a minimally invasive penetration in the chest is significantly different than “ open heart ” or “ open chest ” surgery , i . e . the gross spreading of the ribs or cutting through ribs and / or the sternum . minimally invasive surgery ( mis ) involves formation of penetrations that may be performed intercostally or non - intercostally . metering of drug entails delivering precise amounts of recombinant formulations , such as , angiogenic growth factors to expedite and / or augment collateral artery development . drugs that need frequently repeated administration over longer periods of tine could require repeated hospitalizations or clinic visits — an exception to this is in the case of cancer chemotherapy , where the patient normally goes to the hospital for drug administration in the course of routine treatment . in the case of a drug administered to the heart , where blood circulation may cause a rapid clearance of any therapeutic delivered in or near the channels , the drug would need a time course of action that is rapid enough to have effect before it is cleared . one set of applications of such drug delivery involve certain antibody treatments , where it is desirable to target the antibody to the area of intended treatment in order to achieve the highest possible local concentration of a relatively extremely expensive reagent . for example , in enzyme - linked antibody therapy currently under investigation in the treatment of certain cancers , an enzyme linked to an antibody specific to a tumor is delivered and allowed to bind to the tumor cells . thus , two applications for which the drug delivery module of the present invention is especially adapted are ( 1 ) delivery of angiogenic factors alone or in conjunction with cardiac procedures and ( 2 ) delivery of a chemotherapeutic to a solid tumor , in a variety of applications including either before or after a laser is used to ablate tumor tissue , before or after systemic drug treatment , etc . a normally toxic chemotherapeutic such as doxorubicin or taxol that is made systemically non - toxic by being modified to a prodrug is injected into the tumor . the drug would remain non - toxic until it meets the enzyme linked to the antibody , where the prodrmg is converted into active drug . in this way , higher local concentrations of the drug could be created near the tumor than would be possible by traditional chemotherapy , where systemic toxicity is the limiting factor . therapeutics which may be advantageous to deliver through a drug delivery device can be broadly placed into five overlapping therapeutic categories : 4 ) agents that may be used in the treatment of cancer , and these categories are broadly overlapping , so that many agents will fall into more than one category . antibody agents , for example , may appear in all five categories . certain growth inhibitors can be used for anti - cancer treatment as well as for the treatment of other disease processes . agents named in the following charts are illustrative and are not meant to be a comprehensive listing of all agents available for the given therapeutic category . agents appearing as examples in one category may have uses in other therapeutic categories . it will be understood that there are additional categories which may become useful , such as agents directed at bone or implanted in semi - permeable sacs , radioisotopes , and future gene therapies . photodynamic therapy is another important delivery and dosing method . drugs or other compounds which have certain therapeutic or other activity or function can be regulated using such technology . photo - active or photo - labile compounds are those whose activity or function is controlled by light energy . while the use of sensitizing agents or protective groups to block activity of the drug or other compounds in topically applied formulations is known , the use of such protective groups is unknown in conjunction with drugs delivered for angiogenic purposes or in conjunction with cardiac procedures . “ caged ” compounds are compounds which have a photo - active reagent which masks the original characteristics of the compounds . thus , these caged or otherwise photo - labile compounds can be delivered to the target tissue or target region in a pharmacologically inactive form . upon irradiation with laser energy or other , operative electromagnetic radiation , the protective group or groups are caused to be rendered inert , thereby initiating therapeutic activity . these photoactive protective groups or “ cage ” molecules are especially useful in conjunction with highly toxic drugs or marker substances . for example , chemotherapeutic agents are particularly toxic and , thus , their toxicity can be eliminated until the agent is delivered to the precise region of the body where it &# 39 ; s toxicity will be most effectively and safely used . irradiation of the photo - labile compound with light energy of a suitable wavelength , frequency and duration can then render the drug or other photo - labile agent active . active compounds which are given systemically have a normal therapeutic window which can be expressed as mg of drug per kg of body weight . the amount of agent which is therapeutically acceptable when administering a drug locally can be approximated as mg of drug per kg of target treatment area ( e . g . organ weight ), optimized accordingly with consideration of toxicity and mechanism of drug action . agents delivered to a specific site can achieve high local concentrations at the delivery point . optimal drug dose may scale differently when the drug is administered locally rather than systemically . thus , the amount of a given agent that should be delivered in order to achieve a therapeutic effect must be optimized accordingly with consideration of toxicity levels ( both locally and systemically ), mechanism of drug action , drug clearance mechanisms , and drug diffusion levels . examples of azents which have an effect on the blood clot cascade these agents work by either promoting or inhibiting blood clot cascade pathways . these agents are actual blood clot cascade participants , which mimic actual blot clot cascade participants , or agents which act as enzymes or inhibit enzymes that are associated with the blood clot cascade . some examples of agents in these categories include : these agents act on cell signaling pathways and recognition processes , and includes receptor agonists and antagonists . a subset of these agents mediate inflammation and the immune response . some examples of agents in the category include : these agents work at various points in the cardiovascular and associated systems . angiogenic factors and anti - angiogenic factors appear in this category as well as in the cancer therapeutics category . some examples of agents in the category include : cancer therapy can proceed along several different lines , all of which seek to kill or limit the growth of cancer cells while doing minimal damage to the host . thus , any difference in cancer cell properties ( e . g . metabolism , cell - surface antigen presentation ) from healthy host cells is a target for exploitation . with the local administration of therapeutics , these differentiating factors may be created and / or exploited . for example , the local administration of cytotoxins or growth inhibitors may allow higher local concentrations of the compounds than would be achievable by systemic administration . differences in cell - surface recognition molecules may be a site for antibody therapy . differences in tumor morphology are also potential sites of intervention : for example , anti - vegf may be useful in retarding the vascularization of the interior of a solid tumor , thereby slowing its growth rate . some examples of agents in the category include : there are two recognized mechanisms for formation of new blood vessels , these are vasculogenesis — the formation of vessels through aggregation of endothelial cells , and angiogenesis — the growth of new vessels from pre - existing vessels . vasculogenesis is particularly critical during development of the embryo . angiogenesis , while important in development , also occurs in the adult during , for example , wound healing and ovulation . new blood vessel growth is also a critical phase of solid tumor growth — without a new blood supply tumors cannot grow more than about 1 - 2 mm in diameter . differential cdna screening is currently being used to identify genes involved in tube formation , a critical process in the development of a blood vessel . since some cardiac procedures create injuries , and induce secondary vascularization , whatever signal is given to induce vascularization could be pharmacologically amplified . mechanisms for this type of induced revascularization may stem from factors induced by tissue damage ( vegf or other growth - factor derived response , or perhaps heat - shock proteins produced by thermal damage caused by a laser ). regardless of the actual mechanism , an angiogenic factor used in conjunction with cardiac procedures such as cabg or tmr may increase the effectiveness of the technique . a preferred one of the angiogenic factors commonly available ( e . g . vegf , fgf - 1 , fgf - 2 , egf ) is vegf , vascular endothelial growth factor . vegf has been shown to be effective in improving vascularization in the rabbit ischemic hindlimb model after a single bolus administration . vegf also has a serum half life of less than 6 minutes ( unpublished results ), and certain isoforms of vegf have the property to bind to the cell surface — i . e . vegf may not need to be present for very long in order to have an effect . thus , it is possible to apply vegf in or near injury sites to increase the revascularization of ischemic myocardium . basic fibroblast growth factor ( bfgf ), also known as fgf - 2 , is another possible angiogenic agent . there is some indication that vegf and bfgf used together are more effective than either one alone . in one general embodiment , the drug - delivery module , or device , of the present invention includes a housing with an actuator mounted thereon for movement between open and closed positions , and a carriage assembly mounted therein for movement between retracted and extended positions . the carriage assembly includes a linkage connectable to a needle for needle movement with the carriage assembly between retracted and extended needle positions . one or more fluid reservoirs are adapted for fluid connection to the needle . advancing means operatively connect the actuator to the carriage assembly , to advance the assembly toward its extended position when the actuator is moved from its open position , toward its closed position . compressing means operatively connect the actuator to the reservoir for compressing the reservoir when the actuator is moved from its open position toward its closed position . several exemplary embodiments of the device will now be described . for clarity of description , it should be noted that the exemplary devices are depicted with their forward regions generally toward the right in the drawings , and their rearward regions toward the left . in the exemplary embodiment of fig1 a - 1e , the delivery device of the invention , indicated generally by the reference numeral 10 , includes a housing 12 configured to be held and manipulated by an operator , such as a surgeon or cardiologist . particularly , housing 12 is designed to be grasped like a wand , stick , or pistol with the operator &# 39 ; s thumb extending over the top of the housing and four fingers wrapped about the lower side of the device . housing 12 can be constructed of any suitable material by any conventional means . for example , the housing can be formed from a plurality of separately formed panels or sections , molded of an impact resistant plastic material or the like , and assembled by way of threaded fasteners , snap - fitting portions , and / or other conventional techniques . an actuator , denoted generally as 14 , is mounted on housing 12 for movement between open and closed positions . particularly , actuator 14 includes a manually operable handle 16 , in the nature of a trigger , mounted at its forward end at a pivotal connection 20 in a forward , lower region of housing 12 . handle 16 is adapted for movement between a normal , open position , projecting downwardly and outwardly from housing 12 , and a closed position , compressed ( squeezed ) upwardly and inwardly toward the housing . a recessed or depressed region 18 along a lower side of handle 16 is configured to accommodate the index finger of an operator for manual actuation , and can include grip - enhancing structure ( e . g ., raised ridges or bumps ) thereon ( not shown ). actuator 14 fuirther includes a pivoting member 22 mounted in hotusing 12 for pivoting movement in forward and reverse directions , as handle 16 is moved toward and away from its closed position , respectively . in this regard , pivoting member 22 is attached at its upper end in housing 12 at a pivot connection 24 for pivotal movement thereabout . movement of pivoting member 22 is effected by sliding contact between upper regions of handle 10 at a location inside housing 12 , with confronting portions of pivoting member 22 . particularly , as best viewed in fig1 b and 1d , pivoting member 22 is provided with side wings , or lateral extensions , denoted as 26 and 28 ( fig1 d ), each having a generally flat , smooth undersurface . handle 16 , in turn , includes an upstanding protrusion on each lateral side — only one of which is visible in fig1 b and 1d , denoted as 30 - with each such protrusion being adapted to engage , along its upper edge , the lower surface of a respective lateral extension . by this construction , as handle 16 is moved from its open position toward its closed position , its upstanding protrusions slidingly engage the lateral extensions of pivoting member 22 , thereby urging the pivotal member to move forwardly , about pivot connection 24 . as handle 16 returns to its open position , pivoting member 22 moves in a reverse direction . a carriage assembly , indicated generally as 32 , is mounted in housing 12 , forwardly of pivoting member 22 , for movement between retracted and extended positions . carriage assembly 32 includes a main body portion 34 , with a linkage 36 extending forwardly from a front face thereof . as described more fully below , linkage 36 is connectable to a remote ( distal ) needle , such as at 186 in fig3 a , for needle movement with carriage assembly 32 between retracted and extended needle positions . carriage assembly 32 further includes a pair of guide rods , denoted as 40 and 42 ( fig1 b ), which also extend from the front face of body 34 . each guide rod is slidably received within a respective bore extending into a front region of the device . sliding movement of the guide rods within their respective bores defines the pathway along which the carriage assembly can travel , as it is moved between its retracted and extended positions . a coil spring , such as 44 , is concentrically mounted over at least one of the guide rods ( e . g ., guide rod 42 in fig1 e ), to normally urge carriage assembly 32 to its retracted position . movement of carriage assembly 32 is effected by the action of actuator 14 . in this regard , advancing means operatively connect the acuator to the carriage assembly , to advance the carriage assembly toward its extended position when the actuator is moved from its open position , toward its closed position . in the present embodiment , the advancing means includes a sliding surface contact between a forward edge of pivoting member 22 and a back - angled portion of the back face of carriage - assembly body 34 , along the regions denoted generally at 48 . thus , the back - angled portion of carriage - assembly body 34 acts as a cam surface against which the forward edge of pivoting member 22 , functioning here as a camn , can act . by this construction , as pivotal member 22 moves along its forward direction , its forward edge engages , and slides upwardly along , the back - angled rearward face of carriage - assembly body 34 , such that , upon overcoming the force of spring 44 , carriage assembly 32 is pressed forwardly , toward its extended position . a fluid reservoir , e . g ., a syringe , vial or cartridge reservoir , is adapted for fluid connection to a remote ( distal ) needle , such as needle 186 in fig3 a . in the drawings , the fluid reservoir is a syringe barrel , denoted as 50 , removably mountable within an upper portion of housing 12 . syringe barrel 50 includes an outlet 52 portion ( fig1 c and 1e ) at its forward end that can be connected in fluid communication with the remote needle , as described below . prior to being mounted in housing 12 , syringe barrel 50 can be loaded with a selected fluid , such as an agent , solvent , carrier , purging fluid , hydraulic fluid , or other substance , as desired . barrel 50 is adapted to hold such fluid until such time that a delivery operation is carried out . compressing means operatively connect the actuator to the reservoir for compressing the reservoir when the actuator is moved from its open position , toward its closed position . in the illustrated arrangement , the compressing means includes a plunger 56 , with the plunger being slidably disposed within syringe barrel 50 for movement toward outlet 52 , to expel fluid from the reservoir . such movement of plunger 56 is effected by forward movement of a sliding bar , denoted as 58 , disposed generally co - extensive with the housing &# 39 ; s central , longitudinal axis and operatively engageable at one bar end with plunger 56 . in this regard , a plunger drive 60 is rigidly mounted at a rearward end of sliding bar 58 . plunger drive 60 includes an upstanding paddle portion , denoted as 62 , with a front face confronting an enlarged head 64 at the rearward end of plunger 56 . as is evident in the figures , paddle portion 62 of plunger drive 60 will push upon enlarged head 64 of plunger 56 as sliding bar 58 is moved forward . forward movement of sliding bar 58 is effected by movement of actuator 14 toward its closed position , via a reciprocating bar 66 extending longitudinally along a lower region of housing 12 and operatively interconnecting actuator 14 and sliding bar 58 . particularly , a forward end of reciprocating bar 66 is pivotally connected to a lower , rearward portion of pivotal member 22 via a pivot - pin connection , as at 68 ( fig1 c and 1 e ). thus , forward movement of pivotal member 22 , as effected by movement of handle 16 toward its closed position , is effective to pull , or drag , reciprocating bar 66 in a forward direction . at its rearward end , reciprocating bar 66 is operably coupled to sliding bar 58 via a releasable locking mechanism , indicated generally at 70 in fig1 e ( described next ), such that successive actuations of actuator 14 are effective to advance sliding bar 58 incrementally in a forward direction effective to expel a defined and incremental quantity of fluid from the reservoir ( here , barrel 50 ) with each such actuation . the locking mechanism includes first and second pivot plates , denoted as 72 and 74 , respectively . a lower region of first plate 72 is coupled to a rearward end of reciprocating bar 66 via a pivot - pin connection , as at 76 , or other pivot - connection mechanism . a bore is forned through an upper region of first plate 72 , through which sliding bar 58 is passed - as shown , for example , in fig1 d . a lower end of second plate 74 is adapted for pivotal motion in a u - shaped pivot mount , denoted as 78 in fig1 b and 1c , formed in housing 12 adjacent ( below ) sliding bar 58 . as shown in the figures , second plate 74 is disposed rearwardly of , and in spaced relation to , first plate 72 . like the first plate , second plate 74 includes a bore through its upper region , through which sliding bar 58 is passed . first and second coil springs , denoted as 80 and 82 , respectively , are mounted over sliding rod 58 , with ( i ) the first spring 80 compressed between a front face of first plate 72 and a rearward face of a first stop member 84 ( fig1 b and 1c ) formed in housing 12 forwardly of first plate 72 , and ( ii ) second spring 82 compressed between a front face of second plate 74 and a rearward face of a second stop member 86 formed in housing 12 forwardly of second plate 74 , and rearwardly of first plate 72 . notably , a rearward , upper portion of first plate 72 is urged by spring 80 toward a forward face of second stop member 86 . in operation , first plate 72 engages or releases sliding bar 58 , as reciprocating bar 66 is advanced in a forward or reverse direction , respectively ; and second plate 74 releases or engages sliding bar 58 as reciprocating bar 66 is advanced in a forward or reverse direction , respectively . additional details of the above components , as well as the relative timing of the various motions effected by actuation of the device , are revealed by the following summary of certain aspects of a typical actuation operation . when actuator 14 is moved from its open position , toward a position intermediate its open and closed positions ( such range of movement being referred to herein as “ early ” actuator movement ), the advancing means is effective to advance carriage assembly 32 toward its extended position , as previously described . during such early actuator movement , however , no reservoir compression takes place . this is because , notwithstanding the fact that reciprocating bar 66 is pulled in a forward direction during such early actuator movement , such early movement is not transmitted to sliding bar 58 . in this regard , first pivot plate 72 acts a motion buffer or absorber , effectively shielding sliding bar 58 from such early movement . in this regard , it should now be recalled that the first pivot plate &# 39 ; s upper end is urged toward the forward face of the second stop 86 by first coil spring 80 . thus , as pivoting member 22 pulls the first plate &# 39 ; s lower end forwardly , and spring 80 maintains its upper end at a rearward position , first plate 72 is caused to tilt back during early movement of the actuator . sliding bar 58 is not pulled forwardly as first plate 72 tilts back . this buffering effect , however , is effective only for movement of actuator 14 up to a certain , predetermined intermediate position . beyond such intermediate position , as the actuator moves from such intermediate position toward its closed position ( referred to herein as “ late ” actuator movement ), the upper and lower edges of the first plate &# 39 ; s bore engage the upper and lower edges of sliding bar 58 , respectively , so as to grab the bar and drag it forward . as previously described , forward movement of the sliding bar effects reservoir compression . it should be noted that the second plate does not resist movement of the sliding bar in the forward direction . during most , or all , of the compression operation , which , as described above , generally takes place only during late actuator movement , little , if any , further advancement of the carriage assembly takes place . this is because the camming that takes place via sliding surface contact between pivoting member 22 and carriage assembly 32 is substantially completed once the actuator is reaches its intermediate position , from its open position . in this regard , attention is directed to fig1 b - 1e , where it can be seen that the back - angled portion along the rearward face of carriage - assembly body 34 extends only up to a certain point . the forward edge of pivoting member 22 reaches this terminal point on the body &# 39 ; s back face as the actuator reaches its intermediate position . thus , no further camming can take place as the actuator is moved beyond its intermediate position toward its closed position . from its closed position , the actuator will typically be allowed to return to its open position . during such return movement , reciprocating bar 66 moves in a reverse ( backward ) direction , with reverse movement of the actuator &# 39 ; s pivoting member 22 . as the reciprocating bar moves back , first plate 72 slides back along sliding bar 58 , and returns to its normal , substantially upright orientation . notably , second plate 74 does not permit reverse movement of sliding bar 58 ( except when a force is applied that tilts the second plate forwardly — e . g ., as by manually pressing in a forward direction on an upstanding release tab 88 ( fig1 b and 1d ) extending from the top of the second plate ). also , as the actuator &# 39 ; s pivoting member moves in a reverse direction , the forward edge of the pivoting member slides downwardly along the back - angled portion of the rearward face of the carriage - assembly body , permitting the carriage to return to its retracted position under the bias of spring 44 . from the above description , it should be appreciated that the illustrated device provides controlled needle advance , followed by rapid fluid ( e . g ., agent ) delivery — with a single sweep of the actuator from its open position to its closed position . optionally , means can be provided for selectably adjusting the volume displaced in the reservoir ( e . g ., syringe barrel 50 ) by the compressing means with each actuation of actuator 14 . such means can be useful , for example , to select an amount of fluid to be expelled from the reservoir with each actuation . in the embodiment of fig1 a - 1e , for example , a displacement - volume - adjustment thumbwheel 92 provides an externally accessible interface permitting an operator to readily adjust the reservoir displacement volume . particularly , thumbwheel 92 is co - axially and rigidly fixed about a rearward region of an externally threaded shaft 94 which , in turn , is mounted for rotation within housing 12 in spaced - apart support members , 96 and 98 , extending off an interior sidewall thereof . a stop arm 102 is threadedly mounted at one ( upper ) end along a forward region of shaft 94 , such that rotation of shaft 94 will cause stop arm 102 to move in a forward or reverse direction , longitudinally within housing 12 , dependent upon the particular direction of shaft rotation . the other ( lower ) end of stop arm 102 is configured generally in the shape of an inverted u , which straddles a forward region of reciprocating bar 66 . an internally threaded , wide - diameter stop nut 104 is mounted on an externally threaded region of reciprocating bar 66 , rearwardly of the stop arm &# 39 ; s u - shaped portion . in operation , forward movement of reciprocating bar 66 brings a front face of stop nut 104 into abutting contact with a rearward side of the stop arm &# 39 ; s u - shaped portion , thereby prohibiting further forward motion of reciprocating bar 66 . by rotating shaft 94 in an appropriate direction ( via thumbwheel 92 ), stop arm 102 can be moved to a desired position alongside reciprocating bar 66 . in this way , the length of travel available for forward movement of the reciprocating bar , and , thus , the length of plunger travel in the reservoir , can readily be set . an indicator , or pointer , denoted as 108 in fig1 a , is viewable through an elongate window 110 formed longitudinally along one side of housing 12 , adjacent shaft 94 . indicator 108 is provided on an annular ring 112 , which is also threadedly mounted on shaft 94 . as shaft 94 is rotated via thumbscrew 92 , indicator 108 is caused to move longitudinally along shaft 94 , in a forward or reverse direction , dependent upon the direction of shaft rotation . the position of indicator 108 at any given time indicates a particular , corresponding position of stop arm 102 along shaft 94 . in this way , the indicator provides an externally visible means of determining the position of the stop arm , without having to directly view the stop arm itself . knowing the position of the stop arm , one can also determine the reservoir volume that will be displaced upon actuation . to this end , a scale ( not shown ) can be imprinted or molded along the exterior of housing 12 , e . g ., alongside window 110 , to provide quantitative volume information to an operator . for example , a double scale can be printed on the housing with both 0 . 01 - 0 . 1 cc scaled markings and 0 . 1 - 0 . 3 cc scaled markings , permitting convenient selection and setting of the desired displacement volume . the scale ranges can be modified as desired , depending upon the application , type of fluid to be delivered , and / or other determinants . a safety switch , or lock , can be provided , for locking the delivery device against inadvertent actuation , when desired . for example , fig1 a - 1d show a slider - type , safety lock 114 that , when shifted to a forward position , locks the handle in its open position . in this way , actuation is not permitted . upon depressing the safety lock and sliding it in a backward direction ( as shown by the arrow in fig1 d ), the handle is unlocked , thereby permitting actuation . delivery device 10 is also provided with a saline or other solution flush connector 116 ( fig1 b - 1 d ), which can be a standard luer - type fitting , or other standard or proprietary connector . typically , sterile bags of saline , vessels , canisters or other reservoirs are suspended to provide gravity feed , or the bags or other reservoirs can be pressurized or the fluid otherwise pumped out . a standard section of tubing or other tubular section ( not shown ) communicates fluid , other material or vacuum through flush connector 116 to a valve assembly 118 disposed at a forward , upper region of the device . in the present embodiment , valve 118 includes two inlets and one outlet . using any suitable tubing or other fluid - connection devices , valve 118 is configured to permit the establishment of fluid communication between its outlet and ( i ) connector 116 ( e . g ., for flush - solution flow ), as well as ( ii ) reservoir 50 ( e . g ., for agent , or other fluid , flow ). preferably , such connections with the valve &# 39 ; s outlet can be established alternatively , one at a time ; or simultaneously , as desired . an alternative embodiment contemplates a valve having two outlets . this can be useful , for example , where it is desired to direct flush solution to more than one downstream location . it will also be understood that a second , third , pseudo , modified or other additional reservoirs containing drug , saline , flush or other solution or material may also be linked or coupled to port 116 . thus , valve 118 may be replaced with a manifold - type system for coupling of multiple internally or externally located reservoirs of different drugs or other materials . device 10 will optionally , therefore , provide delivery with or without pre - mixing or mixing , such as at site of delivery , and with the potential for providing sequential and / or simultaneous administration of drug , medication or other material internally . the delivery device 10 of the invention is particularly well suited for use in connection with a medical appliance , such as an endoscope or a catheter - type assembly . briefly , such appliances typically include an elongate hollow body probe with proximal and distal ends and an inner lumen extending therebetween . for example , in an exemplary endoscope - type assembly , denoted generally as 200 in fig2 a - 2e , the probe is a hollow tube 208 , incorporating such features . in an exemplary catheter - type assembly 300 , shown in fig3 a - 3e , the probe is a hollow catheter sleeve 308 which incorporates such features . assemblies 200 and 300 are described in greater detail later herein . at this point , it is to be noted that , in each of these embodiments , an extension member extends substantially the length of the probe ( 208 or 308 ), from the proximal to the distal probe end . a proximal end of the extension member is adapted to connect to linkage 36 of carriage assembly 32 , for movement therewith . at its distal end , the extension member is adapted to mount a needle , as at 186 in fig2 b and 3a , such that the needle will move with movement of the extension member . in this way , movement of carriage assembly 32 is transmitted to the needle , via linkage 36 and the extension member . thus , when the carriage assembly is disposed at its retracted position , the needle likewise situates at a retracted position — typically within a distal - end region of the probe . when the carriage assembly is advanced to its extended position , the needle , too , will advance to an injection position — extending at least partially out of a distal - end region of the probe . in the embodiment of fig1 a - 1e , linkage 36 is a relatively short , substantially rigid conduit . here , linkage ( conduit ) 36 defines , in part , a fluid connection between reservoir 50 and a remote needle , such as described above . more particularly , linkage ( conduit ) 36 is adapted for fluid communication with reservoir 50 by way of a flow line 128 extending from the linkage ( conduit ), back up through a region of carriage assembly 32 , and to an outlet of valve 118 . flow line 128 includes a flexible mid - region , e . g ., forned of plastic tubing or the like , to accommodate the retracting and extending motions of the carriage assembly 32 that occur during acutation / deactuation . the forward end of linkage ( conduit ) 36 forms a fluid connection with the extension member . here , the extension member is a hollow tube , as shown in part at 182 in fig1 e , having its proximal end received over the forward of the linkage ( conduit 36 ) so as to form a fluid connection therewith , for transmitting fluid pressure from reservoir 50 to the needle . in another embodiment , the extension member is a wire member operatively connected to the linkage at its forward end . the wire member is constructed of a material that is laterally flexible , permitting movement through tortuous pathways , and sufficiently incompressible along the longitudinal direction to provide for the efficient transmission of motion from the carriage assembly to the needle . further in this embodiment , a fluid - carrying tube is provided for transmitting fluid pressure from reservoir 50 to the needle . fig1 f and 1g depict two alternative embodiments of a drug - delivery device , indicated generally as 100 a and 100 b , respectively , adapted for rapid deployment of a remote injection needle , as will now be described . fig1 f shows an over - center - type delivery device mechanism to fire a piercing needle . as an actuator trigger 154 rotates between open and closed positions ( in the direction shown by arrow “ a ”), an actuator cam , or pivoting member , 156 impinges on a follower 158 which meets resistance from two - condition leaf spring 160 . the amount of force required to move follower 158 increases proportionally , as a function of the leaf spring , until an overcoming force is achieved . when the force reaches the predetermined amount , the leaf spring 160 flips , or “ snaps ,” over center . the resultant rapid forward advance of drive rod 162 , in direction “ b ,” moves the carriage assembly 32 quickly forward — providing rapid deployment of associated drumg conduit and piercing needle assemblies ( not shown ). fig1 g is a representative view of another embodiment of a spring loaded - type drug delivery mechanism of the delivery device of the present invention . in this additional embodiment , having particular utility in applications demanding rapid deployment of a drug conduit and piercing needle at a distal position , such as in mis and catheter - type drug delivery , diagnostic and other procedures , actuator trigger 154 rotates as shown by arrow “ a ” causing cam 156 to impinge on follower 158 . follower 158 releases pawl 166 , which pivots about pin 168 and rotates as shown by arrow “ c ,” which allows spring 172 to “ fire ” guide rod 162 forward in direction “ b .” spring - biased drive rod 162 is automatically retracted by tooth 174 in tooth housing 176 by spring 178 , the spring 178 having a greater contractive force than the expansion force developed by spring 172 . actuation of the delivery device of the invention can be manual , as shown , and can also be pneumatic , hydraulic , electronic , controlled by a microprocessor or externally . attention is directed , for example , to the actuation means disclosed in co - pending u . s . patent applications ser . no . 08 / 773 , 430 filed dec . 27 , 1996 and entitled “ laser delivery means adapted for drug delivery ” by murphy - chutorian et al ., inc . and ser . no . 08 / 773 , 872 also filed dec . 27 , 1996 and entitled “ laser - assisted drug delivery ” and by murphy - chutorian et al ., which two disclosures are expressly hereby incorporated by reference . in one embodiment , for example , one or both of the advancing means and compressing means includes electro - mechanical devices that can be electronically activated via an externally accessible electronic trigger , button or switch mounted on the device &# 39 ; s housing . for example , with regard to the advancing means , a solenoid , stepper motor , worm screw , or other electro - mechanical device mounted within the device &# 39 ; s housing can be actuated to advance a carriage assembly from a retracted position to an extended position , thereby effecting needle extension . deactivation , then , can return the needle to its retracted position . the compressing means can also comprise any such electro - mechanical device . for example , a solenoid can be operatively connected to a plunger of a syringe barrel ( reservoir ) in the device &# 39 ; s housing , for driving the plunger a selected distance along the barrel with each actuation . alternatively , one or both of the advancing means and compressing means can include hydraulic components , such as mechanically and / or electronically actuated piston / cylinder assemblies operatively connected , e . g ., via hydraulic fluid lines ( e . g ., liquid or gas ), to respective plunger elements adapted for compressing the reservoir , and / or extending / retracting the carriage assembly . as mentioned above , the delivery device of the present invention is particularly well suited for use in connection with auxiliary equipment , such as catheters , endoscopes , etc . in this regard , an auxiliary equipment mount , such as at 122 in fig1 a - 1e , can be provided along a forward region of the device . mount 122 is configured to bayonet or snap fit into associated endoscope or catheter portions ( as best shown in fig8 ) to position and secure the associated endoscope or catheter portions relative to the device . the mount can be any convenient means for coupling the device to other equipment , including a threaded portion , snap fit , clamps , etc . furthermore , as will be described more fully herein , the device can be incorporated into a unitary endoscope or catheter or other type drug delivery device . as previously mentioned , the reservoir of the delivery device ( e . g ., syringe barrel 50 of device 10 in fig1 a - 1e ) can be employed to hold a therapeutic and / or diagnostic agent to be delivered . however , this will not always be desirable . for example , when the delivery device is used in connection with a medical appliance having an elongate hollow body probe , it would be necessary to pass the agent through the length of such probe in order to move it from a reservoir in the device housing to an injection needle at the distal end of the probe . clearly , it would be advantageous to avoid such a long agent - travel path where expensive agents are being used e . g ., rare proteins , etc . to this end , one embodiment of the invention provides the agent in a distal end of the appliance . in one particular embodiment , a micro - syringe device is provided at a distal end of an extension member that extends through an elongate hollow body probe of a medical applicance . in fig9 a , for example , the extension member is a hollow tube 182 . a micro - syringe 184 , containing a fluidic agent 186 therein ( e . g ., naked dna ) is inserted into a distal opening of the tube . the micro - syringe can be held therein by any suitable means , e . g ., adhesives , frictional forces , heat sealing techniques , etc . upon pressurizing a lumen 183 of tube 182 with a suitable gas or liquid , via the compressing means , a plunger element 188 of the micro - syringe can be pressed forwardly , so as to eject the agent through a needle 190 . certain other embodiments contemplate a drug container that can be inserted into a distal region of a tubular extension member . in fig9 b , for example , an insert 192 includes an expanded - diameter region 194 with a polymer matrix or other material ( e . g ., a filter paper - type material ) 195 lining its interior sidewall . prior to use , one or more selected agents can be precipitated or absorbed onto material 195 . upon passing a suitable solvent , or other appropriate fluid , into the tube so as to contact the agent - bearing material , the agent can be dissolved or otherwise pulled into the fluid and then delivered through needle 190 . fig9 c shows a similar embodiment , except that the agent is precipitated or absorbed into a porous matrix or mesh material 198 extending across a passage of an insert 199 . fig2 a - 2d are representative views of a modular or unitary endoscope - type drug delivery assembly 200 of the present invention . it will be understood that with respect to the cited advantage of providing a drug delivery device adaptable for use as a rigid endoscope - type device suitable for mis or open surgical procedures , a central feature of the present invention is the drug delivery module ( ddm ). thus , the unitary or modular assembly 200 enables a user to both extend a piercing needle and dispense drug or other agent or fluid therethrough , with a single , manual “ draw ” or squeeze force applied to an actuator ( e . g ., a trigger ). the drug delivery assembly 200 utilizes a rigid , viewing endoscope 202 with an eyepiece 204 at the proximal end held in an endoscope housing 206 which couples to the auxiliary mounting portion 122 of device 10 . the present invention is for use with any of a wide variety of commercial , custom or other proprietary endoscopes or other visualization devices . the endoscope 202 , for example , can be a 5 . 0 mm outside diameter standard or custom rigid endoscope , and about 300 mm in length . such device can be used in conjunction with a 10 . 0 mm outside diameter tube 208 . a smaller 2 . 0 mm endoscope can also be used with a smaller , such as a 6 . 0 mm outside diameter tube 208 . this endoscopic viewing assembly is similar to that used in other surgical instruments such as those disclosed in co - pending u . s . patent application ser . no . 09 / 031 , 752 filed feb . 27 , 1998 and entitled “ viewing surgical scope for minimally invasive procedures ” by daniel et al ., which is hereby incorporated by reference . the endoscope assembly 200 has a generally rigid distal , elongated hollow tube portion 208 and a distal tip 210 . it will be understood , and become more apparent by the following , that the elongated hollow tube portion 208 comprises a single or multi - lumen shaft for containing an extension member , drug delivery channel , optional visualization , etc . it will be understood that endoscope port 212 is typically used as an access for providing a light source at the target viewing area , such as via fiber optic cable , bundle , etc . ( not shown ). thus , the inside diameter of endoscope portion 208 which can be used is largely a function and dependent on the outside diameter of the rigid endoscope 202 selected for use with the assembly 200 of the present invention . a hollow tube - type drug conduit 282 extends from the mount portion housing 206 through the elongated portion 208 of the endoscope assembly 200 and terminates in an extendable , piercing needle 186 . the entire drug conduit 282 slides inside a lumen of the elongated portion 208 and couples to the connector tube 182 between the auxiliary equipment mounting portion 122 of the device 10 and the mount housing portion 206 , such that when the connector tube 182 of the device 10 is advanced and retracted , the piercing needle 186 is co - extensively advanced and retracted . drug or other fluid flows from syringe reservoir 50 in device 10 through flow line 128 and connector 182 into drug conduit 282 when the device 10 is actuated . the distal tip 210 of elongated tubular portion 208 can be oriented by scope adjustment knob 290 . as shown , the ergonomic shape of the endoscope assembly 200 provides for a plurality of orientations for the assembly 200 in operation , including using a pistol - grip on the device 10 , gripping the forward , endoscope mount portion 206 , or the assembly 200 can be supported such that the device 10 extends above the endoscope device 200 and the endoscope mount portion 206 . it will be understood that , while in a modular assembly in which the device 10 is used with the endoscope portions , as described with reference to fig2 a - 2d , the actuation trigger is located on the device itself , and that the needle activation trigger may be positioned on the scope portion or other housing portion as desired , resulting in similar action of the needle and drug or other agent dosing function . these embodiments will be considered within the scope of the present invention . the trigger can be moved to any other part of the assembly , however , including to the mounting housing 206 , etc ., as will be apparent to those skilled in the art , and the functions of the device 10 and associated assembly would be essentially identical to as described herein . as shown in fig2 e , yet another preferred embodiment of an endoscope - type drug delivery assembly 200 a with device 10 of the present invention has an articulating portion . pivot connection 209 allows rotational movement between the endoscope 202 and the endoscope mount portion 207 , thus allowing selection of functional angle θ . in operation , a surgeon or cardiologist will find the controllability and selectability of functional angle θ a feature which increases efficiency , ease of operation and adaptability to specialized or general applications . selection of functional angle θ is based on the intended application , however , it will be understood that an angle between about 45 degrees and about 135 degrees , or more or less , is typically used . it will be understood that the embodiment shown in fig2 e will have a locking mechanism , to prevent undesirable , or to perform advantageous , motion of the device 10 relative to the rigid scope portions of the assembly 200 a . such locking mechanism could be ratcheted , or otherwise indexed , continuously adjustable , comprising interlocking teeth , compressible components secured by threadably engaging portions or otherwise , or have a spring activated , retracting pin engageable within one or more engagement slots located radially or otherwise on an opposing member , etc . as described , the locking mechanism could be implemented in numerous ways , and safety and efficacy considerations would be key . elongated , flexible catheter type ddm for percutaneous and other trans - luminal applications fig3 a - 3e are representative views of a modular or unitary catheter - type drug delivery assembly 300 incorporating the delivery device 10 of the present invention . again , as with the endoscope - type ddm assembly of fig2 a et seq ., the unitary or modular assembly 300 enables a user to both extend a piercing needle and dispense drug or other agent therethrough , with a single , manual “ draw ” or squeeze force applied to a trigger . this steerable catheter assembly is similar to that used in other percutaneous instruments such as those disclosed in co - pending u . s . patent application ser . no . 08 / 833 , 352 filed apr . 4 , 1997 and entitled “ steerable catheter ” by giba et al ., which is hereby incorporated by reference . the elongated portion 308 of the assembly 300 comprises a single or multi - lumen flexible sleeve or shaft for containing at least one drug delivery channel in a drug delivery tube 382 , with optional visualization , etc . it will be understood that assembly 300 provides , optionally , a light source at the target viewing area , such as via fiber optic cable , bundle , etc . the delivery device 10 is configured to bayonet or snap fit into the lower extremity of the catheter mount 306 which locks onto the auxiliary equipment mounting portion 122 of the device 10 . the connector tube 182 extends through the catheter mount 306 and is sealed to drug conduit 382 . drug conduit 382 extends through elongated tubular portion 308 of the catheter assembly 300 to the distal tip 310 of the elongated portion 308 where the drug conduit 382 connects to the piercing needle 186 . it will be understood that elongated shaft portion 308 may comprise a single lumen or multi - lumen extrusion . in a preferred embodiment , an inner lumen 309 extends coextensively and / or coaxially with the elongated shaft portion 308 and physically separates control wire 330 , etc ., from drug conduit 382 . thus , the mechanical steering mechanism is physically separated from the drug conduit 382 , thus minimizing the risk of contamination of the drug , fouling of the internal passages or other failure of the steering mechanism , etc . thus , flow of liquid , solid or vapor phase drug , solution or other agent or compound is communicated from the reservoir in the device 10 through drug conduit 382 and is dispensed through piercing needle 186 subsequent to advance of piercing needle 186 through the distal tip 310 of assembly 300 . the distal tip 310 of elongated tubular portion 308 of catheter assembly 300 can be oriented by steering adjustment finger control knob 390 , as will now be discussed . the assembly of the catheter portion is shown in fig3 c . catheter cap 302 is the attaching member for the exterior portion of the elongated steerable catheter sheath 308 , strain relief 312 and steering housing 314 . within the catheter cap 302 , set screw 316 fixes the assembly to the elongated catheter sheath 308 . set screw 318 fixes leadscrew guide 340 axially through the annular opening through leadscrew 342 , maintaining the assembly integrally . the steering housing 314 allows insertion of leadscrew 342 , which is then captured and retained in place when the catheter mount and coupling 306 is installed . leadscrew has external threads with a pitch corresponding to about 2 revolutions per inch of linear travel . in a completed assembly , leadscrew 342 can be moved in a linear fashion to articulate the distal tip 310 of the steerable catheter device 300 by rotation of finger control knob 390 situated on the exterior of steerable housing 314 . articulation of the steerable catheter tip 310 is accomplished by push - pull forces on cable 330 extending between distal tip 310 and leadscrew 342 , coextensive and / or coaxial with steerable catheter sheath 308 . the cable 330 is press fit at the interface of key 322 , which secures the cable 330 and prohibits the advancing bushing 320 from rotating within the steering housing 314 when a linear motion is applied . when the finger control knob 390 is rotated with steering housing 314 , articulation of the attached steerable catheter tip 310 can be achieved . thus , the catheter tip 310 can be guided through the vasculature , through other body lumens , into a body organ or other structure . upon determining a proper target location , the needle 186 can be advanced and the desired dose of the prescribed drug agent can be released by actuating delivery device 10 . at the distal tip 3 10 , elongated catheter sheath 308 couples to protective tip portion 392 . thus , it will be apparent to those skilled in the art , based on the foregoing , that the steerable components of the catheter - type drug delivery assembly 300 is but one choice of catheter assembly . it will be apparent to those skilled in the art that the steerable catheter device 300 is but one example of a catheter having a lumen and an exit port at a distal end , and other known catheter systems may be adapted for use with the device 10 of the present invention . fig4 a - 4d are representative section views of tubular viewing assemblies of the delivery devices of the present invention having clear distal tipped sections with a working channel , and having various orientations at the clear distal tip . the assembly has an optically clear or transparent end tube cap 602 which fits over the visualization port distal end 604 of a scope &# 39 ; s visualization shaft and has a working channel 606 for communication of the drug or other material fluid , solution , solid or vapor to the target region . it will be understood that the distal ends 604 in fig4 a & amp ; 4b lie in planes essentially perpendicular to the central axis of what would be the elongated portions 208 or 308 of the devices 200 or 300 , respectively , such that optics provide essentially direct forward visualization with a predetermined divergence viewing angle φ as shown . in contrast , the end ports 604 shown in fig4 c & amp ; 4d are at a 30 ° angle with respect to what would be the central axes of the elongated portions 208 or 308 of the assemblies 200 or 300 , respectively . distal ends 604 can be varied such that the field of view is at an angle offset with respect to the central axis of elongated portion 208 or 308 of the devices 200 or 300 , respectively . the end cap 602 members are made from an acrylic polycarbonate or other transparent material and coupled to the elongated portion 208 or 308 of the assemblies 200 or 300 , respectively . the distal end of the visualization scope 604 terminates near the transparent end cap 602 . the end caps 602 can be made with desired optical light absorption / reflection characteristics . furthermore , the shape of the end cap 602 can be conical , elliptical or include planar facets at various angles with respect to the central axis of the elongated portion 208 or 308 of the devices 200 or 300 , respectively . the end caps 602 are designed and made in accordance with required optical lens characteristics including but not limited to focus , divergence , convergence , directionability , collimation , polarization or diffusion . the working channels 606 have various designs with differilg bends that cooperatively are attached to the distal ends 600 . the working channels 606 as shown are internal to the assemblies 600 , but can be incorporated into an external lumen or be defined by a structural tube either in the wall of the tip assembly 600 or conformably designed to fit within the inner wall surface of assembly 600 along with the distal end 604 of the visualization scope or an end shaft of an endoscope . the working channel 606 is shown attached to the internal wall of assembly 600 in fig4 a - 4d . tip assembly 600 functions to allow visualization of diagnostic or affected tissue while placing the tip in contact with the target tissue , optionally applying pressure to tissue thereby stopping any bleeding and minimizing active tissue movement , e . g . a beating heart . the working channel 606 directs and protects the operative piercing needle ( not shown ). the working channel 606 can be made of stainless steel , plastic or comparable material . the working channel 606 in fig4 a has a curvature 608 such that the piercing drug delivery needle or other working device is directed through the transparent end cap 602 in a direction essentially parallel with or contiguous with respect to the central axis of the associated elongated sheath portion . in fig4 b & amp ; 4c , the working channel 606 has a curvature 612 which directs the drug delivery piercing needle or other working device through the transparent end cap 602 at approximately 45 ° with respect to the central axis of the elongated portion . likewise , the curvature 614 in the working channel 606 of fig4 d directs the drug delivery piercing needle or other working device through the transparent end cap 602 in a direction approximately 900 with respect to the central axis of the elongated endoscope or catheter portion . other orientations of working channel 606 and / or distal end bends in tube 606 can be used to direct a working device . it will be understood that this tubular assembly may be placed over a conventional endoscope or may be incorporated at the distal end of the unitary or modular mis device shown in fig2 a , or used at the distal end of a catheter assembly . fig5 a & amp ; 5b are representative views of a flexible piercing needle 186 located at the distal end of the elongated , tubular shaft portions 208 ( in the endoscope - type drug delivery assembly 200 ) and 308 ( in the catheter - type assemblies 300 ) of the present invention . piercing needle end portion 702 has a bevel cut end tip 704 or other operable tip for piercing tissue and delivering drug or other compound therethrough . between rigid piercing distal end portion 702 and the remainder of drug conduit 282 and 382 , an intermediary flexible coupling portion 708 allows a degree of flexibility between the distal end portion 702 and the drug conduit 282 and 382 portion of piercing needle 186 . this combination construction allows passage of the piercing needle 186 through a working channel ( such as indicated by reference numeral 606 of fig4 a - 4d ) with bends and curves . as shown in fig5 a , the flexible coupling 708 comprises an integral section of flex tubing , and as shown in fig5 b , the flexible coupling 708 comprises a spliced section of flexible tubing , such as silicone , rubber , or comparable material . the drug conduits 282 or 382 of the present invention are manufactured using high quality , specialized materials and methods of construction . a preferred embodiment is manufactured by putnam precision molding , inc . of putnam , connecticut . the tubing has an inside diameter of about 30 mils and an outside diameter of about 43 mils . the co - extrusion comprising stainless steel wound nylon tubing provides high columnar strength to prevent against failure of the drug conduit 282 or 382 in high flex situations such as articulation of the distal tip of a catheter device , extension of the piercing needle through small radius of curvature bends , etc . fig5 c is a representative section view of a distal end portion of a drug delivery device of the present invention . the tubular wall 720 of the rigid endoscope or elongated catheter shaft coupled to the device 10 ( not shown ) of the present invention has at least one lumen 722 for the drug conduit ( such as 282 and 382 , above ) to pass through protected . another lumen 724 is adapted to receive a visualization device including an endoscope or other fiber optic device . shaped lumen 726 is oriented adjacent the tubular wall 720 to act as a guide channel for a steering wire , push rod or other control mechanism . fig6 a is a representative internal view of a tubular viewing assembly having a controllable distal tip . in this embodiment , and also as shown in fig4 a - 4d with respect to either or both the endoscope - type embodiments as well as the catheter - type assemblies , the elongated , tubular shaft portions 208 ( in the endoscope - type drug delivery assembly 200 ) and 308 ( in the catheter - type assemblies 300 of the present invention ) contain one or more lumens , the lumens optionally containing a visualization scope 604 or other operative device . an advanceable drug conduit 282 ( in the endoscope - type drug delivery assembly 200 ) and 382 ( in the catheter - type assemblies 300 of the present invention ) lies within a controllable working channel 706 . the working channel may also be excluded in optional embodiments , in which case the drug conduit itself , as described herein , would lie within or outside of the elongated portion 208 ( in the endoscope - type drug delivery assembly 200 ) or 308 ( in the catheter - type assemblies 300 of the auxiliary associated equipment of the device 10 of the present invention . it will be understood , therefore , that drug conduit 282 ( in the endoscope - type drug delivery assembly 200 ) and 382 ( in the catheter - type assemblies 300 of the present invention ) terminating in piercing needle 186 passes through the controllable working channel 706 . piercing needle 186 comprises a sharpened distal tip portion 702 and is advanceable through septum member 603 . the precise position at which the piercing distal tip 702 pierces the septum portion 603 is determined by the axial motion of guiding member 605 acting on controllable working channel 706 . thus , the angle of advancement of the distal tip 702 of piercing needle 186 is determined by the orientation of guiding member 605 through which piercing tip 702 passes , as selectively and controllably oriented by control shaft 607 moved according to arrow “ d .” guiding member 605 pivots about pin 709 and is linked to control shaft 607 at pin 611 . guiding member 605 is mounted within the distal tip portion of the viewing assembly , housing assembly , etc . fig6 b is another representative internal view of a tubular viewing assembly having a controllable distal tip . as described above , drug conduit 282 ( in the endoscope - type drug delivery assembly 200 ) and 382 ( in the catheter - type assemblies 300 of the present invention ) terminating in piercing needle 186 passes through the controllable working channel 706 and is advanceable through septum member 603 . in this embodiment , however , the relative radial positions of control shaft 607 and drug delivery piercing needle tip 702 are transposed . in either case , the position at which the piercing distal tip 702 pierces the septum portion 603 as well as the direction at which it pierces , penetrates or otherwise extends to the outer surface of the septum 603 or beyond and into target tissue or to a target region for delivery therein , therethrough or thereabouts , and at which angle relative to the central axis of the elongated tubular portion of the device as also indicated by direction arrow “ d ,” is determined by guiding member 605 . as mentioned above , the elongated portions 208 and 308 have either a single , tubular lumen region or have a plurality of lumens , formed such as by extrusion ( see fig5 c ). fig7 a is a perspective view of a patient , showing a method of use of the endoscope - type device of the present invention . it will be understood that the example given in this drawing is an mis application , and that the device 10 of the present invention may also be used in conjunction with surgical procedures . the perspective view of a patient shows first , second and third minimally invasively formed penetrations in a patient &# 39 ; s chest , 2 , 4 and 6 , respectively . it will be appreciated that the exact location of penetrations 2 , 4 and 6 is not limited to those shown . additionally , from 1 to n + 1 numbers of penetrations may be made . the patient is prepared for the procedure and is positioned similarly to that used for a left thoracotomy . the patient &# 39 ; s left arm is draped . a conventional double lumen endotracheal tube is used to selectively deflate one side or the other of the lungs . preferably the left lung is collapsed which allows access to the chest cavity in the vicinity of the left lung . the other lung remains inflated to provide oxygenation . with regard in particular to cardiac procedures , the distal tip of surgical drug delivery device 200 is positioned to reach a desired aspect of a ventricular wall . a distal portion of the drug delivery device 200 is positioned against tissue of the wall of the heart . the visualization features of the drug delivery device 200 can be used to visualize the area , look for larger coronary vessels , to inspect the condition of the pericardium , and to check for adhesions . the shape of the heart as well as its position is visualized . the endoscope or other interventional device 200 can include a ccd camera device attached to the eyepiece for viewing on a monitor . additionally , additional viewing scope devices can be used during the procedure as inserted in the first penetration and the rigid scope can be inserted into second penetration 4 . the drug delivery conduit with piercing needle is inserted through the working channel of the device 200 ( such as indicated by reference numeral 722 in fig5 c , by 606 in fig4 a - 4d and by 706 in fig6 a and 6 b ). once the desired number of drug delivery tissue sites have been treated , the device 200 can be emplaced in any of the other penetrations . it will be recognized that the procedure will vary , depending on a particular surgical requirement . for instance , drug delivery may be performed prior to , during or after other cardiac procedures , such as cabg and tmr . fig7 b is a perspective view of a patient , showing a method of use of the catheter - type device of the present invention . when the interventional procedure involves using the percutaneous catheter - type delivery assembly 300 , the assembly 300 is positionable adjacent the coronary ostia , within the coronary arteries themselves , inside , beyond or elsewhere with relationship to the various valves and chambers of the heart as well as near any portion of the heart &# 39 ; s endocardial surfaces for drug treatment . as described above , drugs can be delivered to tissue via advanceable drug conduits with piercing needle tips which pass through a working channel of the instrument . the catheter - type assembly 300 can , in preferred embodiments of the methods of the present invention , be inserted through the femoral artery in the groin region and passed into the heart over the aortic arch and , optionally , into the left ventricle . treatment sites within the ventricles typically require a catheter having a length of up to 120 cm . percutaneous drug delivery can be achieved using the drug delivery assembly 300 with delivery device 10 of the present invention . other surgical and / or percutaneous or transluminal procedures in which the devices of the present invention are particularly adapted include delivery of drug or other agents within the gall bladder , tumors or other structures , or in laparoscopy or laparotomy , colosectomy and other mis operations in which auxiliary , working devices for treatment of diseased tissue are used . fig7 c is a flowchart showing the steps of a preferred method of the present invention . as described in the foregoing , an initial step 1910 involves selection of the desired drug , compound or other material to be delivered with the methods and apparatus of the present invention , and loading that drug or other material into a suitable reservoir , syringe , cartridge , etc . it will be understood that drug packaging may be a function of the type of drug or the method of delivery required by the drug , i . e ., cartridge based packaging for efficient device loading , refrigeratable packaging - type material , dual - compound co - loadable cartridge sets , etc . in a subsequent step 1912 , once a drtig or other compound is loaded into the delivery device of the present invention , air and / or other undesirable fluids , gases , solids , etc . are evacuated from the system , including the delivery device components , drug conduit , piercing needle , etc . in general , depending upon the type of procedure being performed and the types of materials being delivered , evacuation of the system will be required to prevent delivery or introduction undesired gases , fluids , etc . it will be understood that purging air or other undesirable substances out of the device 10 prior to delivery of drug therethrough at the target region is generally necessary . as described , a reservoir of flushing solution , such as a bag of saline , can be connected to the device 10 through flush connector 116 . the reservoir can be pressurized in any number of ways . once the reservoir is pressurized , valve 118 can be opened to allow flow through the delivery device . ( any optional safety or check valves will need to be cleared prior to this step .) the delivery device can be actuated to cause needle advance , and flow of saline or other flush solution will be observed at the distal tip 702 of the needle 186 . valve 118 can then be closed . additionally , it will be understood that purging of either the endoscope portions or the catheter portions may be desirable , and flushing around any visualization tip will increase and enhance the quality of images taken therefrom . based on the foregoing , it will be apparent to those skilled in the art to incorporate any of various flushing systems , including directing jets of flushing solution against the distal tip 210 or 310 of the device , etc . furthermore , priming the device 10 and associated auxiliary equipment with actual drug to be used may , in certain circumstances , be necessary or advantageous . these steps will be understood from the apparatus and procedures described herein . once the device 10 and associated drug conduits and piercing tips have been purged , priming of the system would include installing the drug syringe or reservoir into the device , switching valve 118 so as to provide communication from the reservoir , through valve 118 , through line 128 , into the advanceable drug conduit ( such as indicated by 282 and 382 herein ) and through to the distal , sharpened distal piercing tip 702 of needle 186 . selection of variable parameters , as shown in step 1914 , is necessary . depending upon the application for the delivery device and associated endoscope or catheter devices , end - user adjustable variable parameters include , but are not limited to , dosage volume , needle advance / retraction speed , needle advance length , dosage rate , etc . in a subsequent step 1916 , the interventional end ( such as identified as 210 and / or 310 ) is inserted into the patient &# 39 ; s body , e . g ., as described with respect to fig7 a . in step 1918 , the interventional drug delivery distal end ( such as identified as 210 and / or 310 ) is positioned adjacent target tissue or within a target region . as described , a conventional , endoscope with auxiliary illumination , optionally coupled to a ccd camera for visualization on a real - time monitor , or a catheter device with enhanced visualization capability can be used to navigate the interventional distal drug delivery end to the desired internal location . the delivery device - actuated distal drug delivery piercing needle is extended in step 1920 , and as described above , the piercing needle tip can be extended by means of a manually operated trigger - type assembly . alternatively , a rapidly deployable delivery device , such as described with respect to the preferred embodiment of the present invention , can be used . in the heretofore described manner , drug or other material is delivered to the desired site in step 1922 and the drug delivery piercing needle is thereafter retracted , as shown in step 1924 . the method of the present invention requires that a decision be made , either by the physician , surgeon or cardiologist , an operator or by a programmable or pre - programmed logic controller . in step 1926 , if additional treatment , i . e ., additional or alternate drug delivery such as to the same or to different sites is desired , then another decision is made with regard to the current parameters previously set such as in step 1914 . if the pre - set parameters are sufficient to proceed , i . e . no changes to operator adjustable parameters is required , then steps including navigating the interventional distal drug delivery piercing needle end to the additional desired target tissue or region 1918 , extending the needle 1920 as desired , delivery of drug or other compound or material to the desired tissue or region 1922 , subsequent retraction of distal piercing needle 1924 and subsequent repetition of the foregoing steps . if , however , the pre - set parameters need to be changed , as determined in step 1928 , then the desired parameters are changed in step 1930 and the steps of navigating 1918 , extending the needle 1920 , delivery of drug or other material 1922 , retraction of the needle 1924 , and subsequent repetition if and as desired , are repeated . once treatment has been completed , such as determined in step 1926 , the interventional end and / or other portions of the devices of the present invention are retracted from the patient &# 39 ; s body in step 1932 , the re - usable endoscope portions or catheter visualization devices are disconnected 1934 and the associated catheter and / or endoscopic portions of the ddm can be disposed of in an ultimate step 1936 . fig8 is a representative schematic drawing of components of a delivery device 10 kit 800 of the present invention . as described above , the present invention is directed to both modular as well as unitary devices . therefore , the kit 800 comprises the delivery device 10 and associated auxiliary equipment , including endoscope housing mount 206 and elongated tubular portion 208 as well as catheter steering housing 314 , elongated tubular shaft portion 308 and associated assembly . thus , a single kit 800 will serve the medical practitioner with a wide range of drug delivery options . drug delivery in surgical procedures , mis procedures as well as catheter or other percutaneous procedures can be achieved using solely the contents of the delivery device kit 800 of the present invention . according to the present invention , the delivery device 10 provides simple to operate , single squeeze action , manually operated needle advance and drug delivery at some remote target point through an advanceable and controllable drug conduit . unless defined otherwise , all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs . although any methods and materials similar or equivalent to those described can be used in the practice or testing of the present invention , the preferred methods and materials are now described . while the principles of the invention have been made clear in illustrative embodiments , there will be immediately obvious to those skilled in the art many modifications of structure , arrangement , proportions , the elements , materials , and components used in the practice of the invention , and otherwise , which are particularly adapted to specific environments and operative requirements without departing from those principles . the appended claims are intended to cover and embrace any and all such modifications , with the limits only of the true purview , spirit and scope of the invention .
a modular drug delivery system for use by cardiothoracic surgeons and interventional cardiologists for delivery of molecular and cellular therapies that target genes , molecules and peptides . the regulated drug delivery devices comprise a modular mechanically actuated drug delivery module that can be attached to either a surgical viewing endoscope hand - piece or specialized catheter for interventional procedures . the ddm provides metering of drugs to treatment sites and allows for quick interchangeability with other component parts such as a viewing scope end portion for mis or other surgical procedures or a flexible catheter shaft for percutaneous procedures .