accompanying fig1 depicts an exemplary embodiment of a hand - held surgical instrument 10 according to the present invention . in this regard , the surgical instrument 10 includes an elongated handle 12 sized and configured to allow the instrument 10 to be handled manually by a surgeon during surgical procedures . the handle 12 includes a manually operated actuator assembly 10 - 1 which serves to actuate a tool 11 operatively attached to , and extending from , the distal end of the handle . the tool 11 , for example , may be a miniature forceps 11 - 1 positioned at the distal - most end thereof which open and close in response to actuation of the actuator assembly 10 - 1 in a manner that will be described in greater detail below . as is perhaps more clearly shown in accompanying fig2 the distal end 12 - 1 of the handle 12 includes an axially elongate cylindrical recess 12 - 2 which receives a proximal correspondingly configured stem portion 14 - 1 of the actuation pin holder 14 . the stem portion 14 - 1 of the actuation pin holder 14 is most preferably fixed immovably within the recess 12 - 2 by any convenient technique , for example , by press - fitting and / or adhesives , so that the actuation pin holder 14 is a rigid distal extension of the handle 12 . the distal end of the actuation pin holder 14 is provided with a circumferentially enlarged male head portion 14 - 3 which is threadably coupled to a threaded female recess portion 16 - 1 of the lever housing 16 , the purpose and function of which will be described in greater detail below . the actuation pin holder 14 also defines a distally open - ended , axially oriented , cylindrical hollow 14 - 2 which is sized so as to movably receive therewithin the proximal barrel portion 18 - 1 of the actuation pin 18 . the barrel portion 18 - 1 is therefore capable of coaxially longitudinal sliding movements within the hollow 14 - 2 of the pin holder 14 so as to move axially between advanced and retracted conditions . in this regard , the structures are shown in accompanying fig2 as being in their respective rest , or “ normal ” conditions . thus , the “ normal ” condition for the actuation pin 18 is in its retracted condition as shown therein . the distal end of the actuation pin 18 includes a generally conically shaped bearing nib 18 - 2 which distally projects from an axially transverse flange 18 - 3 . an annular channel 18 - 4 is defined between the transverse flange 18 - 3 and the proximally disposed barrel portion 18 - 1 and receives the terminal end regions of each of the circumferentially spaced - apart actuation levers ( a few of which are identified in fig2 by reference numeral 20 ). as shown , each of the actuation levers 20 is generally l - shaped and includes a proximally extending arm section 20 - 1 of substantially greater length as compared to the distal leg section 20 - 2 . the levers 20 are most preferably one - piece structures and define an arcuately shaped bearing surface 20 - 3 along an outer edge region generally at the juncture of the arm and leg sections 20 - 1 , 20 - 2 . the housing 16 defines a plurality of radially oriented slots corresponding in number to the number of actuation levers 20 . the slots 16 - 2 are circumferentially spaced - apart from one another by an equal angular distance so that each receives therein a respective one of the actuation levers 20 generally at the juncture between the arm and leg sections 20 - 1 and 20 - 2 . the levers 20 are thus also circumferentially spaced apart from one another about the central longitudinal axis a l ( see fig2 ) of the device 10 and thus the actuation pin 18 also . in such a manner , the arm sections 20 - 1 of each lever 20 extend proximally outwardly from the housing 16 and thus bridge the space between the housing 16 and the distal tapered end 12 - 3 of the handle 12 in coaxially circumferentially surrounding relationship to the actuation pin holder 14 . these numerous exposed arm sections 20 - 1 of each actuation lever 20 thereby present the attending surgeon with a tactile sensation of a seemingly “ solid ” surface surrounding the central longitudinal axis of the device 10 . thus , the exposed proximally extending outer edge regions of the arm sections 20 - 1 will establish the generatrices of a curved surface which coaxially surrounds the longitudinal axis a l of the device 10 and essentially bridges the distance between the distal lever housing 16 and the proximal handle 12 . the actuation levers 20 are physically retained in each of their respective slots by an annular retaining ring 22 which bounds the housing 16 and the individual actuation levers 20 disposed in the slots 16 - 2 . the retaining ring 22 defines an interior cross - sectionally arcuate stationary guide surface 22 - 1 which conformably mates with the bearing surface 20 - 3 of each of the actuation levers 20 . thus , the radii of curvature of each of the surfaces 22 - 1 and 20 - 3 are coincident with one another . as will be observed particularly in fig1 and 2 , the individual actuation levers 20 are most preferably relatively thin , planar structures which are oriented in the radial slots 16 - 2 of the housing 16 so as to be disposed coincident with radial planes from the central axis a l . the exposed outer proximal edge regions of each of the levers 20 may thus be provided with serrations 20 - 4 so as to promote a more rough feel to the attending surgeon . other means may also be employed in order to improve the tactile sensation and / or feel of the levers 20 , such as , for example coating at least the external exposed edges of the levers with a friction material ( e . g ., an elastomeric material ) or the like . the operation of the actuator assembly 10 - 1 employed in the hand - held surgical device 10 in accordance with the present invention is depicted generally in accompanying fig3 and 4 . in this regard , the proximal end 11 - 2 of the tool 11 ( see fig1 ) may be threadably and removeably connected to the threaded nipple 16 - 3 coaxially extending distally from the housing 16 . although not shown , the tool 11 will conventionally have an actuator rod which extends through the nipple 16 - 3 proximally into operative engagement with the bearing nib 18 - 2 . moreover , the tool 11 is conventionally provided with a spring element which urges the actuation rod thereof into contact with the activation nib 18 - 2 . thus , the force of the tool &# 39 ; s spring element will cause the actuation pin 18 to be displaced proximally within the holder 14 so that it assumes its “ normal ” or rest condition as shown in fig3 . upon application of a radially inwardly directed force ( as noted by the arrows a f in fig3 ), the lever arms 20 - 1 are caused to move collectively toward the holder 14 ( that is , to be moved to a position closer to the central axis a l of the device 10 ). more specifically , the bearing surfaces 20 - 3 of the levers 20 are caused to slide along the cross - sectionally arcuate guide surface 22 - 1 of the retainer ring 22 so that as to cause the radially inwardly directed lever leg 20 - 2 to be moved generally pivotally from its rest condition as shown in fig3 to its active condition as shown in fig4 . as will be observed , since the terminal ends of each of the legs 20 - 2 are received within the annular channel 18 - 4 of the actuation pin 18 , such movement ( or “ throw ”) of the lever legs 20 - 2 will translate in coaxial linear movement of the actuator pin 18 ( and hence its distally extending actuation nib 18 - 2 ) from its rest position as shown in fig3 to its actuation condition in the direction of arrow am as shown in fig4 . thus , the nib 18 - 2 will push the tool &# 39 ; s actuation rod ( not shown ) distally against the bias force of the tool &# 39 ; s spring element ( also not shown ) to cause actuation of the working elements of the tool 11 , such as the miniature forceps 11 - 1 as depicted in fig1 . it should be noted here that , although the tool 11 is in and or itself conventional and of the type that may be employed generally in combination with sutherland - type instruments — that is , will have its own self - contained spring element — the surgical devices 10 in accordance with this invention could alternatively ( or additionally ) be provided with a spring element . for example , a spring element could be positioned within the hollow 14 - 2 of the holder 14 and exert an appropriate bias force on the actuation pin 18 as may be required or desired . accompanying fig5 a and 5b depict alternative embodiments of the actuator assembly 10 - 1 that may be employed in the devices of the present invention . in this regard , each of the actuator assemblies 10 - 1 ′ and 10 - 1 ″ shown in fig5 a and 5b , respectively , is generally identical to the actuator assembly 10 - 1 , with the principal exceptions being the configurations of the levers 20 and the retaining ring 22 . thus , identical structural elements among the various embodiments are noted by the same reference numerals . by way of example , the embodiment depicted in fig5 a includes actuation levers 20 ′ which define a generally semi - circular bearing surface 20 - 3 ′ provided generally at the juncture between the proximally extending lever arm sections 20 - 1 ″ and the downwardly radially projecting leg sections 20 - 2 ′ . this bearing surface 20 - 3 ′ therefore bears against , and cooperates with , a semi - circularly shaped guide surface 22 - 1 ′ defined in cross - section by the retaining ring 22 ′. a retaining lip 20 - 5 is also provided as an extension of sorts of the bearing surface 20 - 3 ′ and therefore projects somewhat distally around the guide surface 22 - 1 ′ so as to assist in the sliding movement of the bearing surface 20 - 3 ′ against the stationary guide surface 22 - 1 ′. the terminal ends of the lever leg sections 20 - 2 ′ terminate in a slightly arcuate terminal edge 20 - 4 ′ which is received within the recessed channel 18 - 4 of the actuation pin 18 . the center of the arcuate terminal edge 20 - 4 ′ is coincident with centers of the semi - circular bearing surface 20 - 3 ′ and guide surface 22 - 1 ′, capturing the levers 20 ′ between them . the arcuate edges 20 - 4 ′ of the leg sections 20 - 2 ′ thereby help to ensure relatively smooth pivoting of the levers 20 - 1 ′ around the coincident centers of the arcs defined by the surfaces 20 - 3 ′, 22 - 1 ′ and 20 - 4 ′ and thus relatively smooth movements of the actuation pin 18 . the coincident centers of the arcs defined by surfaces 20 - 3 ′, 22 - 1 ′ and 20 - 4 ′ may lie outside the major diameter of the handle . it will also be observed that the leg sections 20 - 2 ′ project downwardly and somewhat proximally as compared to the leg sections 20 - 2 discussed previously . thus , instead of the arm and leg sections 20 - 1 and 20 - 2 , respectively forming a substantially right ( or minimally obtuse ) angle therebetween , the arm and leg sections 20 - 1 ′ and 20 ′- 2 ′ form a somewhat acute angle therebetween . the levers 20 ″ shown in fig5 b are substantially identical to the levers 20 ′ shown in fig5 a except for the curvature of the arm sections 20 - 1 ″ thereof . in this regard , it will be observed that , whereas the proximally extending arm sections 20 - 1 ′ of the levers 20 ′ shown in fig5 a have a slight convex curvature , the arm sections 20 - 1 ″ have a slight concave curvature . of course , the levers that may be employed in the practice of this invention may have virtually any geometric configuration and / or curvature combination ( including levers having respective sections of convex and concave curvatures ) as may be desired by an individual physician &# 39 ; s personal preference . thus , for example , instead of having any curvature ( concave and / or convex ), the levers may define a linear edge which is substantially parallel or even somewhat angularly disposed relative to the longitudinal axis a l . while the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment , it is to be understood that the invention is not to be limited to the disclosed embodiment , but on the contrary , is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims .
hand - held instruments have an actuator assembly which may be employed to actuate a distally mounted tool by application of radial force about the entirety of the instrument circumference . most preferably , the actuator assembly includes a plurality of circumferentially spaced - apart generally l - shaped actuator levers defining respective arcuate bearing surfaces along exterior edge regions thereof , and a retaining ring which circumferentially bounds the actuator levers around the exterior edge regions thereof . the retaining ring most preferably defines an interior stationary arcuate guide surface in conformable mated relationship to the bearing surfaces of said actuator levers . radial force applied to the proximally extending arm sections of said levers thereby responsively causes the bearing surfaces thereof to be slideably moved along the guide surface of said retaining ring so as to translate such radial force into longitudinal movements of an elongate actuation pin between retracted and extended positions thereof . by providing a tool which operatively coacts with the actuation pin , a surgeon may actuate the tool as needed by applying radial force at any point about the circumference of the actuator assembly .