Magnetomechanical resonator with reduced mutual attraction

Abstract

Systems for monitoring and / or diagnosing transport through the gastrointestinal tract of a mammal (e.g., a human) are described. The system includes a micromechanical resonator (MMR) device and a tracking system. The sensing device comprises a housing and a first magnetic object having a permanent magnetic moment, where the first magnetic object is coupled to the housing in such a way that the first magnetic object is configured to oscillate about an equilibrium position when excited by a magnetic or electromagnetic excitation field, and where the first magnetic object is configured to oscillate about the equilibrium position when excited by the magnetic or electromagnetic excitation field. The tracking system includes at least one coil for generating a magnetic or electromagnetic excitation field, the at least one coil configured for detecting a responsive magnetic field generated by the sensing device.

Description

Technical Field

[0001] The present invention relates to gastric emptying and devices / methods for gastric emptying analysis, as well as methods of manufacturing such devices. Background Art

[0002] Gastric emptying is the process by which the contents of the stomach move into the duodenum. This is achieved through three mechanisms: (1) peristaltic waves, (2) contractile contractions of the gastric antrum, and (3) reduction in the size of the stomach. To monitor this process, different procedures are used.

[0003] One of the most widely used methods is to monitor the movement of food by using radioactive pills as tracers. The patient will eat a meal containing a radioactive pill (tracer), will lie on an X-ray table, and the radiologist will perform several scans to see how the tracer moves through the patient's body. The tracer will show how the food passes through the stomach. This method has some substantial drawbacks, such as the X-ray machine and the absorbed dose of the tracer. In addition, the tracer is toxic to the patient and difficult to handle. Other similar methods also have significant drawbacks. Barium swallow and radioactive pills have the same drawbacks. Gastric emptying breath tests are inaccurate, and the patient will receive a large dose in X-ray studies. Another known method is to use smart pills, also known as wireless motility capsules. The patient will swallow a small electronic device (also known as a smart pill, Medtronic's smart pill, or just a smart pill), and a receiver will be attached to the waist. The smart pill will pass through the gastrointestinal system and collect data that is sent to the receiver. Then, the receiver will be returned to the doctor for reading the data. This method is very uncomfortable to use because the smart pill is very large, which may cause gastrointestinal (GI) tract obstruction. Generally, retaining the smart pill is a challenge and requires additional studies (such as esophagogastroduodenoscopy), which will cause further discomfort to the patient and complicate the clinical workflow. Moreover, the accuracy of these devices needs to be improved because in many cases, additional studies are required to mitigate the problem of insufficient accuracy.

[0004] Therefore, the object of the present application is to solve these challenges, with the goal of developing new systems and sensors to mitigate the problems of known methods. Summary of the Invention

[0005] The present invention is defined by the independent claims. The dependent claims represent advantageous embodiments.

[0006] The present invention relates to monitoring and / or diagnosing the gastric transit process in mammals (especially humans). Currently, there is no gastrointestinal research application that is low-cost, easy to handle, and has no harmful side effects on human health (such as due to ionizing radiation used in conventional procedures). The present invention aims to introduce a solution that addresses at least one (preferably all) of the mentioned challenges.

[0007] Very small mechanical devices (e.g., in the form of micro-robots or micro-devices) have been developed, which can be advantageously used in applications where strict size limitations are introduced (e.g., in medical applications within the human body). Such micro-devices are useful in the form of positioning devices or sensor devices. A very advantageous type of such micro-devices is the magneto-mechanical resonator (MMR) device. The positioning or sensing of such magneto-mechanical resonator devices relies on the spatially resolved detection of the response signal (e.g., the induced magnetic field) of the magneto-mechanical resonator device, which is generated in response to an excitation signal (e.g., an externally applied magnetic field). Typically, information about the position of the magneto-mechanical resonator device is obtained by using an array of receiving coils with a known spatial sensitivity distribution.

[0008] U.S. Patent Application Publication US2020 / 0397510 describes the general principle of the sensing device and is incorporated herein by reference in its entirety as if fully set forth in the text.

[0009] The inventors of the present invention have recognized that sensing devices (e.g., those described in U.S. Patent Application US2020 / 0397510) can be adapted for use in gastrointestinal research and have developed a completely new method for monitoring and / or diagnosing the gastric emptying process, gastric transit process, and general detection of GI dysfunction in the human body. Since the sensing devices are smaller than smart pill devices (e.g., Medtronic's smart pill), they have the potential to alleviate and / or solve the aforementioned challenges and problems. Generally, attempts have not been made to adapt sensing devices for gastric emptying applications. The inventors of the present invention have developed a completely new MMR-based method for monitoring and / or diagnosing the gastric transit process in mammals. The described method can also be used in other applications.

[0010] The present inventors have recognized that MMR devices may be suitable for use as markers and / or sensors in gastrointestinal applications (e.g., for measuring temperature, pressure), and thus, for example, in the study of gastric emptying time. In such applications, it may often be necessary to ingest more than one sensing device at a time. As a representative example, the sensing device (100) is a magneto-mechanical resonator (MMR) device. Since the sensing devices contain magnetic materials, the MMRs may attract each other, which is generally an undesirable situation. Therefore, the inventors of the present application have developed methods for using sensing devices for gastrointestinal (and other related applications), as well as corresponding devices configured to measure the position, parameters (e.g., temperature) of one or more of the sensing devices of the present application.

[0011] Accordingly, some embodiments of the present invention aim to provide sensing devices that include features or characteristics that can reduce or minimize their mutual attraction. This is particularly useful in the context of gastric emptying applications, but this is a non-limiting example, and other possible applications can be anticipated. Another object of the present invention is to provide such an MMR that is suitable for use in the gastrointestinal (GI) tract, such as being configured to pass through the gastrointestinal tract and capable of performing corresponding measurements. Another aspect of the present invention discloses a tracking system configured to measure signals from the sensing device.

[0012] According to one aspect of the present invention, a system for monitoring and / or diagnosing the transit through the gastrointestinal tract of a mammal (e.g., a human) is disclosed. The system includes a microelectromechanical resonator (MMR) device, a sensing device, and a tracking system, wherein the sensing device includes a housing and a first magnetic object having a permanent magnetic moment, wherein the first magnetic object is coupled to the housing in such a way that the first magnetic object is configured to oscillate about an equilibrium position when excited by a magnetic or electromagnetic excitation field. The device further includes a sensing device that includes a second magnetic object configured to provide a restoring force to the first magnetic object, wherein the distance from the center of the first magnetic object to the outer surface of the housing is at least equal to the diameter of the first magnetic object. The tracking system includes at least one coil for generating the magnetic or electromagnetic excitation field and a controller for controlling the coil system, the at least one coil being configured to detect a response magnetic field generated by the (one or more) sensing devices, the controller being configured to determine whether a sensing device is present in a target detection space.

[0013] In another aspect, a sensing device for monitoring and / or diagnosing the transit through the gastrointestinal tract of a mammal (e.g., a human) is described. The device includes a housing, a first magnetic object having a permanent magnetic moment, wherein the first magnetic object is coupled to the housing in such a way that the first magnetic object is configured to oscillate about an equilibrium position when excited by a magnetic or electromagnetic excitation field. The sensing device includes a second magnetic object configured to provide a restoring force to the first magnetic object; and wherein the distance from the center of the first magnetic object to the outer surface of the housing is at least equal to the diameter of the first magnetic object.

[0014] In some embodiments, a sensing device is described, wherein the distance from the center of the magnetic object to the outer surface of the housing is at least equal to twice the diameter of the magnetic object, preferably three times.

[0015] In some embodiments, a sensing device is described, wherein a filling material is provided inside the housing, and the filling material may include at least one of the following: epoxy resin, or a polymer material (e.g., polypropylene).

[0016] In some embodiments, the sensing device has a cage that defines the outer shape of the sensor. "Defines" means that the housing of the sensing device is configured to be inside the cage, or in other words, the cage surrounds the sensing device.

[0017] In some embodiments, the sensing device is arranged to have a density of 945 to 1155 kg / m 3 and preferably has a density of 1000 to 1050 kg / m 3 For the sensing device, it is preferred to have these densities so that the device can easily pass through the gastric tract. However, other densities can be expected within the scope of this application.

[0018] In some embodiments, the outer surface of the cage is provided with a gastrointestinal tolerance coating.

[0019] In some embodiments, the first magnetic object and / or the second magnetic object includes one or more of the following materials: FeNdB alloy, CoSm, alnico alloy, barium ferrite, and / or barium strontium ferrite. The first magnetic object is configured to be attached to the housing via a filament, and the second magnetic object is either configured to be fixed to the housing by a fixing material (and wherein the first magnetic object is configured to rotate freely in response to an externally applied magnetic field), or is configured to be attached to the housing via a second filament.

[0020] The ratio of the diameter of the filament to the diameter of the magnetic object can be a constant, where the constant will be in the range of 1:1 to 1:1000, and more preferably will be in the range of 1:100 to 1:1000.

[0021] In some embodiments, the housing includes a material that is configured to change its morphological structure, e.g., change the length of the material under the influence of changing the pH level of the environment in which the device is located.

[0022] The sensing device may include a remanent magnetic moment and a total magnetic moment, where the remanent magnetic moment of the device is less than 5% of the total magnetic moment of the device. The remanent magnetic moment of the sensing device is preferably less than 1% of the total magnetic moment of the device, and even more preferably less than 0.5% of the total magnetic moment of the device.

[0023] In some embodiments, the filaments (103) and / or the fixing material of the sensing device may be a group of polymeric materials, preferably polyoxides, such as epoxy resins. It should be understood that these are merely illustrative examples and that other materials of the group and / or other groups of materials can be used.

[0024] In some embodiments, the distance between the first magnetic object (102) and the second magnetic object is preferably less than 10% of the diameter of the first magnetic object, and even more preferably less than 2% of the diameter of the first magnetic object.

[0025] Additionally, a method of administering a sensing device is disclosed. The method includes providing a plurality of sensing devices of any one of the embodiments of the present invention. Administering the sensing device for oral use to a subject; and

[0026] Monitoring the sensing device as it passes through the subject (e.g., through the gastrointestinal tract of the subject) and being configured for readout by a tracking system. In some embodiments, a plurality of sensing devices are present in the gastrointestinal tract simultaneously, and at least some of the sensing devices are independently monitored without interference from other sensing devices among the sensing devices. Additionally, the sensing device can be used for diagnosing gastrointestinal diseases and / or for medication adherence control and / or for gastrointestinal constipation monitoring.

[0027] In some embodiments, a method of manufacturing a sensing device is described, including the steps of:

[0028] Providing at least one sensing device in a fixture;

[0029] Manipulating the position and / or orientation of one or two magnetic objects;

[0030] Measuring the residual dipole moment of at least one sensing device;

[0031] Comparing the measured residual dipole moment with a predefined threshold, where the threshold is preferably 5% of the total available dipole moment of the sensing device, even more preferably 1%, and even more preferably 0.5%;

[0032] If the measured residual dipole moment is greater than the predefined threshold, return to the operation of manipulating the position / orientation of the magnetic object, otherwise continue with the following steps and optional steps, where the following steps are:

[0033] Fixing the position and orientation of the magnetic object; and optionally

[0034] Applying ultraviolet light to the magnetic object.

[0035] In some embodiments, a method of monitoring the transit through the gastrointestinal tract of a mammal (e.g., a human) is disclosed, the method comprising administering a sensing device as described herein.

[0036] In some embodiments, a computer program comprising instructions is disclosed, which when executed by a computer cause the computer to perform the steps of the method.

[0037] According to one aspect of the present invention, a system and / or method for monitoring and / or diagnosing the transit through the gastrointestinal tract of a mammal (particularly a human) comprises an ingestible device (e.g., a sensing device), wherein the sensing device comprises a housing and a sensor, the sensor comprising a magnetic body providing a permanent magnetic moment, wherein the sensor is configured to transduce an external magnetic or electromagnetic excitation field into an induced mechanical oscillation of the magnetic body, and wherein the induced mechanical vibration is independent of the external pressure to which the sensor is subjected, and wherein the induced mechanical vibration generates a response magnetic field or a response electromagnetic field, and wherein the distance from the center of the magnetic body to the outer surface of the housing is at least equal to the diameter of the magnetic body.

[0038] The systems and methods described herein are configured for gastric applications, e.g., tracking one or more ingestible devices in a patient's gastrointestinal (GI) tract. In some embodiments of the present application, the device may be of the sensing device type. For example, the sensing device may be of the microelectromechanical resonator (MMR) type.

[0039] Generally, gastric emptying studies require the ingestion of multiple sensing devices. In the case of multiple sensing devices being present in the stomach, it may be challenging to control whether individual sensing devices have come into contact with each other. Sensing devices in contact with each other may interact, thereby producing unwanted effects. Therefore, preferably, the interaction of the sensing devices needs to be restricted. Additionally, preferably, the readout system is capable of being used to track and adjust sensing device parameters. In this way, the challenges of multiple interacting sensors can be alleviated.

[0040] In some embodiments, the outer surface of the housing comprises a material suitable for passage through the gastrointestinal tract.

[0041] In some embodiments, the distance from the center of the magnetic body to the outer surface of the housing is at least equal to twice the diameter of the magnetic body.

[0042] In some embodiments, the distance from the center of the magnetic body to the outer surface of the housing is at least equal to three times the diameter of the magnetic body.

[0043] In some embodiments, the housing is cylindrical, wherein the diameter of the housing is less than 10 mm.

[0044] In some embodiments, the housing is cylindrical, and the diameter of the housing is less than 5 mm.

[0045] In some embodiments, the housing comprises a material whose length changes as a function of the pH value of the environment in which the device is located.

[0046] In some embodiments, the device further comprises a layer of material disposed around a central region of the housing.

[0047] In some embodiments, the device further comprises a spacer surrounding at least a portion of the housing.

[0048] According to another aspect of the present invention, a sensing device comprises: a housing and a sensor, the sensor comprising a magnetic object providing a permanent magnetic moment, wherein the sensor is configured to transduce an external magnetic or electromagnetic excitation field into an induced mechanical oscillation of the magnetic object, wherein the induced mechanical oscillation is independent of the external pressure to which the sensor is subjected, and wherein the induced mechanical oscillation generates a response magnetic field or a response electromagnetic field, and wherein the remanent magnetic moment of the device is less than 5% of the total magnetic moment of the device.

[0049] In some embodiments, the remanent magnetic moment of the sensing device is less than 1% of the total magnetic moment of the device. The remanent magnetic moment means the standard definition in the art. The remanent magnetic moment describes a magnetic moment in which the magnetization remaining in a magnetized body is no longer affected by an external magnetic field.

[0050] In some embodiments, the remanent magnetic moment of the device is less than 0.5% of the total magnetic moment of the device.

[0051] In some embodiments, the device further comprises a second magnetic object. In some embodiments, there may be more than two magnetic objects.

[0052] In some embodiments, the second magnetic object is fixed to the housing.

[0053] In some embodiments, the distance between the first magnetic object and the second magnetic object is less than 10% of the diameter of the first magnetic object. In some embodiments, this can produce the following technical effects: reducing the magnetic field from at least one sensing device at another location, and reducing the higher magnetic moment (i.e., not only the dipole moment, but also generally other magnetic moments).

[0054] In some embodiments, the sensing device can act as a sensor for measuring certain parameters. Non-limiting examples can include measuring at least one of the following: pressure, pH level, temperature. In some instances, the parameter can be measured by coupling a distance to the measurement value. This can be done by using the techniques described in WO2020253977A1, which is incorporated herein by reference. In some embodiments, the distance between the first magnetic object and the second magnetic object is approximately 2% of the diameter of the first magnetic object.

[0055] In some embodiments, the housing comprises a material whose length changes as the pH value of the environment in which the device is located changes.

[0056] According to another aspect of the present invention, a method includes: providing a plurality of sensing devices; administering the plurality of sensing devices for oral ingestion by an object; and monitoring the sensing devices as the sensing devices pass through the gastrointestinal tract of the object. In the context of the present application, "plurality" means at least two sensing devices. In some embodiments, it is sufficient to ingest only one sensing device.

[0057] In some embodiments, the sensing device includes: a housing and a sensor including a magnetic object providing a permanent magnetic moment, wherein the sensor is configured to transduce an external magnetic or electromagnetic excitation field into an induced mechanical oscillation of the magnetic object, wherein the induced mechanical oscillation is independent of the external pressure experienced by the sensor, and wherein the induced mechanical oscillation generates a response magnetic field or a response electromagnetic field, and wherein the distance from the center of the magnetic object to the outer surface of the housing is at least equal to the diameter of the magnetic object.

[0058] In some embodiments, the sensing device includes: a housing and a sensor including a magnetic object providing a permanent magnetic moment, wherein the sensor is configured to transduce an external magnetic or electromagnetic excitation field into an induced mechanical oscillation of the magnetic object, wherein the induced mechanical oscillation is independent of the external pressure experienced by the sensing device, and wherein the induced mechanical oscillation generates a response magnetic field or a response electromagnetic field, and wherein the residual magnetic moment of the device is less than 5% of the total magnetic moment of the device. There is a certain relationship between the magnetic moment and the diameter. For example, taking the cube root of 5% will result in a ratio relationship of approximately 1:3. Therefore, compared with a sensing device without 5% compensation, the radius of the sensing device is adjusted by 1 / 3.

[0059] In some embodiments, multiple sensing devices are present in the gastrointestinal tract, and at least some of the sensing devices in the sensing devices are independently monitored. In some embodiments, one sensing device can be monitored without interference from another sensing device among the sensing devices. In some embodiments, all of the sensing devices can be monitored. In some other embodiments, at least one or several sensing devices can be monitored, and the positioning of other sensing devices can be inferred based on the measured position information of the sensing devices. As a representative example, one sensing device can have a low magnetic field at the position of the second sensor. The magnetic field from one sensing device will be close to other sensing devices. The sensing device can have a coating that will limit contact between the sensors. In some examples, the magnetic field of an individual sensing device will be around 1 millitesla or less. Preferably, a GI tract-tolerant coating (i.e., a coating that will not dissolve under the influence of GI tract fluid) is applied (e.g., coated) on the sensing device. The coating used is configured to be non-toxic and insoluble in GI tract fluid. In a preferred embodiment, epoxy dip coating can be used. However, other coatings with similar properties (e.g., acrylic resin-based spraying) can also be used.

[0060] According to yet another aspect of the present invention, multiple magnetomechanical resonator (MMR) devices are disclosed, each sensing device comprising: a housing and a sensor, the sensor comprising a magnetic object providing a permanent magnetic moment, wherein the sensor is configured to transduce an external magnetic or electromagnetic excitation field into an induced mechanical oscillation of the magnetic object, wherein the induced mechanical oscillation generates a response magnetic field or a response electromagnetic field, wherein multiple sensing devices are present in the gastrointestinal tract of an object, and wherein at least some of the sensing devices are adapted to be independently monitored without interference from the magnetic field or magnetic attraction of other sensing devices among the sensing devices.

[0061] In some embodiments, a tracking device for tracking the positioning of a sensing device is disclosed. The tracking device can extend to the sensing device, for example, including a tracking arm comprising specific hardware and / or software for receiving, decoding, and analyzing signals from the sensing device. The tracking device can track the position of the sensing device from a certain distance. In an exemplary example, the source-to-image (SID) distance can be about 2 - 10 centimeters. However, other SID distances varying up to several meters can be expected.

[0062] In some instances, the gastric emptying volume can be derived from food movement and / or volume changes. In the context of the present invention, other methods for deriving changes in gastric emptying can be expected.

[0063] Current sensing devices and / or sensing systems, as well as corresponding methods, can be used in a variety of applications for diagnosing gastrointestinal (GI) problems (e.g., for diagnosing abdominal pain, nausea, vomiting, etc.). This is typically done by performing a gastric emptying study. The devices and methods described herein are suitable for performing such gastric emptying studies. However, it should be understood that the gastric emptying tracking applications described in this application are merely examples, and the devices of this application can be applied to the following applications, but are not limited to these applications:

[0064] Sensing device tracking in the GI tract:

[0065] Drug therapy compliance control;

[0066] GI tract constipation monitoring.

[0067] Compared with conventional methods, this application has multiple advantages.

[0068] One of these advantages can be that a high-precision positioning algorithm can improve the accuracy and / or precision of tracking and improve the readout.

[0069] Another advantage can be that the present invention can simulate the emptying of normal eating because the sensing device will be swallowed, for example, together with food.

[0070] Another advantage can be that, due to the alternative use of an electromagnetic reading device, the radiation exposure in GI tract studies can be reduced.

[0071] Another advantage can be that, by using the current system, the aggregation of several markers caused by the magnetic force attracting one marker to another can be avoided.

[0072] Another advantage can be that the potential independent position of the sensing device (e.g., acting as a clinical marker) in, for example, a patient's GI tract or other organs and / or the numerical readings from devices at different positions can be determined.

[0073] Another advantage can be that the safety of the patient is improved because the current device can operate under an attraction that is sufficiently harmless to the patient.

[0074] Another advantage can be that the signal-to-noise ratio (SNR) can be improved as the reading distortion is reduced.

[0075] These advantages are exemplary, and other advantages can be expected in the context of this application.

[0076] It should be understood that embodiments of the present invention can also be generated by any combination of the features in the dependent claims or the above embodiments with the corresponding independent claims.

[0077] These aspects and other aspects of the invention will become apparent and be elucidated with reference to the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 A first exemplary embodiment of a sensing device is shown.

[0079] Figure 2 A second exemplary embodiment of a sensing device is shown.

[0080] Figure 3 A third exemplary embodiment of a sensing device is shown.

[0081] Figure 4 A fourth exemplary embodiment of a sensing device is shown.

[0082] Figure 5 A fifth exemplary embodiment of a sensing device is shown.

[0083] Figure 6 A sixth exemplary embodiment of a sensing device is shown.

[0084] Figure 7 A seventh exemplary embodiment of a sensing device is shown.

[0085] Figure 8 An exemplary method of manufacturing a sensing device is illustrated.

[0086] Figure 9 An exemplary method of performing a diagnostic process using a plurality of sensing devices is illustrated.

[0087] Figure 10 An exemplary sensing device with a cage is illustrated. DETAILED DESCRIPTION

[0088] Figure 1 A first exemplary embodiment of a sensing device (100) is shown. As a representative example, the sensing device is a magnetomechanical resonator (MMR) device. The sensing device 100 includes a first magnetic object 102 and a second magnetic object 104 disposed inside a housing or enclosure 105. Advantageously, the first magnetic object 102 and the second magnetic object 104 include permanent magnets. The first magnetic object 102 is attached to the housing 105 via a filament 103 and can rotate freely (e.g., in response to an externally applied magnetic field). The second magnetic object 104 is fixed to the housing 105 by a fixing material 106. In some embodiments, the fixing material may be glue or epoxy resin. For example, an epoxy resin that can be hardened or cured when exposed to light (e.g., ultraviolet light) can be used.

[0089] In the sensing device 100, the housing 105 is illustrated as cylindrical. However, in other embodiments, the housing may have different shapes, including but not limited to spherical or oval.

[0090] In some embodiments, the magnetic objects 102 and 104 comprise a FeNdB alloy (neodymium magnet). However, there are many other suitable materials. For example, CoSm can be used, but it has some drawbacks, such as being more expensive and more difficult to work with than the FeNdB alloy. Other materials with similar properties (e.g., iron platinum, alnico alloy, barium ferrite (BaFe), barium strontium ferrite (e.g., BaFe 12 O 19 )) can be used in the context of the present application. However, the examples described are non-limiting in any possible aspect, and other materials can be used. Advantageously, the magnetic material can have a strong remanence while being as light as possible.

[0091] In some embodiments, the filament 103 can be made of a high-strength polymer material (e.g., ultra-high molecular weight polyethylene (UHMWPE)). Polyamide (PA) or any other suitable material with similar properties may also be suitable. The length of the filament 103 depends on the sizes of the magnetic objects 102 and 103 and the overall sensing device 100. For example, for a magnetic object 102 with a diameter of 500 μm, the diameter of the filament 103 can be approximately 10 μm. Advantageously, the ratio of the diameter of the filament 103 to the diameter of the magnetic object can approach a constant. The preferred constant will be in the range of 1:1 to 1:1000, preferably in the range of 1:50 to 1:1000, and even more preferably in the range of 1:100 to 1:1000.

[0092] In operation, the magnetic object 102 provides a permanent magnetic moment and can operate as a sensor, where the sensor is configured to transduce an external magnetic or electromagnetic excitation field into an induced mechanical oscillation of the magnetic object 102. Advantageously, the induced mechanical vibration is independent of the external pressure experienced by the sensor, and the induced mechanical vibration generates an induced response magnetic constant or an induced response electromagnetic field, which can be measured by a tracking system for tracking the position of the sensing device 100.

[0093] As explained above, the inventors have realized that MMRs such as the sensing device 100 may be suitable for use as markers and / or sensors for gastrointestinal applications (e.g., for measuring temperature, pressure), and thus, for example, for the study of gastric emptying time. In some embodiments, only the position is measured. In some other embodiments, only the parameters of the body (e.g., temperature, pressure) can be measured. In some embodiments, the position (localization) and parameters of the body can be measured.

[0094] For gastrointestinal applications, it may be desirable for the MMR100 to have certain characteristics. Some non-limiting examples will be described below.

[0095] As an example, for gastrointestinal applications, it is desirable for the outer surface of the housing 105 to include a material suitable for passage through the gastrointestinal tract. There are many suitable materials. Generally, such a material will not dissolve in the gastrointestinal tract and beneficially is non-toxic, although if the material does not dissolve, it is not strictly required that the material be non-toxic. Beneficially, the material may obtain regulatory approval for food use. Suitable plastics may include, but are not limited to: polypropylene (PP), low density polyethylene (LDPE), high density polyethylene (HDPE), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), etc. There are also many suitable metals, particularly non-magnetic stainless steel types and titanium alloys (e.g., TiA6lV4). Cobalt chromium may also be suitable. Many glass materials and ceramic materials may also be suitable. Generally, all glass and ceramic structures are applicable, except those containing steel and / or toxic materials. Alumina and zirconia may be suitable choices, and various inorganic glasses may also be suitable choices. For measuring the pH value in the gastrointestinal tract, PA or nylon may be preferred for embodiments of the present application, although other suitable materials may also be used, depending on the intended application. For example, PA may require regulatory approval for this particular application, and for some embodiments of the present application, other materials may be preferred.

[0096] As another example, the (one or more) sensing devices 100 should have a suitable size for passage through the gastrointestinal tract. Beneficially, the diameter of the sensing device 100 can be less than 10 mm. More beneficially, the diameter of the sensing device 100 is less than 5 mm. In some embodiments, the diameter of the MMR100 can be significantly less than 5 mm, e.g., 1.5 mm or possibly as low as about 0.6 mm. The desired device size depends on clinical, commercial goals, and the technology implementation at hand. For example, a sensing device with a diameter of about 0.6 mm may be beneficial in some specific applications, but is more expensive to produce because more expensive electronics and / or more complex manufacturing steps may be required. On the other hand, devices with a diameter of about 5 mm may be easier to manufacture and less costly, but they may not be suitable for all clinical applications.

[0097] As yet another example, for gastrointestinal applications, it is desirable for the overall density of the (one or more) sensing devices 100 to be similar to the density of gastric contents / gastric fluid, which is typically about 1050 kg / m 3)matched. Advantageously, the overall density of the sensing device 100 can be 0.9 to 1.1 times the average density of the gastric fluid. Generally speaking, this may mean that the overall density of the sensing device 100 is advantageously in the range of approximately 945 to 1155 kg / m 3 3 When additional mass needs to be added to the device to increase its density, the mass should be added as far as possible along the oscillation axis of the magnetic object 102 to increase the moment of inertia, which helps to maintain the high quality factor of the sensing device. For example, the outer shell of the housing 105 can include a high-density material, such as tungsten, tungsten carbide, tantalum, gold, platinum, iridium, osmium, etc. In other embodiments, a layer of high-density material can be provided as a ring or band around the intermediate region of the sensing device 100. In other embodiments, the sensing device 100 can be encapsulated in a spacer material around the housing 105 to achieve the desired density of the entire device.

[0098] In some embodiments, it may be advantageous to include sensing features in the device. For gastric applications, a pH-sensitive resonance frequency may be a useful sensor reading. Advantageously, for such applications, the housing 105 can include a material whose length changes with the change in pH value. For example, simple polyamides (such as nylon) respond to the pH level of the environment. Other polymers (such as biopolymers like chitosan) may respond more strongly to the pH level of the environment. The principle described in this paragraph can be based on the so-called "swelling effect", which is based on the swelling rate of a certain material when placed in, for example, an aqueous solution at different pH levels. In some instances, this may mean that the sensing device 100 may bind / absorb water and thus elongate.

[0099] In gastrointestinal applications, it may be necessary to ingest more than one sensing device at a time. Since the sensing devices contain magnetic materials, the sensing devices will attract each other, which is generally undesirable.

[0100] In some embodiments, when sensing devices 100 are set adjacent to or close to each other, the magnetic coupling between two or more sensing devices 100 can be reduced by increasing the distance between the magnetic objects 102 of the sensing devices 100. Generally, this can be achieved by increasing the ratio of (1) the distance from the center of the magnetic object 102 to the outer surface of the housing 105 to (2) the diameter of the magnetic object 102. In some embodiments, the ratio is at least 2. In other embodiments, the ratio is at least 3 (e.g., 4). In an exemplary embodiment, the ratio of the outer diameter of the housing 105 to the diameter of the magnetic object 102 is 3 or greater. In some embodiments, the diameter of the magnetic object 102 is approximately 500 μm, and the diameter of the housing 105 is approximately 1.5 mm. In one embodiment, the diameter of the magnetic object 102 is at least 200 μm, and the diameter of the housing 105 is approximately 600 μm.

[0101] One way to achieve this is to provide a thick outer shell for the housing 105. In some embodiments, the outer shell will be the difference between the actual radius of the first and / or second magnetic object and the overall sensing device radius, which can be in the range of 2:1 or 3:1, or other ratios depending on the application. The outer shell can also increase the density of the sensing device 100, which may be desirable in some embodiments. In some embodiments, a material layer (e.g., a high-density material as described above) can be provided as a ring or band around the intermediate region of the sensing device 100. In some embodiments, the material layer can be provided around the housing of the sensing device. In other embodiments, the sensing device 100 can be encapsulated in a spacer material formed around the housing 105 to achieve a desired outer diameter. For clarity, in the context of this application, the spacer material is referred to as a "cage".

[0102] However, the above methods may enlarge the size of the sensing device beyond the desired extent. Many applications require the sensing device to have a small overall size. Therefore, the inventors have realized that it is highly desirable to have other means to reduce the attraction between sensing devices.

[0103] The inventors have thought that in applications where multiple sensing devices may be present in the same vicinity of each other, it is desirable for the magnetic field from the sensing device to decay as fast as possible with the distance from other sensing devices. This magnetic field has two components. The first component is the static magnetic field, i.e., the magnetic field of the undisturbed sensing device. The second component is the induced magnetic field, i.e., the magnetic field generated by the MMR in response to exposure to an external magnetic field.

[0104] The inventor further thought that the static magnetic field of the sensing device could be reduced by compensating the dipole moment of the magnetic object (and ideally also compensating higher magnetic moments). The inventor further thought that the induced magnetic field of the sensing device could be reduced by making the sensing device magnetically relatively hard and thus having a low apparent magnetic permeability.

[0105] The sensing device may include at least two magnetic objects (e.g., 102 and 104), and at least one of the magnetic objects is capable of performing rotational oscillations relative to the other magnetic object. For the sensing device, generally the magnetic dipole moments of the two objects may be different from each other.

[0106] The inventor has thought that in order to reduce or minimize the static magnetic field of the sensing device, the dipole moments and should be very close to each other, not only in magnitude (i.e., ), but also the vectors should have as opposite directions as possible (i.e., ).

[0107] However, at small scales, the alignment of the magnetic objects 102 and 104 to achieve this relationship may actually become difficult. The attachment of the filament 103 to the oscillating magnetic object 102 may be challenging. Even a 5° misalignment will produce a remaining dipole moment of approximately 10% of the entire sensing device 100, where the percentage of the remaining dipole moment is the comparison of the total dipole moment of the MMR100 with the dipole moment of one of the magnetic objects 102 / 104.

[0108] This remaining dipole moment may be too large for practical applications in some applications.

[0109] Therefore, the inventor has designed a method to reduce this remaining dipole moment.

[0110] In some embodiments, during the assembly of the sensing device, the residual dipole moment of the sensing device can be measured (e.g., by a suitable magnetometer which may be as simple as a small compass needle around the assembly location or by a proxy method such as resonance frequency). In the case of the sensing device 100, the fixed magnetic object 104 can be glued or epoxied in place in the housing 105 of the sensing device 100 in a fixture that allows adjustment of the angle between the magnetic object 102 and the magnetic object 104. For example, the angle can be adjusted by manipulating the position and / or orientation of the magnetic object 104, and once the residual dipole moment is less than or equal to a defined maximum threshold, the glue or epoxy can be cured, for example, by exposure to light (e.g., ultraviolet light). In some embodiments, the threshold for the residual dipole moment can be 5% or less of the total available dipole moment (|m1| + |m2|) of the MMR. In some embodiments, the threshold for the residual dipole moment can be 0.5% of the total available dipole moment (|m1| + |m2|) of the sensing device 100.

[0111] Non-limiting examples of adjusting the angle of the sensing device are described. In some embodiments, the angle of the sensing device can refer to the angle between the magnetic object (104) and the housing (105). In some embodiments, the angle can be adjusted to achieve a desired angle value according to a clinical application. In some embodiments, this may involve attaching a "rod" (e.g., a wire) and / or manipulating the angle value with the "rod". This can further involve zeroing the magnetic field. When the desired angle is obtained, the magnet can be glued in place and at least part of the "rod" can be removed. In this way, due to the magnetic force, the angle of the (movable) magnetic object (102) can follow the (fixed) magnetic object (104).

[0112] In other embodiments, instead of exactly the same magnetic objects 102 and 104, one (or both) of the magnetic objects 102 and 104 can consist of two or more sub-objects.

[0113] Figure 2 A second exemplary embodiment of a magnetomechanical resonator (MMR) device 200 is shown. Elements in the MMR 200 that are similar or identical to elements in the sensing device 100 will not be described again. In a variant of the sensing device 100, in addition to the fixed magnetic object 104, the sensing device 200 further includes an additional, smaller fixed magnetic object 108. This has the advantage of allowing for finer tuning of the dipole moment by manipulating the smaller magnetic object. It also allows for a larger fixed magnetic object 104, which will be beneficial for minimizing the induced dipole moment, as described below. If appropriately arranged, higher multipole moments can be reduced, resulting in a more rapid decrease of the magnetic field with distance. Additionally, while Figure 2An embodiment is shown with a single smaller magnetic object 708, but other embodiments may include two or more smaller magnetic objects.

[0114] As described above, it is also desirable to reduce the induced dipole moment of the sensing devices 100, 200, etc.

[0115] In some instances, this can be achieved by making the torsion spring between the two magnetic objects 102 and 104 stiffer. The torsion spring mainly consists of the magnetic field generated by the fixed magnetic object 104 at the position of the moving magnetic object 102.

[0116] The filament 103 makes a small contribution to the torsion spring. It is generally not desirable to increase this component as it would significantly reduce the quality factor of the resonance.

[0117] Maximizing the magnetic field between the magnetic objects is one way to make the torsion spring between the two magnetic objects stiffer.

[0118] In some embodiments, for the sensing device (100), it preferably has a substantially spherical or ellipsoidal shape (e.g., in the form of a pill). In a non - limiting example, the sensing device (100) can be a sphere or ellipsoid with a minimum diameter of 4 mm and a maximum diameter of 8 - 10 mm. Preferably, the diameter of the sensing device can be as small as 0.5 mm to 2 mm, with the corresponding magnetic sphere diameter between 0.3 mm and 1 mm. The advantage of this is that there is enough space to keep the shell surface away from the magnetic objects (102, 104), thus avoiding coupling to external objects (e.g., other sensing devices). Preferably, the exterior of the shell is made to be compatible with the stomach (e.g., covered with a material that is not soluble in the stomach).

[0119] In addition, one must ensure that the sensor is suitable for passing through the gastric tube. This means that the density must be higher than water (to avoid floating in the stomach), preferably between 950 kg / m 3 to 1300 kg / m 3 Between. Even more preferably, this will be between 945 and 1155 kg / m 3 Between, and even more preferably between 1000 and 1050 kg / m 3Therebetween. This can be achieved by fabricating a standard tracking sensing device (100), where the housing (105) of the sensing device serves as the inner surface. A filling material can be provided to achieve the correct shape and size, and a gastric tolerance coating (enteric coating) can be applied to the filling material, such as but not limited to cellulose acetate phthalate (CAP), cellulose acetate trimellitate (CAT), hydroxypropyl methylcellulose phthalate (HPMCP), shellac. The filling material is selected such that the sensing device has the aforementioned desired density. Alternatively, air is used as the filling material, where the housing (105) has an inner surface and an outer cage.

[0120] As described above, Figure 2 illustrates a way to make the torsion spring larger. In particular, Figure 2 illustrates the use of a composite fixed magnetic object, which creates a stronger magnetic field between the magnetic objects 102 and 104 by increasing the size of the fixed magnetic object 104.

[0121] Another way to make the torsion spring between two magnetic objects stiffer is to bring the two magnetic objects as close to each other as possible.

[0122] In some embodiments, a tracking system (100a) for receiving readouts from sensing devices (100, 200, etc.) is disclosed. The tracking system 100a includes a housing that includes a transmitting coil 103a, which is connected to a microcontroller 107a via a digital-to-analog converter 107a (DAC) and an audio amplifier 102a for generating an external magnetic or electromagnetic excitation field for the sensing device (100) that can be implemented as described above. A receiving coil 104a is also connected to the microcontroller via a low-noise amplifier 105a and an analog-to-digital converter 108a (ADC) for reading out the resonant frequency. The microcontroller 107a is connected to a display computer 109a. The microcontroller 107a is configured for, e.g., signal generation and reception, frequency evaluation, and control.

[0123] The microcontroller 107a generates a transmit pulse, amplifies the transmit pulse using the audio amplifier 102a, and then transfers the transmit pulse to the transmitting coil 103a, which can also be referred to as the excitation coil. In this embodiment, a separate receiving coil 104a is employed, which is decoupled from the transmitting coil 103a using two additional decoupling coils 110a. The received signal is fed to the low-noise amplifier 105a and transferred to the ADC 108a of the microcontroller 107a, where a typical 1 / 20 second time trace is sampled at a rate of approximately 20 kS / s. The microcontroller 107a may continuously adjust the interval of the excitation pulses 250.

[0124] In the embodiments described herein, the tracking system may specifically correspond to a multi - coil system. Using several coils enables determination of the position of the marker device by determining the position and orientation of an oscillating magnetic dipole in space. The different amplitudes of the received signals, along with the known coil - element sensitivities, can be matched to a dipole model to determine the position and orientation parameters. When many receiving coils and channels are available, additional information can also be used to improve background - signal suppression, as described further below. These several coils can form a multi - coil array, which, for example, can be integrated into a hospital bed.

[0125] Preferably, the coils of the tracking system (100a) are made light enough to be convenient for portable use. In a non - limiting example, the coils can be made of aluminum or an aluminum alloy to reduce weight, which may improve ease of use. However, considering that the outer housing enclosing the coils needs to be both light and stable / robust, composite materials can also be used. For example, in some embodiments, a fiberglass material can be used. Ideally, all the required transmit / receive electronics and power source are integrated in the power source (e.g., a lithium - ion battery). However, in some applications, this is not required, and the device and the corresponding coils can be powered by a cable between the coil array and the electronics.

[0126] In some embodiments, the sensing system (100a) is a hand - held sensing device. To have a hand - held system, some modifications are needed compared to other sensing systems. Advantageously, the system is light enough so that it can be used ergonomically for analyzing the sensing device. The inventors of the present application have recognized that the sensing system (100a) includes dedicated components and software for sensing and / or tracking and / or measuring the sensing device (100) of the present application.

[0127] It should be understood that the tracking system 100a is exemplary and can be applied to any of the sensing devices 100, 200, 300, etc. of the present application.

[0128] In some embodiments, reference markers can be used on the surface of the patient (e.g., placed on the skin) so that it is not necessary to hold the read - out coil when detecting the position of the sensing device 100. Since the external marker can be large, it should give a good SNR and can be detected and located very quickly. The marker should be a 6 - degree - of - freedom (DOF) marker (inherent, or a combination of 2 markers with 5 DOF each for each marker), an LCQ marker, or any other suitable marker. "Degree of freedom" (DOF) is a standard definition within the art, which means and can be generalized as each of the many independent variable factors that affect the range of possible states of a system (especially any of the directions in which independent movement can occur).

[0129] Preferably, the tracking system 100a and the corresponding coils (transmitting coil 103a, receiving coil 104a, decoupling coil 110a, etc.) are placed as close as possible to the sensing device (100, 200, etc.). In a preferred embodiment, the coils are almost in direct contact with the patient, however, with a small gap so that the coil elements do not touch the patient's body. Preferably, the distance from the patient is no more than 5 - 10 cm. However, other distances (e.g., a distance of 1 meter between the coil and the sensing device are also possible). Avoiding direct contact may be useful because patient movement will displace the coil assembly, which would require a correction mechanism. For practical reasons, it may be beneficial to keep the coil array away from the patient. However, this is only possible if the signal-to-noise ratio is high enough and thus depends on the size of the markers.

[0130] The clinical workflow can be as follows. The sensing device (100) is ingested according to a method suitable for a particular clinical application. For example, for gastric emptying, the sensing device is incorporated into a meal and the patient ingests the sensing device 100 during eating. For some clinical applications, a longitudinal study may be required. For example, for Hinton test replacement, the patient may eat several times over the course of a few days (e.g., three times a day for a week).

[0131] Preferably, the sensing device is read out at a certain frequency or within a certain frequency range. The frequency generally depends on the final size of the device. For example, in a sensing device with a 1 mm diameter, the frequency will be between 500 Hz and 1200 Hz. The correlation between the diameter of the sensing device and the frequency range can have a certain linear relationship. For example, when the sensing device has a diameter of 0.5 mm, the frequency range can be between 1000 Hz and 2200 Hz. Other diameters can have other preferred frequency ranges.

[0132] After the sensing device (100, 200, etc.) has been ingested, the position of the markers is recorded. Depending on the clinical objective at hand, the recording can be once, several times, or several times a day. For example, for the Hinton test, usually one measurement is taken at the end of the procedure. On the other hand, for gastric emptying, a readout measurement can be performed every quarter of an hour. When the readout measurement has been performed, the number of markers in different parts of the human (e.g., in the GI tract) is evaluated. For gastric emptying, this is usually the number of sensing devices remaining in the stomach. For the Hinton test, it can be the total number and the number of sensing devices remaining in the colon.

[0133] Those skilled in the art will recognize that: depending on the clinical objective, the number of measurements, the number of sensing devices consumed, the way the sensing devices are consumed, and the way the sensing devices are measured may be different. Thus, the examples described herein are merely exemplary, and other examples may be expected in the context of the present application. Those skilled in the art will also recognize that: depending on the clinical objective at hand, there are many possibilities to perform the required analysis. However, generally speaking, distributed ingestion (e.g., at least once a day or three times a day) is desired. For example, a single ingestion may consume approximately 10 sensing devices, but depending on the clinical objective, this number can vary from 1 to 100. Additionally, it is generally preferred to have a single readout event, but depending on the clinical objective, multiple readouts may be performed by the tracking system 200.

[0134] Figure 3 A third exemplary embodiment of a magnetomechanical resonator (MMR) device 300 is shown. The MMR 300 is similar to the MMR 100, wherein the distance “D” between the magnetic objects 102 and 104 has been reduced. For simplicity, the reference numeral 100 will also be used for embodiments 200, 300, 400, etc.

[0135] The distance D is generally only limited by the thermal expansion of the components of the sensing device 100 (e.g., the housing 105, the filament 103). In some embodiments, at the operating temperature of the sensing device 300, D can be approximately 10% of the diameter of the magnetic objects 102 and 104. For example, when the diameter of the magnetic objects 102 and 104 is approximately 500 μm, then D can be approximately 50 μm. In other embodiments, D can be as small as 2% of the diameter of the magnetic objects 102 and 104.

[0136] In some embodiments, the magnetic objects 102 and 104 can be in contact at a sufficiently low temperature (e.g., 273°K or 32°F or 0°C), but not in contact at the operating temperature (e.g., 310°K or 98.6°F or 37°C).

[0137] Figure 4 A fourth exemplary embodiment of a magnetomechanical resonator (MMR) device 400 is shown. The sensing device 400 is similar to the sensing device 100, the main difference being that in the sensing device 400, the magnetic objects 102 and 104 respectively include different magnetization portions 102a and 104a, which can reduce or minimize the external magnetic field of the MMR 400. This can include two exemplary different magnets used in each of the magnetization portions 102a and 104a, which can have similar or different properties depending on the clinical need at hand.

[0138] Figure 5Shows a fifth exemplary embodiment of the sensing device 500. The sensing device 500 is similar to the sensing device 100, except that in the sensing device 500, the housing 505 has an oval shape instead of a cylindrical shape.

[0139] Figure 6 Shows a sixth exemplary embodiment of the magnetomechanical resonator (MMR) device 600. The MMR 600 is similar to the sensing device 500, except that the sensing device 600 is a twin oscillator design, in which the fixed magnetic object 104 is replaced by a second oscillating magnetic object 604, and the second oscillating magnetic object 604 is connected to the housing 605 by a second filament 603.

[0140] To further increase the magnetic field between the two magnetic objects in the MMR, in some embodiments, the shape of the magnetic objects can deviate from the circular shape shown above (which is easy to produce), but can instead be hemispherical, cylindrical, or other shapes, having substantially flat surfaces that can face each other during use. This increases the resonant frequency, which is generally not desirable in terms of signal-to-noise ratio (SNR) for system constraints in gastrointestinal applications. However, the reduction in the size of the sensing device may justify a relatively modest loss in SNR.

[0141] Figure 7 Shows a seventh exemplary embodiment of the sensing device 700. The sensing device 700 is similar to the sensing device 600, except that in the sensing device 700, the spherical magnetic objects 102 and 104 are replaced by hemispherical magnetic objects 702 and 704.

[0142] from Figure 2-7 The ideas, embodiments, and features can be combined in various ways.

[0143] Additionally, in the context of the present invention, a method of administering a sensing device is described. The exemplary method can be described as follows:

[0144] Administering a plurality of magnetomechanical devices, sensing devices, including:

[0145] Providing a plurality of sensing devices;

[0146] Administering the plurality of sensing devices for oral administration to a subject; and

[0147] Monitoring the plurality of sensing devices when the plurality of sensing devices pass through a mammal (e.g., through the gastrointestinal tract of a mammal),

[0148] Reading out the plurality of sensing devices by a tracking system (100a).

[0149] In some embodiments, the sensing device can be used for diagnosing gastrointestinal diseases and / or for medication adherence control and / or for gastrointestinal constipation monitoring.

[0150] Figure 8 An exemplary method 800 of manufacturing a magnetomechanical resonator (e.g., the magnetomechanical resonators 100, 200, 300, 400, or 500 as described above) is shown.

[0151] A method of manufacturing a sensing device (100, 200, 300, etc.). The method preferably has the following steps:

[0152] Provide (810) at least one sensing device of the sensing device in a fixture;

[0153] Manipulate (820) the position and / or orientation of one or two magnetic objects (102, 104);

[0154] Measure (830) the residual dipole moment of at least one sensing device;

[0155] Compare (840) the measured residual dipole moment with a certain predefined threshold, where the threshold is preferably 5% of the total available dipole moment of the sensing device, even more preferably 1%, and even more preferably 0.5%;

[0156] If the measured residual dipole moment is greater than the predefined threshold, return to operation 820, otherwise continue to steps (850) and optional step (860), where steps (850) and (860) are:

[0157] Fix (850) the position and orientation of the magnetic object (102); and optionally

[0158] Apply ultraviolet light (860) to the magnetic objects (102, 104).

[0159] In some embodiments, some of these steps can be omitted and / or some new steps can be added to the manufacturing method according to the present invention. It should be understood that this is an exemplary method and may involve other method steps. Additionally, this exemplary method will be described in more detail.

[0160] Method 800 includes a first operation 810 of providing (e.g., placing or installing) the MMR in a fixture, and the first operation 810 allows manipulation of the position and / or orientation of one or two magnetic objects. Preferably, the sensing device is fixed, and in some embodiments, fixing can be avoided.

[0161] Operation 820 includes manipulating the position and / or orientation of one or two magnetic objects. In some embodiments, the sensing device may include more than two magnetic objects, and in such a way, more than two magnetic objects may be manipulated.

[0162] Operation 830 includes measuring the residual dipole moment of the MMR. The residual dipole moment of the MMR can be measured, for example, by a suitable magnetometer (which may be as simple as a small compass needle around the assembly position) or by a proxy method such as a resonant frequency. In some embodiments, operations 820 and 830 may be performed by a person. In some other embodiments, these operations may be performed by an automated process run by a robot (e.g., an assembly line robot for production).

[0163] In operation 840, the measured residual dipole moment is compared with a predefined threshold. In some embodiments, the threshold for the residual dipole moment may be 5% or less of the total available dipole moment of the MMR. In some embodiments, the threshold for the residual dipole moment may be significantly less than 5% of the total available dipole moment of the MMR (e.g., 1% or 0.5% of the total available dipole moment).

[0164] If the measured residual dipole moment is greater than the predefined threshold, method 800 continues with operation 820 and further manipulates the position and / or orientation of one or two magnetic objects.

[0165] If the measured residual dipole moment is greater than the predefined threshold, method 800 proceeds to operation 850, where the position and orientation of the fixed magnetic object are fixed. In some embodiments, this includes curing glue or epoxy resin, through which the fixed magnetic object is attached to the housing (e.g., by exposure to light (e.g., ultraviolet light)).

[0166] As a result of method 800, an MMR with a residual dipole moment that is 5% or less of the total available dipole moment of the MMR can be produced. In some embodiments, the residual dipole moment may be significantly less than 5% of the total available dipole moment of the MMR (e.g., 1% or 0.5% of the total available dipole moment).

[0167] Figure 9 An exemplary method 900 for performing a diagnostic process using multiple magnetomechanical resonators is shown.

[0168] Operation 910 includes providing a plurality of MMRs. In various embodiments, the MMRs may include one or more of the various MMRs 100, 200, 300, 400, 500, 600, and / or 700 as described above.

[0169] Operation 920 includes the object ingesting multiple MMRs. Advantageously, the MMRs can be ingested in food (e.g., an omelette, white bread, and / or water).

[0170] Operation 930 includes periodically scanning the object (e.g., the gastrointestinal tract of the object) over a desired scan window. In some embodiments, the scan window can be about 4 to 6 hours, and one scan can be performed over a period of about one hour. It should be understood that these numbers are merely exemplary, and any desired scan period and window can be employed.

[0171] Figure 10 An exemplary sensing device according to the present invention is shown, with a cage around the sensing device. In this non-limiting example, the sensing device is approximately 3 mm, and there is a cage around the sensing device (similar to the previously described cage). It should be understood that the sensing devices can have or not have a cage around them, depending on the clinical application at hand and / or the desired production process. It should also be understood that, preferably, the sensing devices of the present invention will have a housing (105) around the magnetic objects (102, 104). The housing (105) is essentially an outer cover including a first magnetic object (102) and a second magnetic object (104). It should also be understood that the cage around the sensing device is exemplary, and in some embodiments, it can be omitted. One of the benefits of having a cage around the sensing device is to limit the interaction between the sensing devices such that the signals read by the tracking system (100a) are not affected. Thus, in this way, the response magnetic field generated by the sensing device can be detected without interference from other sensing devices.

[0172] Furthermore, it should be understood that, as previously described, the housing has an inner surface and an outer surface. The outer surface of the housing (i.e., the surface facing the GI tract fluid) can be coated with the previously described enteric coating. The inner side of the housing can be covered with a material from, for example, acryloyl (e.g., acrylic resin). It should be understood that the materials mentioned are exemplary, and other materials can also be used in the embodiments of the present application.

[0173] In some embodiments, the cage can dissolve in the GI tract, while in other embodiments, the cage does not dissolve in the GI tract. In embodiments where the sensing device also serves as a sensing device for measuring, for example, at least one of the following parameters: pH, temperature, pressure, and other parameters, the sensing device can measure these parameters within a specific time range. This can range from a few minutes to over 4 hours. In some instances, and in certain clinical applications, it may be beneficial to measure the parameters when the sensing device is close to the rectum. Thus, in some cases, the sensing device can be excited (and thus oscillate) for a longer time (e.g., 24 hours).

[0174] In some embodiments of the above MMRs, it is possible to administer multiple MMRs to an object and have the multiple MMRs coexist in the gastrointestinal tract of the object without a certain degree of magnetic attraction or magnetic field interference between the MMRs (which would otherwise prevent the MMRs from functioning satisfactorily as expected). Thus, when some or all of the MMRs pass through the gastrointestinal tract, they can be monitored without being interfered with by the magnetic attraction or magnetic field of other MMRs.

[0175] In some embodiments, to have a low residual dipole moment, it is preferred to use two identical or nearly identical magnets, which can be used, for example, in magnetic objects 102 and 104, 102a / 104a, etc. Preferably, spherical magnets that are ground to produce uniform spheres are used. However, other embodiments are possible. In an exemplary embodiment, one magnet can be attached to a filament and / or glued to the outer casing surrounding the sensing devices (100, 200, etc.) of the present application. Another magnet can be attached to the other end of the outer casing, with the difference that the other magnet includes a "handle", i.e., a temporarily attached object (e.g., a wire) that allows the magnet to rotate in place. Additionally, a magnetometer can be placed beside the assembly. In its simplest form, the magnetometer can be a small compass. Then the "handle" can be manipulated until the magnetometer shows a measurement result. In some embodiments, it may be preferred to use more than one magnetometer. This is particularly preferred in the case of a simple compass because it only indicates direction and not intensity. However, this may be alleviated for more complex magnetometers.

[0176] By studying the drawings, the disclosure, and the appended claims, those skilled in the art will be able to understand and implement other variations of the disclosed embodiments when practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the words "a" or "an" do not exclude a plurality.

[0177] Furthermore, a computer program is disclosed that is configured to detect oscillations around an equilibrium position from any of the sensing devices in a sensing device when the sensing device is excited by a magnetic or electromagnetic excitation field of a receiving device (100a). The computer program can be run by a general-purpose processor or a special-purpose processor.

[0178] Furthermore, a computer-readable medium is disclosed that is configured to detect oscillations around an equilibrium position from any of the sensing devices in a sensing device when the sensing device is excited by a magnetic or electromagnetic excitation field of a receiving device (100a).

[0179] It should be understood that one or more of the embodiments of the present invention can be combined as long as the combined embodiments are not mutually exclusive.

[0180] The functions implemented by a processor can be implemented by a single processor or multiple separate processing units, which together can be considered to constitute a "processor". In some cases, such processing units can be remote from each other and communicate with each other in a wired or wireless manner.

[0181] The fact that certain measures are recited in mutually distinct dependent claims does not indicate that the combination of these measures cannot be used advantageously.

[0182] A computer program can be stored / distributed on a suitable medium, e.g., an optical storage medium or a solid-state medium supplied with or as part of other hardware, but can also be distributed in other forms, e.g., via the Internet or other wired or wireless telecommunication systems. A computer-readable storage medium can be used.

[0183] As will be appreciated by those skilled in the art, aspects of the present invention can be embodied as an apparatus, a method, or a computer program product. Accordingly, aspects of the present invention can take the form of: a complete hardware embodiment, a complete software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software aspects and hardware aspects, which software aspects and hardware aspects are generally referred to herein as "circuitry", "sensor", or "system". In addition, aspects of the present invention can take the form of a computer program product embodied in one or more computer-readable media having computer-executable code thereon. Any combination of one or more computer-readable media can be utilized. The computer-readable media can be a computer-readable signal medium or a computer-readable storage medium. As used herein, "computer-readable storage medium" includes any tangible storage medium that can store instructions executable by a processor of a computing device or a computing system. A computer-readable storage medium can be referred to as a computer-readable non-transitory storage medium. A computer-readable storage medium can also be referred to as a tangible computer-readable medium. A computer-readable signal medium can include a propagated data signal (e.g., in a baseband or as part of a carrier wave) that contains computer-executable code.

[0184] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory directly accessible by a computing system. "Computer storage device" or "storage device" is another example of a computer-readable storage medium. A computer storage device is any non-volatile computer-readable storage medium. In some embodiments, a computer storage device can also be a computer memory, or vice versa.

[0185] Machine-executable instructions or computer-executable code can include instructions or programs that cause a processor or other computing system to perform an aspect of the present invention. The computer-executable code for performing the operations of the various aspects of the present invention can be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, Smalltalk, C++, etc. and conventional procedural programming languages such as the "C" programming language, and they are compiled into machine-executable instructions. In some instances, the computer-executable code can be in the form of a high-level language or a pre-compiled form and is used in conjunction with an interpreter that generates machine-executable instructions on the fly. In other instances, the machine-executable instructions or computer-executable code can be a programming form for a programmable logic gate array.

[0186] The computer-executable code can run entirely on the user's computer, partially on the user's computer, run as a stand-alone software package, partially on the user's computer and partially on a remote computer, or run entirely on a remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0187] If the term "adapted to" is used in the claims or the specification, it should be noted that the term "adapted to" is intended to be equivalent to the term "configured to". If the term "arranged" is used in the claims or the specification, it should be noted that the term "arranged" is intended to be equivalent to the term "system", and vice versa.

[0188] Any reference signs in the claims shall not be construed as limiting the scope.

Claims

1. A system for monitoring and / or diagnosing the transit through the gastrointestinal tract of a mammal, such as a human, the system comprising a sensing device (100) and a sensing system (100a), wherein, the sensing device comprises: a housing (105); and a first magnetic object (102) having a permanent magnetic moment, wherein the first magnetic object is coupled to the housing (105) in such a way that the first magnetic object is configured to oscillate about an equilibrium position when excited by a magnetic or electromagnetic excitation field; and wherein the sensing device comprises a second magnetic object (104) configured to provide a restoring force to the first magnetic object (102); wherein the distance from the center of the first magnetic object (102) to the outer surface of the housing (105) is at least equal to the diameter of the first magnetic object (102), and wherein the tracking system (100a) comprises at least one coil for generating the magnetic or electromagnetic excitation field and a controller for controlling the coil system, the at least one coil being configured to detect a response magnetic field generated by the sensing device, the controller being configured to determine whether the sensing device is present in a target detection space.

2. A sensing device (100) for monitoring and / or diagnosing the transit through the gastrointestinal tract of a mammal, such as a human, the sensing device comprises: a housing (105); a first magnetic object (102) having a permanent magnetic moment, wherein the first magnetic object is coupled to the housing (105) in such a way that the first magnetic object is configured to oscillate about an equilibrium position when excited by a magnetic or electromagnetic excitation field; and wherein the sensing device (100) comprises a second magnetic object (104) configured to provide a restoring force to the first magnetic object (102); and wherein the distance from the center of the first magnetic object (102) to the outer surface of the housing (105) is at least equal to the diameter of the first magnetic object (102).

3. The sensing device according to claim 2, wherein, the distance from the center of the magnetic object (102) to the outer surface of the housing is at least equal to twice the diameter of the magnetic object (102), preferably three times.

4. The sensing device according to any one of claims 2 or 3, wherein, a filling material is provided inside the housing, wherein the filling material comprises at least one of the following: epoxy resin, and / or a group of polymer materials, and / or a material from acryloyl.

5. The sensing device according to any one of claims 2-4, wherein, the housing further comprises a cage defining the outer shape of the sensor.

6. The sensing device according to any one of claims 2-5, wherein, The sensing device is arranged to have a 945 to 1155 kg / m 3 The density is preferably 1000 to 1050 kg / m 3 density to allow the sensor to pass through the gastrointestinal tract.

7. The sensing device according to any one of claims 5-6, wherein, the outer surface of the cage is provided with a gastrointestinal tolerance coating.

8. The sensing device according to any one of claims 2-7, Wherein, at least the first magnetic object (102) is configured to be attached to the housing (105) via a filament (103), and the second magnetic object (104) is either configured to be fixed to the housing by a fixing material (106) or configured to be attached to the housing via a second filament.

9. The sensing device according to claim 8, wherein, the ratio of the diameter of the filament (103) to the diameter of the magnetic object (102) can be a constant, wherein the constant will be in the range of 1:1 to 1:1000, and more preferably will be in the range of 1:100 to 1:1000.

10. The sensing device according to any one of claims 8 or 9, wherein, the filament (103) and / or the fixing material belong to the group of polymer materials, preferably to the group of polyoxides.

11. The sensing device according to any one of claims 2-10, wherein, the distance between the first magnetic object (102) and the second magnetic object (104) is less than 10% of the diameter of the first magnetic object (102), and preferably less than 2% of the diameter of the first magnetic object.

12. A tracking system (100a) for tracking any one of the sensing devices according to any one of claims 2-11, wherein, the tracking system includes at least one coil for generating the magnetic or electromagnetic excitation field and a controller for controlling the coil system, the at least one coil being configured to detect the response magnetic field generated by the sensing device, and the controller being configured to determine whether the sensing device is present in the target detection space.

13. The tracking system according to claim 12, wherein, the tracking system is a handheld tracking device.

14. A method for monitoring the transit through the gastrointestinal tract of a mammal, such as a human, the method comprising administering a sensing device according to any one of claims 2-11, wherein, the sensing device is configured to be read out by a tracking system according to any one of claims 12-13.

15. A computer program comprising instructions which, when the program is run by a computer, cause the computer to perform the step of reading out a tracking system according to any one of claims 12-13 and / or are configured to determine the position of a sensing device according to any one of claims 1-11.

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