Patent Publication Number: US-2022218384-A1

Title: Vibration type removal apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to a vibration type removal apparatus that peels and removes a hard tissue from a soft tissue using a tool attached to its distal end portion. 
     BACKGROUND ART 
     A vibration type cutting apparatus that comprises a vibration device and cuts an object to be removed by vibrating a tool attached to a distal end portion of the vibration device has been known (e.g., Patent Literature 1). 
     In the vibration type cutting apparatus described in Patent Literature 1 and a general rotation type cutting apparatus, vibration of a tool by a vibration device is controlled to burst oscillation in which stop and vibration are repeated, to improve operability. 
     In the vibration type cutting apparatus described in Patent Literature 1, when surgery for removing a hard tissue adhering to a soft tissue is performed, the hard tissue is cut using the tool from the side of a surface opposite to its surface adhering to the soft tissue, and the hard tissue is cut until the thickness thereof is a small thickness, e.g., a thickness of approximately one sheet. The thinned hard tissue is carefully manually removed by a handpiece such as a curette. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: Japanese Patent Laid-Open No. 2019-088452 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, when a hard tissue is cut until it becomes thin, an unintended deviation of a distal end of a tool easily leads to a damage to a soft tissue because a force is applied to the tool in a direction in which the soft tissue exists. Particularly when a rotary tool is used, frictional heat generated on a contact surface with a thin hard tissue produces the possibility of damaging a soft tissue closest to the hard tissue. Thus, surgery (cutting work) needs to be carefully performed, so that a surgery time period is lengthened. 
     The present invention has been made in view of the foregoing points, and is directed to providing a vibration type removal apparatus capable of efficiently peeling and removing a hard tissue from a soft tissue. 
     Solution to Problem 
     [1] A vibration type removal apparatus according to the present invention is a vibration type removal apparatus that peels and removes a hard tissue from a soft tissue, the vibration type removal apparatus comprising a housing, a vibration device arranged in the housing, a tool provided in a distal end portion of the vibration device, protruding from the housing, and insertable between the hard tissue and the soft tissue, a control device that controls driving of the vibration device to vibrate the tool in an axial direction of the vibration device, and a cooling device that cools the tool, in which the control device controls the vibration of the tool by the vibration device to burst oscillation in which stop and vibration are repeated. 
     According to the present invention, the tool provided in the distal end portion of the vibration device and protruding from the housing is insertable between the hard tissue and the soft tissue. Thus, when the tool is inserted between the hard tissue as an object to be removed and the soft tissue and is vibrated with a force applied in a direction away from the soft tissue, the hard tissue can be peeled and removed from the soft tissue by cutting a surface, which adheres to the soft tissue, of the hard tissue. As a result, the hard tissue can be removed in a shorter time period and more stably than when the hard tissue is cut until it becomes thin. 
     The tool is cooled by the cooling device, and the vibration of the tool is further controlled to burst oscillation in which stop and vibration are repeated. Thus, the tool can be more prevented from generating heat so that heat to be applied to the soft tissue and a peripheral tissue can be more suppressed than when the tool is always vibrated. 
     [2] A first surface, which opposes the soft tissue, of the tool preferably has a plurality of recesses or a groove extending toward a distal end side from a proximal end side of the tool formed thereon. 
     This configuration makes it possible to more efficiently cool the tool than when the first surface, which opposes the soft tissue, of the tool is a flat surface having no unevenness. 
     [3] A second surface, which opposes the hard tissue, of the tool is preferably formed in a circular arc shape, and also a planar shape or a concave shape. 
     This configuration makes it easier to insert the tool between the hard tissue and the soft tissue than when the second surface, which opposes the hard tissue, of the tool has a projection shape. 
     [4] The cooling device is preferably composed of a cooling liquid supply device that supplies a cooling liquid, and the housing is preferably provided with a flow path that causes the cooling liquid supplied from the cooling liquid supply device to flow toward a distal end side of the tool. A distal end of the flow path is preferably provided to spray the cooling liquid toward a distal end portion of the tool. 
     This configuration makes it possible to cool the tool with cooling liquid supplied from the cooling liquid supply device and flowing through the flow path, and thus makes it possible to more efficiently cool the tool. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an explanatory view related to a configuration of a vibration type removal apparatus according to an embodiment of the present invention. 
         FIG. 2A  is a perspective view illustrating a tool. 
         FIG. 2B  is a perspective view illustrating the tool. 
         FIG. 3A  is a schematic view illustrating the tool, a hard tissue, and a soft tissue. 
         FIG. 3B  is a schematic view illustrating a state where the tool is inserted between the hard tissue and the soft tissue. 
         FIG. 3C  is a schematic view illustrating a state where a hard tissue is peeled and removed using the tool. 
         FIG. 4  is a perspective view illustrating a tool having a plurality of recesses formed therein. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     An embodiment of the present invention will be described below with reference to the drawings. 
     As illustrated in  FIG. 1 , a vibration type removal apparatus  2  according to an embodiment of the present invention comprises a housing  10  having a substantially cylindrical shape, a holding member  11 , a tool  12 , a control device  20 , a vibration device  21 , and a cooling pump  22 , which constitute a handpiece. 
     The housing  10  is designed to a size small enough for a normal person to hold it with one hand. Although a handpiece as a high-frequency vibration type cutting apparatus is constituted by components such as the housing  10  and the holding member  11  at least a part of which is arranged in an inner space of the housing  10 , the respective types and specifications of the components may be appropriately selected from the viewpoint of making the handpiece lightweight for simplicity of handling. 
     The holding member  11  has its rear end portion attached to the vibration device  21 , and is supported to be movable in its axial direction on the housing  10  via a support section (not illustrate) fixed to an inner sidewall of the housing  10 . 
     The holding member  11  has a function as a horn for increasing an amplitude. The tool  12  is detachably attached to a distal end portion of the holding member  11 . 
     The tool  12  may be easily insertable between a hard tissue HT and a soft tissue ST (see  FIG. 3B ), and examples of the type of the tool  12  include a curette, a chisel, a scalpel, a file, a long type, and a short type. A blade having a linear shape or a circular arc shape at its distal end or a tool having any shape such as a substantially columnar shape, a spoon shape, or a bent or curved rod shape is adopted as the tool  12 . 
     In the present embodiment, the tool  12  is composed of a curette, a distal end portion of the tool  12  has a hemispherical shape, a first surface  12   a , which is obtained by cutting a sphere in half, of the tool  12  is formed in a circular arc shape and a concave shape, and a groove  12   c  extending toward the distal end portion from a proximal end portion on the holding member  11  side of the tool  12  is formed on a second surface  12   b  as a hemispherical portion of the tool  12 . 
     The vibration device  21  is attached to an attachment section (not illustrated) in the housing  10  and is composed of a piezoelectric element arranged in the inner space of the housing  10  so that the holding member  11  is vibrated or driven to reciprocate in the axial direction. 
     The vibration device  21  and the holding member  11  are arranged such that their respective axes are common and arranged away from each other in their respective axial directions. Accordingly, spaces respectively occupied by the vibration device  21  and the holding member  11  in the inner space of the housing  10 , and thus the housing  10  can be made more compact in a direction perpendicular to the axes than when the axes are arranged parallel to and away from each other or arranged nonparallel to each other. As a result, a vibration type removal apparatus can be configured as a handpiece ease of handling and operability of which are improved. 
     A force of the vibration device  21  is directly transmitted to the holding member  11  without a transmission mechanism being used. Accordingly, a lubricant such as grease to generally be used for the transmission mechanism is not required. Therefore, when the vibration type removal apparatus  2  as medical equipment is subjected to sterilization treatment with high-pressure steam, a situation where contamination of the medical equipment derived from the existence of the lubricant occurs is avoided. 
     The control device  20  is connected to the vibration device  21  via a cable  24  attached to a rear end portion of the housing  10 , to control supply of power to the vibration device  21 . 
     The control device  20  controls an operation of the vibration device  21 . The control device  20  is composed of a microcomputer or a processor. The control device  20 , together with a substrate on which it is mounted, may be arranged in the inner space of the housing  10 . 
     The control device  20  performs control such that a vibration frequency f 2  in an axial direction of the tool  12  via the holding member  11  by the vibration device  21  falls within a range of 20 to 60 [kHz]. The vibration frequency f 2  is more preferably controlled to 25 to 45 [kHz]. 
     Further, the control device  20  controls the vibration of the tool  12  by the vibration device  21  to burst oscillation in which stop and vibration are repeated, and an overall burst frequency f 1  of the tool  12  in which a burst period during which the tool  12  is vibrated and a stop period during which the tool  12  is stopped are combined into one cycle is controlled depending on the cooling efficiency of the tool  12 . 
     With the vibration type removal apparatus  2  having the above-described configuration, the holding member  11  is driven to reciprocate in the axial direction, whereby an object is cut using the tool  12  provided in the distal end portion of the holding member  11 . 
     The control device  20  controls the vibration of the tool  12  by the vibration device  21  to burst oscillation in which vibration and stop are repeated. 
     Specifically, the control device  20  controls the burst frequency f 1  of the tool  12  to a range of 1 to 300 [Hz] as a low frequency at which an operator can recognize a cycle of a burst period and a stop period, and controls a duty ratio dl obtained by dividing a pulse width t 1  of the burst frequency by a pulse period T 1  to a range of 5 to 50 [%]. 
     The cooling pump  22  sends out (supplies) cooling water sent from a cooling water supply source (not illustrated), and the driving thereof is controlled by the control device  20 . 
     A flow path  25  that causes cooling water supplied from the cooling pump  22  to flow is attached to the rear end portion of the housing  10 . The flow path  25  extends to a distal end portion from the rear end portion of the housing  10 . 
     [Peeling and Removal] 
     A case where the hard tissue HT as an object to be removed is peeled and removed using the vibration type removal apparatus  2  will be described. 
     As illustrated in  FIG. 3A , the operator who performs peeling and removal (surgery) first attaches the tool  12  to the distal end portion of the holding member  11 . 
     Then, the operator causes the control device  20  to drive the cooling pump  22 , as illustrated in  FIG. 3B . As a result, cooling water supplied from the cooling pump  22  passes through the flow path  25  in the housing  10 , and is sprayed toward the tool  12  from a distal end of the flow path  25 . In this state, the operator inserts the tool  12  between the hard tissue HT and the soft tissue ST. In  FIG. 3B  and  FIG. 3C , cooling water is indicated by a dotted line for simplification. 
     As illustrated in  FIG. 3C , the operator causes the control device  20  to operate the vibration device  21 , to drive the holding member  11  to reciprocate in the axial direction. As a result, the tool  12  provided in the distal end portion of the holding member  11  is driven to reciprocate (vibrated) in the axial direction. At this time, the operator applies a force in a direction away from the soft tissue ST (in an upward direction in  FIG. 3C ). 
     Due to the vibration of the tool  12 , the hard tissue HT is cut from the side of an adhering surface of the soft tissue ST and the hard tissue HT, and the hard tissue HT is peeled from the soft tissue ST. As a result, the hard tissue HT can be removed in a shorter time period and more stably than when the hard tissue HT is cut until it becomes thin toward the soft tissue ST. 
     In the present embodiment, the hard tissue HT is a bone, an ossified cell, or the like of a predetermined portion of a human body, and the soft tissue ST is a nerve, a blood vessel, or the like adjacent to the hard tissue HT. Accordingly, the safety of the soft tissue ST needs to be ensured in the surgery. 
     In the present embodiment, the control device  20  controls the vibration of the tool  12  by the vibration device  21  to burst oscillation in which vibration and stop are repeated. As a result, the tool  12  can be more prevented from generating heat so that the safety of the soft tissue ST can be more ensured than when the tool  12  is always vibrated or a tool which is rotated. 
     The tool  12  is cooled with cooling water. Thus, the tool  12  can be further prevented from generating heat. 
     Further, the groove  12   c  is formed on the second surface  12   b , which contacts the soft tissue ST, of the tool  12 , and cooling water is also sent to the groove  12   c . As a result, a cooling effect with cooling water can be enhanced. 
     Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the embodiment, but is appropriately changeable without departing from the spirit of the present embodiment. 
     Although the tool  12  is cooled with cooling water in the above-described embodiment, for example, the cooling is not limited to the cooling with cooling water as long as the tool  12  can be cooled. For example, cooling gas may be sprayed onto the tool  12 . 
     The groove  12   c  of the tool  12  may be extended toward a rear end portion of the tool  12  so that cooling water is directly poured into the groove  12   c.    
     Although the first surface  12   a  of the tool  12  is formed in a circular arc shape and a concave shape in the above-described embodiment, the first surface  12   a  may be formed in a circular arc shape and a planar shape. 
     Further, although the groove  12   c  extending toward the distal end side from the proximal end (rear end) side of the tool  12  is formed on the second surface  12   b  of the tool  12  in the above-described embodiment, the shape of the groove  12   c  is appropriately changeable. For example, a spiral groove may be formed. Further, a plurality of grooves may be formed. 
     A plurality of recesses  12   d  as illustrated in  FIG. 4  may be formed instead of or in addition to the groove  12   c . In this case, a cooling effect can also be enhanced. 
     Further, a shape of the flow path  25  is appropriately changeable. For example, the flow path  25  may be formed in such a spiral shape as to surround the holding member  11 . A flow path for causing cooling water to flow may be formed in the tool  12 . 
     REFERENCE SIGNS LIST 
       2  . . . vibration type removal apparatus,  10  . . . housing,  11  . . . holding member,  12  . . . tool,  20  . . . control device,  21  . . . vibration device,  22  . . . cooling pump, HT . . . hard tissue, ST . . . soft tissue