Medical device, device control method, system including the device, and device manufacturing method

Abstract

The present invention relates to a medical device (10), preferably a microrobot, for application inside the body, preferably inside the human body (2). The medical device (10) comprises a body portion (11) and a tail portion (12). A control line (13) is attached to the tail portion (12). The control line (13) has sufficient tensile strength to retract the device from a target location and / or control its velocity, but not sufficient column strength to push the medical device (10).

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to medical devices and methods for performing surgical procedures inside the body. In some non-limiting examples, the medical devices relate to microrobots applied inside the human body. [Background technology]

[0002] Minimally invasive procedures, also known as minimally invasive surgery, are surgical techniques that require minimally sized incisions, thus reducing wound healing time and the risk of trauma to the patient. Specific tools, such as catheters, fiber optic cables, long-rod graspers and pincers, or miniature video cameras, have been designed for minimally invasive surgery.

[0003] A limitation of minimally invasive surgery is that the surgeon must use tools that require a gentle hand, which may become fatigued during prolonged manipulation.

[0004] A further development in the field of minimally invasive surgery is robotic-assisted surgery, or robotic surgery, whereby a robotic system is used to assist the surgeon in a surgical procedure. Multiple robotic arms can perform minimally invasive surgery as the surgeon manipulates the robotic arms, for example, with a joystick. However, the procedure is still invasive to some extent and causes internal and external wounds that require healing time.

[0005] A further development is microrobots that can be injected into the human body to perform diagnosis, surgery, or therapy. These microrobots can be used for real-time disease diagnosis or monitoring, such as measuring glucose levels in diabetic patients, or for delivering drugs to targeted locations, such as tumors (Ornes, 2017, PNAS). These microrobots are small devices, ranging in size from a few millimeters to a few microns. Therefore, microrobots are useful for reaching areas near microvasculature or areas behind tortuous vascular networks. These target areas are difficult to reach through surgical and minimally invasive procedures.

[0006] Edd et al. disclosed a surgical microrobot that moves inside the human ureter, proposing a novel method for destroying kidney stones (Proceedings 2003 IEEE). Peyer et al. disclosed a swimming microrobot with an artificial bacterial flagellum for moving through fluids of various viscosities (2012 IEEE). Due to their size, microrobots cannot carry batteries and motors. A common approach to guiding microrobots to a target position is to use an external magnetic field to control a microrobot containing magnetic material. The Multi-Scale Robotic lab at ETH Zurich has disclosed a tetherless microrobot with a diameter of 285 μm for performing eye surgery.

[0007] Several medical devices for insertion are known in the art and are disclosed, for example, in U.S. Patent Application Publication No. 2013 / 0282173, U.S. Patent Application Publication No. 2008 / 0058835, U.S. Patent No. 6,240,312, U.S. Patent Application Publication No. 2009 / 0076536, Japanese Patent Application Publication No. 2002 / 000556, and German Patent Application Publication No. 10 2005 032371. Summary of the Invention [Problem to be solved by the invention]

[0008] Due to their small size, these microrobots are limited in their ability to move against fluid flow, such as blood flow. While magnetic fields can guide or stop the robots, they may not be strong enough to move the robots quickly within the bloodstream, especially against blood flow that flows in the opposite direction to the microrobot's movement.

[0009] The present invention seeks to alleviate one or more of the above-mentioned problems and in particular to provide a medical device, preferably a microrobot, that is easy to manufacture and use. Some embodiments have the additional advantage of allowing for reliable and safe recapture. [Means for solving the problem]

[0010] According to the invention, this problem is solved by the characterizing features of the independent claims. The present invention relates to a medical device. The medical device may be a microrobot for use in a body vessel. In particular, the medical device or microrobot may be suitable for application inside the human body. The medical device includes a body portion and a tail. A control line is attached to the device, preferably the tail, and may be configured to retract the medical device from a first position and / or control its velocity. In one embodiment, the control line may have insufficient stiffness to move the medical device to a target position.

[0011] The first location may in particular be a target site of a medical device. Preferably, the control line is a recapture line intended to brake and / or stop the medical device.

[0012] In particular, the control line can be used to control the rate at which a fluid, such as blood, flows, especially when the control line is attached to the tail.

[0013] The control line can have sufficient tensile strength to retract the medical device, but insufficient column strength to push the medical device against static or dynamic bodily fluid forces, and thus can be made thin enough to allow easy insertion into a body duct.

[0014] As used herein, the term "line" is intended to encompass any structure that performs the task of pulling a device, while optionally performing other non-limiting tasks as well.

[0015] The medical device may be configured to be injected into a body, particularly a human body. The tail and, optionally, the body portion may have a larger cross section than the control line. The medical device may be held or pulled back mechanically or manually. Such control lines may allow the medical device to be pulled through an opposing fluid flow, such as blood flow. They may also allow the speed of the medical device carried by the blood flow to be controlled, slowed down, or even stopped within the patient's body despite the blood flow. This pulling action may be a slight adjustment of the position of the medical device or recapture. In particular, the device may comprise a handle for the control line.

[0016] The control line can have a length configured to extend from the medical device to an insertion site of the medical device. One embodiment of the present invention relates to a system including a port and a medical device, where the control line extends from the tail to the port.

[0017] The control line may be a string, in particular a flexible string. Advantageously, the string is bendable. An advantage is that such a medical device is small in size and requires only a small incision compared to known catheter devices.

[0018] The medical device can be released into a body vessel, carried by fluid flow through the body vessel to a target site within the vessel, and recaptured in a simple manner. The device can be repositioned by loosening or pulling on the control lines.

[0019] The medical device preferably has at least one drive for actively moving the device in a direction and a control member for controlling and preferably modifying the movement of the medical device within the body. The medical device is capable of moving through the flow of bodily fluids and / or moving on tissue.

[0020] The drive can be any kind of mechanism for moving the medical device. Possible embodiments can be propellers, wheels, continuous tracks (e.g., caterpillars), flagella, legs, hooks, or magnetic drives for external steering. The control member can move, steer, or stop the device by external action, for example, a signal. The control member can adjust the speed or direction of rotation of the drive, and thus control the position. The drive can enable the medical device to move through sharp bends in a blood vessel.

[0021] The medical device preferably has a positioning means for determining the position of the medical device within the body. The positioning means emits a signal that is received by a receiver. The receiver then calculates the location of the medical device. The signal may be radio waves, radioactive tracers, sound waves, Bluetooth, or any other wireless signal. In alternative embodiments, the positioning means may include sensors for measuring various environmental parameters such as temperature, pH, redox potential, salt concentration, viscosity, pressure, electric potential, gas concentration, radioactivity, and / or metabolic levels. The positioning means transmits the measured parameters to the receiver, which calculates the location of the medical device. The measured parameters may also be used to analyze the environment.

[0022] The control line of the medical device preferably comprises a transmission cable for transmitting energy and / or data, in particular optical or electrical signals, to and from the medical device. The transmission cable may comprise two separate cables, one for delivering energy and data and one for receiving data. Alternatively, the transmission cable may be a single cable that transmits energy and data and is configured as the control line. Additionally or alternatively, the transmission line may be a micro-coaxial cable.

[0023] The control line may comprise or consist essentially of a biocompatible material, preferably a material selected from the group of materials consisting of metals, particularly copper, stainless steel, cobalt-chromium-nickel alloys, titanium, titanium alloys, platinum, platinum alloys, Nitinol, nickel-titanium ternary alloys, nickel-free alloys, metal composites, polymers, carbon fibers, graphene, textiles, silk, protein fibers, and carbon nanotubes.

[0024] Particularly suitable polymers are aramids, especially one of Kevlar and Twaron, polyamides (especially nylons, i.e., PA6 and PA66), polytetrafluoroethylene, silicone, polyurethane, polyvinyl chloride (PVC), bioabsorbable polymers such as polyglycolic acid (PGA), polydioxanone (PDO), polylactic acid (PLA, especially one of PLLA and PDLA, and / or their corresponding copolymers such as P(LA-GA)), poly-ε-caprolactone and its corresponding copolymers (e.g., P(LA-CL)). Furthermore, collagen and chitosan are natural polymers that are likewise suitable as materials for the control line.

[0025] It will be appreciated that any of the above polymers may be blended, mixed, or used as copolymers of each.

[0026] Particularly suitable metals are magnesium and magnesium alloys. Magnesium can be biocorrosive and biocompatible. Furthermore, its corrosion (and therefore decomposition) rate can be tailored by alloying and / or accelerated by applying voltage. This property can be used, for example, to release medical devices or parts of medical devices.

[0027] These materials are sufficiently biocompatible so as not to degrade or cause adverse effects, such as thrombosis, over the course of treatment. This ensures that the medical device can be removed whenever necessary. Furthermore, these materials withstand environmental influences within the body, such as varying pH or oxidative stress, for a specific time frame. Typically, such a time frame is several hours, but may be anywhere from 1 to 60 minutes or 1 to 6 hours. Additionally, they have sufficient longitudinal strength to pull the medical device. Furthermore, the above materials preferably resist degradation over at least several hours or days. Some materials may degrade more slowly (i.e., over a longer period than required for treatment). For example, slower degradation can be employed if the medical device, or a portion thereof, is intentionally left in the body after treatment or as a safety mechanism in case the device is lost within the body.

[0028] Preferably, the control line has a smaller cross section than the medical device, especially in a plane perpendicular to the longitudinal direction of the control line. The cross section of the line may be less than 50% of the cross section of the medical device.

[0029] The medical device preferably comprises a material that is detectable by imaging techniques, for example, MRI, CT scanner, ultrasound, X-ray, or fluoroscopy.

[0030] This allows the location of the device to be determined at any time during the procedure. It is also possible to track the location, particularly in real time, if desired. A continuous localization process is beneficial because guiding a medical device can be complicated depending on parameters such as fluid viscosity or external pressure from bodily fluid flow.

[0031] The medical device may be particularly suitable for blood vessels, especially arteries or veins. Another area of ​​application may be the urethra or ureters.

[0032] The control line of the medical device preferably has an outer diameter of 10 to 1000 μm, more preferably 100 to 400 μm.

[0033] The body portion can include a magnetic portion that can be used to guide the medical device by interaction with an external magnetic field, and can be a magnetic micro- or nanoparticle in an inner core, matrix, or coating made of or containing a magnetic material.

[0034] The medical device preferably comprises at least one functional unit such as a clamp, a scalpel, a drill, a hook, a stent, legs, tracks, a propeller, a detonator, a camera or sensor, or a drug-releasing component.

[0035] The functional unit may be attachable to the medical device and may be used to move the medical device over tissue or through a fluid, to attach the medical device to a tissue site, to open a passageway through a blocked opening, or to create a new opening, or to collect data from the body environment.

[0036] The proposed device is particularly suitable for removing arterial clots, filling aneurysms, or delivering drugs to tumors. The detonator can open the clot.

[0037] The functional unit may be activatable. In some embodiments, the functional unit is activated by a magnetic field or electromagnetic wave in a specific environment. This allows, for example, controlled release of a drug. The functional unit may be activatable by energy, for example, an electrical signal.

[0038] The functional unit may be attached or attachable to the medical device and / or the control line, in particular the functional unit may be grafted onto the control line behind the medical device, either directly adjacent to the medical device or remote therefrom.

[0039] Similarly, two or more medical devices can be attached to the same control line, and such multiple medical devices may be attached in series (i.e., as a chain of medical devices), in parallel, or in any other arrangement (circle, tree line, etc.).

[0040] The medical device preferably includes a reservoir for storing and releasing a drug. The reservoir can be used to apply the drug to a specific application site. For example, tumor cells can be treated locally with a toxic drug. The medical device can then be used to carry and release the toxic drug to the application site. The controlled release of the drug also allows for the possibility of timed drug application. The medical device can be inserted, guided to the application site, and wait until the scheduled release time of the drug. It is also possible to control the delayed release of two different drugs, for example, an active drug and an enzyme that inactivates the drug.

[0041] The medical device preferably comprises a transmitter for transmitting data from the medical device to the receiver, in particular via a control line.

[0042] The control lines can be configured to transmit energy, thereby transmitting data acquired by sensors within the medical device.

[0043] The device may be configured to receive energy via the control line and / or transmit data obtained by a sensor in the medical device, particularly the body portion, via the control line. In additional or alternative embodiments, the medical device or the control line may comprise a wireless transmitter and / or a wireless receiver for transmitting and / or receiving energy or data.

[0044] The medical device preferably has a size of 8 to 2000 μm, preferably 50 to 1000 μm, more preferably 200 to 500 μm. This size may be the length, diameter, or longest dimension of the medical device.

[0045] The body portion and / or tail of the medical device preferably comprises a material such as metal, plastic, glass, mineral, ceramic, carbohydrate, nitinol, carbon, a biomaterial, or a biodegradable material.

[0046] Preferably, the control line is removably attached to the medical device. This allows the medical device to be detached from the control line. Any mechanism known in the art for detaching an element from a string of elements can be used for this purpose. For example, the control line can be glued to the medical device, and this glued connection dissolves in blood or another liquid. It is also conceivable that the glue could be configured to dissolve in blood only above or below a certain temperature.

[0047] In particular, the control line can be chemically coupled to the medical device, and this chemical connection can be broken under certain conditions, such as increased temperature, pH change, electrical stimulation, etc.

[0048] Mechanical means are also contemplated. For example, the control line may be attached to the medical device via a hook, knot, carabiner, and / or clamp. Additionally or alternatively, controlThe lines may penetrate at least partially through the medical device and be fixed within or to a surface of the medical device, particularly to a surface located on the opposite side of the medical device compared to the control lines. It is also conceivable to use a mechanical interlock, i.e., a first and second contour that interact with each other to connect the two elements. The use of a mechanical interlock mechanism in combination with an adhesive is particularly advantageous, as the connection is provided by cohesive forces in the adhesive rather than adhesive forces between the adhesive and the medical device / control line.

[0049] Likewise, chemical or physical separation (chemisorption, physisorption, magnetic and / or electric fields) is also conceivable.

[0050] For example, the anchoring point, the medical device, or a portion of the medical device can be at least partially formed from an iron-based material. Applying a current and / or voltage to the control line can result in the migration of ferrous ions from the anode to the cathode, causing dissolution of the iron-based portion. Additionally or alternatively, the control line can have an insulating portion to protect the control line and / or portions of the device from corrosion and dissolution.

[0051] Preferably, the control line is selectively detachable from the medical device, in particular the selective detachment can be triggered by electrical stimulation, rotation of a magnetic portion, physical action, and / or chemical action.

[0052] For example, the control line can be configured to transmit an electrical signal that disconnects the control line from the medical device. This can also be done with magnets and / or electromagnets. The medical device may also receive a wireless signal, e.g., via a wireless signal receiver, that selectively triggers the removal of the medical device from the control line.

[0053] Additionally or alternatively, the medical device may detect properties of the surrounding tissue / fluid and automatically release the control line, for example, temperature, pH, body flow values, inflammation values, or biomarkers, and release the control line based on those values.

[0054] Preferably, the medical device comprises a first and a second portion. In particular, the first portion may be a tail portion and the second portion may be a body portion. The first portion is attached to a control line. The second portion is removably attached to the first portion. The first portion is selectively detachable from the second portion of the medical device, in particular by at least one of electrical stimulation, rotation of a magnetic portion, physical action, and chemical action.

[0055] In particular, any of the mechanisms described above as suitable for selectively detaching a control line from a medical device are also suitable for selectively detaching the second portion from the first portion.

[0056] Preferably, the medical device comprises exactly one line formed by the control line. The medical device may not be attached to any other elements, in particular cables, extending therefrom. If the medical device comprises exactly one control line and this control line is selectively detached from the device, the device will float freely in its environment.

[0057] Preferably, the control line is incapable of transmitting data or energy. It may be made of a non-conductive material or may be incapable of conducting electricity along its length, for example, due to its structure (such as a sandwich structure including an insulator). The control line may be made of metal, but the connection to the medical device may be unsuitable for transmitting electricity, for example, because the connection is made of or coated with an insulating material. Therefore, additionally or alternatively, the device may be incapable of receiving data or energy via the control line.

[0058] Preferably, the control line can be bent into a curve having a radius of curvature of 3 mm, preferably 1 mm, and even more preferably less than 700 μm without substantial material stress. Those skilled in the art will appreciate that the above radii of curvature refer to an otherwise straight control line (i.e., a theoretical stress of 0 Pa at a curvature of 0, i.e., an infinite radius). In particular, the control line can be fabricated from materials and / or structures that have a minimum breaking stress (i.e., the mechanical stress in the control line before plastic deformation and / or material failure occurs) in the range of 0.5 to 4 MPa. Those skilled in the art will appreciate that the present invention can be practiced with control lines having higher breaking stresses (i.e., stronger control lines). However, higher values ​​may not be necessary for the present invention to function.

[0059] The modulus of elasticity of the control line may be in the range of 0.001 to 200 GPa. Preferably, a control line comprising or consisting of a polymeric material may have a modulus of elasticity of 0.001 to 5 GPa. A control line comprising or consisting of a metal may have a modulus of elasticity of 30 to 200 GPa. Of course, materials can be mixed, blended, or combined, such as composite materials, to achieve any desired modulus. In particular, a polymer-metal composite can be used to achieve a modulus of elasticity anywhere in the range of 0.001 to 200 GPa.

[0060] Typically, the breaking stress of the control line is not reached when controlling a medical device. If the control line is NiTi wire, the ultimate tensile strength (UTS) can reach 1300±200 MPa, while for polymer wire, the UTS can be between 30 and 900 MPa.

[0061] Preferably, the control line comprises or is composed of a radiopaque material such as barium compounds, iodine, tantalum, platinum, bismuth, or a polymeric material.

[0062] Preferably, the radiopaque material is disposed as a separate cable parallel to and associated with the control line and / or as a coating on the control line, allowing a user to directly image the control line and determine its location within the patient. Additionally or alternatively, one or more radiopaque markers may be included along the control line. The radiopaque markers may be positioned at regular distances or randomly distributed along the control line.

[0063] Preferably, the control line comprises a hydrophilic surface, such as a surface functionalized with PEG (polyethylene glycol), polyvinylpyrrolidone (PVP), poly(vinyl alcohol) (PVA), polytetrafluoroethylene (PTFE), or any combination thereof. Such a surface allows for wetting by blood, thus allowing easier and safer movement through the blood. Furthermore, a hydrophilic surface can limit protein adsorption to the control line, thus preventing, for example, the induction of an immune cascade.

[0064] The hydrophilic coating may have a thickness of 50 nm to 10 μm, preferably 100 nm to 500 nm.

[0065] Hydrophilic coatings can be produced by grafting hydrophilic molecules. Grafting can be performed with or without surface treatment of the control surface. The surface treatment can be, for example, chemical etching or mechanical polishing. Grafting can be performed by chemical processes, such as chemical vapor deposition or electrochemical vapor deposition. Grafting can be performed according to physical processes, such as physical vapor deposition, layer deposition, spraying, or electrospraying.

[0066] The hydrophilic coating may be a surface functionalization. In an alternative design, the hydrophilic coating can be made with a hydrophilic liner, such as a PTFE liner.

[0067] Preferably, the control line has an antithrombogenic surface. For example, it may be coated with a material that does not cause substantial thrombosis. In particular, the surface may comprise at least one of phosphorylcholine, phenox, polyvinylpyrrolidone, and polyacrylamide. Additionally or alternatively, the control line may be coated with a drug having antithrombogenic properties.

[0068] Preferably, the control line has a surface coated with a hydrogel. The hydrogel may be a synthetic hydrogel and / or a natural hydrogel. Preferably, a hydrogel selected from the group including elastin-like polypeptide (ELP), polyethylene glycol (PEG), 2-hydroxyethyl methacrylate (HEMA), polyhydroxymethacrylate (PHEMA), polyvinylpyrrolidone, polymethacrylic acid (PMA) (and other methacrylate- and methacrylic acid-based polymers), agarose, hyaluronic acid, methylcellulose, elastin, and chitosan is used. Both synthetic hydrogels (ELP, PEG, HEMA, polyvinylpyrrolidone, PMA) and natural hydrogels (agarose, hyaluronic acid, methylcellulose, elastin, chitosan) may be chemically and / or physically crosslinked. Other materials that at least partially reduce friction between the control line and the vessel wall may also be used.

[0069] All types of hydrogels known in the art can be used to practice the invention, particularly homopolymers, copolymers, polymer blends, interpenetrating networks, self-assembled structures, and mixtures of polymers.

[0070] Additionally or alternatively, resilient and / or soft buoys may be attached along the control lines to allow for smoother movement of the control lines.

[0071] Preferably, the control line is attached to the medical device by at least one of a knot, a clip, a welded connection, an adhesive connection, a blend of materials, and a chemical bond.

[0072] Regarding the formation of the control line, a mixture of materials can be provided, particularly arranged in a gradient of material composition along the length of the control line. For example, the tail of the device can comprise a first polymer, while the control line comprises a second polymer. The first and second polymers can be connected via a gradient blend of the first and second polymers. In particular, the control line can comprise a braided and / or twisted structure or other multifilament structure. Alternatively, a monofilament can be used. When a multifilament structure is used, all filaments can be composed of the same material, or different filaments can be used.

[0073] Preferably, the medical device comprises a hollow tube arranged parallel to the control line. The hollow tube is specifically configured for suction purposes, generating a low pressure that draws surrounding fluid and / or tissue into the hollow tube. The suction action can be used to remove blood clots or to aid in stabilizing the microrobot on tissue. Additionally, the hollow tube can be used to inflate a balloon.

[0074] Preferably, the medical device further comprises a trigger wire. Particularly preferably, the trigger wire is associated with the control line and may be arranged parallel to the longitudinal direction of the control line. For example, the trigger wire may be arranged inside the control line. Alternatively, the trigger wire may be arranged next to the control line as a separate element, but is preferably associated with the control line. The trigger wire is configured to trigger a function of the device.

[0075] The trigger wire may, inter alia, transmit a mechanical or electrical signal and may, inter alia, trigger a function to release a drug or to selectively disconnect a medical device from a control line.

[0076] The trigger wire can have a diameter between 10 μm and 150 μm, preferably between 20 μm and 70 μm. The trigger wire can have a cylindrical or strip shape. The trigger wire can be made of a polymer, such as PET, or a metal, such as Nitinol or stainless steel. In one configuration, the trigger wire can transmit a mechanical force to retract an element of the head.

[0077] Furthermore, the present invention provides a method for performing a surgical procedure inside a body, preferably a human body. In a first step, a medical device is inserted into the body. The medical device is then moved to the interaction location without pushing on the control lines. In particular, the medical device is inserted upstream of the target site. A fluid flow can carry the medical device to the target site. The medical device can be positioned and / or guided along a trajectory by loosening or pulling on the control lines.

[0078] The medical device can perform one or more actions in one or more locations and is removed from the body by pulling on the control lines.

[0079] Furthermore, the present invention provides a system for controlling a medical device, the system comprising a medical device, preferably as described above, and a magnetic field generator, such that the medical device is guided by the magnetic field generated by the magnetic field generator.

[0080] The external magnetic field generator generates a magnetic field with a gradient of 0.1 to 20 T / m, preferably 0.2 to 1 T / m. Once the medical device is inserted into the body, the magnetic field can be used to guide the medical device to the application site. Thus, the medical device can be moved, stopped, or steered by the magnetic field, especially while floating in the flow of bodily fluids. The medical device remains attached to the control line the entire time.

[0081] In a further embodiment, the medical device may have magnetic anisotropy, which allows the medical device to be oriented by a magnetic field.

[0082] Furthermore, the present invention relates to a medical device, preferably a microrobot, for application inside the body, preferably for application inside the human body.

[0083] Preferably, the system further comprises a control unit configured to control, preferably continuously, the speed of the medical device. The control unit may in particular control the speed of the medical device by controlling the speed of a control line attached to the medical device. The control unit may in particular comprise a reel for winding and / or unwinding the control line.

[0084] Preferably, the system further comprises a coupling element, which is configured to couple to a control line for connecting the coupling element to the device to control its speed, in particular continuously.

[0085] The system is preferably configured to retract and / or release the control line at a controlled rate, preferably continuously.

[0086] The velocity of the control line, and therefore the velocity of the medical device, can be controlled according to a predetermined velocity function or can be controlled based on the position of the medical device.

[0087] Particularly preferably, the speed and position of the control line is adjusted using a linear motor and / or a spindle / reel mechanism.

[0088] Preferably, the system comprises a mechanism for controlling the position of the microrobot, preferably by controlling the release of the control lines, which may in particular comprise sensors for measuring the retraction / release distance, and may also comprise servo motors for automatically determining the degree of release of the control lines.

[0089] The continuous release or non-release of the control lines can be controlled, inter alia, as a function of the position of the medical device relative to the target trajectory.

[0090] Furthermore, the present invention relates to a method for controlling a device in a fluid flow, the device being preferably a microrobot, even more preferably a device as described herein above. The fluid flow is preferably blood in a blood vessel. The device comprises a control line attached to the device. The speed of the device is controlled via the control line.

[0091] Preferably, the speed is reduced as the device approaches a fork, allowing for more accurate and therefore safer movement along the desired path.

[0092] Preferably, a control is provided which automatically controls the speed of the device, preferably by applying a force to a control line.

[0093] Preferably, the controller automatically detects the bifurcation. Such detection can be based on external imaging, such as ultrasound imaging, MRI, tomography, x-ray, or other known methods. Additionally or alternatively, it can be based on measurement data acquired by a medical device. For example, the medical device can detect characteristics of fluid flow that indicate the presence of a bifurcation.

[0094] Additionally or alternatively, the medical device may be guided by the controller initially along a pre-planned trajectory to a target area, for example, into a vascular network.

[0095] The present invention further relates to a medical device. Preferably, the medical device is any of the medical devices described herein. The medical device comprises a magnetic head portion attached or attachable to a control line. The control line is preferably attached or attachable via a first adhesive component. Particularly preferably, the first adhesive component is a cyanoacrylate component or an epoxy adhesive, which are known and commercially available to those skilled in the art. It will be understood that the first adhesive component may be a medical adhesive. The medical device further comprises a protective layer. The protective layer may include a second adhesive component, preferably composed of the second adhesive component. Particularly preferably, the second adhesive component includes or is composed of a resin. The resin is stable in an aqueous environment. The resin may be an epoxy resin. Epoxy resins can provide particularly advantageous water resistance.

[0096] Alternatively, the protective layer may comprise or consist of a network polymer, for example, a device with a magnetic head attached to control lines may be dipped into a polymer solution that is then cured.

[0097] The protective coating is configured to provide a fluid seal for at least the area of ​​the magnetic head portion that is attached or attachable to the connecting line, and in a preferred embodiment, the protective layer is configured to provide a fluid seal for the entire magnetic head portion.

[0098] The protective coating can exhibit hydrophilic properties. In one configuration, the protective shell can include or consist of a hydrophilic material such as PEG. In one configuration, the protective shell is coated with a hydrophilic material such as PVP or PTFE.

[0099] Preferably, the attachment region is located at the south pole of the magnetic head portion, or alternatively, the attachment region may be located at the north pole or between the south and north poles.

[0100] The fluid seal of the magnetic head portion may be formed entirely or only in part by the protective layer. For example, if control lines are attached to a rounded magnetic head portion, the protective layer may not form a closed capsule due to the opening for the control line. It will be understood that such a configuration can still provide a fluid seal of the magnetic head portion.

[0101] The protective layer is particularly advantageous because it provides a safer attachment of the control lines to the magnetic head portion, reduces the corrosive effect on the magnetic head portion, especially in fluids such as blood, and can further provide an additional attachment mechanism for therapeutic equipment.

[0102] The provision of a protective coating is particularly preferred when the medical device includes control lines attached by at least one of knots, clips, welded connections, adhesive connections, blends of materials, and chemical bonds.

[0103] The protective coating can therefore reduce or prevent corrosion, particularly around the area where the control lines are or can be attached, and can be located at the interface between the adhesive and the magnetic head, particularly if the control lines are attached to the magnetic head via said adhesive, thereby providing a more secure and stable attachment of the control lines to the magnetic head.

[0104] In particular, as a result of the protective layer, the breaking force between the magnetic head part and the control line can be increased, preferably the breaking force being at least 1N, particularly preferably at least 7N.

[0105] Preferably, the protective layer is provided so as to seal the entire magnetic head portion. For this purpose, the protective layer may form a closed capsule.Attachment areas, for example formed by cyanoacrylate adhesive, may be formed on the surface of the protective layer.

[0106] Alternatively, the protective layer may cooperate with other elements to form a seal, particularly the first adhesive component, the control line, and / or another attachment mechanism between the magnetic head portion and the control line, and it will be appreciated that the protective layer may also form a liquid-tight seal with these elements.

[0107] In a further alternative embodiment, the protective layer is formed only partially around the magnetic head portion. Thus, a liquid-tight seal may be provided only at the interface between the mounting region and the magnetic head portion. For example, the protective layer may be formed as a spherical cap or spherical segment that at least partially covers the mounting region on the magnetic head portion.

[0108] Preferably, the magnetic head portion comprises or is composed of a neodymium (Nd-Fe-B) magnet. The magnetic head portion may be substantially spherical, preferably with a diameter of 0.2 to 2 mm, preferably 0.7 to 1.3 mm, particularly preferably 1 mm. The magnetic head portion preferably has a residual induction (Br) of 0.5 to 2.0 T, particularly preferably 1.0 to 1.5 T.

[0109] Additionally or alternatively, the magnetic portion may be Hard ferromagnetic materials such as FePt alloys, Nd-Fe-B alloys, and SrO6Fe2O3 alloys; soft ferromagnetic alloys such as Fe alloys (stainless steel AISI 420C, Fe coated with a protective shell made of graphite, for example), Ni alloys, Co alloys or any combination of these magnetic elements, Ferrimagnetic materials, such as iron oxide (Fe3O4 or Fe2O3) It can be produced in.

[0110] The magnetic head portion can comprise magnetic particles in a polymer matrix. Additionally or alternatively, the magnetic head portion can comprise a hollow tube. The magnetic head portion can be configured as a Janus particle. The magnetic head portion can be configured as a core particle, which can be magnetic or non-magnetic, with a magnetic shell or coating.

[0111] The magnetic head portion can further include a coating having a tracking element. The tracking element can be a radiopaque element, such as barium compounds, iodine, tantalum, platinum, and / or bismuth, for tracking the position of the medical device and / or the magnetic head portion. The radiopaque coating can be made of strips, rings, or powder. For example, a platinum strip (which can be 100 μm wide and / or 50 μm thick) can be applied to the surface of the magnetic head.

[0112] Alternatively, barium powder can be mixed with a polymer such as epoxy and applied to the surface of the magnetic head. The coating thickness can be between 1 μm and 70 μm, preferably between 5 μm and 15 μm. The particles of the radiopaque powder can have a diameter between 20 nm and 3 μm, preferably between 50 nm and 100 nm.

[0113] Additionally or alternatively, a tracking element may be included in the control line. It is therefore possible to track and detect the position and / or velocity of the control line.

[0114] The tracking elements may be grafted, impregnated and / or coated onto the control lines and / or magnetic head portions.

[0115] Additionally or alternatively, the magnetic head portion can include or consist of hard ferromagnetic material, soft ferromagnetic material, ferromagnetic material, and / or superparamagnetic material. It is contemplated that any of the above materials may be combined within a structure. For example, the magnetic head portion can include a core including a hard ferromagnetic material and a shell including a soft ferromagnetic material. Such a structure can be advantageous, particularly when no magnetic field is applied, and can reduce permanent magnetic clumping of the medical device.

[0116] The magnetic head portion including the protective layer may have a diameter of 0.2 to 2 mm, preferably 0.7 to 1.5 mm, and particularly preferably 1.0 to 1.2 mm.

[0117] Preferably, the control lines are attached or attachable to the magnetic head portion via a cyanoacrylate adhesive.

[0118] The control line may comprise or consist of multifilament nylon and may have a diameter of 50 to 500 μm, preferably 100 to 350 μm, and particularly preferably about 200 μm.

[0119] The control line may have a Young's modulus of 1 to 50 GPa, preferably 1 to 20 GPa, and particularly preferably 1 to 3 GPa.

[0120] The control line is 0.01 to 1 N·mm 2 , preferably 0.05 to 0.5 N·mm 2 The bending stiffness may be

[0121] The control line may have a breaking stress of 0.1 to 5 GPa, preferably 0.1 to 1 GPa, and particularly preferably 0.3 to 0.7 GPa.

[0122] The control line is 0.001 to 0.1 mm in the plane perpendicular to the longitudinal axis. 2 , preferably 0.004 to 0.1 mm2 , and particularly preferably 0.01 to 0.05 mm 2 The cross-sectional area of ​​the slit may be 0.05 mm.

[0123] In particular, the control line may be configured to have a breaking force in the range of 1 to 20 N, preferably 8 to 12 N, depending on the diameter, in particular by the selection of at least one of the material, the diameter and the cross section in a plane perpendicular to the longitudinal axis.

[0124] The present invention further relates to a method of manufacturing a medical device, particularly a medical device as described herein. The method includes providing a magnetic head portion having an attachment region that is attached or attachable to a control line. The attachment region may be a first adhesive component, such as a cyanoacrylate. Alternatively, any other attachment mechanism, particularly one described herein, may be used. The method further includes providing a protective layer that at least partially covers and / or forms an interface region between the magnetic head portion and the attachment region. The protective layer preferably includes a second adhesive component, particularly a resin.

[0125] Preferably, the protective layer is provided as a continuous layer covering the surface of the magnetic head portion. The protective layer may cover a central portion and / or a proximal portion of the magnetic head portion.

[0126] Preferably, the protective layer is arranged at a position radially outward relative to the magnetic head portion and the attachment region, however, it is also conceivable to arrange the attachment region on the protective layer, i.e., outside the protective layer relative to the magnetic head portion.

[0127] Non-limiting embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0128] [Figure 1] Schematic diagram of a medical device. [Figure 2] 1 is a schematic diagram of a body insertion site for a medical device. [Figure 3] 1 is a schematic diagram of a medical device having a drive and control member. [Figure 4] 1 is a schematic diagram of a medical device having a positioning means. [Figure 5] Schematic of pulling a medical device with a magnetic field. [Figure 6] Schematic diagram of data and energy transmission over control lines of a medical device. [Figure 7a] Schematic diagram of a functional unit attached to a medical device. [Figure 7b] Schematic diagram of a functional unit attached to a medical device. [Figure 7c] Schematic diagram of a functional unit attached to a medical device. [Figure 7d] Schematic diagram of a functional unit attached to a medical device. [Figure 8] Schematic of a tumor and antibodies delivered to the tumor by a medical device. [Figure 9a] Various embodiments of a medical device releasably attached to a control line. [Figure 9b] Various embodiments of a medical device releasably attached to a control line. [Figure 10] 1 is a schematic diagram of a system according to the present invention; [Figure 11] 10 is an alternative embodiment of a medical device according to the present invention. [Figure 12a] 1 shows a schematic representation of a method according to the invention; [Figure 12b] 1 shows a schematic representation of a method according to the invention; [Figure 12c] 1 shows a schematic representation of a method according to the invention; [Figure 13a] 1 illustrates schematically an alternative method according to the present invention. [Figure 13b] 1 illustrates schematically an alternative method according to the present invention. [Figure 13c] 1 illustrates schematically an alternative method according to the present invention. [Figure 14] 1 shows a schematic representation of a medical device within a blood-filled vessel. [Figure 15a]1A-1C are cross-sectional views of various embodiments of control lines with associated elements. [Figure 15b] 1A-1C are cross-sectional views of various embodiments of control lines with associated elements. [Figure 15c] 1A-1C are cross-sectional views of various embodiments of control lines with associated elements. [Figure 15d] 1A-1C are cross-sectional views of various embodiments of control lines with associated elements. [Figure 15e] 1A-1C are cross-sectional views of various embodiments of control lines with associated elements. [Figure 15f] 1A-1C are cross-sectional views of various embodiments of control lines with associated elements. [Figure 16] 1 illustrates schematically method steps for manufacturing a medical device. [Figure 17a] 1A and 1B show various embodiments of a magnetic head portion in a schematic manner. [Figure 17b] 1A and 1B show various embodiments of a magnetic head portion in a schematic manner. [Figure 17c] 1A and 1B show various embodiments of a magnetic head portion in a schematic manner. [Figure 17d] 1A and 1B show various embodiments of a magnetic head portion in a schematic manner. [Figure 18a] 1A-1C are schematic illustrations of various embodiments of a medical device having a protective layer. [Figure 18b] 1A-1C are schematic illustrations of various embodiments of a medical device having a protective layer. [Figure 18c] 1A-1C are schematic illustrations of various embodiments of a medical device having a protective layer. [Figure 18d] 1A-1C are schematic illustrations of various embodiments of a medical device having a protective layer. DETAILED DESCRIPTION OF THE INVENTION

[0129] 1 shows a schematic diagram of a medical device 10 comprising a body portion 11 and a tail portion 12. A control line 13 is tail 12. Control line 13 is used to pull medical device 10.

[0130] FIG. 2 shows a schematic diagram of an insertion site 20 in a human body 2 for a medical device 10. A heart 1 is connected to the bloodstream. The bloodstream includes various types of blood vessels 6, such as an aorta 3, veins 4, and capillaries 5. The medical device 10 is inserted into the blood vessel 6 at the insertion site 20. Thus, the blood vessel 6 is punctured at the insertion site 20 by a catheter 22. The medical device 10 is inserted into the blood stream B. The blood stream B carries the medical device 10 through the blood vessels until it reaches the site of interaction 25 (FIG. 5). The medical device 10 is always connected to a control line 13 and can be pulled back to the insertion site 20.

[0131] 3 shows a medical device 10 having a control line 13 within a blood vessel 6. The medical device 10 has a drive unit 15 and a control member 16 that controls the drive unit. The drive unit 15 actively moves the medical device 10 in a certain direction. The control member 16 adjusts the operation of the drive unit 15. The control member 16 can reverse the direction of rotation of the drive unit 15 and adjust its speed.

[0132] 4 shows a medical device 10 having a control line 13 in a blood vessel 6. The medical device 10 has a positioning means 17. The positioning means 17 emits a signal 19 that is received by a receiver 18. The receiver 18 calculates the position of the medical device 10 based on the signal 19.

[0133] 5 shows a schematic diagram of a blood vessel 6 having a medical device 10. The medical device 10 is carried by blood flow B and is attached to a control line 13. A magnetic field generator 23 generates a magnetic field 21 at an application site 25. A body portion 11 of the medical device 10 has a magnetic portion 14 that is attracted by the magnetic field 21. At the application site 25, the medical device 10 is held in place by the magnetic field 21 against the force of the blood flow B. After performing any kind of operation, the magnetic field generator 23 is switched off and the magnetic field 21 disappears. The medical device is removed against the force of the blood flow B by pulling on the control line 13.

[0134] 6 shows a schematic diagram of the medical device 10. The control lines 13 comprise an energy transmission cable 30 and a data transmission cable 31. The energy transmission cable 30 transmits energy to the sensor 40 and the compartment 41. The sensor transmits data via the data transmission cable 31. Alternatively, the energy transmission cable 30 and the data transmission cable 31 may be integrated into the same cable. This cable is used to transmit energy to the medical device via the control lines 13 and to transmit data to and from the medical device via the control lines 13.

[0135] 7a-7d show schematic diagrams of a medical device 10 having an attachable functional unit 51. In FIG. 7a, the functional unit 51 is a propeller for moving the medical device 10 forward or backward along a longitudinal axis through the device. FIG. 7b shows a medical device 10 in which the functional unit 51 is a track. The track is used to move the medical device 10 to a tissue site. In FIG. 7c, the functional unit 51 of the medical device 10 is a drill. The drill can be used to drill a hole in tissue and create an opening for moving across a physical barrier. In FIG. 7d, the functional unit 51 of the medical device 10 is a hook. The hook can be used to hold the medical device 10 in place or to drag an object or substance when the medical device 10 is recaptured.

[0136] 8 shows a schematic diagram of a tumor site 63. Tumor cells 61 have a larger size and a faster replication cycle than normal cells 60. The medical device 10 is guided to the tumor site and carries tumor-specific antibodies 62 in the compartment 41. At the tumor site 63, the medical device 10 releases the tumor-specific antibodies 62. The antibodies bind to the tumor cells and trigger the immunotherapy process. After releasing the antibodies 62, the medical device 10 is removed from the tumor site 63 by pulling the control line 13.

[0137] 9a shows another embodiment of a medical device 10 according to the present invention. The medical device 10 comprises a tail portion 12 and a body portion 11 configured as separate elements. The body portion 11 and the tail portion 12 are connected via a connection mechanism 26. The robot is attached to a single control line 13 configured to control the speed of the robot in a fluid flow. The connection mechanism 26 can be selectively deactivated to detach the body portion 11 from the tail portion 12, for example, by applying an electric current. The connection mechanism 26 comprises an iron-based material that disintegrates by electrolysis when an electric current is passed through it. Thus, the connection mechanism 26 releases the body portion 11 of the medical device 10.

[0138] 9b shows an alternative embodiment in which the control line 13 and the medical device 10 are directly connected by a selectively detachable connection mechanism 26. Thus, the medical device 10 can be released from the control line 13 by electrical detachment similar to the detachment described above. The connection mechanism 26 comprises a noble metal portion comprising a noble metal, such as a platinum alloy, attached to a ferrous portion. Application of an electric current causes the ferrous portion to act as an anode, dissolving ferrous ions into the surrounding liquid and thus disintegrating the ferrous portion to, for example, release the medical device. Additionally or alternatively, the connection mechanism 26 can be disintegrated by an increase in temperature induced by any known method, such as a localized heating element or ultrasound.

[0139] 10 shows a schematic diagram of a system 60 according to the present invention. The system 60 comprises a control unit 61 connected to a first end 13′ of a control line 13. A second end 13″ of the control line 13 is attached to the medical device 10. Here, a magnetic field generator 23 is included in the system 60 for guiding or steering the medical device 10 through a fluid flow (not shown).

[0140] 11 shows an alternative embodiment of the medical device 10. The medical device 10 includes a control line 13 for speed control. Additionally, the medical device 10 is connected to a transmission cable 31 that transmits data between the medical device 10 and an external computer (not shown). It is contemplated that the cable 31 can also be used to transmit electrical energy to the medical device 10.

[0141] Figure 12a shows a schematic representation of the first step of the method according to the invention. A microrobot 10 is floating in a blood vessel 6 near a bifurcation B. According to the treatment plan, the microrobot 10 should be directed towards the target site 25 and therefore needs to be steered in the right direction at the bifurcation B. Therefore, the microrobot 10 is slowed down by a control line 13 until it stops at a position upstream of the bifurcation B. The microrobot 10 is now in a fixed position with respect to the direction of blood flow, but the microrobot 10 However, some limited movement is still possible since the control lines are typically flexible elements.

[0142] Figure 12b shows that the microrobot 10 is pushed towards the target side of bifurcation B, which leads to the target site 25. Once the microrobot 10 is positioned, the control line 13 can be released again at a controlled rate so that the microrobot is again carried by the blood.

[0143] Figure 12c shows the robot moving through the blood flow at substantially the same speed as the blood flow towards a target site 25. Once the target site is reached, the robot can be stopped by holding the control line.

[0144] Figures 13a to 13 c shows an alternative method for controlling a medical device 10 within a blood vessel 6. This method is similar to the method shown schematically in Figures 12a-12c, except that the microrobot 10 never comes to a complete stop.

[0145] 13a thus shows a microrobot 10 attached to a control line within a blood vessel 6. As the microrobot 10 approaches bifurcation B, the microrobot 10 is slowed down by a control line 13.

[0146] FIG. 13b shows how the magnetic field 21 is used to steer the microrobot 10 towards the target site 25 in parallel with the deceleration.

[0147] FIG. 13c shows the microrobot 10 again floating within the blood vessel. FIG. 14 shows a schematic diagram of a microrobot 10 in a vasculature 6 with several branches B, B', B'', and B'''. A catheter C is used to bring the microrobot 10 into the vasculature 6 to be treated. The speed of the microrobot 10 is controlled by the controlled release or tension of a control line 13 attached to the microrobot 10, particularly in the vicinity of the branches B, B', B'', and B'''. The control line 13 is made of raw silk and coated with hydrogel. For this reason, it is mechanically flexible and can bend to fit the vasculature 6. Furthermore, the hydrogel surface reduces the thrombogenicity of the control line 13 and reduces friction at the vessel wall.

[0148] FIG. 15a shows in cross section a control line 13 made from a single material, here Kevlar.

[0149] Figure 15b shows a control line 13 having a radiopaque line 71 arranged parallel to the longitudinal axis of the control line 13. The radiopaque line 71 is composed of a composite of a biocompatible polymer and barium sulfate, and is therefore visible under x-ray imaging. Additionally or alternatively, a platinum or gold ring can be combined and connected to the control line.

[0150] 15c shows a control line 13 having an anti-thrombogenic hydrogel coating 72 on its surface, where the hydrogel is PEG-based. However, the hydrogel can include any material selected from the group consisting of ELP, HEMA, PHEMA, polyvinylpyrrolidone, PMA (or other methacrylate / methacrylic acid-based polymers), agarose, hyaluronic acid, methylcellulose, elastin, and chitosan.

[0151] 15d shows a control line 13 with a transmission cable 30 for energy transmission configured as a separate element arranged parallel to the longitudinal direction of the control line 13. The transmission line is constructed of gold and is capable of transmitting electrical energy. Alternatively, the transmission line may be constructed of platinum or any conductive metal (such as copper) coated with gold and / or platinum. Additionally or alternatively, the transmission line may be used to transmit data.

[0152] Figure 15e shows an alternative embodiment of the control line 13 in which a transmission cable 31 for data transmission is arranged inside the control line 13. Additionally or alternatively, the transmission line 13 may also transmit energy.

[0153] Figure 15f shows an alternative embodiment of control line 13 in which hollow tube 73 is positioned parallel to and outside of control line 13. The hollow tube is configured for suction purposes to obtain tissue samples or remove fluids and / or cells from a target area.

[0154] 16 schematically illustrates method steps for manufacturing a medical device. A magnetic head portion 100 having a south pole 101 and a north pole 102 is brought into operative contact with a magnet 101 so as to orient the magnetic head portion 100 relative to the magnetic field of the magnet 101. This allows a control line 13 to be selectively attached to the magnetic head portion 100 at its south pole 101. Alternatively, the control line 13 can be attached to the north pole 102 or any other location on the magnetic head portion 100. The use of the magnet 101 facilitates attachment by knowing the orientation of the magnetic head portion 100 relative to the magnetic property.

[0155] 17a shows one embodiment of a magnetic head portion 100. The magnetic head portion 100 includes a plurality of magnetic particles 104 disposed within a polymer matrix 105.

[0156] One possible method for producing such an embodiment is described below. Demagnetized hard ferromagnetic particles can be incorporated into a polymer matrix. The particles are then magnetized. Additionally or alternatively, soft ferromagnetic, superparamagnetic, or ferrimagnetic particles can be incorporated into the polymer matrix. Particles with diameters between 5 nm and 5 μm, preferably between 30 nm and 100 nm, can be incorporated by emulsion, molding, or prilling. The polymer matrix can be bioabsorbable (e.g., PLLA, PLGA, PDO, PCL) or non-bioabsorbable, e.g., silicone, PDMS, polyurethane.

[0157] Furthermore, the magnetic head part 100 comprises an outer layer 103 comprising a tracking material (not visible) in the form of radiopaque particles. The magnetic head part 100 has a diameter in the range of 300 μm to 1.5 mm, preferably 400 μm to 800 μm.

[0158] 17b shows another embodiment of the magnetic head part 100, comprising a substantially spherical magnetic material 106 with a hollow tube 107. The hollow tube can be used for fluid transmission or suction, in particular for creating a vacuum and / or delivering liquids, gases, therapeutic solutions, for moving therapeutic instruments in front of the device and / or microrobot, or for guiding optical or electrical cables. The hollow tube 107 has a diameter between 70 μm and 200 μm, preferably 0.1 mm, and extends substantially across the central region of the magnetic head part 100. However, it is also conceivable to arrange the hollow tube in a position laterally displaced from the central part. Hollow tube 107 The magnetic head portion 100 may be at least partially curved and / or straight. The diameter of the magnetic head portion 100 was 1.1 mm.

[0159] 17c shows another embodiment of a magnetic head portion 100 configured as a Janus particle, where the Janus particle includes a portion of magnetic material 106 and a portion including active material 108.

[0160] Additionally or alternatively, Janus particles may be made of two different magnetic materials, such as FePt and Fe2O3. In such a configuration, the magnetic particles exhibit hard ferromagnetic behavior (FePt) and ferrimagnetic behavior (Fe2O3). In another configuration, one side is made of a magnetic material and the other side is made of a non-magnetic material. The non-magnetic material may be a metal such as NiTi or a polymer such as polyurethane. The non-magnetic material can be used to configure or activate a microrobot therapeutic device. For example, the non-magnetic material can be made of NiTi, which changes its shape under a stimulus, such as an increase in temperature, which can be induced by an electric current.

[0161] FIG. 17d shows yet another embodiment of the magnetic head portion 100, including a magnetic material 106 configured as an outer shell. The inner core 109 may be any other suitable material, which may be magnetic or non-magnetic. For example, the outer layer may be made of Fe3O4 with a thickness of 200 μm, and the inner core may be made of FePt with a diameter of 400 μm. Alternatively, the outer layer may be made of a mixture of Fe2O3 and FePt with a thickness of 300 μm, and the inner core may be made of PDMS with a diameter of 400 μm. This design contributes to reducing the stiffness of the microrobot.

[0162] It will be appreciated that any of the features described in the context of Figures 17a-17d may be used in any of the devices disclosed herein, particularly in combination with any other feature disclosed herein.

[0163] 18a shows one embodiment of a medical device 10 comprising a magnetic head portion 100 and a control line 13 attached thereto, where the control line 13 has an attachment region comprising a cyanoacrylate adhesive that provides attachment between the magnetic head portion 100 and the control line 13. 110 18b and 18d), the magnetic head part 100 is attached to the mounting area 110. Furthermore, a protective layer 111 configured as a layer of epoxy resin is disposed on the magnetic head part 100. Here, the protective layer 111 is disposed continuously over the entire surface of the magnetic head part 100 and the mounting area 110. The control lines 13 attached to the mounting area 110 protrude through the protective layer 111. The protective layer therefore seals the magnetic head part 100 from fluids that may be present around the medical device 10 and reduces the effects of corrosion. It will be appreciated that in some alternative embodiments, the protective layer may not contact the control lines 13 but may only partially cover the mounting area 110 in a circumferential area (see FIGS. 18b and 18d), which still provides a fluid seal for the magnetic head part 100.

[0164] FIG. 18b illustrates a different embodiment of the medical device 10 similar to the embodiment of FIG. 18a. The medical device 10 includes a magnetic head portion 100 attached to a control line 13 via an attachment region. Here, the magnetic head portion 100 is partially covered with a protective layer 110 formed as a band and covering an interface 112 between the attachment region 110 and the magnetic head portion 100. The protective layer configuration shown here can provide sufficient corrosion reduction, particularly over a typical treatment timeframe, to provide secure attachment of the control line 13 to the magnetic head portion 100, for example. Yet, advantageously, less material is required to provide the protective layer 111, which is more economical, more environmentally friendly, and can reduce the overall size of the medical device 10. It will be appreciated that the protective layer 111 in the illustrated embodiment does not provide a complete fluid seal for the magnetic head portion 100, as the proximal and central portions of the magnetic head portion 100 are not covered by the protective layer 111. However, the interface 112 is fluid-sealed by the protective layer 111. In some alternative embodiments, it is also contemplated that the central portion 114 and the proximal portion 113 may be covered with a protective layer 111, for example to provide a fluid seal around the entire magnetic head portion 100.

[0165] This approach makes it possible to have two different coatings: one for securing the attachment of the control lines to the magnetic part, and one for functionalizing the head of the microrobot. For example, therapeutic devices such as drug reservoirs or hooks can be attached to the uncovered magnetic surface with a resin layer.

[0166] Alternatively, the magnetic head can be constructed from two sections that are closed together along with the control lines. With this design, the control lines are embedded in the magnetic sections. For example, one magnetic section has a female design and the other has a male design. Both sections have areas for the control lines. The control lines are compressed between the two sections during assembly.

[0167] 18c shows yet another embodiment of the medical device 10. Here, the magnetic head portion 100 is continuously coated over its entire surface with a protective layer 111. An attachment region 110 comprising a cyanoacrylate adhesive is arranged on the outer surface of the protective layer 111. The control lines 13 are attached to the magnetic head portion 100 via the attachment region 110. Such a configuration can provide a particularly secure attachment of the control lines 13.

[0168] Figure 18d shows yet another embodiment of the medical device 10. The embodiment shown here is similar to the embodiment shown in Figure 18b. Here, the protective layer 111 is again formed as a band covering the interface 112 between the attachment region 110 and the magnetic head portion 100. However, the band is configured to cover more than 50% of the surface of the magnetic head portion 100. The attachment region 110, which is formed by hot melt adhesive, is not covered with the protective layer 111. The proximal region 113 of the magnetic head portion 100 is not covered with the protective layer 111. Here, the control line 13 can be attached to the attachment region 110 by heating the hot melt adhesive to secure the control line 13 thereto.

[0169] It will be understood that features of the embodiments of Figures 18a-18d can be freely combined. In particular, any magnetic head portion 100 may be attached to the control line 13 or may be separately attachable to the control line 13. Likewise, any of the protective layer configurations shown in Figures 18a-18d can be used in combination with any other embodiment or feature shown here or further disclosed herein.

Claims

1. A system for controlling a medical device (10), comprising: a medical device (10), a magnetic field generator (23), and a control unit, wherein the medical device (10) a body portion (11) including a magnetic portion (14); Tail (12) and It contains a control line (13) attached to the medical device, the control line (13) configured to retract and / or control the velocity of the medical device (10) from a target location, the stiffness of the control line being insufficient to move the medical device (10) to a target location, the medical device (10) being capable of being guided by a magnetic field (21) generated by the magnetic field generator (23); The control unit is configured to retract and / or release the control line to control the speed of the medical device.

2. The medical device (10) comprises: i) a drive (15) for actively moving the device in a direction; and ii) a control member (16) for changing the direction of movement within the body by external action; 2. The system of claim 1, further comprising at least one of:

3. 3. The system according to claim 1 or 2, characterized in that the medical device (10) comprises positioning means (18) for determining the position of the medical device (10) within the body.

4. System according to any one of claims 1 to 3, characterized in that the control line (13) comprises a transmission cable (30, 31) for transmitting energy and / or data.

5. 5. The system of any one of claims 1 to 4, wherein the control line (13) comprises a material selected from the group of materials consisting of metal, stainless steel, cobalt-chromium-nickel alloy, titanium, titanium alloy, platinum, platinum alloy, Nitinol, nickel-titanium ternary alloy, nickel-free alloy, metal composite, polymer, carbon fiber, graphene, textile, raw silk, protein fiber, aramid, and carbon nanotube.

6. The system of any one of claims 1 to 5, wherein the control line has a smaller cross section than the medical device.

7. The system of any one of claims 1 to 6, characterized in that the medical device (10) comprises a material that allows detection by at least one of the group of imaging techniques including MRI, scanner, ultrasound, X-ray, and fluoroscopy.

8. A system according to any one of the preceding claims, characterized in that the control line (13) has an outer diameter of 10 to 1000 μm.

9. The system according to any one of the preceding claims, characterized in that the body portion (11) comprises a magnetic portion (14).

10. The system according to any one of the preceding claims, characterized in that the body portion (11) comprises at least one functional unit (51).

11. The system according to any one of the preceding claims, characterized in that the body portion (11) comprises a compartment (41) configured to store and release a drug (62).

12. The system of any one of claims 1 to 11, characterized in that the body portion (11) includes a transmitter (17) configured to transmit data from the medical device to a receiver (18).

13. The system according to any one of claims 1 to 12, characterized in that the medical device has a size of 8 to 2000 μm.

14. The system of any one of claims 1 to 13, characterized in that the body portion (11) and the tail portion (12) of the medical device (10) comprise a material selected from the group consisting of metal, plastic, glass, mineral, ceramic, carbohydrate, nitinol, carbon, biomaterial, or biodegradable material.

15. 10. A system according to any one of the preceding claims, wherein the control line (13) is removably attached to the device (10).

16. 16. The system of claim 15, wherein the control line (13) is selectively removable from the device (10).

17. 10. The system of any one of the preceding claims, comprising first and second portions of the medical device, the first portion attached to the control line, the second portion removably attached to the first portion, and the first portion selectively detachable from the second portion of the medical device (10).

18. 10. A system according to any one of the preceding claims, comprising a single line formed by said control line (13).

19. The system of claim 1 , wherein the control lines are incapable of transmitting data or energy.

20. 10. A system according to any one of the preceding claims, wherein the control line can be bent into a curve having a radius of curvature of less than 3 mm.

21. 10. The system of any one of the preceding claims, wherein the control line comprises a radiopaque material.

22. 22. The system of claim 21, wherein the radiopaque material is disposed as a separate cable (71) associated with and parallel to the control line and / or as a coating on the control line.

23. The system of any one of claims 1 to 22, wherein the control line comprises a hydrophilic surface.

24. The system of any one of claims 1 to 22, wherein the control line comprises a surface that is anti-thrombogenic.

25. The system of any one of claims 1 to 22, wherein the control line has a surface coated with a hydrogel.

26. 10. The system of any one of the preceding claims, wherein the control line is attached to the medical device by at least one of a knot, a clip, a welded connection, an adhesive connection, a blend of materials, and a chemical bond.

27. 10. The system of any one of the preceding claims, further comprising a hollow tube arranged parallel to the control line.

28. 10. The system of any one of the preceding claims, further comprising a trigger wire configured to trigger a function of the device.

29. A medical device in a system according to any one of claims 1 to 28, comprising a magnetic head part attached or attachable to a control line, It also has a protective layer, A medical device, characterized in that the protective layer is configured to provide a fluid seal at least for an area of ​​the magnetic head portion that is attached or attachable to the control line.

30. 30. A method of manufacturing the medical device of claim 29, comprising: - providing an attachment area on the magnetic head portion to be attached or attachable to a control line; providing a protective layer at least partially covering and / or forming an interface area between said magnetic head portion and said attachment area; A method comprising:

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