameter is taken as the main channel direction of this part, and the average value of one or more cavity diameters orthogonal to the main channel direction is taken as the inner diameter of this part. After the system control and processing module or the detection program of the capsule obtains the depth and / or morphological data of the inner wall of the digestive tract in the time series collected by the capsule, the data can be first converted into a point cloud and then surface fitting is performed. The extraction of morphological features can be directly based on the original depth and / or morphological data, or the data of the surface after fitting. According to the data of the surface and the anatomical morphological features of the digestive tract, the main channel direction of each point in the digestive tract can be estimated. The calculation of the surface curvature is a classic topic in differential geometry, and there are a large number of algorithms available. The partial derivatives can be calculated for the data of the inner wall surface of the digestive tract or the data obtained after downsampling the inner wall surface of the digestive tract. Different parts may have different curvature radius characteristics, and the curvature of the surface data with different spatial frequencies corresponds to different curvature radii. For the calculation of the volume, a line segment (L1, L2) with an adjustable length can be selected along the main channel direction as the height, where L1 and L2 are the coordinates of the endpoints. Vertical planes S1 and S2 of the main channel direction are made through L1 and L2 respectively. A closed body surrounded by the planes S1, S2 and the surface data of the inner wall of the digestive tract can be regarded as a volume at point Pc, and its calculation can adopt the numerical solution of integration. For the calculation of the volume, a simplified algorithm can also be adopted, that is, the product of three mutually orthogonal cavity diameters is taken as the equivalent volume of this part; the orthogonality includes a tolerance of 38°. This is based on equivalent the volume of the digestive tract part to a cuboid. Since when using the volume as a morphological feature to judge the anatomical position of the digestive tract, the focus of concern is the relative size.The above algorithm has good consistency for different parts, so it is a feature with good discriminability. Further, let the diameters of the three pairwise orthogonal direction cavities be r1, r2, and r3 respectively, then r = (r1 * r2 * r3)^1 / 3 [4] can be defined as an equivalent inner diameter of the digestive tract part. The motion data of the capsule, including displacement, velocity, and frequency, can be obtained through a magnetic positioning device. The change rate and change amplitude of the above-mentioned digestive tract morphological features can be extracted from the feature data of the time series, and the frequency characteristics obtained from the change of the morphological features can be correlated and matched with the frequency characteristics of the capsule motion obtained from magnetic positioning. The following is combined with... Figure 7 Further illustrate that the capsule obtains digestive tract motility parameters including the emptying time of the capsule based on the time series of morphological features. The arrows in the figure represent the emptying direction of food, that is, the main channel direction. The dotted lines D1, D2, and D3 respectively represent the inner diameters at the digestive tract parts W1, W2, and W3 detected by the capsule. The coordinate system XYZ is located outside the digestive tract. P1->P2->P3 is the motion trajectory of the capsule detected by magnetic positioning at times t1, t2, t3 (t3 > t2 > t1), P1, P2, and P3 are the coordinate positions of the capsule in this coordinate system, and P(t) is the operation function for magnetic positioning to obtain the capsule position, that is, P(t1) = P1, P(t2) = P2, P(t3) = P3. D(t) is the operation function for the capsule to obtain the inner diameter of the digestive tract, that is, D(t1) = D1, D(t2) = D2, D(t3) = D3. D1 is located at the fundus of the stomach and has the largest inner diameter (usually 6 - 7 cm in adults), D2 is located at the pylorus and has the smallest inner diameter (usually 1 - 2 cm in adults). D3 is located in the duodenum and the inner diameter is between the two (usually 3 - 4 cm in adults). And D1 > D3 > D2 [5].

[0018] Formula [5] and the corresponding statistical data express a set of anatomical correspondence relationships of the inner diameter of the digestive tract near the pylorus, which can be used as a basis for determining that the capsule passes through the pylorus. Further, the inner diameter D and the equivalent inner diameter r obtained from the above volume calculation [4] are related, and combining them can improve the accuracy of anatomical position recognition. Further, the W(t) function can represent a time series of the digestive tract anatomical position. Based on this time series, the emptying time of the capsule between different anatomical positions can be directly obtained, such as the time to pass through the pylorus, the time of the small intestine, ileum, and colon, etc.

[0019] That is, W(t1, t2, t3) = (W1 fundus of the stomach -> W2 pylorus -> W3 duodenum) [6].

[0020] Further, the position of the capsule obtained by magnetic positioning in the XYZ coordinate system in vitro can be matched, aligned, registered, and fused with the anatomical position of the digestive tract part obtained by the probe. Or, if the data of magnetic positioning and the data of the capsule are seriously inconsistent, it can be prompted that there is a problem with the program.

[0021] Different foods or drugs can affect digestive tract motility, and the above detections can be carried out in a food environment such as clear water, starch, and alcoholic beverages.

[0022] Such as Figure 3 As shown, the first digestive tract motility detection system of the present invention includes A data acquisition module, a system control and processing module, and a capsule. The data acquisition module and the system control and processing module are connected by a wired or wireless communication link; the system control and processing module is usually located in an external control terminal or host computer, or is distributed, that is, part of the functions are completed in the external control terminal or host computer, and part of the functions are completed in the capsule. The system control and processing module includes at least one processor and at least one solid-state storage medium. The solid-state storage medium contains instructions and parameters that can be read by the at least one processor, and is used to run a digestive tract motility detection program to coordinate the work of each module. The data acquisition module is disposed in the capsule and is used to acquire one or more of the depth, morphology, and image data of the digestive tract inner wall; the system control and processing module is used to receive one or more of the depth, morphology, and image data from the data acquisition module, process the data, and extract morphological features of the digestive tract, including one or more of the curvature, inner diameter, and volume of the digestive tract, as parameters for digestive tract motility evaluation; wherein, the changes in the inner diameter and curvature are directly related to the frequency of the jump in the convexity and concavity of the curvature of the digestive tract surface, the frequency, strength, and weakness of gastrointestinal peristalsis, and the system can obtain the frequency and strength of gastrointestinal peristalsis according to the changes in the inner diameter and curvature. The system further includes a magnetic positioning module, which includes at least one magnet or a first magnetic sensor disposed in the capsule; the magnetic sensor disposed outside the digestive tract receives the magnetic field signal generated by the at least one magnet, or the first magnetic sensor receives the magnetic field signal of the magnet disposed outside the digestive tract to obtain the pose data of the capsule. The system further includes a magnetic drive module, which includes an external magnetic control device and a magnet in the capsule, and is used to generate a magnetic field to drive the capsule to move to, or stay at, one or more concerned parts in the digestive tract to achieve fixed-point detection. The system control and processing module performs morphological feature recognition of the digestive tract part on the acquired digestive tract data to determine the part where the capsule is located. Referring to the pose data of the capsule, multiple depth maps or point clouds are fused, and the point cloud is fitted to obtain surface data. The data acquisition module includes an ultrasonic ranging device or a camera. The ultrasonic ranging device includes at least one pair of ultrasonic ranging probes for synchronously and bidirectionally acquiring the depth and / or morphological data of the opposite sides related to the digestive tract inner wall. Corresponding to any pose of the capsule, probe 1 of the probe pair measures the first distance from probe 1 to one side of the digestive tract in the direction α0 from probe 2 to probe 1, and its actual measurement direction is α1; probe 2 measures the second distance from probe 2 to the other side of the digestive tract in the direction -α0 from probe 1 to probe 2, and its actual measurement direction is α2; the sum of the first distance, the second distance, and the third distance between the two probes is the direction cavity diameter obtained by the capsule in any of the above poses and corresponding to the above pose. Wherein |α1 - α0| < Tα; |α2 + α0| < Tα; where Tα = 19°.

[0023] The ultrasonic ranging device can also obtain data on the position of any part of interest in the digestive tract, drive the capsule to the part of interest, obtain the main channel direction passing through the part of interest, and obtain the average value of the diameters in multiple directions perpendicular to the main channel direction as the main direction diameter or inner diameter of the digestive tract at the part of interest. When the number of probe pairs is greater than one, or when multiple single-direction ranging ultrasonic probes are used simultaneously, the probes are arranged on the outer surface of a centrosymmetric body including a sphere, and the outer surface of the centrosymmetric body includes the housing of the capsule, for isotropically obtaining multi-directional depth and / or morphological data including a panoramic view.

[0024] The first digestive tract motility detection method of the present invention includes the following steps: obtaining morphological characteristics of the digestive tract, including one or more of curvature, inner diameter, and volume, as parameters for evaluating digestive tract motility. The obtaining of the morphological characteristics of the digestive tract includes the following steps: obtaining one or more of the depth, morphology, and image data of the inner wall of the digestive tract, and extracting the morphological characteristics from the data; or obtaining the curved surface data of the inner wall of the digestive tract, and extracting the morphological characteristics from the curved surface data; obtaining the frequency and intensity of gastrointestinal peristalsis according to the changes in the inner diameter and curvature, including the frequency of jumps in the convexity and concavity of the curvature of the digestive tract curved surface. The obtaining of the inner diameter of the digestive tract includes the following steps: obtaining a part of interest in the digestive tract; obtaining the main channel direction of the part of interest, where the main channel direction is the food evacuation direction; obtaining the average value of the diameters in multiple directions perpendicular to the main channel direction as the inner diameter of the digestive tract at the part of interest; where obtaining any one direction diameter includes the following steps: S1: Obtaining the first distance from the first probe in a pair of ultrasonic probes along the first direction to one side of the inner wall of the digestive tract; S2: Obtaining the second distance from the second probe in the pair of ultrasonic probes along the direction opposite to the first direction to the other side of the inner wall of the digestive tract; S3: Calculating and obtaining the sum of the first and second distances and the third distance between the first and second probes.

[0025] The obtaining of the volume of the digestive tract includes the following steps: Obtaining a part of interest; Obtaining the curved surface data of the inner wall of the digestive tract at the part of interest; Obtaining the main channel direction of the part of interest, where the main channel direction is the food evacuation direction; Obtaining a line segment (L1, L2) along the main channel direction, where L1 and L2 are the coordinates of the endpoints of the line segment; Respectively obtaining the vertical planes S1 and S2 passing through L1 and L2 and perpendicular to the main channel direction; Calculate and obtain the volume of a closed body enclosed by the planes S1, S2 and the inner wall surface.

[0026] As Figure 4 shown, the above-described ultrasonic capsule for gastrointestinal tract detection of the present invention includes at least one pair of ultrasonic ranging probes for bidirectionally and synchronously obtaining depth and / or morphological data of opposite sides related to the inner wall of the gastrointestinal tract. The pair of ultrasonic ranging probes includes probe 1 and probe 2. Corresponding to any pose of the capsule, probe 1 is used to obtain the first distance from probe 1 to one side of the gastrointestinal tract in the direction α0 from probe 2 to probe 1, and obtain the measured direction α1; probe 2 is used to obtain the second distance from probe 2 to the other side of the gastrointestinal tract in the direction -α0 from probe 1 to probe 2, and obtain the measured direction α2; the sum of the first distance, the second distance and the third distance between the two probes is obtained as a measure of the inner diameter of the gastrointestinal tract of the capsule; wherein |α1 - α0| < Tα; |α2 + α0| < Tα; where Tα = 19°.

[0027] When the number of probe pairs is greater than one, or when multiple one-way ranging ultrasonic probes are used simultaneously, the probes can be arranged on the outer surface of a centrosymmetric body including a sphere. The outer surface of the centrosymmetric body includes the shell of a capsule, which is used to isotropically obtain multi-directional depth or morphological data. The capsule contains at least one processor and at least one solid-state storage medium. The at least one solid-state storage medium contains instructions and parameters that can be read by the at least one processor for running a digestive tract detection program. The capsule can be a component of the first digestive tract motility detection system described above, transmitting control data and collected digestive tract data wirelessly, or it can be an independent device. The digestive tract data collected by it is stored in the storage medium inside the capsule and collected and processed after being excreted from the body. A first magnet or a first magnetic sensor is also arranged inside the capsule; a second magnetic sensor arranged outside the digestive tract receives the magnetic field signal generated by the first magnet, or the first magnetic sensor receives the magnetic field signal of a second magnet arranged outside the digestive tract to obtain the pose data of the capsule. At least one processor of the capsule performs morphological feature recognition of the digestive tract part on the collected digestive tract data to determine the part where the capsule is located. Further, data on the position of a concerned part inside the digestive tract is obtained, the capsule is driven to the concerned part, the main channel direction passing through the concerned part is obtained, and the average value of the diameters of multiple directions perpendicular to the main channel direction passing through the concerned part is used as the main direction diameter or inner diameter of the digestive tract at the concerned part. Further, multiple depth maps or point clouds are fused with reference to the pose data of the capsule, the point cloud is fitted to obtain surface data, and morphological features of the digestive tract are extracted, including one or more of the curvature, inner diameter, and volume of the digestive tract, as parameters for digestive tract motility evaluation. Among them, since the changes in the inner diameter and curvature, including the frequency of the jump in the convexity and concavity of the digestive tract surface curvature, are directly related to the frequency, strength, and weakness of gastrointestinal peristalsis, the frequency and strength of gastrointestinal peristalsis can be obtained according to the changes in the inner diameter and curvature. An external magnetic control device is used to generate a magnetic field to drive the magnet inside the capsule to move the capsule in the digestive tract to, or stay at, one or more concerned parts to achieve fixed-point detection.

[0028] Such as Figure 6As shown, the second digestive tract motility detection system of the present invention includes: a system control and processing module, a magnetic drive module, and a capsule; the system control and processing module, the magnetic drive module, and the capsule are connected by a communication link; the system control and processing module is usually located in a control terminal or a host computer outside the body. The system control and processing module contains at least one processor and at least one solid-state storage medium, and the solid-state storage medium contains instructions and parameters that can be read by the at least one processor for running a digestive tract motility detection program to coordinate the work of each module. The capsule is provided with at least one driving magnet for being driven by the magnetic field generated by the magnetic drive module to move the capsule in the digestive tract; the system control and processing module acquires the data of the movement and estimates the digestive tract motility according to the data and the driving magnetic force. The system further includes a magnetic positioning module. The system control and processing module includes acquiring the pose data of the capsule through magnetic positioning and extracting the movement data of the capsule, including position, displacement (including rotation angle), and velocity (including angular velocity), acceleration (including angular acceleration), and frequency characteristics. At least one positioning magnet and at least one magnetic sensor can also be provided in the capsule. The above positioning magnet can be the same or different from the driving magnet. The first positioning method of the magnetic positioning module obtains the first pose data by receiving the magnetic field signal of the at least one positioning magnet by a second magnetic sensor provided outside the body; the second positioning method of the magnetic positioning module includes obtaining the second pose data by receiving the magnetic field signal of the positioning magnet provided outside the body by the at least one magnetic sensor. The system control and processing module can switch between the above two positioning methods as needed; including obtaining the pose and movement data of the capsule under the action of digestive tract motility by using the first positioning method, and obtaining the second pose and movement data of the capsule under the combined action of digestive tract motility and driving magnetic force by using the second positioning method. The shell of the capsule can preferably have a smooth outer shape without edges and corners, including a sphere or an ellipsoid.

[0029] The above-mentioned second gastrointestinal motility detection method includes the following steps: obtaining the motion data of a capsule with a magnet in the gastrointestinal tract under the action of a magnetic field; the motion data includes the position, displacement (including rotation angle), and velocity (including angular velocity), acceleration (including angular acceleration), and frequency characteristics of the capsule. Estimating the motility of the gastrointestinal tract based on the motion data and the magnetic field force. The above method further includes sampling magnetic positioning to obtain the pose data of the capsule; obtaining the motion data of the capsule according to the pose data. The above method further includes the following implementation steps: obtaining the data of the position of any concerned part in the gastrointestinal tract; driving the capsule to the concerned part; obtaining the first time of the capsule at a concerned part under the action of gastrointestinal motility; obtaining the second evacuation time of the capsule at the concerned part under the action of the driving magnetic force; estimating the gastrointestinal motility of the concerned part based on the first and second evacuation times and the driving magnetic force. The above method further includes the following implementation steps: obtaining the motion data of the capsule at a concerned part under the action of gastrointestinal motility; generating an interference magnetic field for the motion of the capsule, the interference magnetic field causing the capsule to stay at the concerned part; estimating the gastrointestinal motility based on the magnitude and direction of the magnetic field force.

Claims

1. A capsule, characterized in that, It is internally provided with multiple pairs of ultrasonic ranging probes for obtaining the morphological features of the digestive tract part. Among them, probe 1 of any probe pair is used to obtain the first distance from the first direction to one side of the inner wall of this part, and probe 2 is used to obtain the second distance from the second direction to the other side of this inner wall. The sum of the first distance, the second distance, and the distance between probe 1 and probe 2 is calculated to obtain a directional cavity diameter. The included angle between the first direction and the reverse direction of the second direction is less than the direction tolerance threshold.

2. The capsule according to claim 1, wherein The ratio of the longest directional cavity diameter to the shortest directional cavity diameter among the directional cavity diameters obtained by multiple probe pairs is calculated as the length-to-width ratio. If the length-to-width ratio is greater than or equal to the length-to-width ratio threshold, the direction of the longest directional cavity diameter is taken as the main channel direction of this part, and the directional cavity diameter orthogonal to the main channel direction or the average value of multiple directional cavity diameters is taken as the inner diameter of this part. If the length-to-width ratio is less than the length-to-width ratio threshold, the shortest directional cavity diameter is taken as the inner diameter of this part. The orthogonality includes the direction tolerance threshold.

3. The capsule according to any one of claims 1-2, characterized in that The length-to-width ratio threshold depends on the part or is set to 2. When the number of probe pairs is equal to 2 or 3, the ranging directions of the probe pairs are orthogonal to each other pairwise. When the number of probe pairs is greater than 3, at least 3 of the ranging directions of the probe pairs are orthogonal to each other pairwise.

4. The capsule according to claim 1, wherein The capsule or the device or processor communicatively connected to the capsule obtains one or more of the curvature and volume of this part based on the directional cavity diameter. The capsule or the device or processor communicatively connected to the capsule takes the product of 3 pairwise orthogonal directional cavity diameters as the equivalent volume of this part. The cube root of the equivalent volume is set as the equivalent inner diameter.

5. The capsule according to any one of claims 1-4, characterized in that, The direction tolerance threshold is set to 38°. The capsule or the device or processor communicatively connected to the capsule identifies the position characteristics of this part based on the morphological features and by referring to the corresponding relationship of the digestive tract part, and determines the anatomical position of this part.

6. The capsule according to any one of claims 1-5, characterized in that, The capsule or the device or processor communicatively connected to the capsule obtains one or more of the frequency, amplitude of digestive tract peristalsis, the movement trajectory of the capsule, and the time for the capsule to move between digestive tract parts based on the time series data of one or more of the morphological features and anatomical position.

7. The capsule according to claim 6, wherein The capsule or the device or processor communicatively connected to the capsule obtains the frequency of gastric peristalsis by referring to the spectral analysis of the time series data of the inner diameter or equivalent inner diameter of the stomach.

8. The capsule according to claim 5, wherein The capsule or the device or processor communicatively connected to the capsule sets the anatomical position as the first position, and performs one or more of matching, alignment, registration, and fusion on the first position and the second position data of the capsule in the external coordinate system.

9. The capsule according to claim 1, wherein The housing of the capsule includes an axisymmetric body, and the number of probe pairs with the ranging direction perpendicular to the longest axis of symmetry is greater than the number of probe pairs with the ranging direction parallel to this axis.

10. The capsule according to claim 1, wherein, The ranging of the probe pairs is synchronous.

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