JP5392770B2 - Needle-like surgical instrument insertion support device - Google Patents

Description

  The present invention relates to a needle-like surgical instrument for inserting a needle-like surgical instrument into an organ deep in a patient for biopsy, liquid injection, or ablation while observing with an ultrasonic image or a magnetic resonance image during surgery. The present invention relates to an insertion support apparatus.

  Medical practice using a puncture needle is various, such as a biopsy taking a sample of a lesion, an injection that directly administers a drug solution to the lesion, and an ablation where the tissue is cauterized by radio waves. Since damage to normal tissue by puncture is limited to the puncture route, it is a very minimally invasive surgical treatment diagnostic act. In particular, when reaching a lesion of an organ in the deep part of a patient, the insertion path and the periphery of the lesion are observed with an ultrasonic image or a magnetic resonance image, and the patient is inserted while confirming safety.

  However, as described in Non-Patent Document 1 below, many difficulties are involved in accurately reaching a lesion in an organ deep in a patient. One of the difficulties is the deformation of organs and needle-like surgical instruments. In other words, the cutting force and frictional force generated when inserting a needle-like surgical instrument deforms the organ and the needle-like surgical instrument, which causes the target to deviate significantly from the insertion path and reach the target. There are cases where it is not possible.

Apart from this, as disclosed in Patent Document 1 below, various methods for predicting the deformation of an organ have been developed for a surgical simulation for simulating a surgical operation. Among them, deformation prediction by the finite element method is the most common. The finite element method is easy to solve a continuous field when predicting a state quantity when a specific boundary condition is applied to a continuous field expressed by a specific governing equation and having a specific region. This is a method of discretizing into a finite number of elements and performing a numerical approximation.
In organ deformation prediction, the shape of each organ is numerically expressed from tomographic images such as MRI and X-ray CT, and is divided into elements of an appropriate size. Then, an elastodynamic equation such as Hooke's law is selected, and an appropriate elastodynamic value is selected for each element. Then, boundary conditions such as displacement restraint, frictional force, and cutting force are set. The amount of deformation satisfying these equations and the boundary conditions is obtained numerically by solving linear equations and nonlinear equations.
However, since the elastodynamic values of organs and lesions differ from patient to patient, accurate organ deformation prediction is difficult, and therefore, even if used for surgical simulation, it cannot be applied to actual treatment.

On the other hand, in order to discover lesions due to differences in elasticity, many elastography methods have been developed that non-invasively measure the distribution of elastic mechanical values such as elastic modulus and strain.
For example, as seen in Patent Documents 2 and 3 below, in ultrasonic elastography, mechanical vibration is applied while changing the phase little by little in synchronization with the ultrasonic vibration, and each organ is changed according to the phase at this time. Visualize the distribution of elastodynamic values such as the elastic modulus of the organ from the displacement generated in the region.

  Further, in Patent Documents 4 and 5 below, in the magnetic resonance elastography, similarly, mechanical vibration is applied while changing the phase little by little in synchronization with the MRI imaging. It has been proposed to visualize the distribution of elastic mechanical values such as the elastic modulus of an organ from the displacement that occurs.

JP 2008-134373 A JP-A-11-216139 JP 2004-057653 A JP 2005-507691 A Japanese translation of PCT publication No. 2002-543952

Abolhasani, et. al. , "Needle insertion into soft tissue: A survey", Medical Engineering & Physics 29 (2007), 413-431.

  However, none of the prior art documents proposes to use elastomechanical numerical values of different organs in real time for insertion of an actual needle-like surgical instrument. Accordingly, an object of the present invention is to accurately perform organ deformation prediction based on patient-specific elastic mechanical values while observing with tomographic images such as ultrasonic images and magnetic resonance images during insertion, The aim is to allow the instrument to be inserted safely and accurately into organs deep within the patient.

In order to achieve this object, the insertion support device for a needle-like surgical instrument according to the present invention employs the following technical means.
That is,
(1) Based on the tomographic image of the organ imaged by the tomographic imaging apparatus, the numerical value information of the shape of the organ and the shape of the inserted needle-like surgical instrument, and the numerical value of the position shape for calculating the numerical information of the position of both Elastic means for calculating the elastic force distribution of the organ by analyzing the vibration of the organ by the calculating means, the vibrating means for giving minute vibrations to the organ, and the elastography by the tomographic imaging apparatus About each of the numerical information calculated by the distribution calculating means, the position shape numerical information calculating means, the elastic mechanical numerical distribution of the organ obtained by the elastic mechanical numerical distribution calculating means, and the acicular surgical instrument Based on pre-input elastodynamic values, numerically predict elastodynamic deformation of the organ and the acicular surgical instrument due to insertion of the acicular surgical instrument An elastic mechanical deformation predicting means, based on the prediction result by the elastic mechanical deformation estimating means, was and a support information presenting means for presenting the support information at the time of piercing the needle-like surgical instrument.

(2) In the insertion support device for a needle-like surgical instrument according to (1), the support information is control information for a puncture manipulator that operates the needle-like surgical instrument.

(3) In the insertion support device for a needle-like surgical instrument according to (1) and (2) above, the support information is displayed on a display.

(4) In the insertion support device for a needle-like surgical instrument according to the above (1) to (3), the support information is displayed by voice.

(5) In the insertion support device for a needle-like surgical instrument according to the above (1) to (4), the support information is force-presented.

(6) In the insertion support device for a needle-like surgical instrument according to (1) to (5) above, the elastography is arranged at the base of the needle-like surgical instrument, which is in contact with the patient's skin at the time of insertion. The patient's internal organs were vibrated with the vibration element provided.

(7) In the insertion support device for a needle-like surgical instrument according to the above (1) to (5), the elastography is performed by vibrating the patient's internal organs with a vibration element disposed inside the tomographic imaging apparatus. I made it.

(8) In the insertion support device for a needle-like surgical instrument according to (1) to (5), the elastography is performed by vibrating a patient's internal organs with a vibration element arranged in the needle-like surgical instrument. I made it.

  According to the present invention, based on the shape of the organ, the position of the inserted needle-like surgical instrument, shape information, and the elastic mechanical numerical distribution of the organ calculated by elastography, the organ to be diagnosed and treated as a needle It is possible to predict the elastic mechanical deformation of the surgical instrument numerically, present support information when inserting the needle-like surgical instrument, and use it as control information for the puncture manipulator. It becomes possible to puncture the organ deep in the area safely and accurately.

An embodiment in which an injection needle is inserted by a puncture manipulator while observing a tumor in a liver of a patient placed on a bed in a magnetic resonance imaging apparatus with a magnetic resonance image. The block diagram at the time of using the insertion assistance apparatus concerning the Example of this invention is shown.

  Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a state where an injection needle 8 is inserted into a tumor 5 in a liver 4 of a patient 3 lying on a bed 2 in a magnetic resonance imaging apparatus 1 with a puncture manipulator 9. The injection needle 8 punctures the liver 4 through the surrounding tissue 6. In addition to the tumor 5, there is an important tissue 7 such as a large blood vessel around the puncture route.
In the embodiment shown in FIG. 1, the needle insertion target of the needle-like surgical instrument is the tumor 5, and the target of insertion is the liver 4, the tumor 5, and the surrounding tissue 6. The imaging device 1 is used as a needle-like surgical instrument, and an injection needle 8 for injecting a drug solution into the tumor 5 is used. The insertion is performed by the puncture manipulator 9. The puncture manipulator 9 is precisely controlled based on the control information. A vibration element 10 is disposed at a proximal end portion that comes into contact with the abdomen of the patient 3 so that vibration is applied to the abdomen of the patient before and during the operation.

  Although not shown, in the embodiment, a computer comprising a computer having a position shape numerical value calculation means, an elastic mechanical numerical distribution calculation means, a boundary condition input means, a deformation prediction means, a puncture plan determination means, and support information are presented. A support information presentation device including a display or the like is provided.

  FIG. 2 shows a block diagram when the insertion support device of the embodiment is used. An organ deformation prediction means using elastography, which is a feature of the present invention, will be described.

  The tomographic image obtained before or during the operation is taken into a computer, and numerical information on the position and shape of the liver 4 and tumor 5, the surrounding tissue 6 and the injection needle 8 is calculated by known position shape numerical information calculation means. . Further, the liver 4, the surrounding tissue, and the injection needle 8 are discretized into a finite number of elements by a known means.

  In this embodiment, a mechanical vibration is applied to the liver 4, tumor 5, and surrounding tissue 6 by the vibration element 10, and at the same time, a tomographic image is taken by the magnetic resonance imaging apparatus 1, and an elastic mechanical numerical distribution is used by using known elastography. Can be calculated.

  Further, boundary conditions such as restraint of the patient 3 by the bed 2 and cutting force or frictional force generated between the liver 4 or the surrounding tissue 6 and the injection needle 8 are input. If puncturing is in progress, a difference from a preoperative tomographic image or a state obtained using a known technique such as a force sensor attached to the puncture manipulator 9 or the like can be added as a boundary condition.

  A well-known finite element method is used for deformation prediction. The finite element method requires a governing equation, positional shape information of elements that are discretized into a finite number, elastic mechanical values, and boundary conditions. The governing equation is an equation that describes the relationship between strain and stress. Here, Hooke's law and Mooney-Rivlin equation suitable for predicting large deformation are used. Numerical information on the position and shape of the liver 4 and tumor 5, the surrounding tissue 6 and the injection needle 8 calculated by the above-described position shape numerical information calculation means, elastic mechanical numerical values analyzed using the above elastography, and the above input Boundary conditions are used respectively. For unknown numerical conditions, statistical numerical values are used or estimated from known numerical conditions, but the method is not specified here.

  The insertion position and direction of the injection needle 8, the insertion and the insertion speed are appropriately selected and set as initial conditions. Then, the strain and stress of each element satisfying the boundary condition and the governing equation are obtained using a well-known solution of a linear equation or a nonlinear equation. By repeatedly calculating the boundary conditions when the injection needle 8 is gradually inserted, deformation of the injection needle 8, the liver 4, the tumor 5, and the surrounding tissue 6 at this time is predicted.

  The optimal insertion plan is found by repeating the deformation prediction while changing the initial conditions such as the insertion position and direction of the injection needle 8, the insertion, and the insertion speed. The optimum plan is that the target position can be reached accurately and that the injection needle 8 does not interfere with the important tissue 7 such as a large blood vessel.

  Support information is determined and presented based on the determined puncture plan. The support information includes the insertion position and direction, the insertion, the insertion speed, and the like. These pieces of support information are converted into control information for the puncture manipulator 9, and puncture is executed. When the puncture manipulator 9 or the injection needle 8 has a function of actively changing the insertion direction of the injection needle 8, support information can be used as the control information.

  The puncture manipulator 9 performs puncture based on the control information.

  During the puncture, a magnetic resonance image is taken, and the appearance of the injection needle 8, the liver 4, the tumor 5, and the surrounding organ 6 are observed, and it is predicted whether the injection needle 8 has reached the tumor 5 or does not interfere with the important organ 7. Make sure that you are not significantly off the route.

  When the penetration goal is reached, the puncture is terminated and the necessary treatment or diagnosis is performed.

  If the insertion path of the injection needle 8 or the difference between the insertion and the prediction is less than a predetermined value, the insertion is continued according to the established insertion plan. If it is above a predetermined value or if it is likely to interfere with the vital organ 7, puncture is stopped or replanned. At this time, the numerical information of the position and shape of the injection needle 8, the liver 4 and the tumor 5, and the surrounding tissue 6 is calculated by the position shape numerical information calculation means described above, and the elastic mechanics of the liver 4, the tumor 5 and the peripheral tissue 6 by elastography Based on the numerical value distribution calculation and deformation prediction, the insertion plan is formulated again, and the above-described flow is repeated.

  In the above embodiment, the case where the magnetic resonance imaging apparatus 1 is used as a means for capturing a tomographic image has been described. However, the present invention is also effective when an ultrasonic imaging apparatus is used.

  In the above-described embodiment, the case where the puncture manipulator 9 is used as a means for inserting the injection needle 8 has been described, but it is also effective in the case of manual puncture by a doctor. In that case, for example, the insertion position and direction of the injection needle 8 based on the established insertion plan, and the puncture input to be given are presented to the doctor as support information on the display, voice, and force sense presentation device, and then inserted again. When it is necessary to formulate an insertion plan, a warning is issued and a minute operation of the injection needle for re-establishing the insertion plan is urged.

  Further, in the above-described embodiment, the vibration element 10 is provided at the proximal end portion of the injection needle 8 for performing elastography. Even if it is arranged, vibration may be efficiently transmitted to the deep part of the liver 4 by arranging it on the injection needle 8.

  The present invention improves the accuracy and safety of the insertion position when performing a biopsy in which a sample of a lesion is taken from an organ deep in the patient, injection of a drug solution into the lesion, irradiation with a needle-like surgical instrument, heating, or the like. It can be widely used as a device that greatly increases.

DESCRIPTION OF SYMBOLS 1 Magnetic resonance imaging device 2 Bed 3 Patient 4 Organ 5 Tumor 6 Peripheral tissue 7 Important tissue 8 Injection needle 9 Puncture manipulator 10 Vibration element

Claims (8)

Position shape numerical information calculation means for calculating numerical information of the shape of the organ and the shape of the inserted needle-like surgical instrument based on the tomographic image of the organ imaged by the tomographic imaging apparatus, and numerical information of the position of both ,
Vibration means for applying minute vibrations to the organ;
By means of elastography by the tomographic imaging apparatus, the vibration of the organ by the vibration means is analyzed, and the elastic mechanical numerical distribution calculating means for calculating the elastic mechanical numerical distribution of the organ;
Each of the numerical information calculated by the position shape numerical information calculating means, the elastic mechanical numerical distribution of the organ obtained by the elastic mechanical numerical distribution calculating means, and elasticity inputted in advance for the acicular surgical instrument An elastic-mechanical deformation prediction means for numerically predicting an elastic-mechanical deformation of the organ and the acicular surgical instrument due to insertion of the acicular surgical instrument based on a mechanical numerical value;
An insertion support device for a needle-like surgical instrument comprising support information presenting means for presenting support information when inserting the needle-like surgical instrument based on a prediction result by the elastic mechanical deformation prediction means.   2. The insertion support device for a needle-like surgical instrument according to claim 1, wherein the support information is control information for a puncture manipulator that operates the needle-like surgical instrument.   The insertion support device for a needle-like surgical instrument according to claim 1 or 2, wherein the support information is displayed on a display.   The insertion support device for a needle-like surgical instrument according to claim 1, wherein the support information is displayed by voice.   The insertion support device for a needle-like surgical instrument according to claim 1, wherein the support information is hapticly presented.   6. The elastography is performed by vibrating a viscera of a patient with a vibration element disposed at a base of a needle-like surgical instrument that contacts the patient's skin at the time of insertion. Assist device for insertion of needle-like surgical instruments.   6. The insertion support device for a needle-like surgical instrument according to claim 1, wherein the elastography is performed by vibrating a patient's internal organs with a vibration element disposed inside the tomographic imaging apparatus.   6. The insertion support device for a needle-like surgical instrument according to claim 1, wherein the elastography is performed by vibrating a patient's internal organs with a vibration element arranged in the needle-like surgical instrument.