SIMULATED ORGAN

A simulated organ includes two simulated blood vessels intersecting with each other.

BACKGROUND

1. Technical Field

The present invention relates to a simulated organ.

2. Related Art

As a tool for practicing vascular injections, a structure in which a plurality of simulated blood vessels is arranged in parallel is known (JP-UM-A-6-4768).

In the related-art technique, since a plurality of simulated blood vessels is arranged in parallel, the arrangement of blood vessels in an actual living body cannot be reproduced.

SUMMARY

An advantage of some aspects of the invention is that simulated blood vessels can be arranged similarly to blood vessels in an actual living body.

The invention can be implemented in the following forms.

(1) An aspect of the invention provides a simulated organ. The simulated organ includes a first simulated blood vessel, and a second simulated blood vessel intersecting with the first simulated blood vessel. According to this configuration, the simulated blood vessels can be arranged more similarly to blood vessels in an actual living body. This is because, in an actual living body, blood vessels may intersect with each other.

(2) In the aspect of the invention, the simulated organ may further include a third simulated blood vessel intersecting with the first simulated blood vessel. According to this configuration, a site having intersections at a plurality of positions can be reproduced.

(3) In the aspect of the invention, a distance between the second simulated blood vessel and the third simulated blood vessel may be 3 mm or shorter. According to this configuration, a site which is dense with blood vessels can be reproduced.

(4) In the aspect of the invention, the second simulated blood vessel may be arranged at a deeper position than the first simulated blood vessel, at a site intersecting with the first simulated blood vessel, and the third simulated blood vessel may be arranged at a shallower position than the first simulated blood vessel, at a site intersecting with the first simulated blood vessel. According to this configuration, a site with complex intersections can be reproduced.

(5) In the aspect of the invention, a site intersecting with the first simulated blood vessel, of the second simulated blood vessel, may be arranged at a deeper position than a site intersecting with the first simulated blood vessel, of the third simulated blood vessel. According to this configuration, a site with complex intersections can be reproduced.

(6) In the aspect of the invention, a color appearing in the second simulated blood vessel when damaged may be different from a color appearing in the third simulated blood vessel when damaged. According to this configuration, it is easier to find out which of the second simulated blood vessel and the third simulated blood vessel is damaged. The color appearing in the second simulated blood vessel when not damaged may be the same as or different from the color appearing in the third simulated blood vessel when not damaged.

(7) In the aspect of the invention, a site intersecting with the second simulated blood vessel, of the first simulated blood vessel, may be arranged at a shallower position than a site intersecting with the third simulated blood vessel. According to this configuration, a site where the first simulated blood vessel changes in the direction of depth can be reproduced.

(8) In the aspect of the invention, the first simulated blood vessel may be in different colors between a site arranged at a shallower position than the second simulated blood vessel and a site arranged at a deeper position than the third simulated blood vessel. According to this configuration, at what depth the site of the first simulated blood vessel is can be found more easily.

(9) In the aspect of the invention, a color of a site situated between a site intersecting with the second simulated blood vessel and a site intersecting with the third simulated blood vessel, of the first simulated blood vessel, may be different from a color of the site intersecting with the second simulated blood vessel and different from a color of the site intersecting with the third simulated blood vessel. According to this configuration, the site situated between the site intersecting with the second simulated blood vessel and the site intersecting with the third simulated blood vessel can be discriminated more easily from the site intersecting with the second simulated blood vessel and the site intersecting with the third simulated blood vessel.

(10) In the aspect of the invention, the first simulated blood vessel may be in a different color from a color of the second simulated blood vessel. According to this configuration, the first simulated blood vessel and the second simulated blood vessel can be discriminated from each other more easily.

(11) In the aspect of the invention, the simulated organ may further include a simulated tissue filling peripheries of the first and second simulated blood vessels. The simulated tissue may be in different colors between a first site situated below the second simulated blood vessel and a second site different from the first site. According to this configuration, whether the first site has been successfully excised or not can be found more easily.

(12) In the aspect of the invention, the first site may be a site situated below a site where the first simulated blood vessel and the second simulated blood vessel intersect with each other. According to this configuration, a site that is difficult to excise can be set as the first site.

(13) In the aspect of the invention, a color of the first site maybe different from a color of the first simulated blood vessel and different from a color of the second simulated blood vessel. According to this configuration, the first site can be discriminated more easily from the first and second simulated blood vessels.

(14) In the aspect of the invention, the simulated tissue may be excised by a liquid provided with an excision capability.

The invention can also be implemented in various other forms. For example, the invention can be implemented as a method for preparing a simulated organ.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 1schematically shows the configuration of a liquid ejection device20. The liquid ejection device20is a medical device used in a medical institution and has the function of excising an affected part by ejecting a liquid to the affected part.

The liquid ejection device20has a control unit30, an actuator cable31, a pump cable32, a foot switch35, a suction device40, a suction tube41, a liquid supply device50, and a handpiece100.

The liquid supply device50has a water supply bag51, a spike52, first to fifth connectors53ato53e,first to fourth water supply tubes54ato54d,a pump tube55, a blocking detection mechanism56, and a filter57. The handpiece100has a nozzle unit200and an actuator unit300. The nozzle unit200has an ejection tube205and a suction tube400.

The water supply bag51is made of a transparent synthetic resin and its inside is filled with a liquid (specifically, physiological saline solution). In this description, this bag is called the water supply bag51even if it is filled with a liquid other than water. The spike52is connected to the first water supply tube54avia the first connector53a.As the spike52stings the water supply bag51, the liquid filling the water supply bag51becomes available to be supplied to the first water supply tube54a.

The first water supply tube54ais connected to the pump tube55via the second connector53b.The pump tube55is connected to the second water supply tube54bvia the third connector53c.A tube pump60has the pump tube55inserted therein. The tube pump60feeds the liquid inside the pump tube55from the side of the first water supply tube54atoward the second water supply tube54b.

The blocking detection mechanism56measures the pressure inside the second water supply tube54band thereby detects blocking inside the first to fourth water supply tubes54ato54d.

The second water supply tube54bis connected to the third water supply tube54cvia the fourth connector53d.To the third water supply tube54c,the filter57is connected. The filter57collects foreign matters contained in the liquid.

The third water supply tube54cis connected to the fourth water supply tube54dvia the fifth connector53e.The fourth water supply tube54dis connected to the nozzle unit200. The liquid supplied through the fourth water supply tube54dis intermittently ejected from the tip of the ejection tube205by the driving of the actuator unit300. As the liquid is thus ejected intermittently, an excision capability can be secured with a low flow rate.

The ejection tube205and the suction tube400form a double-tube structure with the ejection tube205being the inner tube and the suction tube400being the outer tube. The suction tube41is connected to the nozzle unit200. The suction device40sucks the content inside the suction tube400through the suction tube41. By this suction, the liquid and excised piece or the like near the tip of the suction tube400are sucked.

The control unit30controls the tube pump60and the actuator unit300. Specifically, the control unit30transmits drive signals via the actuator cable31and the pump cable32while the foot switch35is pressed down with a foot. The drive signal transmitted via the actuator cable31drives a piezoelectric element (not illustrated) included in the actuator unit300. The drive signal transmitted via the pump cable32drives the tube pump60. Therefore, while the user keeps his or her foot down on the foot switch35, the liquid is intermittently ejected. When the user does not keep his or her foot down on the foot switch35, the ejection of the liquid stops.

A simulated organ will be described hereafter. A simulated organ is also called a phantom. In this embodiment, a simulated organ is an artificial object whose part is to be excised by the liquid ejection device20. The simulated organ in this embodiment is used in a surgical simulation for the purpose of performance evaluation of the liquid ejection device20, practice of operation of the liquid ejection device20, and the like.

FIGS. 2 and 3show a simulated organ600.FIG. 2is a top view.FIG. 3is a cross-sectional view. The cross section shown inFIG. 3is taken along3-3inFIG. 2. In this embodiment, the horizontal plane is defined as an X-Y plane, and the vertical direction (direction of depth) is defined as a Z-direction.

The simulated organ600includes a first simulated blood vessel611, a second simulated blood vessel612, a third simulated blood vessel613, a simulated tissue620, and a support member630. The first simulated blood vessel611, the second simulated blood vessel612and the third simulated blood vessel613may be collectively called simulated blood vessels610.

The simulated blood vessels610are artificial objects simulating blood vessels in a living body (for example, human cerebral blood vessels). In this embodiment, simulated blood vessels610are formed as solid members. The simulated blood vessels610are members that should avoid damage in a surgical simulation.

The simulated tissue620is an artificial object simulating peripheral tissues around blood vessels in a living body (for example, brain tissues) and fills the peripheries of the simulated blood vessels610. The simulated tissue620includes a simulated tumor621. InFIG. 2, the simulated tissue620is illustrated as a transparent member in order to illustrate the simulated blood vessels610. However, the actual simulated tissue620is not transparent. The support member630is a metallic container which supports the simulated blood vessels610and the simulated tissue620.

The liquid ejected intermittently from the ejection tube205gradually excises the simulated tissue620. As the excision proceeds, the simulated blood vessels610become exposed. The exposed simulated blood vessels610may be subjected to the liquid ejection in some cases. The simulated blood vessels610become damaged when subjected to an ejection under conditions exceeding their strength.

As shown inFIGS. 2 and 3, the first simulated blood vessel611is arranged in such a way as to intersect with each of the second simulated blood vessel612and the third simulated blood vessel613. The intersection in this embodiment refers to grade-separated intersection as a general expression and refers to a skew position as a mathematical expression. Specifically, the first simulated blood vessel611intersects with each of the second simulated blood vessel612and the third simulated blood vessel613when projected on the X-Y plane, and is shifted in the Z-direction from the second simulated blood vessel612and the third simulated blood vessel613at the points of intersection.

The first simulated blood vessel611, the second simulated blood vessel612and the third simulated blood vessel613extend horizontally straight. The second simulated blood vessel612and the third simulated blood vessel613are arranged at deeper positions than the first simulated blood vessel611. Therefore, the second simulated blood vessel612and the third simulated blood vessel613are arranged at deeper positions than the first simulated blood vessel611at the sites intersecting with the first simulated blood vessel611.

The angle θ2shown inFIG. 2is an angle that satisfies the condition of 0 degrees<θ2≦90 degrees, of the angles formed by the first simulated blood vessel611and the second simulated blood vessel612in the X-Y plane. The angle θ2is, for example, 10 degrees≦θ2≦90 degrees. In this embodiment, the angle θ2is 90 degrees.

The angle θ3shown inFIG. 2is an angle that satisfies the condition of 0 degrees<θ3≦90 degrees, of the angles formed by the first simulated blood vessel611and the third simulated blood vessel613in the X-Y plane. The angle θ3is, for example, 10 degrees≦θ3≦90 degrees. In this embodiment, the angle θ3is 90 degrees. The angle θ2and the angle θ3may be the same value or different values.

The distance D shown inFIG. 2is the distance between the second simulated blood vessel612and the third simulated blood vessel613in the X-Y plane. The distance D is defined at a site where the spacing between the second simulated blood vessel612and the third simulated blood vessel613is the narrowest. In this embodiment, since the second simulated blood vessel612and the third simulated blood vessel613are parallel to each other, the distance D may be measured at an arbitrary position in the X-direction (direction in which the second simulated blood vessel612and the third simulated blood vessel613extend).

The distance D is set, for example, to 0 mm or longer and 3 mm or shorter. In this embodiment, the distance D is set to 3 mm. If the distance D is 0 mm, it means that the second simulated blood vessel612and the third simulated blood vessel613are in contact with each other.

InFIG. 3, the hatchings on the second simulated blood vessel612and the third simulated blood vessel613mean that the color of the second simulated blood vessel612and the third simulated blood vessel613is different from the color of the first simulated blood vessel611. In this embodiment, the first simulated blood vessel611is formed in yellow, whereas the second simulated blood vessel612and the third simulated blood vessel613are formed in red. These colorings indicate that the second simulated blood vessel612and the third simulated blood vessel613are arranged at deeper positions than the first simulated blood vessel611.

The simulated tumor621is a site set as an extirpation target in a surgical simulation. The simulated tumor621is formed in a color that is different from the simulated blood vessels610and the simulated tissue620. Specifically, the simulated tissue620is formed in white and the simulated tumor621is formed in green.

As shown inFIG. 2, the simulated tumor621is arranged at a site where the first simulated blood vessel611and the second simulated blood vessel612intersect with each other on the X-Y plane. The simulated tumor621is arranged below the first simulated blood vessel611and below the second simulated blood vessel612, as shown inFIG. 3.

FIG. 4is a cross-sectional view taken along3-3inFIG. 2and shows the state where the simulated tumor621has been extirpated. The ejection tube205shown inFIG. 4is illustrated as approaching the simulated tumor621from behind the first simulated blood vessel611in this illustration. The ejection tube205shown inFIG. 2is in the same approaching state.

As described so far, using the simulated organ600in which the simulated tumor621is arranged in a way that makes it is difficult to extirpate the simulated tumor621, a circumstance closer to a living body can be reproduced. The arrangement that makes it difficult to extirpate the simulated tumor621refers to an arrangement in which the simulated tumor621is arranged below a site where simulated blood vessels610(first simulated blood vessel611and second simulated blood vessel612) intersect with each other and in which another simulated blood vessel610(third simulated blood vessel613) is arranged closely to the site of intersection.

In addition, since the first simulated blood vessel611, the second simulated blood vessel612and the third simulated blood vessel613, the simulated tissue620, and the simulated tumor621are formed in different colors, it is easy to understand which element is excised or damaged.

FIG. 5is a flowchart showing a method for preparing the simulated organ600. First, the simulated blood vessels610are prepared (S810). In this embodiment, PVA (polyvinyl alcohol) is employed as the material of the simulated blood vessels610. Then, a solid member with a predetermined strength is formed by molding.

The strength of the simulated blood vessels610will be described.FIG. 6is a view for explaining a strength test on the material of the simulated blood vessels610. Using the following test, a material with a strength close to the intended blood vessels is prepared.

A sheet650is a test sample formed by shaping the material of the simulated blood vessels610into a sheet. The sheet650is placed on a table (not illustrated) and fixed to the table at its peripheral edges. The table has a hole opening at a position opposite to a pin700via the sheet650. In the strength test, the pin700is pressed into the sheet650so as to deform the sheet650until the sheet650breaks. A load cell (not illustrated) is used to press in the pin700, and the press-in force is measured in real time.

FIG. 7shows an example of experiment data obtained from the strength test. The vertical axis represents press-in force. The horizontal axis represents time. The pressing of the pin700is carried out at 1 mm/sec. Therefore, the press-in force increases almost linearly with time, as shown inFIG. 7.

The press-in force increases in this manner and eventually drops sharply. The sharp drop in the press-in force occurs because of the breaking of the sheet650. Based on the sharp drop in the press-in force, the maximum value of the press-in force can be decided. The material strength is acquired as a stress value (MPa) by dividing the maximum value (N) of the press-in force by the area of a tip710of the pin700(in this embodiment, 0.5 mm2).

By this test, a material with a strength close to the strength of the blood vessels to be reproduced is prepared as the material of the simulated blood vessels610. Using the material thus prepared, the simulated blood vessels610are produced.

Next, the simulated blood vessels610are fixed to the support member630(S820).FIG. 8is a cross-sectional view (Y-Z plane) showing the state where5820has been executed on the second simulated blood vessel612and third simulated blood vessel613.FIG. 8shows a cross section taken along8-8inFIG. 2(Y-Z plane).

As shown inFIG. 8, grooves633are provided in the support member630. The grooves633are provided on both sides of the support member630. The second simulated blood vessel612and the third simulated blood vessel613are fitted into the grooves633in5820and thus fixed to the support member630. The same applies to the first simulated blood vessel611as well.

Next, a stirred mixture of a base resin of urethane and a hardener is poured into the support member630(S830). Subsequently, the urethane changes into a urethane gel in the form of an elastomer gel (S840). Thus, the simulated tissue620is formed and the simulated organ600is completed.

A modification will be described.FIG. 9shows a cross section of simulated organ600a.The simulated organ600ahas a third simulated blood vessel613ainstead of the third simulated blood vessel613and has a simulated tumor622and a simulated tumor623instead of the simulated tumor621.

The second simulated blood vessel612is arranged at a deeper position than the first simulated blood vessel611at a site intersecting with the first simulated blood vessel611, as in the embodiment. Meanwhile, the third simulated blood vessel613ais arranged at a shallower position than the first simulated blood vessel611at a site intersecting with the first simulated blood vessel611.

The third simulated blood vessel613ais formed in a color (for example, orange) that is different from the color of the first simulated blood vessel611and the color of the second simulated blood vessel612. With such colorings, the depths of the simulated blood vessels610can be indicated by their colors. Consequently, for example, if a simulated blood vessel610intersecting with the first simulated blood vessel611is damaged, whether this simulated blood vessel610is the second simulated blood vessel612or the third simulated blood vessel613acan be easily understood.

Another modification will be described.FIG. 10shows a cross section of a simulated organ600b.The simulated organ600bincludes a first simulated blood vessel611binstead of the first simulated blood vessel611.

The second simulated blood vessel612is arranged at a deeper position than the first simulated blood vessel611bat a site intersecting with the first simulated blood vessel611b,as in the embodiment. Meanwhile, the third simulated blood vessel613is arranged at a shallower position than the first simulated blood vessel611bat a site intersecting with the first simulated blood vessel611b.However, the second simulated blood vessel612and the third simulated blood vessel613are arranged at the same depth, similarly to those in the embodiment.

The first simulated blood vessel611bis divided into an upper part611bU, a slant part611bS, and a lower part611bD, as shown inFIG. 10. The upper part611bU and the lower part611bD are sites extending horizontally. The upper part611bU is arranged at a shallower position than the second simulated blood vessel612. That is, the second simulated blood vessel612is arranged at a deeper position than the first simulated blood vessel611bat a site intersecting with the first simulated blood vessel611b,as in the embodiment.

The lower part611bD is arranged at a deeper position than the third simulated blood vessel613. That is, the third simulated blood vessel613is arranged at the same depth as the second simulated blood vessel612but is arranged at a shallower position than the first simulated blood vessel611bat a site intersecting with the first simulated blood vessel611b.

The slant part611bS is a site connecting the upper part611bU and the lower part611bD together and extends slantly between the second simulated blood vessel612and the third simulated blood vessel613.

The upper part611bU, the slant part611bS and the lower part611bD are formed in different colors from each other. Each of these colors is different from each of the colors of the second simulated blood vessel612, the third simulated blood vessel613, the simulated tissue620and the simulated tumor621. With such colorings, the user can discriminate each site of the first simulated blood vessel611bby its color.

The invention is not limited to the embodiment, examples and modifications in this specification and can be implemented with various configurations without departing from the scope of the invention. For example, technical features described in the embodiment, examples and modifications corresponding to technical features of each configuration described in the summary of the invention can be replaced or combined according to need, in order to solve a part or all of the foregoing problems or in order to achieve a part or all of the advantageous effects. Technical features can be deleted according to need, unless described as essential in the specification. For example, the following examples can be employed.

The simulated organ may be excised by measures other than a liquid that is intermittently ejected. For example, the simulated organ may be excised by a liquid that is continuously ejected or by a liquid provided with an excision capability by ultrasonic waves or an optical maser. Alternatively, the simulated organ may be excised by a metallic surgical knife.

The number of the simulated blood vessels may be any number equal to or greater than two.

The material of the simulated blood vessels is not limited to the above example. For example, the material may be a synthetic resin other than PVA (for example, urethane) or may be a natural resin.

The material of the simulated tissue is not limited to the above example. For example, the material may be a rubber-based material other than urethane or may be PVA.

The simulated blood vessels may be prepared using ejection and deposition (3D printing by an inkjet method or the like).

The simulated tissue may be prepared using 3D printing.

The simulated blood vessels and the simulated tissue may be collectively prepared using 3D printing.

The arrangement of the simulated blood vessels is not limited to the above examples. For example, the simulated blood vessels may be curved or bent in an S-shape and may be bent within the horizontal plane (within the X-Y plane).

In the arrangement of the simulated blood vessels, it suffices that at least two simulated blood vessels intersect with each other. For example, the second simulated blood vessel and the third simulated blood vessel may intersect with each other.

The positional relation between the simulated blood vessels that do not intersect with each other may be parallel as in the embodiment or need not be parallel.

The simulated blood vessels may be hollow members. As a technique for forming the simulated blood vessels as hollow members, the following method may be employed. That is, PVA before hardening is applied to the outer circumferences of extra fine wires, and the extra fine wires are pulled out after the hardening of the PVA. The outer diameter of the extra fine wires is made to correspond to the inner diameter of the blood vessels. The extra fine wires are made of metal, and for example, formed by piano wires.

The colors of the simulated blood vessels maybe any colors. For example, all of the simulated blood vessels may be in the same color. Alternatively, different colors may be used for the site of intersection and for the other sites.

As a method for discriminating the damaged simulated blood vessel, the colors of the simulated blood vessels need not be different from each other. For example, the color of simulated blood may be used. That is, the simulated blood vessels maybe formed as hollow members, and the first simulated blood vessel and the second simulated blood vessel may contain simulated bloods in different colors from each other.

While the configuration using the piezoelectric element as the actuator is employed in the embodiment, a configuration in which a liquid is ejected using an optical maser, or a configuration in which a liquid is pressurized by a pump or the like and thus ejected, may be employed. The configuration in which a liquid is ejected using an optical maser refers to the configuration in which a liquid is irradiated with an optical maser to generate air bubbles in the liquid, so that a pressure rise in the liquid caused by the generation of the air bubbles can be utilized.

The entire disclosure of Japanese Patent Application No. 2015-059278 filed Mar. 23, 2015 is expressly incorporated by reference herein.