Abstract:
The present invention relates to a volume-adjustable micro-injection device. The device includes a base structure having a syringe positioning structure and a grip, in which the syringe positioning structure can flexibly accommodate injection syringes with different volumes; a holding structure capable of flexibly adjusting an injection angle of syringe content for easier operation; a qualitative controller capable of accurately controlling injection volume; a pressure pushing structure to hold and push a plunger; an injection controller interlinked with the qualitative controller and the pressure pushing structure; and an eject structure facilitating simple operation and easy replacement of injection syringes. In contrast to conventional structures, the present invention provides advantages that control injection volume more accurately, address better injection angle control, allow for the syringe contents to be free from air exposure, require no special syringes, and allow for single-handed replacement of the injection syringe.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a volume-adjustable micro-injection device capable of being applied to liquid or semi-liquid soft tissue filler transplantation or drug delivery, and more particularly to delivery that can properly, evenly and precisely place a filler or drug into a correct position in the human body. It can be applied to soft tissue augmentation, reconstructive surgery or cosmetic surgery, to achieve low cost, high precision, and simple operation. 
       BACKGROUND OF THE INVENTION 
       [0002]    It has been over one century since fat transplantation/fat grafting was proposed in literature by German doctor, Neüber in 1893 [1]. Fat transplantation/fat grafting has been considered for a long time as a procedure for soft tissue augmentation or filling and thus has been often applied to aspects of reconstructive surgery and cosmetic surgery [2.3]. 
         [0003]    In general, the side effects of fat transplantation/fat grafting can be one or a combination of absorption, infection, embolism, cyst formation, calcification, ossification, pseudotumor, necrosis, asymmetry, skin necrosis/fistula formation, iatrogenic nerve/vascular injuries, carvenous sinus thrombosis and so forth [4]. After investigation into the causes of said side effects, most are directly related to improper, uneven or excess placement of fat during the fat transplantation/fat grafting procedure. As a result, the correct positioning of fat in a proper, even and precise manner becomes the most critical concern during the clinical application of fat transplantation/fat grafting. 
         [0004]    According to the article “Structural Fat Grafting: More Than a Permanent Filler”, composed by celebrated plastic surgeon SR Coleman in the well-known journal, Plast. Reconstr. Surg. in 2006, several valuable points [5] pertinent to the correct placement of fat were disclosed. The important points are summarized as follows; 
         [0005]    While transplanting fat, the accuracy of the placed volume is extremely important; once the fat is injected into human body, the fat mass can hardly be manipulated again. 
         [0006]    When an infiltration cannula is withdrawn each time and the fat is injected spontaneously into the human body during facial fat transplantation, the transplanted fat volume must be precisely controlled down to 1/10 cc per injection. 
         [0007]    The maximum fat injection volume into a specific area of the body, e.g. the eyelid, should be approximately 1/30 cc or even as low as 1/50 cc. 
         [0008]    However, while performing fat transplantation using the 1-cc syringe suggested by SR Coleman during clinical application, a precise advancement of 1/10 cc of fat per-injection is a very difficult task and, not to mention that an injection volume with an accuracy of 1/30 or 1/50 cc is actually beyond human control. For the sake of better surgical effects, the Byron Medical Co. has marketed the DISPOS-A-JECT™ SYSTEM as illustrated in  FIG. 1 . However, such a system secures a minimum output volume of 1/10 cc only and obviously fails to achieve the smaller volume demands of 1/30 or 1/50 cc. Besides, the 1-cc syringe connected with the DISPOS-A-JECT™ SYSTEM requires a more costly 1-cc BD luer-lock syringe instead of a regular 1-cc syringe supplied in most hospitals and clinics, thus resulting in the deficiency of both operational convenience and universality. 
         [0009]    While using the DISPOS-A-JECT™ SYSTEM to perform fat transplantation surgery, as shown in  FIG. 1 , the plunger  81  of syringe  8  is removed first; then an adapter  82  of the SYSTEM is inserted into syringe  8  to thereby advance the fat. During the operation, the fat is exposed to air and there are concerns that the fat cells may be contaminated and have a low survival rate. Moreover, as the included angle between the gun surface of the SYSTEM and the injection needle  83  and the injection needle aperture  84  is fixed, surgeons do not have flexibility in adjusting the injection angle while the SYSTEM is being clinically applied to fat grafting surgery. As a result, injection surface deviation or injection difficulty easily takes place in the case of a rough operation. 
         [0010]    Taking into account the aforementioned descriptions, accuracy of surgery, airtight property of the equipment, simple operation and so on, a novel fat transplantation device is indeed required to resolve these drawbacks arising from the conventional technique. 
       Notes: 
       [0000]    
       
         [1] Neüber. Fetttransplantation. Zentrabl. Chir. 22:66, 1893 
         [2] Chajchir, A., and Benzaquen, I. Fat-grafting injection for soft-tissue augmentation. Plast. Reconstr. Surg. 84:921-24, 1989. 
         [3] Chajchir, A., Benzaquen, I., Wexler, E., et al. Fat injection. 14:127-36, 1990. 
         [4] Khawaja, H. A., Handez-perez, E. Fat transfer review: controversies, complications, their prevention, and treatment. Int. J. Cosmet. Surg. Aesth. Dermatol. 4:131-38, 2002. 
         [5] Coleman, S. R. Structural fat grafting: more than a permanent filler. Plast. Reconstr, Surg. 118:108s-20s, 2006. 
       
     
       SUMMARY OF THE INVENTION 
       [0016]    In regards to the first aspect of the present invention, an adjustable micro injection device featuring high accuracy, and easy operation for application to liquid or semi-liquid soft tissue filler transplantation or drug injection is provided. The micro injection device contains a qualitative controller and an injection controller disposed in the base structure. The qualitative controller is employed to precisely control the advancing stroke of the injection controller to control the injection dose of filler or drug. The present invention ensures enhanced surgery accuracy and facilitates operation thereof. 
         [0017]    In regards to the second aspect of the present invention, an adjustable micro injection device featuring easy control over an injection direction for application to liquid or semi-liquid soft tissue filler transplantation or drug injection is provided. The micro injection device contains a syringe positioning structure and a holding structure found on the base structure. The syringe positioning structure fastens a syringe, and the holding structure contains a movable angle adjustment knob, having one end for mounting the syringe and the other end for connecting the syringe. By turning the angle adjustment knob, change of the output direction of the filler or the drug inside the syringe is achieved, demonstrating that the present invention provides the function to easily control the injection direction. 
         [0018]    In regards to the third aspect of the present invention, an adjustable micro injection device featuring a high airtight property and less expensive cost for application to liquid or semi-liquid soft tissue filler transplantation or drug injection is provided. The micro injection device contains a holding structure at one end of the syringe positioning structure with a pressure pushing structure and an eject structure at the other end. The device can employ a regular syringe commonly seen on the market by virtue of its stabilizing structure to achieve an excellent holding effect without requiring a special syringe that is costly and not commonly available on the market, thereby reducing the cost of injection. 
         [0019]    Furthermore, the syringe positioning structure can accommodate syringes with different volumes. Hence, the present invention serves for multiple purposes and can be applied to various surgeries or medical procedures requiring different injection volumes. While replacing the filler or drug, through the design of the eject structure, the overall syringe is directly replaced. As the filler or drug inside the syringe is not exposed to ambient air, the present invention assumes a highly airtight property and lowers the chance of contamination due to contact with external air. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is an external view of a conventional fat transplantation device; 
           [0021]      FIG. 2  is an exploded view showing parts of the present invention; 
           [0022]      FIG. 3  is a combined external view of the present invention; 
           [0023]      FIG. 4  is a combined plane view of the present invention; 
           [0024]      FIG. 5  is an operational movement view showing the injection controller of the present invention; 
           [0025]      FIG. 6  is an enlarged view showing a partial portion of  FIG. 5 ; 
           [0026]      FIG. 7  is an operational movement view showing the eject structure of the present invention; 
           [0027]      FIG. 8  is a partial movement view showing the eject structure of the present invention; 
           [0028]      FIG. 9  is an enlarged view showing a partial portion of  FIG. 7 ; and 
           [0029]      FIG. 10  is an operational movement view showing the qualitative controller of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0030]    The volume-adjustable micro-injection device of the present invention can be applied to liquid or semi-liquid soft tissue filler augmentation or to drug delivery. An injection dose and injection angle are simply and precisely controlled by a precise injection dose control function and an accurate injection angle adjustment function. 
         [0031]    To stand out and fully comprehend the aforementioned objective, features and advantages of the present invention, one preferred embodiment of the present invention is specifically presented along with detailed illustrative descriptions: 
         [0032]    In cooperation with the illustration of  FIG. 2  and  FIG. 3 , the preferred embodiment of the present invention pertains to an injection device for liquid or semi-liquid tissue filler transplantation or drug delivery. The device includes a base structure, formed by a left case  11  and a right case  12  and is composed of a metal or non-metal material, e.g. plastic material. The base structure contains a syringe positioning structure  1  for fixing an injection syringe  8  (as shown in  FIG. 4 ) and a grip for the hand to hold and operate the device. 
         [0033]    The syringe positioning structure  1  includes a support seat  13  and a syringe positioning block  14 . The support seat  13  can either be integrally extended from the left and right cases  11 ,  12  or individually assembled for forming the position capable of supporting the injection syringe  8 . The syringe block  14  is placed in a slide groove  15  on the left and the right cases  11 ,  12  to allow it to be adjusted and fixed on both sides of the injection syringe  8 . 
         [0034]    The injection device for liquid or semi-liquid tissue filler augmentation or drug injection in the preferred embodiment of the present invention further includes: a holding structure  2  located at one end of the syringe positioning structure  1  and at least having an angle adjustment knob  21 , a fastener  22  and an angle tenon  23 , in which the fastener  22  and the angle tenon  23  are tightly integrated on the base structure. The angle adjustment knob  21  is a movable member and is fitted with the fastener  22  in a tight-fit manner. An injection needle  83  (as shown in  FIG. 4 ) is fitted on one end of the angle adjustment knob  21 , and the syringe  8  is successively connected with the other end. The design of the polygonal urging sides  24  of the angle adjustment knob  21  is employed such that after the direction of an aperture  84  of the injection needle  83  is rotationally adjusted, the polygonal urging side is pushed and fixed by the angle tenon  23 , the effect of which allows the output direction of the filler or drug inside the injection needle  83  to be adjusted; 
         [0035]    a pressure pushing structure  3  containing a push rod adjustment knob  31 , a push plate  32 , a drive rod  33 , two partition plates  34  and two guide blocks  35 , in which the two partition plates  34  are tightly integrated in the base structure for fixing the two guide blocks  35  at predetermined positions within the left and the right cases  11 ,  12  and for penetrating the drive rod  33  through the two guide blocks  35  and reciprocally sliding therebetween. One end of the drive rod  33  is connected with the push rod adjustment knob  31  through the push plate  32 , and the push rod adjustment knob  31  is adjusted to push against one end of the plunger  81  of the injection syringe  8 ; 
         [0036]    an eject structure  4  containing an eject tenon  41  and a spring  42 , in which the eject tenon  41  has a conical part  43  formed thereon and is movably mounted between the left and the right cases  11 ,  12  after passing through the spring  42 , and is located near the drive rod  33 ; 
         [0037]    an injection controller  5  containing a trigger  51 , a return spring  52 , a link block  53 , a thrust spring  54  and a drive plate  55 , wherein the trigger  51  is pivotally positioned between the left and the right cases  11 ,  12 . The link block  53  is used to pivotally connect one end of the trigger  51  and the drive plate  55 . The return spring  52  is disposed around the pivot of the trigger  51  (as shown in  FIG. 4 ) for constant urging of one end of the trigger  51  pivotally connected the link block  53  against a fixed column  56 . A through hole  57  is provided on the drive plate  55  for the drive rod  33  to pass through, and the thrust spring  54  is mounted to the pivot of the drive plate  55  and the link block  53  for constant urging of a movable end of the drive plate  55  against the eject tenon  41 ; 
         [0038]    a qualitative controller  7  containing a dose control knob  71 , a control knob positioning member  72 , a synchronous control shaft  73 , a knob  74  and a positioning spring  75 , in which the dose control knob  71  and the control knob positioning member  72  are all pivotally positioned between the left and the right cases  11 ,  12 . The dose control knob  71  is constituted by a block-like body with unequal sides. A movable end of the control knob positioning member  72  is connected with the above-mentioned fixed column  56  such that the control knob positioning member  72  constantly urges against one of the sides of the dose control knob  71 . One end of the synchronous control shaft  73  pivotally mounted to the dose control knob  71  penetrates through the base structure and is fixed with the knob  74  by a forced synchronous coupling selected from the non-circular hole and shaft coupling, key, pin and hub so as to synchronously rotate the knob  74  and the dose control knob  71 . 
         [0039]    In cooperation with the reference to  FIG. 4  and  FIG. 5 , when pulling the trigger  51 , the link block  53  drags the drive plate  55  for synchronous displacement. Together with the illustration of  FIG. 6 , as the surface of the drive rod  33  has plenty of tiny wavy spiral ripples, the through hole  57  of the drive plate  55  is engaged with the spiral ripples so as to drag the drive rod  33  to synchronously slide. The drive rod  33  drives the push rod adjustment knob  31  to push the plunger  81  of the injection syringe  8  to send out the filler or drug inside the injection syringe  8 . 
         [0040]    When a protrusion  511  of the trigger  51  urges against one of the sides of the dose control knob  71 , the maximum displacement of the trigger  51  is pulled. As such, the pulling angle of the trigger  51  is limited by the dose control knob  71 . Meanwhile, the displacement of the plunger  81  pushed by the pressure pushing structure  3  can be constrained accordingly to attain the control effect of the injection dose. 
         [0041]    As shown in  FIG. 7 , when replacing the injection syringe  8 , the eject tenon  41  of the eject structure  4  is pushed to axially slide. As shown in  FIG. 8 , the conical part  43  of the eject tenon  41  pushes the movable end of the drive plate  55  to wobble in an angular orientation. Together with the illustration of  FIG. 9 , the through hole  57  of the drive plate  55  then disengages from the spiral ripples on the surface of the drive rod  33  such that the pressure pushing structure  3  can be completely pulled out, thereby releasing the injection syringe  8  from a pushing and holding state and facilitating the replacement with another injection syringe  8 . 
         [0042]    While replacing the injection syringe  8  of the device, the whole structure is replaced. Therefore, the contents inside the injection syringe  8  during the replacement process do not contact with ambient air. As such contamination of the filler or drug inside the syringe is prevented, the bioability of delivered filler or drug is enhanced. 
         [0043]    As illustrated in  FIG. 10 , the device can provide an injection dose control function. The knob  74  is used to select an allowable displacement between the dose control knob  71  and the protrusion  511  of the trigger  51 . The control knob positioning member  72  is used to fix a selected side of the dose control knob  71 . 
         [0044]    In view of different radial distances between each side of the dose control knob  71  and its pivot, the allowable displacement between each side and the protrusion  511  of the trigger  51  is relatively variable as well. The accuracy for a single injection dose can reach 1/100 of the maximum volume of the injection syringe. Consequently, the device can provide a multitude of choices for injection doses without the replacement of the injection syringe  8  or the injection device depending on the requirements of injection doses. The present invention provides the advantage that a single system suits for various injection dose demands, the progressiveness in operating convenience and lower cost in contrast to the conventional structure. 
         [0045]    In sum, the present invention has better airtight properties, inexpensive cost and completely solves the operational inconvenience and insufficient control accuracy of injection doses arising during surgery. The device of the present invention is extensively applied to fat transplantation in reconstructive and cosmetic surgery, injection of soft tissue fillers (hyaluronic acid, collagen, etc.), delivery of botulinum toxin type-A and other drugs. From the above-mentioned characteristics, these features not only have novel and progressive properties compared to similar products but also have an industrial utility. 
         [0046]    While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, which are to be in accordance with the broadest interpretation so as to encompass all such modifications and similar structures.