Paracentesis needle holder

A paracentesis needle holder attachable to an ultrasonic probe is provided. The holder includes a needle guide, an adjustment mechanism, and an open/close mechanism. The needle guide includes a first base and a second base and is configured to guide a needle in a plurality of directions between the first and second bases. The adjustment mechanism is provided at the needle guide and configured to adjust spacing between the first base and the second base in accordance with a diameter of the needle. The open/close mechanism is coupled with the needle guide and configured to close the first and second bases so that the needle is guided in one of the directions and to open the first and second bases so that the needle becomes releasable from the holder.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. P2003-198646, filed on Jul. 17, 2003, the entire content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a paracentesis needle holder which is attachable to an ultrasonic probe. The present invention further relates to an ultrasonic probe having the paracentesis needle holder.

2. Discussion of the Background

A paracentesis operation is conducted with a needle while an operator such as a doctor or a radiological technologist is observing ultrasound images displaying internal conditions of a patient. In the paracentesis operation, the operator, for example, samples patient's tissues such as tumor tissues and injects medical agents into a patient's body. The ultrasound images are typically obtained by an ultrasonic probe specifically manufactured for the paracentesis operation.

Recently, however, a new type of an ultrasonic probe has been introduced. The new type of an ultrasonic probe can be used not only as an ordinary ultrasonic probe but also with an attachable holder of a needle for the paracentesis operation. Such a new type of the ultrasonic probe has been improved in various manners. One example is disclosed in Japanese Patent Application Publication No. PH10-248849. The Japanese Patent Application Publication discloses a needle holder is formed with a plurality of holes to guide a needle in different angles. Another known example is a needle holder with a single hole to guide a needle. The hole can be moved in a predetermined range of angles.

In the above first example, however, it is required to replace the needle holder with another one when a needle in a different size is required in the paracentesis operation.

In the other example mentioned above, the needle holder is likely to be large in size and quite heavy. Therefore, when this needle holder is mounted on an ultrasonic probe, it is difficult for the operator to manipulate the ultrasonic probe during the paracentesis operation.

SUMMARY OF THE INVENTION

According to the first aspect of the present invention, there is provided a paracentesis needle holder attachable to an ultrasonic probe. The holder includes a needle guide, an adjustment mechanism, and an open/close mechanism. The needle guide includes a first base and a second base and is configured to guide a needle in a plurality of directions in between the first and second bases. The adjustment mechanism is provided at the needle guide and is configured to adjust spacing between the first base and the second base in accordance with a diameter of the needle. The open/close mechanism is coupled with the needle guide and is configured to close the first and second bases so that the needle is guided in one of the directions and to open the first and second bases so that the needle becomes releasable from the holder.

According to the second aspect of the present invention, there is provided a paracentesis needle holder attachable to an ultrasonic probe. The holder includes a holder member, a fixed member, a pivoted member, and a handle. The holder member is attachable around the ultrasonic probe. The fixed member is attached to the holder member and is configured to have a needle bearer. The pivoted member is coupled to the fixed member and is configured to have a gutter unit. The pivoted member is biased to the fixed member by a bias member. The handle is attached to the pivoted member and is configured to turn the pivoted member against a force of the bias member and to open the pivoted member and the fixed member. The gutter unit and the needle bearer are configured to face to each other and to guide a needle in a plurality of directions.

According to the third aspect of the present invention, there is provided a paracentesis needle holder for an ultrasonic probe. The holder includes a guide unit, a bear-up unit, and an adjustment mechanism. The guide unit is configured to have a gutter unit with a gutter portion capable of holding a needle at a plurality of angles with respect to the ultrasonic probe. The bear-up unit is coupled to the guide unit and is configured to have a needle bearer with a support member. The gutter portion and the supporter member are configured to securely hold the needle in place when the guide unit and the bear-up unit are closed. The adjustment mechanism is provided to at least one of the guide unit and the bear-up unit and is configured to adjust spacing between the gutter portion and the supporter member when the guide unit and the bear-up unit are closed.

According to the fourth aspect of the present invention, there is provided an ultrasonic probe. The probe includes a main unit and a paracentesis needle holder. The paracentesis needle holder is mounted onto the main unit. The paracentesis needle holder includes a needle guide, an adjustment mechanism, and an open/close mechanism. The needle guide includes a first base and a second base and is configured to guide a needle in a plurality of directions between the first and second bases. The adjustment mechanism is provided at the needle guide and is configured to adjust spacing between the first base and the second base in accordance with a diameter of the needle. The open/close mechanism is coupled with the needle guide and is configured to close the first and second bases so that the needle is guided in one of the directions and to open the first and second bases so that the needle becomes releasable from the holder.

According to the fifth aspect of the present invention, there is provided an ultrasonic probe. The probe includes a main unit, a holder member, a fixed member, a pivoted member, and a handle. The holder member is attached around the main unit. The fixed member is attached to the holder member and is configured to have a needle bearer. The pivoted member is coupled to the fixed member and is configured to have a gutter unit. The pivoted member is biased to the fixed member by a bias member. The handle is attached to the pivoted member and is configured to turn the pivoted member against a force of the bias member and to open the pivoted member and the fixed member. The gutter unit and the needle bearer are configured to face to each other and to guide a needle in a plurality of directions.

According to the sixth aspect of the present invention, there is provided an ultrasonic probe. The probe includes a main unit and a paracentesis needle holder. The paracentesis needle holder is mounted onto the main unit and includes a needle guide and an open/close mechanism. The needle guide includes a first base having a first side and a second base having a second side. The needle guide is configured to guide a needle in at least one direction between the first and second bases. The first and second bases are opposed to each other when the first and second bases are closed. The first and second bases face to the ultrasonic probe at the first and second sides along a proximal end to a distal end of the ultrasonic probe when the first and second bases are closed. The open/close mechanism is coupled with the needle guide and is configured to close the first and second bases so that the needle is guided in one of the at least one direction and to open the first and second bases so that the needle becomes releasable from the paracentesis needle holder.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Embodiments of a paracentesis needle holder and an ultrasonic probe having a paracentesis needle holder will be described with reference to the accompanying drawings.

FIGS. 1 and 2show an ultrasonic probe having a paracentesis needle holder according to one embodiment.FIG. 3shows a paracentesis needle holder according to one exemplary embodiment. Precisely,FIG. 1shows a side view of an ultrasonic probe10.FIG. 2shows a perspective view of the ultrasonic probe10with a cable13from its one end.FIG. 3shows a paracentesis needle holder20without holder members21aand21b. Two paracentesis needles (hereinafter referred to as needles)91and92in different directions or orientations are shown inFIG. 1. This is only for the purpose of explanation. Only one needle90is usually used in practice, as shown inFIG. 2.

The ultrasonic probe10generates ultrasound beams in an arc form and scans a patient's body. Such a probe is known as a convex type ultrasonic probe. However, other types of an ultrasonic probe such as, for example, a linear scan type and a sector scan type may be used as the ultrasonic probe10.

The ultrasonic probe10includes an acoustic lens11, a handle body12, and the cable13. The acoustic lens11is provided at a distal end of the ultrasonic probe10. When the ultrasonic probe10generates ultrasound beams, the acoustic lens11is brought in contact with the patient's body to scan the patient's body. The operator typically holds the handle body12during the scanning. Since the ultrasonic probe10can be a part of an ultrasound diagnosis apparatus (not shown in the drawings), the cable provided at the proximal end of the ultrasonic probe10is typically connected to a main unit of the ultrasound diagnosis apparatus.

The ultrasonic probe10is equipped with the paracentesis needle holder20as shown inFIGS. 1 and 2. The paracentesis needle holder20includes the holder members21aand21b, which may be made of metals or any other suitable material. The holder members21aand21bare coupled by a hinge22. AS shown in the embodiment inFIG. 2, the holder members21aand21bmay be a belt strapped around the ultrasonic probe10. The belt may be attached to the hinge22. The holder members21aand21bstrap around the ultrasonic probe10so that the paracentesis needle holder20is mounted on the ultrasonic probe10. In one embodiment, the holder members21aand21bmay have two belts fixed at the other ends by a screw fixer23. Since there may be a space between the other ends of the holder members21aand21bwhen the holder members21aand21bare clipped on the ultrasonic probe10, the screw fixer23is used to further tighten the holder members21aand21baround the probe. Accordingly, the holder members21aand21bare fixed at their respective another ends (SeeFIG. 9). The holder members21aand21bmay be elastic. Due to the elastic behavior, the holder members21aand21bmay be tightly fixed by the screw fixer23.

As shown inFIG. 2, the holder member21aincludes a pedestal24which protrudes from a portion where the hinge22is provided. A needle guide30is connected to the pedestal24. The needle guide30includes a bear-up unit31(or the second base or a fixed member) and a guide unit32(or the first base or a pivoted member). The bear-up unit31and the guide unit32are coupled by a hinge33. A base of the bear-up unit31may be fixed on the pedestal24by a screw fixer, welding, or any other appropriate means. As shown inFIG. 2, the bear-up unit31may include a needle bearer311horizontally protruding from its base. Although not shown in the drawings, a spring (or a bias member) may be provided at the hinge33so that the guide unit32is biased towards the bear-up unit31. The hinge33and the spring may be an open/close mechanism.

The guide unit32includes a base321and a needle gutter unit322. The base321can be configured in a form similar to the letter ‘L’. The needle gutter unit322is provided at the distal end of the base321. The distal end may be closer to the needle bearer311. The needle gutter unit322can be moved closer to or away from the needle bearer311.

The spring causes the needle gutter unit322and the needle bearer311to be in an open position as shown inFIG. 3. The needle bearer311has protrusions or supporters311aand311bformed in different directions. InFIG. 3, there are two supporters. The needle bearer311may have more supporters in accordance with predetermined angles for the needle90in the paracentesis operation. The needle gutter unit322includes valley-like grooves or gutters322aand322bconfigured to meet with the supporters311aand311b. The supporters311aand311bhold the needle90inserted through the gutters322aand322bin place. When the needle gutter unit322is moved towards and meets the needle bearer311in to a closed position, there is spacing between the supporters311a,311band the gutters322a,322b. The needle90can be inserted and guided along one of the gutters322aand322band supported by corresponding one of the supporters311aand311b.

The needle gutter unit322may be slidably coupled to the base321through, for example, three guide members324. These three guide members324may be positioned to form a triangle. An adjustment screw325may be provided inside the triangle. The guide members324and the adjustment screw325may be an adjustment mechanism and will be described in detail later.

On the base321, a handle326is provided which extends from a proximal side of the needle guide30with respect to the ultrasonic probe10and also in a direction against the surface of the ultrasonic probe10. Therefore, when the handle326is pressed down towards the surface of the ultrasonic probe10(or towards the holder member21a), the guide unit32is turned against the bias force around an axis of the hinge33so that the needle gutter unit322is opened from the needle bearer311. As a result, the needle90guided by one of the gutters322aand322band one of the supporters311aand311bcan be released from the paracentesis needle holder30. For example, even during the paracentesis operation, it may be possible to easily release the needle90inserted in the patient's body. In other words, the paracentesis needle holder30(and the ultrasonic probe10) can be removed from the needle90.

On the needle bearer311, there are one or more convex members312as shown inFIG. 3. In a manner corresponding to the convex members312, there are one or more concave members327on a surface of the needle gutter unit322as shown inFIG. 3. When the needle gutter unit322is moved towards and faces the needle bearer311, the convex members312and the concave members327may be engaged so as to ensure alignment between the needle gutter unit322and the needle bearer311.

An adjustment screw325will be described with reference toFIGS. 4 and 5.FIG. 4illustrates the ultrasonic probe10having the paracentesis needle holder20with an adjustment screw325according to one embodiment. Similarly,FIG. 5illustrates the ultrasonic probe10having the paracentesis needle holder20with an adjustment screw325according to another embodiment. The difference betweenFIG. 4andFIG. 5is only a diameter of the needle90. The needle90inFIG. 4has a larger diameter than the one inFIG. 5. A top of the needle90to be held by the operator is not shown inFIGS. 4 and 5so that the difference can easily be recognized.

The adjustment screw325is rotatably engaged with the base321and is also screwed together with the needle gutter unit322. Accordingly, the base321is coupled to the needle gutter unit322. When the adjustment screw325is rotated, the needle gutter unit322is moved up or down relative to the base321in a direction A. For example, when the adjustment screw325is rotated clockwise, the needle gutter unit322moves towards the needle bearer311or moves away from the base321. Alternatively, when the adjustment screw325is rotated counterclockwise, the needle gutter unit322moves towards the base321or moves away from the needle bearer311.

In the above movement of the needle gutter unit322, the needle gutter unit322is guided by the three guide members324. Each guide member324includes a tube member324aand a rod member324b. The tube member324ais fixed to the base321. The rod member324bis fixed to the needle gutter unit322. The rod member324bis slidably inserted in the tube member324a. The tube member324aand the rod member324bmay be telescopically coupled. Therefore, the spacing between the needle gutter unit322and the needle bearer311can be adjusted in accordance with the thickness (or the diameter) of the needle90to be guided by one of the gutters322a,322band corresponding one of the supporters311a,311b. A distance between the one gutter322a(322b) and the one supporter311a(311b) can be adjusted in accordance with the thickness (or the diameter) of the needle90to be guided. The diameter of the needle90may be, for example, eleven gauges or twenty-two gauges. InFIG. 4, the needle90is small. Therefore, the needle gutter unit322is lowered a lot, and the rod member324bis exposed a lot. On the other hand, inFIG. 5, the needle90is large. Therefore, the needle gutter unit322is not as much lowered as inFIG. 4, and the rod member324bis not as much exposed as inFIG. 4.

In the above adjustment, the three guide members324help the needle gutter unit322to smoothly descend and ascend so as to keep an appropriate distance from the needle bearer311. As a result, the needle90is held in an appropriate pressure to be allowed to move along the gutter311a(311b).

The operations of the ultrasonic probe10and the paracentesis needle holder20will be described below. The ultrasonic probe10can be used independently from the paracentesis needle holder20.

Since a scan direction with ultrasound beams is predetermined in the ultrasonic probe10, the ultrasonic probe10is required to be used in consideration of the scan direction. Otherwise, images obtained by the scan are displayed reversely. Therefore, it is necessary to consider a position of the paracentesis needle holder20relative to the ultrasonic probe10when the paracentesis needle holder20is mounted on the ultrasonic probe10. That is, it is preferable to mount the paracentesis needle holder20in accordance with the scan direction.

FIG. 6is an illustration showing an exemplary view of the ultrasonic probe10according to one embodiment.FIG. 7is an illustration showing another exemplary view of the ultrasonic probe10according to one embodiment.FIG. 6shows the ultrasonic probe10having a small notch14aon its side surface.FIG. 7shows the ultrasonic probe10having a small notch14bon its opposite side surface. The notch14amay be different from the notch14b. The notches14aand14bmay be the first mechanism. For example, the notches14aand14bare in an asymmetric position on each side of the ultrasonic probe10. The paracentesis needle holder20has prongs (not shown in the drawings) which can engage the notches14aand14b. Such prongs may be the second mechanism. Since the notches14aand14bare in the asymmetric position, the paracentesis needle holder20can always be mounted on the ultrasonic probe10in a unique direction. Further, it could avoid the paracentesis needle holder20from loosening around the ultrasonic probe10.

Alternatively, the ultrasonic probe10may have prongs instead of the notches14aand14b. The paracentesis needle holder20may have notches corresponding to the prongs of the ultrasonic probe10. In addition, the notches14aand14bmay be formed in different sizes or shapes, instead of the asymmetric positions. Three or more notches and corresponding prongs may be applied to accomplish the above purpose.

After the paracentesis needle holder20has been mounted on the ultrasonic probe10, the ultrasonic probe10is contacted to the patient's body by the operator. The operator observes ultrasound images obtained in the scan by the ultrasonic probe10and confirms a position of a paracentesis operation target such as a diseased part. Once the target position is confirmed, the operator decides which size of the needle90to use. The adjustment screw325is winded counterclockwise so that the needle gutter unit322is lifted up towards the base321. Accordingly, the spacing between the gutters322a,322bof the needle gutter unit322and the supporters311a,311bof the needle bearer311is widen enough for the determined needle90to be inserted along one of the gutters322aand322bas shown inFIG. 2. After the insertion, the adjustment screw325is then winded clockwise so that the needle gutter unit322is lowered towards the needle bearer311. The spacing is adjusted appropriately to guide and allow the needle90to slide along the gutter322a(322b). The operator penetrates the needle90up to the target along the gutter322a(322b) and confirms a position of the penetrated needle90in the ultrasound images displayed in a monitor of an ultrasound diagnosis apparatus.

When the operator recognizes the needle90has reached the target, the needle90may be released from the paracentesis needle holder20as shown inFIGS. 8 and 9.FIG. 8illustrates the ultrasonic probe10having the paracentesis needle holder20particularly showing an example of a needle release according to one embodiment.FIG. 9illustrates the ultrasonic probe10having the paracentesis needle holder20particularly showing the needle release viewed from a side of the acoustic lens11according to one embodiment.

The operator presses down the handle326towards the holder member21a, that is, in a direction B. In response to the press-down, the guide unit32is turned around the hinge33as a turning axis in a direction C. The gutters322a,322bof the needle gutter unit322are released from the supporters311a,311bof the needle bearer311. Accordingly, the ultrasonic probe10having the paracentesis needle holder20can be removed in the left direction inFIG. 8or in the right direction inFIG. 9while the needle90is penetrated in the patient's body. The operator then uses the independent needle90for obtaining target tissues inside the patient's body or injecting medical agents into the patient's body through the needle90.

When there are two gutters322aand322bon the needle gutter unit322, it would be clinically helpful if concrete guided angles are recognizable for the operator. Therefore, the angles to be guided by the gutters322aand322bmay be displayed on a part of the needle gutter unit322. The displayed angles may be angles against a horizontal direction of images to be displayed in the monitor of the ultrasound diagnosis apparatus. The angles are, for example, displayed on a surface322cwhich is a part of the needle gutter unit322and above the gutters322aand322b. Each angle is displayed in a recognizable manner. As shown inFIG. 8, a display ‘80’ above the gutter322arepresents an angle in degrees guided by the gutter322a. Also, a display ‘67’ above the gutter322brepresents an angle in degrees guided by the gutter322b. Such angle difference may be understood as needles91and92inFIG. 1. The needle91guided by the gutter322ais angled at 80 degrees from an horizontal line of ultrasound images obtained through a scan with ultrasound beams generated from the acoustic lens11when the images are displayed. Similarly, the needle92guided by the gutter322bis angled at 67 degrees from the horizontal line. Therefore, the operator observes ultrasound images displayed in the monitor and determines which angle can be appropriate for the needle insertion. Based on the determination, the operator selects an appropriate one of the gutters322aand322band inserts the needle90into the selected gutter322a(322b). Therefore, the operator can easily conduct the paracentesis operation. The angles guided by the needle gutter unit322may be more than two angles according to the necessity. The angle display may alternatively be made on a part of the needle bearer311or anywhere as long as the guided angles are recognizable.

As described above, the guide unit32and the bear-up unit31are coupled by the hinge33. The needle gutter unit322is usually biased towards the needle bearer311by the force of the spring provided at the hinge33. Therefore, the operator can immediately and easily insert the needle90into one of the gutters322aand322bby pressing the handle326according to the necessity. For example, however, if the operator accidentally touches the handle326, the handle326may happen to be pressed towards the holder member21a, for example, during the needle insertion. This results in releasing the fit between the needle gutter unit322and the needle bearer311. Therefore, the operator may not be able to accurately insert (or penetrate) the needle into the patient's body since the needle is unstable. In order to avoid such an undesired situation, the paracentesis needle holder20may be provided with a stopper mechanism which prevents the needle gutter unit322from turning in response to touching the handle326.

Such a stopper mechanism will be described with reference toFIGS. 9 to 11.FIG. 10is an illustration for explaining an exemplary stopper mechanism according to the embodiments.FIG. 11illustrates the exemplary stopper mechanism viewed from another direction.

InFIG. 10, the holder members21aand21bare omitted, and the needle gutter unit322is released from the needle bearer311. As shown inFIG. 10, posts313aand313bare provided on the base of the bear-up unit31in an upward direction. The guide unit32is coupled to top ends of the posts313aand313bby the hinge33. The guide unit32includes a prong328which bypasses the hinge33and has a through-hole328aat its distal end. When the base321is pressed down towards the needle bearer311, the through-hole328ais positioned on an extension of an operative shaft314aof a knob314while the needle gutter unit322and the needle bearer311are fitted each other.

Therefore, when the needle90is held in between one of the gutters322a,322band one of the supporters311a,311b, the operator can push the knob314towards a direction D. In response, the operative shaft314ais pushed out so as to be inserted into the through-hole328a. Accordingly, since the guide unit32is locked relative to the bear-up unit31, the guide unit32is prevented from turning even if the handle326is accidentally pressed towards the holder member21a. That is, the needle90can always be locked and be kept stable as long as the operative shaft314ais remained in the through-hole328a. If the knob314is pulled out towards a direction opposite to the direction D, the operative shaft314ais drawn back from the through-hole328aand, accordingly, the needle90is unlocked and is ready to be released from the paracentesis needle holder20.

For the above stop mechanism, the operative shaft314aand the through-hole328amay alternatively be screwed together by rotating the knob314so that the guide unit32can be fixed more stably to the bear-up unit31. Accordingly, holding stability of the needle90can be improved and secured.

According to the embodiments described above, the needle90in various size of diameter can be guided in various angles. In addition, the paracentesis needle holder20can be made light and compact, and easily operated by the operator. Further, if all the materials constituting the paracentesis needle holder20are made of metals, it may be possible to sterilize the paracentesis needle holder20per se by boiling. Therefore, the operator can use the paracentesis needle holder20hygienically and safely.

A modification to the paracentesis needle holder20will be described with reference toFIG. 12.FIG. 12illustrates an example of a modified paracentesis needle holder mounted on the ultrasonic probe10according to one embodiment. A paracentesis needle holder1200modified to the paracentesis needle holder322includes a needle gutter unit1201and an adjustment screw1202, instead of the needle gutter unit322and the adjustment screw325, respectively. The needle gutter unit1201has an extended outer side wall (or a distal wall)1201aand an extended entrance side wall (or an entrance wall)1201b. Compared to the side surfaces, for example, shown inFIG. 3, the extended outer side wall1201aand the extended entrance side wall1201bextend towards the needle bearer311. Therefore, when the needle90is inserted into between the needle gutter unit1201and the needle bearer311, the needle90can be prevented from deviating or coming out of the extended side surface1201a, even if the operator inserts the needle90in a wrong direction (i.e., towards the extended side wall1201a). Also, in the insertion, the needle90can be prevented from deviating from one of gutters of the needle gutter unit1201, even if the operator accidentally gives a force to the needle90towards from the one gutter to the other gutter while the operator is holding the top of the needle90. The extended entrance side surface1201bmay not be extended at a portion adjacent to the ultrasonic probe10. Also, an inner side surface of the needle gutter unit1201facing the ultrasonic probe10may not extend towards the needle bearer311. This is because the body of the ultrasonic probe works to prevent the needle90from deviating or coming out of the inner side surface. This modification may be advantageous particularly when the spacing between the needle gutter unit1201and the needle bearer311is not adjusted yet by the adjustment screw1202so that the needle90is easily inserted.

The adjustment screw1202is smaller in diameter than the adjustment screw325. In addition, a head of the adjustment screw1202has a predetermined height and a round shape. This shape may be advantageous of preventing the adjustment screw1202from being winded as much as possible when a part of the operator's or patient's body contacts the adjustment screw1202.

Finally, the paracentesis needle holder20according to the embodiments and a conventional type of a paracentesis needle holder will be compared in their needle positions relative to the ultrasonic probe.FIG. 13Aillustrates a view of an exemplary relationship between the ultrasonic probe10, the paracentesis needle holder20, the needle90, a radiated ultrasound1300, and a patient's body1301according to one embodiment. Detailed elements of the paracentesis needle holder20are omitted inFIG. 13A.FIG. 13Bis an illustration viewing the ultrasonic probe10mounting the paracentesis needle holder20from a side of the cable13according to the embodiments.

As shown in13B, the paracentesis needle holder20faces to the ultrasonic probe10at the first side1303of the guide unit32and the second side1304of the bear-up unit31when paracentesis needle holder20is attached to (or mounted on) the ultrasonic probe10. As shown inFIG. 13A, the ultrasonic probe10mounting the paracentesis needle holder20contacts a surface of the patient's body1301. The needle90is inserted or penetrated into the patient's body1301under the guide of the paracentesis needle holder20while the ultrasound1300is radiated to the patient's body1301. Since the needle90is guided close to the ultrasonic probe10, only a little portion1302of the needle90is out of the radiated ultrasound1300. In other words, the little portion1302of the needle90cannot be imaged by the ultrasound radiation. Such a range of the needle90like the little portion1302may be called a blind field.

Compared toFIGS. 13A and 13B, the conventional type of a paracentesis needle holder has a large blind field as shown inFIGS. 14A and 14B.FIG. 14Aillustrates one known relationship between an ultrasonic probe1400, a needle holder1401, a needle1402, a radiated ultrasound1403, and a patient's body1404. Detailed elements of the needle holder1401are omitted inFIG. 14A.FIG. 14Bshows the known ultrasonic probe1400having the needle holder1401from a side of a cable1405.

As shown inFIG. 14B, the needle holder1401includes a needle gutter unit1401aand a needle bearer1401b. The needle gutter unit1401has a gutter1401cat a distal end from the ultrasonic probe1400. The needle1402(not shown inFIG. 14B) is guided by the gutter1401cand held by the needle gutter unit1401aand the needle bearer1401b. Since the needle1402is not guided close to the ultrasonic probe1400because of the thickness of the needle gutter unit1401a, quite a large portion1406of the needle1402is out of the radiated ultrasound1403. In other words, the large portion1406of the needle1402cannot be imaged by the ultrasound radiation.

Therefore, the paracentesis needle holder20can reduce the blind field, compared to the conventional needle holder1401. The reduced blind field may help the operator to conduct the needle insertion more accurately.

The embodiments described above are examples described only for making it easier to understand the present invention, and are not described for the limitation of the present invention. Consequently, each component and element disclosed in the embodiments of the present invention may be redesigned or modified to its equivalent within a scope of the present invention. Furthermore, any possible combination of such components and elements may be included in a scope of the present invention as long as an advantage similar to those obtained according to the above disclosure in the embodiments of the present invention is obtained.