Method and system for determining the position of a needle tip

Abstract

To provide a method and a system for determining the position of a needle tip.SOLUTION: Providing an ultrasound head of an imaging ultrasound system, providing a transmission device having a plurality of ultrasound position transmitters and at least one fixing portion, the transmission device being releasably fixed to the ultrasound head in a defined relative position with respect to the ultrasound head by means of the fixing portion, ultrasound position signals being introduced by the plurality of ultrasound position transmitters, the ultrasound position signals being received by a sensor attached to a needle located in the body and arranged at a known axial distance from the needle tip, signal transit times being determined by an evaluation device connected to the sensor and to the transmission device, and the position being determined by the evaluation device depending on the signal transit times, the relative position of the transmission device with respect to the ultrasound head and the axial distance between the sensor and the needle tip.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method and system for determining the location of a needle tip inside the body. [Background technology]

[0002] Such methods and systems are used, inter alia, in the field of regional anesthesia. From the prior art, a system known as "OnVision" is configured to display the position of the needle tip in the image plane of an ultrasound image. The known system is fully integrated into a basic imaging ultrasound system. Summary of the Invention [Problem to be solved by the invention]

[0003] It is an object of the present invention to provide a method and system of the type mentioned at the beginning which exhibits advantages over the prior art. [Means for solving the problem]

[0004] This object is achieved by providing a method having the features of claim 1 and a medical system having the features of claim 8. Advantageous embodiments are specified in the dependent claims, the language of which is incorporated into the subject matter of this specification by reference.

[0005] A method according to the present invention includes the steps of providing an ultrasound head of an imaging ultrasound system, providing a transmitting device having a plurality of ultrasound position transmitters and at least one fixing portion, fixing the transmitting device to the ultrasound head, the transmitting device being releasably fixed to the ultrasound head by the fixing portion in a defined relative position with respect to the ultrasound head, introducing a plurality of ultrasound position signals into a body, the ultrasound position signals being coupled in by the plurality of ultrasound position transmitters, receiving the ultrasound position signals by a sensor attached to a needle in the body and positioned a known axial distance from the needle tip, determining a signal transit time of the ultrasound position signals, the signal transit time being determined by an evaluation device connected to the sensor and the transmitting device, and determining a position of the needle tip relative to the ultrasound head, the position being determined by the evaluation device according to the signal transit time, the relative position of the transmitting device to the ultrasound head, and the axial distance between the sensor and the needle tip. The method according to the present invention does not need to be incorporated into the imaging ultrasound system and therefore can be used generally in particular. Instead of being incorporated into the imaging ultrasound system in a software-based and / or hardware-based manner, the method according to the present invention involves releasably securing a transmitting device to an ultrasound head of the imaging ultrasound system. To secure the transmitting device to the ultrasound head, the transmitting device comprises at least one securing portion, which can be releasably secured to the ultrasound head by force-fitting and / or form-fitting. The securing is performed at a defined relative position with respect to the ultrasound head. An ultrasound location transmitter of the transmitting device is configured to introduce multiple ultrasound location signals into the body. These ultrasound location signals are received by sensors attached to a needle; in one embodiment of the present invention, the multiple sensors are attached to the needle.The position of the needle tip is actually determined by an evaluation device. The evaluation device is connected to at least one sensor and a transmitting device, for example, by a wired or wireless connection. To determine the position of the needle tip, the signal transit time of the ultrasonic location signal between each ultrasonic location transmitter and at least one sensor is first determined. Those skilled in the art are familiar with different techniques for determining the signal transit time, and therefore further details on this matter need not be explained in more detail. If the signal transit time is known, it is possible to determine the respective distance between each ultrasonic location transmitter and at least one sensor at the needle tip, in particular depending on the frequency and / or propagation speed of the ultrasonic location signal. The position of the needle tip is then determined depending on the determined signal transit time and / or distance, the relative position of the transmitting device with respect to the ultrasound head, and the axial distance between the at least one sensor and the needle tip. The at least one sensor is preferably positioned at the needle tip so that the axial distance is practically zero or is negligibly small with respect to the accuracy of the position determination. The position is determined based on a known geometric relationship, in particular a trigonometric relationship. In embodiments with multiple sensors, these are positioned at known axial distances from the needle tip. In this case, the orientation of the needle can also be determined. The orientation can be determined by the evaluation device based on known geometric relationships, in particular trigonometric relationships. In addition, multiple sensors allow for more accurate position determination. Furthermore, multiple sensors, which may be located further away from the needle tip, prevent the function of the needle tip from being impaired by the presence of sensors located as close as possible to the needle tip.

[0006] The method according to the invention is particularly suitable for use in local anesthesia.

[0007] In one embodiment, at least one first ultrasonic location signal is introduced by a first ultrasonic location transmitter and a second ultrasonic location signal is introduced by a second ultrasonic location transmitter. In this embodiment, the transmitting device therefore includes at least two ultrasonic location transmitters, namely a first ultrasonic location transmitter and a second ultrasonic location transmitter. This embodiment therefore enables the determination of a position with respect to two coordinate axes, i.e., in one plane. Such a planar location determination may already be sufficient for some use cases.

[0008] In a further embodiment, a third ultrasonic location signal is introduced by a third ultrasonic location transmitter. In this embodiment, the transmitting device thus includes at least three ultrasonic location transmitters: a first ultrasonic location transmitter, a second ultrasonic location transmitter, and a third ultrasonic location transmitter. This embodiment enables the location of the needle tip with respect to three coordinate axes. Such spatial location determination is more important than planar location determination. In a further embodiment, the transmitting device includes four or more ultrasonic location transmitters, for example, four, five, six, or more ultrasonic location transmitters. In this case, a corresponding number of ultrasonic location signals are introduced. This can enable even more accurate location determination.

[0009] In a further embodiment, the ultrasound location signal has a frequency different from the transmission frequency of the ultrasound head. The frequency of the ultrasound location signal is different from the transmission frequency of the ultrasound head to prevent the imaging ultrasound method from being impaired by the location determination. Such impairments may occur if the frequency of the ultrasound location signal and the transmission frequency of the ultrasound head are identical or very similar. In one embodiment, the ultrasound location signal is introduced / transmitted at the same frequency. In a further embodiment, the ultrasound location signal has a different frequency. In a further embodiment, the ultrasound location signal is introduced in time synchronization with the ultrasound signal of the ultrasound head, e.g., with a time offset. In one embodiment, the ultrasound location signal and the ultrasound signal of the imaging ultrasound method are introduced intermittently. For example, so-called frames may be identified based on the received ultrasound signal of the imaging ultrasound method, and the temporal transmission of the ultrasound location signal may be adapted and / or synchronized accordingly to avoid impairments in the imaging ultrasound method.

[0010] In a further embodiment, the fixing portion is latched to a complementary fixing portion of the ultrasound head. Alternatively or additionally, the fixing portion is plugged into the complementary fixing portion. In this embodiment, the transmitting device is thus fixed to the ultrasound head with a releasable latching connection and / or a releasable plug connection. In one embodiment, the fixing portion is a latching portion. In a further embodiment, the fixing portion is alternatively or additionally a plug portion. The same applies mutatis mutandis to the complementary fixing portion of the ultrasound head. It should be understood that the transmitting device may have multiple fixing portions. The ultrasound head may also have multiple complementary fixing portions. The complementary fixing portion of the ultrasound head is preferably formed by its outer contour. At least one fixing portion of the transmitting device is in this case adapted to the outer contour of the ultrasound head. This means that structural adjustments of the ultrasound head for fixing the transmitting device can be omitted.

[0011] In a further embodiment, the method includes the further step of outputting the position, the position being audibly and / or visually perceptibly output by an output device. In one embodiment, the output device has a speaker configured for audible output of the position. In a further embodiment, the output device alternatively or additionally has a screen configured for visually perceptible output of the position. For example, the position may be displayed graphically and / or in a text-based manner. In one embodiment, the output device is a component of an imaging ultrasound system, and the evaluation device is configured to connect to the output device of the imaging ultrasound system.

[0012] In a further embodiment, the ultrasound signal, particularly the ultrasound location signal, is not transmitted from the needle. The ultrasound signal or ultrasound location signal is only received by at least one sensor, particularly attached to the needle. In other words, the needle is passive or a passive medical product. In contrast to the fundamentally conceivable and conceivable introduction of ultrasound signals from the needle, this has advantages, particularly improved patient safety.

[0013] A medical system according to the present invention is configured to determine the position of a needle tip inside a body and includes a transmitting device, a needle, and an evaluation device. The medical system is preferably configured to implement the method according to the present invention and / or embodiments thereof. The transmitting device includes multiple ultrasound location transmitters and at least one fixing portion. The fixing portion is configured to be releasably fixed to a complementary fixing portion of an ultrasound head. The ultrasound head is a component of an imaging ultrasound system. The ultrasound head is not a component of the medical system. Each ultrasound location transmitter is configured to introduce an ultrasound location signal into the body. The needle includes a needle tip and at least one sensor. The sensor is configured to receive the ultrasound location signal. The sensor is positioned at a known axial distance from the needle tip. The axial distance is preferably zero or at least negligibly small with respect to position determination. That is, the sensor is preferably positioned directly at the needle tip. The evaluation device is connected to the sensor and the transmitting device. The connection may be wired and / or wireless. The evaluation device is configured to determine a signal transit time of the ultrasound location signal. The evaluation device is also configured to determine the position of the needle tip relative to the ultrasound head, the determination being made as a function of the signal transit time, the determined relative position of the transmitting device relative to the ultrasound head, and the axial distance of the sensor from the needle tip.

[0014] Further features and advantages of the medical system can be derived from the disclosure of the method according to the invention, and vice versa. The same applies to the respective embodiments of the medical system according to the invention and the method according to the invention.

[0015] In a further embodiment, the at least one fixing portion is a latch portion configured to latch onto the outer contour of the ultrasound head. Alternatively or additionally, the at least one fixing portion is a plug portion configured to plug into the outer contour of the ultrasound head. In this embodiment of the invention, the outer contour of the ultrasound head forms a complementary fixing portion for fixing the transmitting device. A structural adaptation of the ultrasound head to the medical system, in particular to its transmitting device, can therefore be omitted. This allows for a particularly universal use of the medical system.

[0016] In a further embodiment, the transmitting device comprises at least two ultrasonic position transmitters, which allows for the determination of the position of a plane with respect to two coordinate axes.

[0017] In a further embodiment, the transmitting device comprises at least three ultrasonic position transmitters, which allows spatial position determination about three coordinate axes.

[0018] In a further embodiment, the needle does not have a transmitting device for transmitting ultrasound signals, in particular ultrasound location signals. The needle is therefore configured exclusively to receive ultrasound signals, more particularly ultrasound location signals, and is equipped with at least one sensor for this purpose. The needle is therefore passive, or a passive medical product. In contrast to the fundamentally conceivable and conceivable introduction of ultrasound signals from the needle, this has advantages, in particular improved patient safety.

[0019] Further advantages and features of the invention emerge from the claims and from the following description of preferred exemplary embodiments of the invention as shown in the drawings. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic block diagram of one embodiment of a method according to the present invention for determining the position of a needle tip inside a body; [Figure 2]2 is a schematic diagram of an embodiment of a medical system according to the invention configured to perform the method according to FIG. 1; [Figure 3] 3 is a schematic simplified diagram of an exemplary use scenario of the medical system according to FIG. 2; [Figure 4] 4 is a diagram corresponding to FIG. 3 of a further exemplary use situation. DETAILED DESCRIPTION OF THE INVENTION

[0021] According to FIG. 1, a method 100 is provided for determining a position P of a needle tip 41 inside a body K (see FIGS. 3 and 4).

[0022] The method 100 can be implemented using the medical system 1 according to FIG. 2 and includes steps 110 to 170.

[0023] The medical system 1 comprises a transmitting device 2, a needle 4 and an evaluation device 5. In the illustrated embodiment, the medical system 1 also comprises an optional output device 6.

[0024] The transmitting device 2 includes a plurality of ultrasonic location transmitters 21, 22, and 23, which may also be referred to as a first ultrasonic location transmitter 21, a second ultrasonic location transmitter 22, and a third ultrasonic location transmitter 23. The transmitting device 2 also includes at least one fixed portion 24, 25. The ultrasonic location transmitters 21, 22, and 23 are configured to transmit ultrasonic location signals S1, S2, and S3, respectively. The ultrasonic location signals S1, S2, and S3 may also be referred to as a first ultrasonic location signal S1, a second ultrasonic location signal S2, and a third ultrasonic location signal S3. The at least one fixed portion 24, 25 is configured to be releasably fixed to a complementary fixed portion 31 of the ultrasound head 3. The ultrasound head 3 is not part of the medical system 1, but is a component of the imaging ultrasound system, as is commonly known in the medical arts.

[0025] The needle 4 includes a needle tip 41 and at least one sensor 42. The needle tip 41 is positioned distally in a conventional manner. The sensor 42 is positioned a known axial distance D from the needle tip 41. The axial distance D is small compared to the overall length of the needle 4. The axial distance D extends along the longitudinal axis L of the needle 4. In one embodiment, not shown, multiple sensors are attached to the needle, each located a known axial distance from the needle tip.

[0026] The evaluation device 5 is connected to the sensor 42 and the transmitting device 2. A signal connection 7, in this case a wired connection, is provided for connection to the sensor 42. A further signal connection 8, also wired, is provided for connection to the transmitting device 2. Alternatively, a wireless connection may be provided.

[0027] The method 100 begins at step 110 with providing an ultrasound head 3 .

[0028] In step 120, a transmitting device 2 is provided.

[0029] In step 130, the transmitting device 2 is fixed to the ultrasound head 3. In this case, the transmitting device 2 is releasably fixed to the ultrasound head 3 by at least one fixing part 24, 25. Fixing takes place here at the complementary fixing part 31.

[0030] The transmitting device 2 is fixed to the ultrasound head 3 at a defined relative position with respect to the ultrasound head 3. As a result, the positions of the ultrasound position transmitters 21, 22, 23 are known with respect to the ultrasound head 3. The above-mentioned positions of the ultrasound position transmitters 21, 22, 23 may for example be defined with respect to a central point M of the ultrasound head 3, which may also be called the center.

[0031] In the illustrated embodiment, the transmitting device 2 comprises a first fixed part 24 and a second fixed part 25. It should be understood that this number is merely an example.

[0032] The two fixing parts 24, 25 are each designed as a latching part R in the embodiment shown, which can be latched directly onto the outer contour A of the ultrasound head 3. The outer contour A of the ultrasound head 3 in this case therefore forms the above-mentioned complementary fixing part 31 for releasable fixing with the fixing parts 24, 25 of the transmitting device 2.

[0033] In an embodiment not shown in the figures, the fixing parts are each designed as a plug part.

[0034] The method 100 includes, at step 140, introducing ultrasound signals S1, S2, S3 into the body K.

[0035] In the illustrated exemplary use situation (see FIGS. 3 and 4), an ultrasound head 3, together with a transmitting device 2 attached thereto, is located above a body K. In the actual imaging ultrasound method of this case, an ultrasound signal B is introduced into the body K by the ultrasound head 3; this ultrasound signal in this case may also be called a beam. The term "beam" is familiar to those skilled in the art. The beam B is introduced into the body K along an imaging plane E of the imaging ultrasound method. The imaging plane E extends in this case along the depth and longitudinal directions.

[0036] In contrast to the ultrasound signal B of the ultrasound head 3, the ultrasound position signals S1, S2, S3 of the ultrasound position transmitters 21, 22, 23 are not used to determine the ultrasound image, but rather to determine the position of the needle tip 41.

[0037] In step 150, the method 100 involves receiving ultrasonic location signals S1, S2, S3. The ultrasonic location signals S1, S2, S3 are received by the sensor 42.

[0038] In step 160, method 100 determines signal transit times t1, t2, and t3 of ultrasonic location signals S1, S2, and S3. Signal transit times t1, t2, and t3 are graphically represented by arrows in FIG. 3 and may also be referred to as the first signal transit time t1, the second signal transit time t2, and the third signal transit time t3. The first signal transit time t1 is the transit time of the first ultrasonic location signal S1, i.e., the time elapsed between the transmission of the ultrasonic location signal S1 by the first ultrasonic location transmitter 21 and its reception by the sensor 42. The same applies mutatis mutandis to the second signal transit time t2 (the transit time of the second ultrasonic location signal S2) and the third signal transit time t3 (the transit time of the third ultrasonic location signal S3). The signal transit times t1, t2, and t3 are determined by evaluation device 5. For this purpose, the ultrasonic position signals S1, S2, S3 are evaluated in a manner known to those skilled in the art.

[0039] In step 170, the method 100 proceeds to determine the position P of the needle tip 41 relative to the ultrasound head 3, in particular relative to the center point M of the ultrasound head 3. The position P is here determined by the evaluation device 5 as a function of the signal transit times t1, t2, t3, which allow conclusions to be drawn regarding the respective distances between the ultrasonic position transmitters 21, 22, 23 and the sensor 42 when the propagation velocities of the ultrasonic position signals S1, S2, S3 are known. The position P is then determined as a function of the signal transit times t1, t2, t3 and on the basis of simple geometric, in particular trigonometric, relationships.

[0040] 4 shows a further use situation in which the needle 4 occupies a different position relative to the ultrasound head 3. The needle tip 41 therefore occupies a changed position P'. In addition, there are changed signal transit times t'1, t'2, t'3.

[0041] In this case, the position P (or modified position P') can be determined spatially and with respect to three coordinate axes relative to the center point M. If only two ultrasonic position transmitters are available, the position can be determined with respect to two coordinate axes, which is therefore sometimes referred to as planar position determination.

[0042] In the illustrated embodiment, the ultrasound location signals S1, S2, S3 are transmitted at a frequency that is different from the transmission frequency of the ultrasound head 3 and therefore different from the frequency of the ultrasound signal B. This prevents the ultrasound location signals S1, S2, S3 from interfering with the ultrasound imaging method.

[0043] In the illustrated embodiment, the method also results in outputting the position P by means of an output device 6. The output device 6 is configured for an audibly and / or visually perceptible output of the position P. To this end, the output device 6 may comprise, for example, a speaker (auditory output) or a screen (visual output). In one embodiment, the output device 6 is assigned to an imaging ultrasound system which also comprises an ultrasound head 3. In this case, the evaluation device 5 can be connected to the output device 6.

[0044] In this case, the evaluation device 5 also comprises a memory unit 51 and a processor unit 52. The processor unit 52 is configured to perform at least steps 160, 170. [Explanation of symbols]

[0045] 1. Healthcare system 2. Sending Device 3 ultrasonic heads 4 needles 5 Evaluation Device 6 Output Devices 7 Signal Connections 8 Signal Connections 21 Ultrasonic Position Transmitter 22 Ultrasonic Position Transmitter 23 Ultrasonic Position Transmitter 24 Fixed part 25 Fixed part 31 Complementary fixing portion 41 Needle tip 42 sensors 51 Memory Unit 52 processor unit

Claims

1. A method (100) for determining the position (P) of a needle tip (41) inside a body (K), comprising: Providing (110) an ultrasound head (3) of an imaging ultrasound system; providing (120) a transmitting device (2) including a plurality of ultrasonic location transmitters (21, 22, 23) and at least one fixed portion (24, 25); a step (130) of fixing the transmitting device (2) to the ultrasound head (3), wherein the transmitting device (2) is releasably fixed to the ultrasound head (3) in a defined relative position with respect to the ultrasound head (3) by the fixing parts (24, 25); a step (140) of introducing a plurality of ultrasonic location signals (S1, S2, S3) into said body (K), said ultrasonic location signals (S1, S2, S3) being introduced by said plurality of ultrasonic location transmitters (21, 22, 23); a step (150) of receiving the ultrasonic location signals (S1, S2, S3), wherein the ultrasonic location signals (S1, S2, S3) are received by at least one sensor (42) attached to a needle (4) located within the body (K) and positioned a known axial distance (D) from a tip (41) thereof; a step (160) of determining signal transit times (t1, t2, t3) of said ultrasonic position signals (S1, S2, S3), said signal transit times (t1, t2, t3) being determined by an evaluation device (5) connected to said sensor (42) and said transmitting device (2); a step (170) of determining the position (P) of the needle tip (41) relative to the ultrasound head (3), wherein the position (P) is determined by the evaluation device (5) depending on the signal transit times (t1, t2, t3), the relative position of the transmitting device (2) relative to the ultrasound head (3), and the axial distance (D) between the sensor (42) and the needle tip (41); A method (100) comprising:

2. 2. The method (100) of claim 1, wherein at least one first ultrasonic location signal (S1) is introduced by a first ultrasonic location transmitter (21) and a second ultrasonic location signal (S2) is introduced by a second ultrasonic location transmitter (22).

3. 3. The method (100) of claim 2, wherein the third ultrasonic location signal (S3) is introduced by a third ultrasonic location transmitter (23).

4. 4. The method (100) according to any one of claims 1 to 3, wherein the ultrasonic position signals (S1, S2, S3) have a frequency different from the transmission frequency of the ultrasonic head (3).

5. 5. The method (100) according to any one of claims 1 to 4, wherein the fixed parts (24, 25) are latched and / or plugged into complementary fixed parts (31) of the ultrasound head (3).

6. a step of outputting said position (P), wherein said position (P) is outputted so as to be audibly and / or visually perceptible by an output device (6); 6. The method (100) of any one of claims 1 to 5, further comprising:

7. 7. The method (100) according to any one of claims 1 to 6, wherein no ultrasound signal is transmitted from the needle (4).

8. A medical system (1) for determining the position (P) of a needle tip (41) inside a body (K), comprising: a transmitting device (2) having a plurality of ultrasonic position transmitters (21, 22, 23) and at least one fixed portion (24, 25), the fixed portions (24, 25) configured to be releasably fixed to complementary fixed portions (31) of an ultrasound head (3) of an imaging ultrasound system, the ultrasonic position transmitters (21, 22, 23) each configured to introduce an ultrasonic position signal (S1, S2, S3) into the body (K); a needle (4) having the needle tip (41) and at least one sensor (42), the at least one sensor (42) configured to receive the ultrasonic position signals (S1, S2, S3) and positioned at a known axial distance (D) from the needle tip (41); an evaluation device (5) connected to the sensor (42) and the transmitting device (2), the evaluation device (5) configured to determine signal transit times (t1, t2, t3) of the ultrasonic position signals (S1, S2, S3) and to determine the position (P) of the needle tip (41) relative to the ultrasound head (3), the determination being made depending on the signal transit times (t1, t2, t3), a defined relative position of the transmitting device (2) relative to the ultrasound head (3), and the axial distance (D) between the sensor (42) and the needle tip (41); A medical system (1) that includes:

9. 9. The medical system (1) according to claim 8, wherein the at least one fixing portion (24, 25) is a latch portion (R) configured to latch onto the outer contour (A) of the ultrasound head (3) or a plug portion configured to plug into the outer contour (A) of the ultrasound head (3).

10. 10. The medical system (1) according to claim 8 or 9, wherein the transmitting device (2) comprises at least two ultrasonic position transmitters (21, 22).

11. 11. The medical system (1) according to any one of claims 8 to 10, wherein the transmitting device (2) comprises at least three ultrasonic position transmitters (21, 22, 23).

12. 12. The medical system (1) according to any one of claims 8 to 11, wherein the needle (4) is devoid of a transmitting device for transmitting an ultrasound signal.

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