Abstract
The invention discloses a first gastrointestinal motility measurement system comprising a data acquisition module and a data processing module. The data acquisition module comprises an ultrasonic ranging device or a 3D camera for acquiring depth map or point cloud data. The data processing module processes the depth map or the point cloud to extract morphological features including curvature, inner diameter and volume of the digestive tract.
The invention provides a second gastrointestinal motility measurement system, comprising a control module, a magnetic driving module, a magnetic positioning module and a capsule. The capsule is provided with a positioning magnet and a driving magnet. The positioning magnet generates a magnetic field signal, which is detected by the magnetic positioning module obtaining the position and motion data of the capsule in the digestive tract relative to an external coordinate system. The control module obtains a first position and motion data of the capsule under the action of gastrointestinal motility; obtains a second position and motion data of the capsule under the joint action of gastrointestinal motility and driving magnetic force; and estimates gastrointestinal motility according to the first and second position and motion data and the driving magnetic force.
Claims
1-11. (canceled)
12. A system for measuring gastrointestinal motility, comprising: a control module, a magnetic driving module, and a capsule; the control module, the magnetic driving module and the capsule are configured to be connected by a communication link; the capsule comprises a driving magnet, and the magnetic driving module is configured to generate a magnetic field, wherein the magnetic field act on the driving magnet to generate a driving magnetic force to drive the capsule to move in digestive tract; the control module is configured to obtain motion data of the capsule and estimate the gastrointestinal motility based on the motion data and the driving magnetic force.
13. The system of claim 12, further comprising a magnetic positioning module; the capsule further comprising a positioning magnet; wherein the magnetic positioning module is configured to receive magnetic signal generated by the positioning magnet in the capsule to obtain data of position of the capsule.
14. The system of claim 12, wherein the positioning magnet and the driving magnet comprise a single magnet or two separate magnets.
15. The system of claim 11, wherein the motion data comprise displacement and velocity of the capsule.
16. The system of claim 11, wherein the control module is configured to obtain a first set of motion data of the capsule under the action of gastrointestinal motility, and a second motion data of the capsule under the action of the gastrointestinal motility and the driving magnetic force.
17. A method for measuring gastrointestinal motility, comprising the following steps: obtaining motion data of a capsule with a magnet in digestive tract under action of a magnetic field; estimating motility of the digestive tract according to the motion data and magnetic field force generated by the magnetic field over the magnet.
18. The method of claim 17, wherein the motion data include displacement and velocity of the capsule.
19. The method of claim 17, wherein the motion data further include a first set of data wherein the capsule moves under action of digestive tract motility and a second set of data wherein the capsule moves under action of the digestive tract motility and the magnetic field.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 is a schematic diagram of gastric peristalsis.
[0014] FIG. 2 is an example of an ultrasonic capsule operation.
PREFERRED EMBODIMENT
[0015] The present invention is further described in detail in combination with the drawings and the embodiments are for the purpose of explaining and not limiting the present invention.
[0016] FIG. 1 is a schematic diagram of gastric peristalsis. It shows the changes of gastric wall morphology during peristalsis in the order from 1 to 4.
[0017] FIG. 2 is an example of an ultrasonic capsule operation. After the capsule enters a subject's body, it can get to a point Pa first. A probe takes a measurement of the distance between a point on an exterior wall of the capsule A210 to a point A21 on the gastric wall along an arbitrary direction of (θ, φ) in a spherical coordinate system with its coordinate origin at Pa, wherein the distance is expressed by |a210, A21|. At the same time, another probe located at A200 on the opposite side of the capsule takes a measure of the distance between A200 to a point A20 on the gastric wall along the opposite direction (−θ, −φ), wherein the distance is expressed by |A200, A20|. Distance of |A210, A21|+|A200, A20|+|A200, A210| is a directional cavity diameter d passing through point Pa. A200 and A210 are the coordinates for two reversely positioned ultrasonic probes. Coordinates (θ, φ, |A210, A21|+½*|A200, A210|) and (−θ, −φ, |A200, A20|+½*|A200, A210|) are a pair of data of ultrasonic depth map obtained by the capsule at point Pa. The collection of the depth data of all points of gastric wall acquired by the capsule at point Pa is the depth map at point Pa. The depth map obtained from different points, such as Pb, Pc, can be matched and fused into a depth map, and then the depth map can be transformed into a point cloud, or each depth map can be transformed into a point cloud, and then the point cloud can be matched and fused. Magnetic positioning may preferably be used to track and mark the pose and position of the capsule as a parameter for depth map or point cloud fusion. The point cloud can be regarded as a sample of the inner surface of digestive tract. Sparse point clouds can be smoothed and denoised by surface fitting to obtain surface data. With the peristalsis of the alimentary canal, the surface data of the inner wall of the whole alimentary canal can be accumulated. Because different parts of the human digestive tract have unique local morphological characteristics and corresponding relationship, the data processing module can recognize the local morphological characteristics of the digestive tract through machine learning. In an example to take a measure of an area of interest, such as a point Pc in FIG. 2, assuming the current position of the capsule being at a point Pa, the magnetic control device can be started to drive the capsule from point Pa to point Pc. When the magnetic positioning device confirms that the capsule has reached point Pc, the system control software of the data processing module starts the ultrasonic ranging device of the capsule to collect data. Furthermore, the data processing module will match the current pose and position data of the capsule collected in real time by magnetic positioning with the pose and position data obtained from analysis of the data of the inner wall of the digestive tract collected by the capsule to ensure the accuracy of the positioning. During a motility test, it may be optimized to minimize the perturbation of the test on the surrounding physiological environment, such as the design of the capsule of a small volume and with a round shape, a sleek shell of the capsule body, and a close density to that of chyme. In a test without intervention, the driving force of the magnetic control equipment can usually be in the zero state. In an intervention test, intervention force can be applied to maintain the capsule in an area of concern, or the capsule motion can be obstructed to measure the gastrointestinal force in the balance. As an embodiment, the capsule is observed at point Pc, near the pylorus. When the magnetic force reaches a first threshold, the transit time of the capsule increases. When the magnetic force reaches a second threshold, the capsule can not be emptied. The peristaltic force of the capsule can then be estimated according to the transit time, the magnitude and direction of the magnetic force, the physical characteristics of the capsule and the physical characteristics of the gastric contents. After obtaining the depth map of the inner wall of digestive tract from the time series collected by the capsule, the data processing module can first convert the depth map into point cloud, and then perform surface fitting. Since the main function of the digestive tract is to move around the food, the direction of food motion can be regarded as the principal axis direction or the principal transit direction of the digestive tract. A statistical average value of a plurality of directional cavity diameters perpendicular to the principal axis at any point in the digestive tract can be set as an inner diameter of the digestive tract at that point. According to the surface data and the anatomic characteristics of digestive tract, the path of the principal transit connecting the points in the digestive tract can be estimated. The calculation of curvature of a surface is a classic subject of differential geometry, and there are a large number of algorithms to choose from. For volume calculation, a length-adjustable line segment (L1, L2) can be selected along the direction of the principal transit as a height, where L1 and L2 are the coordinates of the end points. Through L1 and L2, the vertical plane S1 and S2 in the direction of principal transit are made respectively. A closed body surrounded by surface data of plane S1, S2 and the surface of inner wall of digestive tract can be regarded as a volume at point Pc, which can be calculated by integral numerical method. The motion data of the capsule, including displacement, velocity and frequency, can be obtained by magnetic positioning device. The change rate and range of the above gastrointestinal morphological features can be extracted from the time series data, and the frequency characteristics can be correlated with the frequency characteristics of the capsule motion. Different foods or drugs can affect gastrointestinal motility. The above tests can be carried out in food environment such as water, starch and wine.
