Methods and systems for characterizing the movements of body structures

Abstract

The invention relates to a method and a system for characterizing the movement of one or more body structures, and an associated use. In a method (1) for characterizing the movement (15) of a body structure (2), a magnetic material (8) located in or on a body structure (2) in a human or animal body (1) performs a movement (15) together with the body structure (2). Information regarding the movement (15) of the magnetic material (8) is detected by means of a magnetic field sensor (45).

Description

[0001] The invention relates to a method and a system for characterizing the movement of one or more body structures and an associated use.

[0002] The three-dimensional structure of the body is very well understood in medicine. In comparison, the body's internal dynamics are much less well described. To a certain extent, dynamic studies can be conducted on dissected anatomical models. However, the movements studied in this way are far removed from natural movements. Measuring the relative movements of individual body structures in a living human or animal is both complex and only possible with a very limited range of motion. In imaging procedures such as CT or MRI, the body is in a confined space that allows only minimal movement. Furthermore, the technically required measurement time severely limits the feasibility of dynamic studies, especially for larger body regions. In addition, the spatial resolution is generally limited to a few hundred micrometers.

[0003] Examples of the few movement patterns that can be investigated so far include the diagnosis of "adhered fascia", i.e., inhibited relative movement of tissue structures using ultrasound, triggered computed tomography imaging of the beating heart, and Magnetic Particle Imaging (MPI), which is currently under development and visualizes the movement of particles in the bloodstream, although this requires a large device with a tube similar to an MRI or CT scanner.

[0004] As a result, most natural movement patterns can only be described using assumptions and estimations. Due to a lack of technical capabilities, measurement is impossible in the vast majority of cases.

[0005] German patent application DE 10 2008 002 864 A1 relates to a substrate with multiple electromagnetic microsensors that can be attached to an internal organ or tissue. DE 103 18 849 A1 discloses a device for localizing, influencing, and guiding tracking bodies in a physiological structure. DE 10 2015 101 834 A1 relates to a method for detecting and localizing particles. DE 20 2019 100 330 U1 discloses a device for imaging analysis of bodies.

[0006] The object of the invention is to better characterize the movement of at least one body structure.

[0007] The method according to claim 1, as well as the use and system according to the dependent claims, serve to solve the problem. Advantageous embodiments are specified in the dependent claims.

[0008] To solve this problem, a method for characterizing the movement of a body structure is used. A magnetic material located in or on a body structure within a human or animal body moves in conjunction with the body structure. Information regarding the movement of the magnetic material is detected by a magnetic field sensor. The magnetic field sensor is designed to detect a magnetic field generated by an accumulation of the magnetic material. Magnetic nanostructures are used as the magnetic material. Magnetic material is located on at least two spaced-apart regions of the body structures. A relative movement of the first region of the two body structures with respect to the second region of the two body structures is detected.

[0009] In this way, a detailed statement about the movement of body structures can be obtained. It is possible to characterize and, if necessary, record natural movements. The use of a large, stationary piece of equipment like an MRI or CT scanner is not required.

[0010] The magnetic material is located in or on the body structure. This body structure can be, for example, a muscle, tendon, bone, or fascia. In the case of muscles, the magnetic material is located specifically within the body structure. In the case of tendons or bones, the magnetic material is located specifically on the body structure. Typically, a cluster of magnetic material is found in or on the body structure.

[0011] The magnetic material is located inside the human or animal body, i.e., inside the body.

[0012] A magnetic field sensor according to the invention is a sensor that can detect one or more magnetic properties of a magnetic material. For example, the magnetic field sensor is configured to detect a magnetic field generated by a collection of magnetic material. The magnetic field sensor can, for example, detect information about the distance from the magnetic field sensor to a magnetic material and / or the distance between two collections of magnetic material. The magnetic field sensor can, for example, detect saturation magnetization and / or susceptibility.

[0013] The magnetic field sensor typically includes at least one coil, such as an induction coil. An induction coil can detect the magnetic fields of moving magnetic material by inducing a current. The magnetic field sensor can be constructed similarly to a metal detector. To enable more precise position determination, an alternating magnetic field frequency mixing technique (AC frequency mixing technique) can be used. Typically, information about movement and / or spatial position is detected and / or recorded over time.

[0014] The magnetic material according to the invention is a material that exhibits or generates magnetic properties that can be detected externally. These magnetic properties, in particular a generated magnetic field, can be detected by means of the magnetic field sensor. Specifically, there is an accumulation of magnetic material within the body structure. In the case of multiple accumulations of magnetic material, these are located within the same body.

[0015] In particular, the magnetic material is contained within the body structure, localized in a reference volume, immobilized, and / or anchored. Thus, at least one spatial region exists containing more magnetic material than its surrounding area, allowing the region to be detected due to the higher concentration of magnetic material. Specifically, magnetic material is located within a spatial region of the body structure, while the surrounding area contains almost no magnetic material or no magnetic material at all. In particular, there is no relative movement between the magnetic material or its reference volume and the body structure or the body itself. The detected movement of the magnetic material then corresponds to the movement of the body structure.

[0016] In one embodiment, a liquid magnetic material can be used. The liquid material can be arranged as a limited volume within the body structure, but is typically not immobilized. Movement of the magnetic material within the liquid volume is possible. This can allow for desired adaptability to the body structure, e.g., rotation within the body structure, which may lead to a higher signal during detection.

[0017] Information regarding the movement of the magnetic material is detected. This information is linked to and / or dependent on the movement of the magnetic material. The movement itself can be determined. In a simple embodiment, the movement of the magnetic material is detected relative to the magnetic field sensor and / or to a coordinate system. For example, relative movement between the magnetic material and the magnetic field sensor can be detected, for instance, by measuring the distance between the magnetic field sensor and the magnetic material. Several magnetic field sensors can be used, particularly simultaneously, to determine a position in a three-dimensional coordinate system. In another embodiment, as described below, relative movement between the body structure and at least one other body structure can be detected.

[0018] Motion is a change in position over time. For example, several different positions are detected at different, particularly consecutive, points in time. The more measurement points are acquired per unit of time, the higher the temporal resolution. In particular, several measurement points are recorded per second, for example, at least 4 measurement points per second, preferably at least 10, particularly at least 20, and in one embodiment at least 50 measurement points per second. In other words, motion over time is detected. The method characterizes the motion of the body structure, especially over time.

[0019] This method can be used to map movement. In particular, the detected movements are recorded.

[0020] This procedure corresponds to an examination phase in a diagnostic process. However, the procedure does not include a comparison of the obtained data with normal values, a determination of any deviations that may exist, or a human or veterinary medical decision regarding a possible classification as a disease.

[0021] According to the invention, magnetic material is located on two spaced-apart regions of body structures. Relative movement and, optionally, a distance between a first region of the two body structures and a second region of the two body structures are detected.

[0022] The two areas can be located in the same body structure or in two different ones. The two body structures can, for example, be adjacent. The two areas can therefore be different parts of the same body structure. The only decisive factor is that there is a distance between the two areas.

[0023] For example, a distance can be determined between a muscle and another muscle (or another part of the same muscle), a tendon, a bone, or a fascia. For example, a distance can be determined between a tendon and another tendon (or another part of the same tendon), a bone, or a fascia. For example, a distance can be determined between a bone and another bone (or another part of the same bone) or a fascia. For example, a distance can be determined between a fascia and another fascia (or another part of the same fascia).

[0024] Characterizing relative motions can reveal the temporal progression of the spacing between accumulations of magnetic material. Using relative motions allows for significantly higher resolution compared to using motion relative to the sensor, as the potentially variable position of the sensor relative to the body is not a factor. This enables the detection of movements in the micrometer range or below. In one embodiment, the resolution of a detected movement is at most 50 µm, typically at most 10 µm, particularly at most 5 µm, and preferably 1 µm. In particularly preferred embodiments, the resolution is at most 0.5 µm or below.

[0025] In order to map larger body regions up to and including the entire body, the aforementioned embodiment can be repeated with one or two other body structures and / or more than two areas of magnetic material can be detected simultaneously.

[0026] In one embodiment, magnetic material is located on at least two spaced-apart body structures. In another embodiment, magnetic material is located on three or more spaced-apart body structures. Relative movements of the respective accumulations of material, in particular between each accumulation of material and every other accumulation of material, are detected. Each accumulation of magnetic material preferably has a unique magnetic signature to allow for unambiguous identification during detection. This eliminates the need to continuously track the path of each individual accumulation of magnetic material to enable identification. This simplifies the measurement process.

[0027] Different magnetic signatures are characterized, for example, by the fact that each accumulation of magnetic material generates a different magnetic field. It is generally known to utilize the different magnetic properties, especially of magnetic nanoparticles, in this way, for example, for labeling. This technique can be used here. In particular, the magnetic field sensor(s) are configured for the simultaneous or sequential detection of magnetic materials with different magnetic signatures.

[0028] In one embodiment, magnetic nanostructures are used as the magnetic material. Magnetic nanostructures are composed of magnetic particles on the nanometer scale. A ferromagnet is divided into domains, which represent regions with different magnetization directions. In particular, magnetic nanostructures are smaller than the size of a single domain. Typically, a magnetic nanostructure has only one domain and / or a coherent spin structure.

[0029] Regardless of the nature of the magnetic material, it is preferably biodegradable and / or can be broken down and excreted via the body's own processes.

[0030] In one embodiment, magnetic nanoparticles are used as the magnetic material. Preferably, the magnetic nanoparticles are contained within a shell. In particular, the material is biocompatible.

[0031] Magnetic nanoparticles are nanoparticles that can be manipulated with magnetic fields and / or exhibit externally measurable magnetic properties. Magnetic nanoparticles typically comprise a magnetic material, such as iron, nickel, and / or cobalt. In particular, a nanoparticle has a diameter of less than 1 micrometer, preferably at least 1 nanometer, and / or at most 100 nanometers. Magnetic nanoparticles can be encapsulated and / or exist as clusters.

[0032] In particular, the shell is biologically compatible. Biologically compatible means that the shell has no negative impact on the surrounding body structure(s). For example, no direct interaction occurs at all. The shell can be bioinert or biotolerant. However, the shell may be functionalized, or modified, to concentrate the shell and the particle(s) at the desired body structure, as described below.

[0033] In one embodiment, each magnetic nanoparticle is contained within its own shell. In another embodiment, several magnetic nanoparticles are contained within a common shell. The shell containing the magnetic nanoparticles can be, for example, a vesicle, capsule, and / or droplet.

[0034] The shell can contain molecules and / or be functionalized in such a way that it allows concentration and / or immobilization at a desired body structure.

[0035] In one embodiment, a magnetic contrast agent is used as the magnetic material. Preferably, the magnetic contrast agent is contained in a shell. In particular, the shell is biocompatible.

[0036] In particular, an MRI contrast agent is used, for example, one containing chelated gadolinium ions. The shell containing the magnetic contrast agent can be in the form of vesicles, capsules, and / or droplets. The contrast agent can be liquid.

[0037] In a further interpretation, the body structure is a muscle, a tendon, a bone, or a fascia. In particular, it refers to a specific body structure, such as the right femur.

[0038] In another embodiment, the magnetic field sensor is located outside the body. This allows the method to be performed without any (further) intervention inside the body. It is preferred to position the magnetic field sensor as close as possible to the body surface, possibly directly on the body surface. Proximity increases the signal strength and improves the signal-to-noise ratio.

[0039] In a further embodiment, one or more magnetic field sensors are arranged on a support structure that attaches the magnetic field sensor(s) to the outside of the body.

[0040] The support structure can, for example, include straps that can be attached to the body, such as with fasteners like buckles. The support structure can be a single piece or multi-piece, for example, comprising one or more bandages and / or cuffs designed for placement on specific parts of the body. The support structure can be designed as a corset. This allows the magnetic field sensor(s) to be attached as close to the body as possible. However, as an alternative, it is also possible to position the magnetic field sensors in a stationary position and perform the movement in their vicinity.

[0041] In one embodiment, the characterization of movement or movements on a person's body is performed outside of a medical device, preferably during the person's everyday activities. It is not necessary to perform the movement in a medical or hospital setting. It is not necessary to perform the characterization in a medical device such as an MRI scanner. The invention enables the characterization of movements under everyday conditions. This is particularly easy when a support structure is used on which the magnetic field sensor and suitable evaluation electronics are mounted. In one embodiment, the characterization of movement takes place during sports, at work, and / or while traveling.

[0042] In one embodiment, the motion is characterized to investigate at least one disturbance of the motion. For example, a difference from an undisturbed motion, which might be available as a reference dataset, can be identified or characterized. Differences can be visualized. This can be valuable preliminary work to facilitate diagnosis. However, the diagnosis itself is not performed. Diagnosis is always carried out by medical professionals.

[0043] In one configuration, movements of different body structures are detected and / or recorded. Specifically, a 4-dimensional position map of at least one body region is created. This can be a position map of a part of a body or of the entire body.

[0044] For example, movements of different body structures are detected in relation to the magnetic field sensor and / or in relation to other body structures. A body region refers to a region of the body in which one or more body structures can be located, such as a shoulder.

[0045] The 4-dimensional position map is a data set that includes a fourth, temporal dimension for each three-dimensional point in the body region. Specifically, a particular time interval is considered. Each point in the body region is assigned an absolute and / or relative position for every point in time within that interval. A 4-dimensional motion model of the body is generated, particularly based on three-dimensional anatomical data of a human or animal body. In one embodiment, a 4-dimensional position map of the entire body is generated.

[0046] Such a positional map, for example of a healthy body, can be used as a reference to identify differences or deviations in a patient's body. In this way, the diagnosis of diseases and, if necessary, subsequent therapy can be prepared and / or supported. In one embodiment, the method involves detecting a patient's movements to investigate the patient's complaints. For example, locally isolated joint or bone injuries, or complaints limited to internal cell walls, can be examined.

[0047] In particular, the recording and / or creation of the motion map is computer-aided. Different times or time intervals can be used for different body structures and / or different body regions, for example, due to limitations on the number of simultaneously usable collections of magnetic material, each with different magnetic signatures.

[0048] In one embodiment, the method comprises creating an image depicting selected or all of the detected movements. In other words, the method can be implemented as an imaging technique.

[0049] One application is the production of medical devices such as prostheses and / or implants. Thanks to the high-resolution data from systematic mapping, these can be manufactured to precisely fit the patient's individual anatomy. Another application is the local monitoring of relative membrane movements, for example, in cases of localized discomfort, injuries, or inflammation. This allows, for instance, the immediate detection of swelling reduction to assess healing progress.

[0050] In principle, it is also possible to apply the method according to the invention outside of medicine, for example, to investigate relative movements in machines that are difficult to access. An independent aspect of the invention is therefore a method for characterizing the movement of a structure of a device, in which a magnetic material located in or on the structure of the device moves together with the structure of the device, and the movement of the magnetic material is detected by means of a magnetic field sensor. All features, advantages, and embodiments of the method described above apply analogously to this method, and vice versa.

[0051] In one embodiment, multiple magnetic field sensors are used, particularly simultaneously. The use of multiple magnetic field sensors allows for the simultaneous detection of movements of different body structures. Each detection of one or more body structures can occur independently of any further detection of one or more body structures. In this way, the creation of a position map can be accelerated. Typically, the body structures to be examined using a first magnetic field sensor are located closer to that first sensor than to any subsequent sensors.

[0052] In one embodiment, the magnetic material is incorporated into the body structure.

[0053] The insertion may involve the injection of the magnetic material. While this is an invasive step, it is a relatively simple, routine procedure with no significant health risks. Typically, the body structure does not include the heart, brain, eye, or internal organ. The magnetic material is not a medicinal agent and does not contain any medicinal substance. The insertion is not a surgical or therapeutic procedure. Human or veterinary practitioners are in no way restricted in providing their patients with the best available treatment.

[0054] In one embodiment, the magnetic material is introduced directly into the body structure from outside the body, for example by injection.

[0055] In one embodiment, the magnetic material is introduced into the bloodstream, for example, by injection. The magnetic material is then concentrated at the desired body structure. This can be achieved through biologically targeted drug delivery, for example, using functionalized shell ligands. It is generally known to design substances, such as tracers, to bind to specific tissue types. This technique can be used to immobilize the magnetic material at a desired location. Suitable molecules that enable such concentration and / or immobilization are commercially available and are based, for example, on polysaccharides or antigen-antibodies.

[0056] Another aspect of the invention is the use of a magnetic material to characterize the movement of a body structure. In particular, the magnetic material is located in or on a body structure within a human or animal body. Specifically, the magnetic material performs a movement together with the body structure. All features, advantages, and embodiments of the method described above apply equally to this use, and vice versa.

[0057] Another aspect of the invention is a system for characterizing the movement of a body structure. The system comprises a magnetic material that can be arranged in or on a body structure in a human or animal body, and at least one magnetic field sensor for detecting the magnetic material located in or on the body structure. All features, advantages, and embodiments of the method and use described above also apply to the system, and vice versa.

[0058] The system can include a support structure as described above.

[0059] The system may include a computer, particularly for recording detected information. Preferably, the computer comprises a processor and memory containing computer program code, i.e., instructions that can be stored in or are stored in memory. The processor, memory, and computer program code are configured to record detected information, for example, by storing it electronically. The computer may be mounted on the support structure.

[0060] The system may include evaluation electronics to process signals from the magnetic field sensor. The evaluation electronics may be part of the computer and / or mounted on the support structure. The system may also include a portable power storage device, in particular a rechargeable battery, to provide the magnetic field sensor and, if applicable, other components such as the evaluation electronics and / or the computer with independent electrical power. The power storage device may be mounted on the support structure.

[0061] However, it is also possible for the computer and / or the evaluation electronics to be stationary. In this case, the person being examined typically only wears the magnetic field sensor(s), which are connected to the computer and / or the evaluation electronics, for example, via cable or wirelessly. A hybrid system is also possible, in which the magnetic field sensors and the evaluation electronics are worn by the person, while a computer connected to the evaluation electronics for data recording is stationary.

[0062] Exemplary embodiments of the invention are explained in more detail below, also with reference to figures. Features of the exemplary embodiments can be combined individually or in multiples with the claimed subject matter, unless otherwise specified. The claimed scope of protection is not limited to the exemplary embodiments.

[0063] They show: Fig. 1: a flowchart of a procedure for characterizing a movement, Fig. 2: a schematic representation of body structures, as well as Fig. 3: a schematic arrangement of magnetic field sensors on a body.

[0064] Fig. Figure 1 shows a flowchart of a method according to the invention. After the optional step of introducing 10 and, in particular, immobilizing a magnetic material into a body structure, the magnetic material moves 15 together with the body structure. Information regarding the movement 15 of the magnetic material is detected 20 by means of a magnetic field sensor. Subsequently, the determined information can be recorded 25 and, optionally, a mapping 30 of the body structure or the body can be performed. Within the framework of the mapping 30, a 4-dimensional position map of at least one investigated body region can be created.

[0065] Fig. Figure 2 schematically illustrates the investigation of a relative movement 15 between two adjacent body structures 2. A muscle 4 and a tendon 5 are shown as examples, with the tendon 5 shown in a longitudinal section. A collection of magnetic material 8 is located at a first position in or on the muscle 4. Adjacent to this, another collection of magnetic material 8 is located at a second position in or on the tendon 5. According to the invention, it is now possible to detect the positions of the two collections of magnetic material 8 and / or to detect a distance or a relative movement between the two collections of magnetic material 8. In this way, relative movements of the two adjacent body structures 2 can be investigated.

[0066] The result of such an investigation could, for example, be the function of the distance between the two accumulations of magnetic material 8 over time.

[0067] Fig. Figure 3 schematically shows a human body 1 to which, by means of a support structure 40, four magnetic field sensors 45 are attached (purely by way of example). More magnetic field sensors 45, for example more than 6 magnetic field sensors 45, and / or fewer than 50 magnetic field sensors 45, in particular fewer than 30 magnetic field sensors 45, may be present.

[0068] The support structure 45 comprises, by way of example, two separate and / or interconnected straps. Preferably, the support structure 40 is designed such that the magnetic field sensors 45 are attached close to and relatively immobile on the body 1. Reference symbol list 1 body 2 Body structure 4 Muscle 5 tendon 8 Magnetic material 10. Bring in 15 Movement 20 Detection 25 Recording 30 Mapping 40 Support structure 45 Magnetic field sensor

Claims

[1] Method (1) for characterizing a movement (15) of a body structure (2) in which a magnetic material (8) located in or on a body structure (2) in a human or animal body (1) performs a movement (15) together with the body structure (2) and information regarding the movement (15) of the magnetic material (8) is detected by means of a magnetic field sensor (45), wherein the magnetic field sensor (45) is configured to detect a magnetic field generated by an accumulation of the magnetic material (8), characterized by , that magnetic nanostructures are used as magnetic material (8), wherein magnetic material (8) is located on at least two spaced-apart regions of body structures (2), and wherein a relative motion of a first region of the two body structures (2) in relation to a second region of the two body structures (2) is detected. [2] Method (1) according to the preceding claim, wherein the magnetic material (8) of each body structure (2) has a different magnetic signature. [3] Method (1) according to one of the preceding claims, wherein magnetic nanoparticles are used as the magnetic material (8), wherein the magnetic nanoparticles are in particular contained in a biocompatible shell. [4] Method (1) according to one of the preceding claims, wherein a magnetic contrast agent is used as the magnetic material (8), wherein the magnetic contrast agent is in particular contained in a biocompatible shell. [5] Method (1) according to any of the preceding claims, wherein the body structure (2) is a muscle (4), a tendon (5), a bone or a fascia. [6] Method (1) according to one of the preceding claims, wherein the magnetic field sensor (45) is located outside the body (1). [7] Method (1) according to the preceding claim, wherein one or more magnetic field sensors (45) are arranged on a support structure (40) which attaches the magnetic field sensor(s) (45) to the outside of the body (1). [8] Method (1) according to one of the preceding claims, wherein movements (15) of different body structures (2) are detected and recorded, and a 4-dimensional position map of at least one body region is created. [9] Method (1) according to one of the preceding claims, wherein several magnetic field sensors (45) are used, in particular simultaneously. [10] Method (1) according to one of the preceding claims, wherein the magnetic material (8) is introduced into the body structure (2). [11] Use of a magnetic material (8) located in or on a body structure (2) in a human or animal body (1) and performing a movement (15) together with the body structure (2), for characterizing a movement (15) of the body structure (2), wherein information regarding the movement (15) of the magnetic material (8) is detected by means of a magnetic field sensor (45), wherein the magnetic field sensor (45) is configured to detect a magnetic field generated by an accumulation of the magnetic material (8), characterized by , that magnetic nanostructures are used as magnetic material (8), wherein magnetic material (8) is located on at least two spaced-apart regions of body structures (2), and wherein a relative motion of a first region of the two body structures (2) in relation to a second region of the two body structures (2) is detected. [12] System for characterizing a movement (15) of a body structure (2), comprising a magnetic material (8) which can be arranged in or on a body structure (2) in a human or animal body (1), and at least one magnetic field sensor (45) for detecting the magnetic material (8) located in or on the body structure (2), wherein the magnetic field sensor (45) is configured to detect a magnetic field generated by an accumulation of the magnetic material (8), characterized by , that magnetic nanostructures are used as magnetic material (8), wherein magnetic material (8) is arranged on at least two spaced-apart regions of body structures (2) in order to detect a relative motion of a first region of the two body structures (2) in relation to a second region of the two body structures (2).

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