SURGICAL HANDPIECE EQUIPPED WITH COUPLINGS FOR SUCTION AND SALINE SOLUTION
Technical Field The present invention relates to a surgical handpiece for use in the plastic surgery on the face or the removal of bone tumor and projections. More particularly, the handpiece of the present invention includes a mechanism section for converting the rotation of a motor into linear reciprocation within a handpiece body, a suction coupling for sucking bone fragments produced during a bone-cutting operation and a saline solution-supplying connector tube placed coaxial with the suction coupling, and the saw or rasp is coupled with the handpiece to perform the bone cutting or bone grinding operation.
Background Art A conventional method for the reshaping generally is to cut off the bone with saw or to grind the same with the rasp. In the plastic surgery on the face, it is to be considered seriously that a large quantity of bone be ground for a short time period to minimize incision, bleeding, swelling and nerve injury as well as muscle and bone tissue particles be discharged together with ground bone. While cutting can be performed by large quantities with a manual saw or rasp, its slow operation speed increases the fatigue of a surgeon thereby degrading the concentration of the operation. A powered or pneumatic handpiece has a high cutting speed, but bone fragments pressed against the saw or rasp may be solidified owing to the friction heat generated during the bone-cutting operation. In this circumstance, since the bone fragments inserted into the cutting teeth are rubbed with the bone, it is difficult to continuously cut a large quantity of bone and it is inconvenient to clean the cutting teeth for every several seconds. Further,
there is a risk that the heat generated from the cutting face may cause burn or deformation to soft tissues surrounding the incision. In order to solve this problem, saline solution is supplied to the rasp or saw, which is as an acting portion, and then sucked out together with cut bone fragments. However, because this solution sucks saline solution in an opened space, sucking the bone fragments compressed by the cutting teeth is more difficult and lower in suction efficiency than sucking cut bone fragments into a small space within the rasp under the same negative pressure.
Disclosure of the Invention The present invention relates to a surgical handpiece comprising a saline- supplying connector tube and a suction coupling tube placed coaxial with the saline-supplying connector tube. The handpiece is connected with accessory for reshaping of mandible, zygoma or cutting the bone. The accessory such as surgical saw or rasp forming a hollow space is a small size in order to be inserted into incision hole smaller than the existing operation, to cut or grind the bone tissues. The accessory is attached to the handpiece which can give the linear reciprocation to the said rasp or saw. The said accessory could be connected additionally with a protector. The protector prevents the accessory from damaging soft tissues around an incised region as well as to ensure a space for the movement of the accessory. And the said protector supplies a saline solution therein. The handpiece includes a bone fragment discharge channel and a saline solution channel. The saline solution from an external unit can be supplied through the said saline solution channel to restrain heat generation and prevent bone fragments and periostea from clogging the accessory during the bone-cutting operation. The bone fragments is sucked into the inside of accessory then discharged through the bone fragment discharge channel. Therefore it is possible to cut bone continuously through minimum incision in a short time.
The present invention relates to a surgical handpiece used together with accessory such as a rasp or saw for cutting or grinding the bone. The handpiece is an element for converting the rotation of a motor into linear reciprocation and affording the linear reciprocation to the rasp or saw. The handpiece has a suitable internal mechanism structure for converting the rotation into the linear reciprocation, a desirable shape of housing for protecting the internal mechanism structure so that the handpiece can be held by a hand in an operation and in particular an accessory-connecting adaptor for supplying saline solution while sucking foreign substances during a bone-cutting or bone- grinding operation in cooperation with the accessory such as the saw and the rasp connected to the accessory-connecting adaptor. The accessory is an element coupled with the handpiece to cut or grind a bone in response to the linear reciprocation of the accessory-connecting adaptor. The accessory has a cutting face in the form of a saw or rasp formed at an end of an elongated rod to enable bone-cutting or bone-grinding by large quantities through a small incision. In particular, a bone fragment discharge channel is formed inside the rod of rasp to rapidly suck and discharge foreign substances such as bone fragments by large quantities from an action portion. The protector has a pipe structure coupled with the handpiece to prevent the burn through the contact of the rod of the saw or rasp on the skin as well as form a room from the rod so that saline solution can be supplied through the room. In the case where the a large quantity of bone is cut as in the plastic surgery on the face, conventional surgical handpieces have a single function of supplying power to surgical accessories (e.g., a rasp or saw) or sucking cut bone fragments from the outside of the surgical accessories. However, the handpiece of the present invention supplies saline solution from outside the accessory such as a rasp or saw rod to reduce the friction between the bone and the accessory thereby dropping the heat generation during the bone-cutting operation as well as dissolve cut bone fragments into saline solution thereby
preventing clogging to the rasp or saw so as to smoothen the cutting operation. Further, the suction is carried out through the hollow space inside the accessory to raise the suction efficiency, when compared with outside suction, even under the same negative pressure to shorten the operation time as well as enable effective cutting operation.
Brief Description of the Drawings FIG. 1 is a sectional view illustrating a surgical handpiece of the present invention; FIG. 2A illustrates an accessory-connecting adaptor coupled with an accessory; FIG. 2B is an exploded view of an accessory-locking nut, an accessory and an accessory-connecting adaptor; FIG. 3A is an exploded perspective view illustrating a protector having a connecting groove together with protector-connecting projections of an accessory-connecting adaptor; FIG. 3B is a plan view illustrating a protector and protector-connecting projections of an accessory-connecting adaptor; FIG. 4A illustrates a cooperative structure of a silicon connector tube, a suction coupling, a saline solution- supplying connector tube, a valve and a valve mount of a valve section; FIGS 4B and 4C illustrate locked and opened positions of a valve controlling the supply of saline solution, respectively; FIGS. 5A and 5B illustrate the assembly of a power transmission shaft and a power transmission joint; FIGS. 6A and 6B are sectional views illustrating the assembly and the linear reciprocation of a crank shaft, an inclined ball joint, a power transmission shaft housing and a power transmission shaft; FIG. 6C illustrates the assembly of a crank shaft and a crank mount;
FIG. 7A is an exploded sectional view of an inclined ball joint section including an inclined shaft, thrust bearings, an inclined ball joint, a radial bearing and a flange bearing! FIG. 7B is an exploded sectional view of a power transmission shaft section including a power transmission shaft, thrust bearings, radial bearings, a spacer and a power transmission shaft housing;
Best Mode for Carrying Out the Invention Hereinafter a handpiece, a protector, a saw and a rasp according to preferred embodiments of the present invention will be described in detail with reference the accompanying drawings. FIG. 1 is a sectional view illustrating a surgical handpiece of the present invention. An external drive unit 23 is provided with a motor, and powers a handpiece 20 via a flexible cable 22. The inside of the handpiece is divided into front and rear sections about a rubber bellows, in which the rear section as a mechanism section for converting the rotation of the motor into linear reciprocation includes a power transmission shaft 19, an inclined ball joint 13, a crank shaft 12 and a crank mount 11, and the front section includes an accessory-connecting adaptor 10 that is connected to the mechanism section for transmitting the linear reciprocation of the mechanism section into a surgical rasp or saw. The adaptor 10 has a bone fragment discharge channel 4 therein connected to a suction coupling 1 via a connector tube 6 made of an elastic material such as silicon. There are also provided with a rubber bellows 8 interposed between the crank mount 11 and the adaptor 10, a saline solution channel 3, a valve 5 for regulating the supply of saline solution, the suction coupling 1, a connector tube 2 for the supply of saline solution, protector- connecting projections 7 and a power transmission joint 15. The inside of the handpiece is constituted of the mechanism section for converting the rotation of the motor into the linear reciprocation, the adaptor 10
and the saline solution channel 3 which are discriminated from one another by the rubber bellows 8. The rubber bellows 8 water seals saline solution supplied into the saline solution channel 3 by the saline solution- supplying connector tube 2 so that saline solution does not flow into the handpiece, and a reactive action in response to the linear reciprocation. The linear reciprocation shifts the crank shaft 12 connected to the inclined ball joint 13 for about 3mm, and then the accessory adapt 10 connected to the crank shaft 12. Therefore, the accessory-connecting adaptor 10 is connected to the suction coupling 1 via the connector tube 6 made of silicon for the suction of bone fragments through the bone fragment discharge channel 4. FIG. 2A illustrates the accessory-connecting adaptor 10 coupled with an accessory 29 such as a saw and a rasp in order to transmit the linear reciprocation from the crank shaft 12 to the accessory 29. The accessory- connecting adaptor 10 has one end shaped as male threads for coupling with the accessory 29 to be fixed with an accessory-locking nut 33 and the other end shaped as female threads for coupling with male threads of the crank shaft 12. The accessory-connecting adaptor 10 has a hollow suction hole formed therein to function as the bone fragment discharge channel 4, and a projection 32 formed in a middle portion of the accessory-connecting adaptor 10 for adapting the silicon connector tube so that the silicon connector tube 6 is connected to the projection 32 to suck bone fragments from the projection 32. The silicon connector tube 6 is connected at one end with the suction coupling 1 and at the other end connected to the projection 32 to suck and send saline solution together with cut bone fragments during into the suction coupling 1 during a bone-cutting operation while flexibly reacting to the linear reciprocation. FIG. 2B is an exploded view of the accessory-locking nut 33, the accessory 29 and the accessory-connecting adaptor 10. A projection 31 at one end of the accessory-connecting adaptor 10 is coupled with a groove in a connecting portion 30 of the accessory 29 such as a saw and rasp and then the projection 31 and the connecting portion 30 are fixed by the accessory-locking
nut 33. According to the projection 31, a blade of a rasp is oriented at 180 degree and a blade of a saw to be oriented at 90 degree when connected to a handpiece body, and a surgeon can carry out an operation in a cozy posture while having the optimum filed of view during the bone-cutting operation. FIG. 3A is an exploded perspective view illustrating a protector 21 having a connecting groove 21a together with the protector-connecting projections 7 of the accessory-connecting adaptor 10, and FIG. 3B is a plan view illustrating the protector 21 and the protector-connecting projections 7 of the accessory- connecting adaptor 10. In a position that the accessory 29 is connected to the accessory- connecting adaptor 10 within the handpiece, the protector 21 coupled with the handpiece surrounds the accessory 29 to prevent the accessory 29 from damaging soft tissues around an incised region as well as to ensure a space for the movement of the accessory 29. Also saline solution can be flown into the incised region through a gap in the inside space of the protector 21 that is not occupied by the accessory 29. The connecting groove 21a is formed at a distal end of the protector 21 and the projections 7 are extended from a front outside wall of the handpiece 20 body in four directions. Thus, turning the protector 21 coupled with the body for 45 degrees locks the protector 21 so that it may not unlock or get loose during the bone-cutting operation. FIG. 4A illustrates a cooperative structure of the silicon connector tube 6, the suction coupling 1, the saline solution-supplying connector tube 2, the valve 5 and a valve mount 27 of a valve section, and FIGS 4B and 4C illustrate locked and opened positions of the valve 5 that controls the supply of saline solution, respectively. Saline solution is supplied or cut off by the valve 5 coupled with the saline solution-supplying connector tube 2 to flow through the saline solution channel 3 and into the rasp or saw via the protector 21. The supply of saline solution reduces the friction between a bone and the accessory in the bone-cutting operation to restrain heat generation and prevents bone fragments from clogging the rasp or saw to ensure smooth cutting as well as improves the
suction efficiency because the bone fragments are mixed into saline solution. The inside of the valve 5 has a Teflon ring 26 that provides water sealing with a sliding bearing. A hole 9a is perforated through a portion of the valve 5 connected to the saline solution-supplying connector tube 2 and a side of the Teflon ring 26 to allow the passage of saline solution through the same. Two holes 9b are extended horizontally in the valve mount 27: Turning the valve 5 for 90 or 270 degrees in a position perpendicular to the handpiece 20 aligns the Teflon-side hole 9a with the valve mount-side holes 9b so that saline solution is supplied through the holes 9a and 9b into the saline solution channel 3. Turning the valve 5 for 90 degrees in a position linear with the handpiece 20 causes the hole 9a to he misaligned from the holes 9b, thereby stopping the supply of saline solution. Hereinbefore the accessory-connecting adaptor 10, the saline solution channel 3 and the valve 5 in the front section about the bellows tube 8 has been described, and the mechanism section in the rear section will be described as follows. When external power is supplied to the handpiece 20 via the flexible cable 22, the inclined ball joint 13 and the crank shaft 12 convert the rotation of the motor into the linear reciprocation and four radial bearings 16a and two linear hearings 17 hold the crank shaft 12 in the crank mount 11 coupled with the crank shaft 12 to facilitate the linear reciprocation while reducing the heat generation. FIGS. 5A and 5B illustrate an embodiment of the power transmission shaft 19 within the handpiece and the power transmission joint 15 of the flexible cable coupled with each other for connecting the handpiece 20 to the flexible cable 22. Connecting portions of the power transmission shaft 19 and the power transmission joint 15 are cut respectively at suitable angles to form inclines so that the power transmission shaft 19 can be easily connected to the power transmission joint 15. Then, the inclines are engaged into each other regardless of the coupling direction so that a horizontal plane of the power
transmission shaft 19 is inserted into a groove of the power transmission joint 15 at the side of the flexible cable. FIGS. 6A and 6B are sectional views illustrating the mechanism section for converting the rotation into the linear reciprocation in which the crank shaft 12, the inclined ball joint 13, a power transmission shaft housing 18 and the power transmission shaft 19 are coupled together. These parts have following connecting structures. The power transmission shaft 19 has an inclined head, and an inclined shaft 36 extended through the inclined ball joint 13 is coupled to the inclined head of the power transmission shaft 19. A ball 37 is projected from a lateral portion of the inclined ball joint 13, and the crank shaft 12 has a hole in one end so that fixed insertion of the ball 37 of the inclined ball joint 13 into the hole connects the Inclined ball joint 13 to the crank shaft 12. The inclined ball joint 13 and the crank shaft 12 are connected to the power transmission shaft 19 performing rotation to carry out the linear reciprocation as follows. As power is supplied, the motor installed in the external drive unit 23 rotates and the power is transmitted via the flexible cable 22 so that the power transmission shaft 19 perform the rotation. • When the power transmission shaft 19 rotates as shown in FIG. 6B, the inclined shaft 36 connected to the head is rotated in the same direction and the inclined ball joint 13 is moved forward along the incline. The inclination of the inclined ball joint 13 and the rotation of the inclined shaft 36 are partially transmitted to the crank shaft 12 connected to the ball 37 of the inclined ball joint 13. As shown in FIG. 6C, the four radial bearings 16a and the two linear bearings 17 are provided in the crank mount 11, which supports the crank shaft 12 but allows only the linear motion to the crank shaft 12, so that the crank shaft 12 is coupled while passing through the bearings. When the inclined ball joint 13 is inclined forward, the ball 37 is also shifted forward so that the crank shaft 12 carries out the linear motion corresponding to the width of the inclination of the inclined ball joint 13. The linear bearings 17 are placed inside the cylindrical crank mount 11 to support the crank shaft
12 against any perpendicular force while ensuring the linear reciprocating path of the crank shaft 12. The radial bearings 16a are placed outside the crank mount 11 to ensure the linear reciprocating path of the crank shaft 12 to facilitate its movement while preventing the separation of the crank shaft 12 owing to the rotation. The radial bearings 16a also reduce friction to decrease heat generation. When the power transmission shaft 19 is rotated again as shown in FIG. 6A, the inclined shaft 36 is rotated, the inclined ball joint 13 is inclined backward, and the ball 37 returns to the original position so that the crank shaft 12 performs backward linear movement to establish one linear reciprocating stroke. FIG. 7A is an exploded sectional view of an inclined ball joint section including the inclined shaft 36, thrust bearings 14, the inclined ball joint 13, a radial bearing 16c and a flange bearing 35. The radial bearing 16c and the flange bearing 35 are installed within the inclined ball joint 13 to facilitate the rotation of the inclined shaft 36. The thrust bearings 14 are provided at both ends of the radial bearing 16c and the flange bearing 35 to disperse the axial load during the linear reciprocation to smooth the power transmission so that a resultant structure can endure even under high speed rotation. FIG. 7B is an exploded sectional view of a power transmission shaft section including the power transmission shaft 19, thrust bearings 14, radial bearings 16b, a spacer 34 and the power transmission shaft housing 18. The spacer 34 is provided inside the cylindrical power transmission shaft housing 18 to form spaces which house the two radial bearings 16b both in front and rear of the spacer 34 in order to facilitate the rotation of the power transmission shaft. The thrust bearings 14 are provided to reduce friction and abrasion while assisting the power transmission shaft 19 to endure the axial load when received the power of the motor rotating at a rate of about 12000 to 18000rpm. The inside of the power transmission shaft housing 18 is count bored to form installation spaces of the thrust bearings 14, which are positioned in front and rear of the radial bearings 16b. The power transmission shaft 19 is coupled
with the power transmission shaft housing 18 while extending through the thrust bearings 14 and the radial bearings 16b, then fixed by a shaft-locking nut 25 in the rear of the power transmission shaft housing 18 in order to prevent separation of these parts. The four thrust bearings 14 provided in front and rear of the inclined ball joint 13 and the count bored portions of the power transmission shaft housing 18 hold the inclined shaft 36 and the power transmission shaft 19 against axial outward thrust or pulling force so as to enable continuous and strong cutting. While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.