Device and method for monitoring and / or controlling the feed of a medical tool, computer program and data carrier

Abstract

Device for monitoring and / or controlling the advance of a medical tool (2) through a vascular system (3) of a patient (4), wherein a processing unit (5) of the device (1) is configured to perform at least one test point (6) each - to capture or receive from an external source velocity information (7) relating to the speed of the advancement of the medical instrument (2), - to detect or receive force information (8) relating to a force acting on the medical device (2) from the device or another external source, - to evaluate a trigger condition (9) whose fulfillment depends on both the velocity information (7) and the force information (8), and - upon fulfillment of the trigger condition (9) to, on the one hand, control a warning device (10) to issue a warning (11) to a user of the device (1) and / or, on the other hand, to control an actuator (12) moving the medical tool (2) to stop the advance of the medical tool (2).

Description

[0001] The invention relates to a device for monitoring and / or controlling the advancement of a medical instrument through a patient's vascular system. The invention also relates to a method for monitoring the advancement of a medical instrument, a computer program, and a data storage medium.

[0002] Minimally invasive procedures utilize tools that are guided through the patient's vascular system to a relevant location, for example, via a catheter or probe. This allows for the collection of diagnostic information and / or the performance of a local intervention. In rare cases, an unexpected characteristic of the vascular system and / or incorrect tool guidance can lead to an unintended perforation of a vessel wall. If such a perforation is detected in a timely manner, adverse consequences for the patient can be avoided or minimized through the rapid initiation of countermeasures, such as local cauterization.

[0003] Such a perforation of the vessel wall can be detected by experienced medical personnel, for example, using fluoroscopy, i.e., continuous monitoring of the procedure via X-ray imaging, such as with a C-arm angiography system. Alternatively or additionally to fluoroscopic monitoring of the procedure, it is possible to determine the shape of the instrument within the body using approaches that analyze light reflections from Bragg gratings in multiple optical fibers integrated into the instrument. The determined shape of the instrument is then superimposed onto a previously acquired image of the vascular system. Such a system is presented, for example, on the website https: / / shapesensing.com / .

[0004] When the instrument is advanced manually, a perforation of the vessel wall can potentially be detected directly based on the haptic feedback of the forces involved. However, with automated advancement, for example by a treatment robot or in the field of telemedicine, haptic feedback is often either unavailable or at least not sufficiently detailed for this purpose.

[0005] The invention aims to better support a user in quickly detecting and / or preventing perforation of a vessel wall by a medical tool.

[0006] The object is achieved according to the invention by a device for monitoring and / or controlling the advancement of a medical tool through a patient's vascular system, wherein a processing unit of the device is configured to perform at least one test test at each - to capture or receive speed information relating to the speed of the advancement of the medical instrument from a source external to the device, - to detect or receive force information relating to a force acting on the medical device from the device or another external source, - to evaluate a trigger condition whose fulfillment depends on both the velocity information and the force information, and - upon fulfillment of the trigger condition, on the one hand, to activate a warning device to issue a warning to a user of the device and / or on the other hand, to activate an actuator moving the medical tool to stop the advance of the medical tool.

[0007] An analysis of the force information makes it possible, for example, to detect a noticeable increase in the axial force acting on the front end of a medical instrument when it encounters a vessel wall and threatens to perforate it. By recognizing this situation, timely notification or activation of the actuator may make it possible to completely prevent perforation of the vessel wall.

[0008] Since this increase in force before or during penetration of the vessel wall only occurs for a short time and therefore does not in itself allow for robust detection of a vessel wall penetration in all cases, it is preferably additionally or alternatively exploited that a further advancement of the medical instrument after penetration of the vessel wall leads, depending on the environment of the vessel, in almost all cases to significantly higher or significantly lower forces opposing the advancement than those that occur during an advancement within the vessel.

[0009] Thus, the trigger condition can always be met, for example, if the force information deviates sufficiently from an expected value for the counterforce occurring during a feed within the vascular system. The expected magnitude of the force acting on the medical instrument, in particular the magnitude of the axial force acting along the medical instrument or the vessel, which opposes the feed, depends strongly on the feed rate. Therefore, according to the invention, the velocity information is additionally taken into account within the trigger condition to improve the robustness of the detection.

[0010] Thus, the inventive method robustly enables the detection of a prior perforation of the vessel wall by the medical instrument and alerts the user of the device, for example, a physician performing the procedure, to this injury to the vessel wall, so that they can quickly and reliably take countermeasures or prevent further penetration in order to minimize damage to the vascular system or the surrounding tissue. It may even be possible to prevent perforation of the vessel wall by the medical instrument by detecting an increased force caused by contact with the wall in a timely manner.

[0011] The processing unit can be configured, in particular, to activate the notification device to issue a notification or a specific notification only when the trigger condition is met. Additionally or alternatively, the processing unit can be configured to activate the actuator when the trigger condition is met, and in particular only when the trigger condition is met, in such a way that the advancement of the medical instrument is stopped even if a request to continue advancing the medical instrument is received via an input interface, such as a joystick or a telemedicine data connection.

[0012] The velocity information can be provided, for example, by a robot moving the medical instrument, and the force information by a measuring device separate from the robot. With robotic feeding, the velocity information is typically already available as control information for an actuator or can be determined based on such control information. Particularly when manual feeding of the medical instrument is used, but also when feeding by a robot, the feed rate can alternatively or additionally be measured by suitable sensors.

[0013] The processing device can be configured to determine an expected value for the force acting on the medical tool from the speed specified by the speed information using a specified assignment rule, whereby the trigger condition is met if an amount of the force acting on the medical tool described by the force information falls below the expected value by a specified deviation value.

[0014] Thus, a known or previously determined relationship between the speed of advancement and the force expected at that speed for advancing the medical instrument within the vascular system can be used to detect unexpectedly low forces, indicating that the vessel wall has been perforated and the medical instrument is therefore being advanced into an area outside the vascular system where advancement requires less force. Such an area could, for example, be a cavity in the patient's body adjacent to the vascular system.

[0015] In a simple example, the assignment rule can describe a linear relationship between the velocity specified by the velocity information and the expected value of the force acting on the medical instrument. However, more complex relationships are also possible, which can be modeled as an assignment rule, for example, using a lookup table, preferably with interpolation (e.g., linear interpolation).

[0016] The processing device may additionally or alternatively be configured to determine, from the speed specified by the speed information, the expected value or an expected value for the force acting on the medical tool by means of the speed or a specified allocation rule, wherein the trigger condition is met if an amount of the force acting on the medical tool described by the force information exceeds the expected value by the expected value or a specified deviation value.

[0017] This allows for the detection of unexpectedly high forces, which can occur, for example, when the vessel wall has already been perforated and the medical instrument is advanced into tissue adjacent to the vascular system. Detecting unexpectedly high forces is also advantageous for identifying pressure of the medical instrument against the vessel wall and thus potentially preventing perforation of the vessel wall through timely warning or appropriate control of the actuator.

[0018] The processing device may be configured to capture or receive from the external source(s) a respective reference value pair consisting of a reference velocity value relating to the feed rate of the medical tool at the respective reference time and a reference force value relating to a force acting on the medical tool at the respective reference time, at several reference times before the test time or at least at one of the test times, and to determine the specified assignment rule and / or the specified deviation value or a specified relationship between the specified deviation value and the velocity information depending on these reference value pairs.

[0019] Thus, the expected value of the force, or a permissible degree of deviation from this expected value, can be based on empirical data collected during a previous advancement of the medical instrument, particularly within the vascular system of the same patient, and specifically during the same procedure. For example, a user input can detect the start of a procedure or the initial advancement of the medical instrument within the vascular system, and the processing unit can be configured to acquire and receive reference value pairs from this point onward, particularly periodically at short intervals.

[0020] The reference value pairs can be statistically evaluated to determine the assignment rule and / or the deviation value or the predefined relationship. For example, a look-up table can be determined as the assignment rule, which is then used directly or interpolated to determine the expected value. In this case, in general, regarding the statistical evaluation of the reference value pairs, binning can be performed with respect to the reference velocity values. For example, for several velocity intervals, a mean value of all reference force values ​​assigned to reference velocity values ​​within the respective velocity interval is calculated and assigned as the expected value of the mean velocity of that velocity interval.

[0021] The assignment rule can assign a deviation value to all velocities within the respective velocity interval, for example, the standard deviation or a predefined multiple of the standard deviation of those reference force values ​​that are assigned to reference velocity values ​​within the velocity interval. Alternatively, this standard deviation or multiple can be assigned only to the mean velocity in the respective interval, and the resulting look-up table can be interpolated for other velocities. Another alternative is to use the same deviation value for all velocity information, which can be chosen, for example, as the mean of these standard deviations or a predefined multiple of this mean.

[0022] Alternatively, the reference value pairs can be used, for example, to determine parameters of an analytical, e.g., linear, relationship between the speed information and the expected value through a fit or regression analysis. The assignment rule or the specified deviation value can then be determined, for example, as the standard error of the regression or as a specified multiple thereof.

[0023] The processing device may be configured to always use the force information determined for that test time as the reference force value of the reference value pair for the reference time corresponding to the test time, and the velocity information as the reference velocity value of this reference value pair, in cases where the trigger condition is not met at the respective test time, or when an additional condition is met.

[0024] Thus, the force and velocity information already determined at the time of testing for evaluating the triggering condition can be used in this case—especially if no vessel wall perforation appears to have occurred—to provide an additional reference value pair for subsequent testing. In other words, the assignment rule and, optionally, the deviation value or the predefined relationship between the deviation value and the velocity information can be adjusted quasi-continuously during the feed to obtain an increasingly accurate profile of the forces expected during the feed.

[0025] The device can comprise the medical tool, wherein the medical tool has at least one sensor component in a front section of the medical tool, which is configured to be arranged within the vascular system during the advancement of the medical tool through the vascular system, by means of which a force component of the force acting on the front section in a longitudinal direction of the medical tool, which extends along the vessel within which the front section is arranged during the advancement of the medical tool in the vascular system, is to be detected as force information or as part of force information.

[0026] The sensor components thus allow for the measurement of the force or force component that opposes further advancement of the front end of the medical instrument. Within the vascular system, this force typically results primarily from the displacement of the blood in front of the medical instrument. Depending on the specific design of the sensor component, friction between the medical instrument and the vessel wall in the anterior segment can also contribute to the measured force component.

[0027] For example, if a medical instrument is advanced into a body cavity after penetrating a vessel wall, the measured force component is typically significantly lower than within the vascular system. Conversely, this force component can increase considerably compared to movement within the vascular system if the medical instrument is advanced through adjacent tissue after penetrating a vessel wall.

[0028] In addition to or as an alternative to using such a sensor component, the total feed force required to advance the medical instrument, or a correlated quantity such as the motor current of the actuator providing the feed, can also be measured. Measuring only the total force required for the feed can reduce the technical effort required to implement the device according to the invention, since measurements outside the patient's body are technically easier to implement than force measurements inside the body.By utilizing the sensor components located in the front section of the medical instrument, an impending or actual injury to the vessel wall can potentially be detected more reliably. This is because, when solely evaluating the total required thrust force, the friction between the medical instrument and the vascular system can contribute significantly to the force along the entire length of the instrument. Therefore, the forces that actually change during or after a vessel wall rupture contribute only minimally to the measured value when evaluating the total required thrust force. Consequently, this typically results in a significantly lower signal-to-noise ratio compared to using the sensor component in the front section.

[0029] The medical device can be or comprise at least one optical fiber extending from the front section to a rear section of the medical device, which is configured to be located outside the patient during the advancement of the medical device through the vascular system, wherein the sensor component is formed by at least one Bragg grating configured as part of the optical fiber, wherein a light source of the device is configured to irradiate light into the respective optical fiber, wherein a sensor device of the device is configured to detect a portion of the light reflected by the respective Bragg grating and to provide sensor data relating to this portion of the light to the processing device, wherein the processing device is configured to determine the force information as a function of this sensor data.

[0030] A Bragg grating can be created, for example, by periodically varying the refractive index of the fiber material along the length of the fiber and thus the medical device. Such a variation can be achieved, for instance, by locally heating a plastic fiber using a laser interference pattern. Essentially, only light of a specific wavelength, determined by the Bragg grating's periodicity, is backscattered by such a grating.

[0031] A force acting on the front section compresses the Bragg grating due to the elasticity of the tool or the optical fiber, thus shifting the wavelength of the backscattered light to shorter wavelengths. By shining light into the optical fiber and determining the wavelength of the backscattered light, the force acting on the front section can be determined, allowing the Bragg grating there to serve as a sensor component of a fiber optic sensor.

[0032] Using such a fiber optic sensor to determine force information is advantageous because a light-conducting fiber with one or more Bragg gratings requires only a small installation space perpendicular to the tool's feed direction. Compared to an electrical sensor, it also results in lower susceptibility to interference, for example, when X-ray imaging is used during the procedure. Furthermore, such a sensor, especially when multiple light-conducting fibers, each with several Bragg gratings, are used, can be used to obtain additional information about the tool, such as its current shape.

[0033] Additionally or alternatively, the force component could be formed, for example, by a pressure sensor in the front section, such as a pressure sensor based on a piezoelectric or film capacitor.

[0034] The respective light-conducting fiber can be formed continuously or in several spaced-apart subsections as a Bragg grating in a measuring section that extends from the front section of the medical instrument over at least 20% or at least 50% of the length of the medical instrument between the front and rear sections.

[0035] In the case that the measuring section is designed as a Bragg grating in several spaced-apart subsections, in particular at least three or at least five such subsections may be present and / or at least one of these subsections may be adjacent to the end of the measuring section facing away from the front section of the tool.

[0036] If multiple Bragg gratings or a continuous Bragg grating are used in the measurement section, a curvature of the measurement section, for example, leads to varying degrees of compression and / or expansion of the different Bragg gratings or different sections of the continuous Bragg grating. This results in a light component of a different wavelength being reflected at different positions in the measurement section, depending on the extent of the local compression or expansion. By analyzing which spectral component of the light is received after which transit time(s) – for example, when the light source is pulsed – information about the deformation of the optical fiber, and thus about the shape of the tool or the forces acting on the tool along the entire length of the measurement section, can be determined.In principle, the measuring section can extend over the entire length of the tool or the light-conducting fiber.

[0037] The medical tool can comprise at least three of the light-conducting fibers, which are arranged at least in several measuring planes within the measuring section, each perpendicular to the longitudinal direction of at least one of the fibers, wherein the processing device is configured to determine, depending on the sensor data, a local curvature of the medical tool in the area of ​​the respective measuring plane and thus shape information relating to the shape of the medical tool.

[0038] A curvature of the tool in the area of ​​the respective measurement plane causes the various light-conducting fibers to be stretched or compressed to varying degrees, depending on the direction and severity of the curvature. A Bragg grating in the area of ​​the respective measurement plane, or a section of a continuous Bragg grating located in the area of ​​the respective measurement plane, allows the respective stretching or compression to be detected and quantified. Thus, with a known arrangement of the light-conducting fibers in the measurement plane, the local curvature in the area of ​​the respective measurement plane can be determined. This allows the shape of the tool in the measurement section to be determined, assuming a substantially rigid connection between the light-conducting fibers and the tool.This can, for example, serve to visualize the medical tool for the user, whereby the shape determined on the basis of the sensor data can be superimposed on a previously determined image data set of the vascular system.

[0039] As explained at the outset, determining the shape of a medical instrument using fiber optic sensors is a known method. However, it has been recognized that, according to the invention, fiber optic sensors, which, for example, serve to determine the current shape of the medical instrument, can additionally be used to determine the force information evaluated within the triggering condition. This makes it possible, for example, to detect an impending or actual perforation of a vessel wall by the medical instrument. Therefore, the device according to the invention can be implemented particularly easily if, for example, the shape of the instrument is already to be detected using fiber optic sensors.The speed information is typically known anyway, especially in the case of automatic tool feed, so that the device according to the invention can be implemented with little effort on the basis of already known or used devices, for example by a suitable software modification.

[0040] The processing unit can be configured to periodically check the fulfillment of the trigger condition at test points spaced less than 50 ms or less than 10 ms apart. In particular, the test points can be spaced less than 5 ms apart, for example, one millisecond apart. The force and velocity information can be recalculated for each test point. Using the approaches described above for determining this information, this is easily achievable with the specified intervals between test points or the corresponding sampling frequency. This allows for virtually instantaneous responses to a vessel wall rupture that has already occurred or is imminent.

[0041] In addition to the device according to the invention, the invention relates to a computer-implemented method for monitoring the advancement of a medical instrument within a patient's vascular system, comprising the steps performed at at least one testing time: - Receiving or determining speed information relating to the speed of advancement of the medical instrument, - Receiving or determining force information relating to a force acting on the medical instrument, - Evaluating a trigger condition whose fulfillment depends on both velocity information and force information, and - Activating a notification device to issue a notification to a user when the trigger condition is met, and / or - Determination of control information for an actuator used to move the medical tool, depending on whether the trigger condition is met, wherein the control information determined when the trigger condition is met relates to stopping the feed of the medical tool.

[0042] The advancement of the medical instrument within the vascular system and / or the determination of the velocity or force information can be carried out outside the method according to the invention. Alternatively, at least one or all of these steps can be included as process steps in the method.

[0043] The device according to the invention, in particular its processing unit, can be configured to carry out the computer-implemented method according to the invention. Accordingly, the computer-implemented method according to the invention can be implemented and optionally further developed by the features of the device according to the invention described above. If features and configurations described above for the device according to the invention are transferred to the computer-implemented method according to the invention, the advantages discussed above are also achieved. In general, the computer-implemented method according to the invention can thus be further developed with the features described for the device according to the invention, and vice versa, thereby achieving the advantages described for each feature.

[0044] The invention also relates to a computer program with instructions configured to execute the computer-implemented method according to the invention and / or to implement the processing unit of the device according to the invention when implemented on a data processing device. The data processing device can be configured together with other components of the device, for example, with an actuator for feeding the medical tool and / or an operating interface for this actuator, or it can be configured separately from the other components of the device described above, for example, as a workstation, server, or cloud solution.

[0045] The invention also relates to a data carrier comprising the computer program according to the invention.

[0046] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

[0047] Further advantages and details of the invention will become apparent from the following exemplary embodiments and the accompanying drawings. These schematically illustrate: Fig. 1 an embodiment of the device according to the invention, Fig. 2 a flowchart of an embodiment of the method according to the invention, and Fig. 3 a sectional view of the in Fig. 1. Medical tool used 2.

[0048] Fig. Figure 1 shows a device for monitoring and controlling the advancement of a medical instrument 2 through a patient's vascular system 3. In the Fig. In the usage scenario shown, the medical instrument 2, for example a catheter, is already partially inserted into the vascular system 3 of the patient 4, with access to the vascular system 3 being via the patient's lumbar region. In this example, the medical instrument 2 is advanced within the vascular system 3 by the actuator 12 of the device 1, for example by being picked up from a roller (not shown). The advancement can be controlled, for example, via a local control device (not shown), such as a joystick, or even remotely via telemedicine.

[0049] A processing unit 5 of the device 1 is configured to periodically acquire, at several test points 6, for example at intervals of 1 ms, on the one hand, velocity information 7 relating to the feed rate of the medical tool 2, and on the other hand, force information 8 relating to a force acting on the medical tool 2. Possibilities for acquiring these quantities will be explained later. Alternatively, these quantities could also be acquired by a separate source or by several separate sources, for example, by suitable sensors and / or robotics designed separately from the device 1.

[0050] Furthermore, at each test time, the processing unit checks whether a trigger condition 9 is met, the fulfillment of which depends on both the speed information 7 and the force information 8. If the trigger condition 9 is met, in this example, a warning device 10 (in this example, a monitor) is activated to display a message 11 to a user of the device 1, and the actuator 12 moving the medical tool 2 is activated to stop the advance of the medical tool 2, since in this case it is assumed that a vessel wall of the vascular system 3 has been punctured by the end of the tool 2 furthest from the actuator 12.

[0051] Further details of device 1 are described below with additional reference to the one in Fig. The flowchart shown in section 2 is explained.

[0052] In step S1, the tool 2 was first introduced into the vascular system 3. In step S2, an initial assignment rule 13 is also specified, which assigns an expected value 14 for the force acting on the medical tool 2 to each of the different values ​​of the velocity information. In addition, an initial relationship 20 between the permissible deviation value 15 and the velocity information 7 is specified.

[0053] An example of such an allocation rule 13 and of the resulting deviation values ​​15 for various pieces of information provided as a courtesy 7 is in Fig. 1 is shown in the right-hand diagram. The initial assignment rule 13 and the initial relationship 20 can be based on empirical data or the monitoring of previous procedures, whereby this information may be specific to a particular type of procedure and / or a specific person controlling the procedure. As will be explained later, the assignment rule 13 and the relationship 20 can be dynamically adjusted during the monitoring of the advancement of the medical instrument 2 in order to adapt the force-velocity profile specified by these parameters to the specific patient 4 and the specific procedure, for example, the section of the vascular system 3 used to advance the medical instrument 2.

[0054] In step S3, the velocity information 7 and the force information 8 are then determined for the respective test time 6. In the example, each point corresponds to the value shown in the left diagram. Fig. 1. Scatter plots shown represent a pair of values ​​for a respective test time. 6.

[0055] Speed ​​information can be directly obtained from control information for the actuator 12, which in the example is provided by the processing unit 5 itself; in the case of repetitions of the procedure, in particular the control information 36 provided in step S7 during the previous repetition.

[0056] To determine the force information 8, a fiber optic sensor is used in this example. The medical device 2 comprises at least one optical fiber 25 extending longitudinally along the device 2, which, in this example, includes several Bragg gratings in a measuring section 33. Light 29 is shone into the optical fiber 25 by a light source 28 of the device 1. Each of the Bragg gratings 27 reflects exclusively a light component 31 in a narrow frequency band, which is defined by the grating constant of the respective Bragg grating 27. The respective reflected light component 31 is deflected by the semi-transparent mirror 41 onto the sensor 30. If the light source 28 is operated in pulsed mode, for example, the different travel times of the light components 31 reflected by different Bragg gratings allow the determination of the light component 31 from which the Bragg grating 27 is currently receiving the reflection.By spectral analysis of the respective light component 31, the actual grating constant of the respective Bragg grating 27 can be deduced, which allows a deformation of the light-guiding fiber 25 in the area of ​​the respective Bragg grating 27 to be quantified, and, given known mechanical properties of the fiber 25 of the tool 2, a force input in the area of ​​the respective Bragg grating 27 can also be deduced.

[0057] As will be explained later with reference to step S8, the resulting sensor data 32 can also be used to obtain information about the current shape of the tool.

[0058] In step S3, only the reflection by the Bragg grating located at the front end or in the front section 21 of the medical instrument 2 is initially considered. A deformation of this Bragg grating 27, and thus a shift in the frequency of the light component 32 reflected by this Bragg grating 27, is determined, at least approximately, by a force component 23 of the force acting on the front section 21 in a longitudinal direction of the medical instrument 2, i.e., in particular by the force component that opposes a forward movement of the medical instrument 2. This Bragg grating 27 thus acts as a sensor component 22, by means of which the desired force information 8 can be determined.

[0059] In step S4, based on the velocity information 7 determined in step S3, an expected value 14 for the magnitude of the force component 23 is determined on the one hand using the assignment rule 13 and on the other hand a deviation value 15 is determined using the relationship 20.

[0060] In step S5, it is then checked whether the amount of force acting on the medical tool, described by the force information 8, exceeds or falls short of the expected value 14 by a predetermined deviation value 15, i.e., whether it deviates sufficiently from a value expected for a feed within the vascular system 3.

[0061] If this is the case, it indicates, as already explained in the general part of the description, that the front end of the medical instrument 2 is threatening to perforate, or has already perforated, a vessel wall of the vascular system 3. Therefore, in this case, control information 35 is provided to the actuator 12 in step S6, which stops the advance of the medical instrument 2. In addition, the warning device 10 is activated to issue a warning 11, enabling a user to react promptly to the potential vessel wall injury. For example, a user can withdraw the instrument 2 and cauterize the perforation.

[0062] If, however, the trigger condition 9 is not met, the feed of the medical instrument 2 can be continued by outputting the control information 36 to the actuator 12. Since it is assumed in this case that the feed occurred within the vascular system at test time 6, the determined force information 8 can be temporarily stored as a reference force value 19 and the determined velocity information 7 as a reference velocity value 18 of a reference value pair 17. As soon as a sufficient number of reference value pairs 17 are available, an updated assignment rule 13 and an updated relationship 20 between the deviation value 15 and the velocity information 7 can be determined based on reference value pairs 17, in particular after each test time 6 or after a predetermined number of test times 6.

[0063] For example, each of the items in the left diagram can be in Fig. The points shown correspond to such a reference value pair 17. For the scatter plot shown, a fit to a predefined function or a binning of the reference value pairs can then be performed to determine means, as already explained in detail in the general part of the description, in order to determine the updated assignment rule 13. The updated relationship 20 can be determined, as also already explained in the general part, by the fit error or the standard error of the regression or a standard deviation in the binning.

[0064] Optionally, for each test time 6 or, for example, after a predetermined number of test times 6 in step S8, a form of the medical tool 2 can be determined in a manner known per se, for example, to superimpose a synthetic representation of the medical tool 2 on the display device 10 with a previously acquired image of the vascular system 3 or of the patient 4.

[0065] Since local curvatures in different directions and with different strengths are to be detected and quantified, it is advantageous if the medical tool 2 comprises at least three of the light-conducting fibers 25, as exemplified in Fig. As shown in Figure 3, the fibers 25 are arranged in several measuring planes 34 within the measuring section 33, each spaced apart perpendicular to the longitudinal direction of the fibers 25. As already explained in the general section, a curvature of the medical instrument 2 in the region of such a measuring plane 34 causes the different translucent fibers 25 to be compressed or stretched to varying degrees. If a Bragg grating 27 is located in each fiber in the region of the measuring plane 34, the varying degrees of compression or stretching can be quantified, allowing conclusions to be drawn about the shape of the medical instrument 2 if its mechanical properties are known.

[0066] In the Fig.In the example shown, the processing device 5 is implemented by a freely programmable data processing device 37, for example by a workstation or a server, whose processor 38 executes a computer program 40 implementing the processing steps described. The computer program 40 is stored on a data carrier 39.

Claims

[1] Device for monitoring and / or controlling the advance of a medical instrument (2) through a vascular system (3) of a patient (4), wherein a processing unit (5) of the device (1) is configured to perform at least one test time (6) each - to capture or receive from an external source velocity information (7) relating to the speed of the advancement of the medical instrument (2), - to detect or receive force information (8) relating to a force acting on the medical device (2) from the device or another external source, - to evaluate a trigger condition (9) whose fulfillment depends on both the velocity information (7) and the force information (8), and - upon fulfillment of the trigger condition (9) to, on the one hand, control a warning device (10) to issue a warning (11) to a user of the device (1) and / or, on the other hand, to control an actuator (12) moving the medical tool (2) to stop the advance of the medical tool (2). [2] Device according to claim 1, characterized by , that the processing device (5) is configured to determine an expected value (14) for the force acting on the medical tool (2) from the speed specified by the speed information (7) by means of a specified allocation rule (13), wherein the trigger condition (9) is met if an amount of the force acting on the medical tool described by the force information (8) falls below the expected value (14) by a specified deviation value (15). [3] Device according to claim 1 or 2, characterized by, that the processing device (5) is configured to determine, from the velocity specified by the velocity information (7) by means of the or a specified allocation rule (13), the expected value (14) for the force acting on the medical tool (2), wherein the trigger condition (9) is met if an amount of the force acting on the medical tool (2) described by the force information (8) exceeds the expected value (14) by the or a specified deviation value (15). [4] Device according to claim 2 or 3, characterized by, that the processing device (5) is configured to detect or receive from the or the further external source a respective reference value pair (17) consisting of a reference velocity value (18) relating to a velocity of the feed of the medical tool (2) at the respective reference time (16) and a reference force value (19) relating to a force acting on the medical tool (2) at the respective reference time (16) at several reference times (16) before the test time (6) or at least one of the test times (6), and to determine the specified assignment rule (13) and / or the specified deviation value (15) or a specified relationship (20) between the specified deviation value (15) and the velocity information (7) depending on these reference value pairs (17). [5] Device according to claim 4, characterized by, that the processing device (5) is configured to always use the force information (8) determined for that test time (6) as the reference force value (19) of the reference value pair (17) for the reference time (16) corresponding to the test time (6), or when an additional condition is met, either as the reference force value (19) of the reference value pair (17) for the test time (6) and the velocity information (7) as the reference velocity value (18) of this reference value pair (17). [6] Device according to one of the preceding claims, characterized by, that the device (1) comprises the medical tool (2), wherein the medical tool (2) has in a front section (21) of the medical tool (2), which is configured to be arranged within the vascular system (3) during the advancement of the medical tool (2) through the vascular system (3), at least one sensor component (22) by means of which a force component (23) of the force acting on the front section (21) in a longitudinal direction of the medical tool (2), which extends along the vessel (24) within which the front section (21) is arranged during the advancement of the medical tool (2) in the vascular system (3), is to be detected as the force information (7) or as part of the force information (7). [7] Device according to claim 6, characterized bythat the medical tool (2) is or comprises at least one optical fiber (25) extending from the front section (21) to a rear section (26) of the medical tool (2), which is configured to be located outside the patient (4) during the advancement of the medical tool (2) through the vascular system (3), wherein the sensor component (22) is formed by at least one Bragg grating (27) configured as part of the optical fiber (25), wherein a light source (28) of the device (1) is configured to irradiate light (29) into the respective optical fiber (25), and wherein a sensor device (30) of the device (1) is configured to detect a light component (31) of this light (29) reflected by the respective Bragg grating (27) and to provide sensor data (32) relating to this light component (31) to the processing device (5).wherein the processing unit (5) is configured to determine the force information (7) depending on these sensor data (32). [8] Device according to claim 7, characterized by , the respective light-conducting fiber (25) in a measuring section (33) which extends from the front section (21) of the medical instrument (2) over at least 20% or at least 50% of the length of the medical instrument (2) between the front and rear sections (21, 26) is formed continuously or in several spaced-apart subsections as a Bragg grating (27). [9] Device according to claim 8, characterized by, that the medical tool (2) comprises at least three of the light-conducting fibers (25) which are arranged at least in several measuring planes (34) within the measuring section (33) perpendicular to the longitudinal direction of at least one of the fibers (25), wherein the processing device (5) is configured to determine, depending on the sensor data (32), a local curvature of the medical tool (2) in the area of ​​the respective measuring plane (34) and thus shape information relating to the shape of the medical tool (2). [10] Device according to any one of the preceding claims, characterized by , that the processing equipment (5) is set up to periodically check the fulfillment of the triggering condition (9) at test times (6) that are spaced less than 50 ms or less than 10 ms apart. [11] Computer-implemented method for monitoring the advancement of a medical instrument (2) within a vascular system (3) of a patient (4), comprising the steps performed at at least one testing time point (6): - Receiving or determining speed information relating to the speed of the advance of the medical instrument (2) (7), - Receiving or determining force information (8) relating to a force acting on the medical instrument (2), - Evaluating a trigger condition (9) whose fulfillment depends on both the velocity information (7) and the force information (8), and - Controlling a notification device (10) to issue a notification (11) to a user when the trigger condition (6) is met, and / or - Determination of control information (35, 36) for an actuator (12) used to move the medical tool (2) depending on whether the trigger condition (9) is met, wherein the control information (35) determined when the trigger condition (9) is met relates to stopping the feed of the medical tool (2). [12] Computer program with instructions configured to perform the computer-implemented method according to claim 11 and / or to implement the processing unit (5) of the device (1) according to any one of claims 1 to 10 when executed on a data processing device (37). [13] Data storage devices, characterized by that it comprises the computer program (40) according to claim 12.

Images