Safety penetrating instrument with cannula moving during penetration and triggered safety member protrusion

A safety penetrating instrument for penetrating an anatomical cavity wall to gain access to an anatomical cavity includes a penetrating member having a distal end for penetrating the anatomical cavity wall, a distally-biased safety member having a distal end movable between an extended position where the safety member distal end protrudes distally from the penetrating member distal end to protect the distal end of the penetrating member and a retracted position where the safety member distal end is disposed proximally of the penetrating member distal end to expose the penetrating member distal end, an extending mechanism for moving the safety member to the extended position and for permitting the safety member to move proximally toward the retracted position, a mechanism for manually moving the safety member proximally to the retracted position and a locking mechanism for locking the safety member in the retracted position to prevent movement of the safety member to the extended position during penetration of the anatomical cavity wall. The safety member can be a cannula movable proximally from the retracted position during penetration of the anatomical cavity wall and distally toward the retracted position in response to entry into the anatomical cavity, a safety shield or probe, or both a cannula and a safety shield or probe. A releasing mechanism for the safety penetrating instrument is responsive to movement of the cannula distally toward the retracted position to trigger release of the locking mechanism to permit the extending mechanism to move the safety member to the extended position.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention pertains to safety penetrating instruments and, more 
particularly, to safety penetrating instruments for use in forming portals 
for establishing communication with anatomical cavities wherein tissue and 
organ structures are protected from the tips of the penetrating members 
and to methods of penetrating anatomical cavity walls with safety 
penetrating instruments. 
2. Discussion of the Prior Art 
Penetrating instruments are widely used in medical procedures to gain 
access to anatomical cavities ranging in size from the abdomen to small 
blood vessels, such as veins and arteries, epidural, pleural and 
subarachnoid spaces, heart ventricles and spinal and synovial cavities. 
Use of penetrating instruments has become an extremely popular and 
important first step in endoscopic, or minimally invasive, surgery to 
establish an endoscopic portal for many various procedures, such as 
laparoscopic procedures in the abdominal cavity. Such penetrating 
instruments typically include a cannula or portal sleeve and a penetrating 
member disposed within the cannula and having a sharp tip for penetrating 
an anatomical cavity wall with the force required to penetrate the cavity 
wall being dependent upon the type and thickness of the tissue forming the 
cavity wall. Once the wall is penetrated, it is desirable to protect the 
sharp tip of the penetrating member from inadvertent contact with or 
injury to tissue or organ structures in or forming the cavity in that, 
once penetration is achieved, the lack of tissue resistance can result in 
the sharp tip traveling too far into the cavity and injuring adjacent 
tissue or organ structures. 
Various safety penetrating instruments have been proposed, generally 
falling into protruding and retracting categories. In protruding safety 
penetrating instruments, a safety member is spring biased to protrude 
beyond the tip of the penetrating member in response to the reduced force 
on the distal end of the safety member upon entry into the anatomical 
cavity. The safety member can be disposed around the penetrating member in 
which case the safety member is frequently referred to as a shield, or the 
safety member can be disposed within the penetrating member in which case 
the safety member is frequently referred to as a probe. In retracting 
safety penetrating instruments, the penetrating member is retracted into 
the cannula upon entry into the anatomical cavity in response to distal 
movement of a component of the safety penetrating instrument such as the 
penetrating member, the cannula, a probe or a safety member such as a 
shield or probe. 
While protruding safety penetrating instruments have been well received, 
there is room for improvement in reducing the force required to penetrate 
the cavity wall which necessarily includes the force required to overcome 
the spring bias on the safety member as well as the resistance of the 
cavity wall and insuring that the safety member protrudes which normally 
requires increasing the spring bias on the safety member and, thus, the 
force to penetrate. Retracting safety penetrating instruments have the 
disadvantages of requiring relatively complex mechanisms to hold the 
penetrating member in an extended position during penetration and to 
release the penetrating member for retraction and, concomitantly, not 
retracting sufficiently quickly and reliably. 
SUMMARY OF THE INVENTION 
Accordingly, it is a primary object of the present invention to improve 
safety penetrating instruments of the type having a penetrating member and 
a safety member biased distally to protrude beyond the distal end of the 
penetrating member by easing penetration and assuring protrusion of the 
safety member. 
Another object of the present invention is to reduce the force-to-penetrate 
required to penetrate an anatomical cavity wall with a safety penetrating 
instrument of the type having a distally biased safety member with a 
distal end for protruding beyond a distal end of a penetrating member once 
penetration into the cavity has been achieved. 
A further object of the present invention is to increase the force biasing 
a safety member distally in a safety penetrating instrument to assure 
protrusion of the safety member after penetration into an anatomical 
cavity without increasing the force-to-penetrate required for penetration. 
The present invention has an additional object to use a cannula of a safety 
penetrating instrument as a safety member and to trigger distal movement 
of the cannula to an extended protruding position beyond a distal end of a 
penetrating member in response to distally-biased movement of the cannula 
upon penetration into an anatomical cavity. 
Another object of the present invention is to use a safety shield or probe 
as a safety member in a safety penetrating instrument and to trigger 
distal movement of the safety shield or probe to an extended protruding 
position beyond a distal end of a penetrating member in response to 
distally-biased movement of the cannula upon penetration into an 
anatomical cavity. 
Yet another object of the present invention is to use both a cannula and a 
safety shield or probe as safety members in a safety penetrating 
instrument and to trigger distal movement of the safety members to 
extended positions protruding beyond a distal end of a penetrating member 
in response to distally-biased movement of the cannula upon penetration 
into an anatomical cavity. 
Some of the advantages of the safety penetrating instrument of the present 
invention are that the distal bias force on a safety member can be 
designed to assure protrusion of the safety member upon penetration 
regardless of the anatomical cavity being penetrated, that the 
force-to-penetrate of a safety penetrating instrument can be minimized to 
permit use in delicate tissue, that release of the safety member for 
movement to the extended protruding position can be triggered by slight 
distal movement of the cannula in response to penetration through the 
tissue, and that the safety penetrating instrument can be inexpensively 
manufactured with minimum components to reduce cost, facilitate 
sterilization for re-use and allow economical single-patient use. 
The present invention is generally characterized in a safety penetrating 
instrument including a penetrating member having a distal end for 
penetrating an anatomical cavity wall to gain access to an anatomical 
cavity, a safety member having a distal end movable between an extended 
position where the safety member distal end is disposed distally of the 
penetrating member distal end to protect the penetrating member distal end 
and a retracted position where the safety member distal end is disposed 
proximally of the penetrating member distal end to expose the penetrating 
member distal end, extending means for moving the safety member distally 
to the extended position and for permitting the safety member to move 
proximally to the retracted position, means for manually moving the safety 
member proximally from the extended position to the retracted position and 
locking means for locking the safety member in the retracted position to 
prevent movement of the safety member to the extended position prior to 
penetrating into the anatomical cavity. The safety member can be a 
cannula, a safety shield or probe, or both a cannula and a safety shield 
or probe. Releasing means responsive to distally-biased movement of the 
cannula upon penetration into the anatomical cavity triggers release of 
the locking means to permit the extending means to move the safety member 
to the extended position. 
Other objects and advantages of the present invention will become apparent 
from the following description of the preferred embodiments taken in 
conjunction with the accompanying drawings wherein, unless specified 
otherwise, like parts or parts that perform like functions are identified 
in each of the several figures by the same reference character or by 
reference characters sharing the same last two digits.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The safety penetrating instrument of the present invention is described 
hereinafter for use as an instrument for inserting a portal sleeve through 
a wall of an anatomical cavity to form a portal for the introduction of 
various surgical and diagnostic instruments into the cavity during 
endoscopic procedures, such as laparoscopy. It is understood, however, 
that the safety penetrating instrument of the present invention can be 
used for safe penetration or introduction into anatomical cavities of 
needles with fluid flow therethrough and catheters as well as for other 
instruments engaging tissue during surgical or diagnostic procedures. 
Accordingly, the cannula or outer tubular member of the safety penetrating 
instrument can be a portal sleeve, a needle, a catheter or a tubular 
component of a medical instrument. 
A safety penetrating instrument 20 according to the present invention, as 
shown in FIG. 1, is formed of a portal unit 22 and a penetrating unit 24. 
The portal unit 22 can be made of any desirable, medical grade materials 
depending on procedural use and desirability of being for single patient 
use or re-usable. The portal unit 22 includes an elongate portal sleeve, 
cannula or catheter 26 and a housing 28 mounting a proximal end of portal 
sleeve 26. Portal sleeve 26 terminates distally at a distal end 30 and 
proximally at a transverse flange 32 disposed in housing 28 with the 
portal sleeve passing through an opening in a front wall 34 of the 
housing. Portal sleeve 26 can have any desirable cross-sectional 
configuration, including cylindrical or tubular configurations, in 
accordance with the procedure to be performed and the anatomical cavity to 
be penetrated. Preferably, portal sleeve 26 is made of a substantially 
cylindrical length of rigid or flexible and transparent or opaque 
material, such as stainless steel or other medically acceptable plastic or 
metal material, and has a tubular configuration defining a lumen between 
the distal and proximal portal sleeve ends for receiving a penetrating 
member 25 of penetrating unit 24. 
A rail member 36 is disposed in housing 28 and is generally U-shaped 
including a forward wall 38 disposed transverse or perpendicular to a 
longitudinal axis of the penetrating instrument, a rearward wall 40 in 
configuration parallel to forward wall 38 and a side wall 42 transversely 
joining the forward and rearward rail member walls. Flange 32 is disposed 
between the rail member forward and rearward walls with the rail member 
forward wall 38 having an opening therein allowing passage therethrough by 
the portal sleeve 26. The rail member forward and rearward walls are 
disposed parallel or substantially parallel to flange 32, and a bias 
member 44 is connected between flange 32 and the rail member rearward wall 
40 to bias the portal sleeve distally. As shown, bias member 44 includes a 
helical coil spring 44 disposed around the penetrating member 25 and 
mounted in compression between flange 32 and the rail member rearward wall 
40 to bias the portal sleeve 26 distally to cause flange 32 to abut the 
rail member forward wall 38. However, bias member 44 can include various 
other types of springs as well as other types of bias devices including 
compression springs, tension springs, torsion springs, pan springs, leaf 
springs, rubber, plastic or magnets, for example. Rail member rearward 
wall 40 extends toward an upper wall 46 of housing 28, and an extending 
member 48 is mounted between rail member rearward wall 40 and a rear wall 
50 of housing 28 to bias the portal sleeve 30 in a distal direction to an 
extended protruding position where distal end 28 of the portal sleeve is 
disposed beyond a sharp tip of the penetrating member 25 as will be 
explained further below. The extending member can include a helical coil 
spring 48 mounted in compression between rail member rearward wall 40 and 
the housing rear wall 50 as shown, or the extending member can include any 
other type of spring or other bias device as discussed for bias member 44. 
If desired, a guide rod 51 can be connected between the front wall 34 and 
the rear wall 50 of housing 28 with the spring 48 disposed around the 
guide rod. 
Flange 32 extends toward the upper wall 46 of housing 28, and a pin 52 
extends from flange 32 through a slot 54 in the housing upper wall 46 to 
terminate at a handle or knob 58 positioned in an elongate, trough-like 
recess 60 in the housing upper wall. Slot 54 and recess 60 extend 
longitudinally in parallel with the longitudinal axis of the safety 
penetrating instrument 20, and an indicator strip 62 extends proximally, 
perpendicularly from flange 30 to be visible through and along the length 
of slot 54 when the portal sleeve is in the extended protruding position 
as will be described further below. The indicator strip 62 can be colored 
and/or can be provided with any desirable indicia, and the slot 54 or the 
recess 60 can be provided with a transparent window or cover for viewing 
of the indicator strip therethrough. 
A locking and releasing mechanism 64 for locking the portal sleeve in a 
retracted position, shown in FIG. 1, exposing the sharp distal end of the 
penetrating member and for releasing the portal sleeve to allow the portal 
sleeve to move to the extended protruding position includes a latch or 
locking spring 66, made of a strip of resilient material, formed to have a 
substantially flat base 68 secured to a bottom wall 70 of housing 28 and a 
bend 72 joining the base 68 with an upwardly angled arm 74 spaced from the 
base. Arm 74 carries or forms a latch 76 having a distal angled latching 
surface joining a proximal latching surface 78 disposed substantially 
transverse to the longitudinal axis of the safety penetrating instrument 
and substantially parallel to the rail member forward wall 38. Arm 74 has 
an extension 80 positioned proximally of latch 76, and a releasing member 
or trigger 82 is juxtaposed with extension 80. The trigger 82 is pivotally 
mounted in the housing on a pin 84 secured to a wall or walls of the 
housing or structure supported in the housing, and the trigger is 
generally L-shaped with a leg 86 overlying extension 80 and a leg 88 
extending transversely from leg 86 but at a slight angle toward the 
proximal end of the safety penetrating instrument. A torsion spring (not 
shown) is coiled around pin 84 and fixed to trigger 82 to bias the trigger 
counterclockwise, looking at FIG. 1, such that leg 86 is biased toward 
extension 80. 
The portal sleeve distal end 30 can have various configurations to protect 
tissue within an anatomical cavity by covering the distal tip of the 
penetrating member in the extended protruding position; and, as shown, the 
portal sleeve distal end defines an annular or peripheral edge having a 
blunt configuration to protect tissue within the anatomical cavity. The 
portal sleeve is provided with a shape or surface texture to increase 
resistance of the portal sleeve to passage through anatomical tissue such 
that the portal sleeve moves proximally against the bias of bias member 44 
during penetration of anatomical tissue by the penetrating instrument. The 
resistance of the portal sleeve can be increased in many various ways such 
as by roughening, texturing or dimpling the external surface of the portal 
sleeve, providing the external surface with bumps, threads, ridges or 
other irregularities or by providing the portal sleeve with a formation, 
such as a slight enlargement or protrusion, having a configuration to 
increase the resistance of the portal sleeve 26 to penetration or passage 
through anatomical tissue to cause the portal sleeve to move proximally 
against the bias of spring 44 during penetration of anatomical tissue. 
Movement of the portal sleeve against the bias of bias member 44 can also 
be assured by selecting the strength of bias member 44 to cause proximal 
movement of the portal sleeve during penetration in response to a force 
from tissue contact such that the shape or external surface of the portal 
sleeve need not be modified and can be conventional. As shown in FIG. 1, 
the external surface of the portal sleeve 26 is ribbed or grooved and is 
slightly enlarged along a distal segment 27 adjacent the portal sleeve 
distal end to increase the resistance of the portal sleeve. 
The housing 28 can be made of any desirable material and can have any 
desirable configuration to facilitate grasping by a user and includes a 
rear wall having an opening therein aligned with the opening in the 
housing front wall to allow passage therethrough by the penetrating 
member. The housing 28 is preferably constructed to sealingly engage 
instruments passing therethrough and to include a valve 90 biased to a 
closed state when no instrument passes through the portal sleeve. A 
flapper valve 90 is shown; however, any suitable valve construction can be 
utilized, for example, trumpet or nipple valves. 
The penetrating unit 24 includes penetrating member 25 having an elongate 
shaft or body, a proximal end mounted to a hub 92, and a sharp distal end 
or tissue penetrating tip 94 extending from a transverse dimensional 
transition 95 in the shaft or body. The penetrating member distal end 94 
can have any configuration desired by a user for a particular procedure, 
for example, the pyramidal trocar configuration shown or conical, 
threaded, multi-faceted or open, slanted or needle configurations. The 
penetrating member 25 can be made of any suitable, medical grade materials 
and can be made of multiple components such that, for example, the distal 
tip 94 is made of stainless steel and secured in any conventional manner, 
such as by threads, to the distal end of the shaft, which can be tubular 
and made of a less expensive material, such as plastic or metal. Hub 92 
can be made of any desirable medical grade material and can have any 
desired configuration in cross-section to facilitate grasping of the hub 
and the housing by a user with one hand. 
The portal unit 22 and the penetrating unit 24 can be provided to a user 
separately or assembled together as shown in FIG. 1, and either or both of 
the portal and penetrating units can be manufactured in a manner to be 
disposable for single patient use or to be sterilizable for re-use. The 
hub 92 can be coupled to the housing 28 by suitable detent or latch 
mechanisms if desired, and the penetrating unit can be withdrawn from the 
portal unit leaving the portal sleeve 26 in place within an anatomical 
cavity. 
In use, when a user desires to penetrate into an anatomical cavity using 
the safety penetrating instrument 20, the instrument is in the condition 
shown in FIG. 3 with the portal sleeve 26 in the extended protruding 
position to cover sharp distal tip 94 of the penetrating member 25. With 
the safety penetrating instrument 20 in the condition shown in FIG. 3, 
flange 32 will be in abutment with the forward wall 38 of rail member 36 
due to the bias of bias member 44, and handle 58 will be disposed at a 
distal end of slot 54 due to the bias of extending member 48 with 
indicator strip 62 viewable along the length of the slot 54. Prior to 
commencing penetration of an anatomical wall W, handle 58 is grasped and 
manually moved proximally to move the portal sleeve 26 proximally against 
the bias of the extending member 48 until the forward wall 38 of rail 
member 36 rides over latch 76 by engaging the distal latching surface to 
move arm 74 toward base 68. At this time, the user can feel the rail 
member 36 lock into place in engagement with proximal latching surface 78 
as arm 74 springs back and can also visually determine that the portal 
sleeve is locked in the retracted position by noting the position of 
handle 58 at a proximal end of slot 54 at which time the indicator strip 
62 will no longer be visible or will be only slightly visible. 
The safety penetrating instrument 20 is now in the position illustrated in 
FIG. 1 with the portal sleeve 26 locked in the retracted position by 
locking and releasing mechanism 64 and the penetrating member 25 extending 
from the distal end of the portal sleeve. With the portal sleeve 26 locked 
in the retracted position, portal sleeve distal end 30 will be disposed 
proximally of penetrating member tip 94, and flange 32 will be in abutment 
with the forward wall 38 of rail member 36 and will be disposed distally 
of leg 88 of trigger 82. 
As penetration of the anatomical cavity wall W is commenced, the 
force-to-penetrate is limited to the force required to cause sharp distal 
end 94 to pass through the cavity wall W since the penetrating member does 
not move during penetration. As penetration continues, the safety 
penetrating instrument will advance through the cavity wall W as shown in 
FIG. 2, and the force from tissue contact on the distal end of the portal 
sleeve 26 will cause the portal sleeve to move proximally causing the 
operating member formed by flange 32 to move proximally until flange 32 
abuts the rearward wall 40 of rail member 36 which serves as a stop or 
abutment limiting proximal movement of the portal sleeve. As the flange 32 
moves proximally, the operating member formed thereby engages leg 88 to 
pivot trigger 82 clockwise, looking at FIG. 2, to allow the operating 
member to pass thereby. The clockwise pivotal movement of trigger 82 does 
not cause movement of the latch 76 since there is no engagement by either 
leg 86 or 88 with arm extension 80. Once the operating member passes by 
leg 88, a torsion spring or the like returns trigger 82 to its normal 
position with leg 86 adjacent arm extension 80. Accordingly, during 
penetration of the anatomical cavity wall W, no force is required to 
overcome the bias of extending member 48. 
Once the distal end 30 of the portal sleeve 26 has passed through the 
cavity wall W, a reduction in the force from tissue contact on the distal 
end of the portal sleeve will cause the portal sleeve to move distally due 
to the bias of bias member 44. As the portal sleeve 26 moves distally, 
flange 32 engages leg 88 of trigger 82 causing the trigger to pivot 
counterclockwise looking at FIG. 3 and causing leg 86 to engage arm 
extension 80 moving arm 74 toward base 68 against the force of spring 
strip 66. The movement of arm 74 away from the longitudinal axis of the 
safety penetrating instrument causes latch 76 to move out of engagement 
with the rail member forward wall 38 thereby allowing extending member 48 
to move the portal sleeve further distally to the extended protruding 
position where distal end 30 protrudes beyond the sharp distal tip 94 of 
the penetrating member as illustrated in FIG. 3 thereby protecting tissue 
within the anatomical cavity from inadvertent contact with the sharp 
distal tip 94. With the distal end 30 of portal sleeve 26 in the 
anatomical cavity, the penetrating unit 24 can be withdrawn from the 
portal unit 22 leaving the portal sleeve in place such that instruments 
for performing endoscopic procedures can be introduced into the cavity via 
the portal formed by the portal unit 22. 
Although the portal sleeve is disclosed herein as the safety member, it 
will be appreciated that the safety member can be any other member 
including a shield or probe. By forming extending member 48 to be 
relatively strong, protrusion of the safety member is assured even should 
the safety member engage tissue in the anatomical cavity wall or within 
the anatomical cavity or should any tissue be jammed between the safety 
member and the penetrating member and/or the portal sleeve. Additionally, 
the strong force of spring 48 provides the user with the psychological 
benefit of knowing the safety member is protecting the penetrating member. 
Should tissue within the anatomical cavity be contacted by the distal end 
of the safety member, the safety member can bounce or give a little in the 
manner of a shock absorber to protect such contacted tissue. Movement of 
the safety member can be seen by the user by noticing movement of the 
handle toward a distal end of the slot and observation of the indicator 
strip. The strong force of spring 48 also provides the user with an easily 
felt tactile signal that the safety member has moved to the extended 
position and that penetration into the cavity has occurred which also can 
be visually confirmed by the position of the handle and the indicator 
strip. The distal bias of spring 44 and/or the resistance of the portal 
sleeve need only be great enough to produce slight longitudinal movement 
of operating flange 32 past the trigger such that the force-to-penetrate 
is minimized. Release of the safety member to move distally to the 
extended protruding position can be triggered by distal movement of the 
safety member itself or of any other member. The safety member can have 
various configurations so long as the distal end protrudes beyond the 
sharp tip of the penetrating member to provide a protective function, and 
a plurality of safety members can be employed in the safety penetrating 
instrument. 
A modification of the safety penetrating instrument according to the 
present invention is shown at 120 in FIG. 4. Safety penetrating instrument 
120 is similar to safety penetrating instrument 20 except that the safety 
member for safety penetrating instrument 120 includes a safety shield, and 
movement of the safety shield to the extended protruding position is 
triggered by movement of the portal sleeve in response to a reduction in 
the force from tissue contact following entry in the anatomical cavity. 
Safety penetrating instrument 120 includes a portal unit 122 and a 
penetrating unit 124, the penetrating unit 124 being similar to 
penetrating unit 24. Portal unit 122 is similar to portal unit 22 and 
includes portal sleeve 126, safety shield 127 and housing 128. Portal 
sleeve 126 is similar to portal sleeve 26 except that portal sleeve 126 is 
provided without textured segment 27. Portal sleeve 126 terminates 
distally at distal end 130 and proximally at flange 132 disposed in 
housing 128. Flange 132 is similar to flange 32 except that flange 132 has 
a finger 133 extending perpendicularly or transversely therefrom in a 
proximal direction to terminate at a barb 135. 
Safety shield 127 is disposed in portal sleeve 126 and terminates distally 
at a distal end 137 and proximally at a transverse flange or plate 138 
disposed in housing 128. Safety shield 127 can have any desirable 
configuration in cross-section to couple safety shield distal end 137 with 
plate 138. A bias member 144 including a helical coil spring is disposed 
around the safety shield 127 and held in compression between flange 132 
and plate 138 to bias the portal sleeve 126 in a distal direction to cause 
flange 132 to abut front wall 134 of housing 128. The strength of spring 
144 is selected to allow proximal movement of portal sleeve 126 in 
response to the force from tissue contact during penetration of an 
anatomical cavity wall and to cause distal movement of the portal sleeve 
in response to a reduction in the force from tissue contact upon 
penetration into the anatomical cavity. An extending member 148 including 
a helical coil spring is connected between plate 138 and a rear wall 150 
of housing 128 to bias the safety shield to an extended protruding 
position where the distal end 137 of the safety shield is disposed beyond 
the distal end 194 of the penetrating member 125; and, if desired, spring 
148 can be disposed around a guide rod 151 connected between the forward 
wall 134 and the rearward wall 150 of the housing. Plate 138 extends 
toward upper wall 146 of housing 128, and a pin 152 extends from plate 138 
through slot 154 in the housing upper wall 146 to terminate at a handle or 
knob 158. An indicator strip 162 extends proximally, perpendicularly from 
plate 138 to be visible through and along the length of slot 154 when the 
safety shield is in the extended protruding position as will be described 
further below. 
Safety penetrating instrument 120 includes a locking and releasing 
mechanism 164 for locking the safety shield 127 in a retracted position 
exposing the sharp distal tip 194 of the penetrating member 125 and 
releasing the safety shield to allow the safety shield to move to the 
extended protruding position. Locking and releasing mechanism 164 is 
similar to locking and releasing mechanism 64 except that trigger 182 for 
locking and releasing mechanism 164 is disposed distally of a protruding 
latch 176. The latch or locking spring 166 for locking and releasing 
mechanism 164 is made of a strip of resilient material formed to have a 
substantially flat base 168 secured to a bottom wall of housing 128 and a 
bend 172 joining the base 168 with an arm 174 disposed parallel or 
substantially parallel with a longitudinal axis of the safety penetrating 
instrument 120 and with base 168. Arm 174 carries latch 176 which has a 
distal angled latching surface 177 joining a proximal latching surface 178 
disposed substantially transverse to the longitudinal axis of the safety 
penetrating instrument and substantially parallel to the plate 138. 
Trigger 182 is juxtaposed with arm 174 to be disposed distally of latch 
176 and is similar to trigger 82 with a leg 186 overlying arm 174 and a 
leg 188 extending substantially transversely from leg 186 but at a slight 
angle toward the proximal end of the safety penetrating instrument. 
Trigger 182 is biased counterclockwise, looking at FIG. 4, such that leg 
186 is biased toward arm 174. 
Use of the safety penetrating instrument 120 is similar to that described 
above with respect to safety penetrating instrument 20 in that, when a 
user desires to penetrate into an anatomical cavity, the safety 
penetrating instrument will normally be provided with the safety shield 
127 in the extended protruding position where the distal end 137 of the 
safety shield protrudes beyond the penetrating member distal end 194. The 
safety shield 127 will be biased to the extended protruding position by 
extending member 148 such that handle 158 will be disposed at a distal end 
of slot 154 with plate 138 disposed distally of latch 176. The portal 
sleeve 126 will be biased distally by bias member 144 with flange 132 
biased in abutment with housing forward wall 134. 
Prior to commencing penetration of an anatomical cavity wall, handle 158 is 
grasped and manually moved proximally to move safety shield 127 proximally 
against the bias of extending member 148 until plate 138 rides over latch 
176 by engaging distal latching surface 177 to move arm 174 toward base 
168. The safety shield 127 will then be locked in the retracted position 
due to engagement of plate 138 with proximal latching surface 178 as shown 
in FIG. 4. As previously noted, the user can feel the plate lock into 
place in engagement with latch 176 and can also visually determine that 
the safety shield is in the locked retracted position by noting the 
position of the handle 158 at a proximal end of slot 154 at which time 
indicator strip 162 will no longer be visible or will be only slightly 
visible along the slot. With the safety shield 127 locked in the retracted 
position, the distal end 137 of the safety shield and the distal end 130 
of the portal sleeve will be disposed proximally of the sharp tip 194 of 
the penetrating member, and flange 132 will remain biased by spring 144 
into abutment with housing forward wall 134 with barb 135 disposed 
distally of trigger 182. 
With the safety penetrating instrument 120 in the position illustrated in 
FIG. 4, penetration of the cavity wall is commenced, and the force from 
tissue contact on the distal end 130 of the portal sleeve 126 will cause 
the portal sleeve to move proximally against the bias of spring 144 
causing barb 135 to move past trigger leg 188 without causing movement of 
latch 176; and, accordingly, the barb 135 is now positioned proximally of 
the trigger 182. Upon entry into the anatomical cavity, the counterforce 
on the distal end of the portal sleeve will be reduced allowing spring 144 
to move the portal sleeve distally causing barb 135 to engage leg 188 of 
trigger 182 and pivot the trigger counterclockwise causing leg 186 to 
engage arm 174. The engagement of leg 186 with arm 174 causes arm 174 to 
move toward base 168 moving the latch 176 out of engagement with plate 138 
thereby allowing spring 148 to cause the safety shield to move distally to 
the extended protruding position wherein the safety shield distal end 137 
protrudes beyond the distal end 194 of penetrating member 125. The 
penetrating unit 124 can then be withdrawn from the portal unit 122 
leaving the portal sleeve 126 and the safety shield 127 in place. 
Another modification of a safety penetrating instrument according to the 
present invention is shown in FIG. 5 at 220. Safety penetrating instrument 
220 is similar to safety penetrating instrument 120 except that the safety 
shield for the safety penetrating instrument 220 is part of the 
penetrating unit and both the portal sleeve and safety shield are 
triggered to move to extended protruding positions to serve as safety 
members upon penetration of the portal sleeve into the anatomical cavity. 
Safety penetrating instrument 220 includes a portal unit 222 and 
penetrating unit 224. Portal unit 222 is similar to portal unit 22 and 
includes a portal sleeve 226 and a housing 228 mounting the proximal end 
of the portal sleeve. Portal sleeve 226 is similar to portal sleeve 26 
except that portal sleeve 226 is provided without textured segment 27. 
Portal sleeve 226 terminates distally at distal end 230 and proximally at 
flange 232 disposed in housing 228. Flange 232 is similar to flange 32 
except that flange 232 has a finger 233 extending transversely or 
perpendicular therefrom in a proximal direction relative to flange 232 to 
terminate at a barb 235. A rail member 236 is disposed in housing 228 and 
is generally U-shaped including a forward wall 238 disposed transverse or 
perpendicular to a longitudinal axis of the penetrating instrument, a 
rearward wall 240 in configuration parallel to forward wall 238 and a side 
wall 242 transversely joining the forward and rearward rail member walls. 
Flange 232 is disposed between the rail member forward and rearward walls 
with the rail member forward wall 238 having an opening therein allowing 
passage therethrough by the portal sleeve 226. The rail member forward and 
rearward walls are disposed parallel or substantially parallel to flange 
232, and a bias member 244 is connected between flange 232 and the rail 
member rearward wall 240 to bias the portal sleeve distally. As shown, 
bias member 244 includes a helical coil spring 244 in compression between 
flange 232 and the rail member rearward wall 40 to bias the portal sleeve 
226 distally to cause flange 232 to abut the rail member forward wall 238. 
However, bias member 244 can include various other types of springs as 
well as other types of bias devices including compression springs, tension 
springs, torsion springs, pan springs, leaf springs, rubber, plastic or 
magnets, for example. Rail member rearward wall 240 extends toward an 
upper wall 246 of housing 228, and an extending member 248 is mounted 
between rail member rearward wall 240 and a rear wall 250 of housing 228 
to bias the portal sleeve 226 in a distal direction to an extended 
protruding position where distal end 228 of the portal sleeve is disposed 
beyond the sharp tip 294 of penetrating member 225. The extending member 
can include a helical coil spring 248 mounted in compression between rail 
member rearward wall 240 and the housing rear wall 250 as shown, or the 
extending member can include any other type of spring or other bias device 
as discussed for bias member 244. If desired, a guide rod 251 can be 
connected between the front wall 234 and the rear wall 250 of housing 228 
with the spring 248 disposed around the guide rod. 
Penetrating unit 224 includes penetrating member 225, safety shield 227 and 
hub 292 mounting proximal ends of the penetrating member and the safety 
shield. Safety shield 227 is disposed in portal sleeve 226 and terminates 
distally at a distal end 237 and proximally at a transverse flange or 
plate 232' disposed in hub 292. Safety shield 227 can have any desirable 
configuration in cross-section to couple safety shield distal end 237 with 
flange 232'. Extending members 248' including helical coil springs are 
connected between flange 232' and a rear wall 293 of hub 292 to bias the 
safety shield to an extended protruding position where the distal end 237 
of the safety shield is disposed beyond the distal end 294 of the 
penetrating member 225; and, if desired, springs 248' can be disposed 
around respective guide rods 251' connected between the forward and 
rearward walls 296 and 293 of the hub. 
Penetrating member 225 is similar to penetrating member 125 and has a sharp 
distal end or tip 294 and a proximal end secured to the rear wall 293 of 
hub 292. As shown, penetrating member 225 includes a hollow cylindrical or 
tubular main body 202 having an opening or slot 204 formed intermediate 
proximal and distal ends of the penetrating member in alignment with a 
similar opening 206 formed in safety shield 227. A latching spring clip 
208 is mounted within the penetrating member main body 202 and includes a 
generally U-shaped member formed from a strip of resilient material to 
have a pair of longitudinal legs 210 and 212 contacting diametrically 
opposed portions of the internal surface of penetrating member main body 
202 and being joined at respective proximal ends by a curved transverse 
section 214. Legs 210 and 212 are of unequal length and are normally 
biased apart. The longer leg 212 has a distal portion 216 configured to 
protrude through slots 204 and 206 in the penetrating member and safety 
shield to lock the safety shield 227 in the retracted position and to 
prevent distal movement of the shield relative to the penetrating member. 
Locking and releasing mechanism 264 for safety penetrating instrument 220 
is similar to locking and releasing mechanism 64 for safety penetrating 
instrument 20 and includes a latch 276 for locking the portal sleeve rail 
member 236 in the retracted position and a trigger 282 for releasing the 
rail member to move the portal sleeve to the extended protruding position. 
Additionally, a lever 218 is rotatably mounted on a pin 219 extending 
perpendicularly between walls of the housing 228 adjacent the protruding 
spring clip distal portion 216 of the safety shield 227 and the barb 235 
carried at the proximal end of portal sleeve finger 233. A torsion spring 
(not shown) is attached between the lever 218 and the pin 219 to bias the 
lever in a clockwise direction looking at FIG. 5 and into contact with the 
protruding spring clip distal portion 216. 
Handles 258 and 258' are coupled with the portal sleeve 226 and safety 
shield 227, respectively, for movement along slots 254 and 254' formed in 
the housing 228 and hub 292, respectively, to move the portal sleeve and 
safety shield from their extended protruding positions to locked retracted 
positions as previously explained above. 
Use of the safety penetrating instrument 220 is similar to that previously 
described; however, both the portal sleeve 226 and the safety shield 227 
will initially be in the extended protruding position shown in FIG. 8 with 
the portal sleeve distal end 230 and the safety shield distal end 237 
disposed beyond the distal end 294 of penetrating member 225 to protect 
the sharp tip of the penetrating member. In order to move the portal 
sleeve and safety shield to the retracted positions shown in FIG. 5, 
handles 258 and 258' are grasped one at a time or simultaneously to move 
the portal sleeve and safety shield proximally until the portal sleeve 
rail member forward wall 238 rides over latch 276 to be latched in the 
retracted position with the rail member forward wall 238 locked against 
proximal latching surface 278 and slots 204 and 206 in the penetrating 
member and safety shield are aligned allowing the distal portion 216 of 
spring clip 208 to pop through the aligned slots to lock the shield in the 
retracted position. As previously noted, the user can feel the rail member 
forward wall 238 lock into place in engagement with the latch 276 and can 
also visually determine that the safety shield and portal sleeve are 
locked in retracted positions by noting the position of the handles 258 
and 258' at proximal ends of their respective slots. 
With the safety penetrating instrument 220 in the locked retracted position 
illustrated in FIG. 5, the respective distal ends of the portal sleeve and 
safety shield will be disposed proximally of the distal tip of the 
penetrating member. The safety shield is locked against movement relative 
to the penetrating member so only the portal sleeve is able to move 
between forward and rear rail member walls. Penetration of a cavity wall W 
is commenced, and the force from tissue contact on the distal end 230 of 
the portal sleeve 226 will cause the portal sleeve to move proximally 
against the bias of bias member 244 causing flange 232 to move past 
trigger leg 288 and barb 235 to move past lever 218. Movement of flange 
232 proximally past trigger leg 288 does not cause movement of latch 276 
since there is no contact of trigger leg 286 with arm extension 280; and, 
accordingly, flange 232 is then positioned proximally of trigger leg 288 
as shown in FIG. 6. Similarly, movement of barb 235 proximally past lever 
218 does not cause movement of spring clip 208 since the lever 218 is made 
to rotate counterclockwise looking at FIG. 6 away from the protruding 
distal portion 216 of the spring clip. 
Upon entry into the anatomical cavity, the counter force on the distal end 
230 of the portal sleeve will be reduced allowing bias member 244 to move 
the portal sleeve distally causing flange 232 to engage trigger leg 288 
and pivot the trigger 282 counterclockwise looking at FIG. 7 causing leg 
286 to engage arm extension 280. The engagement of leg 286 with arm 
extension 280 causes arm 274 to move toward base 268 moving the latch 276 
out of engagement with the rail member forward wall 238 thereby allowing 
spring 248 to cause the portal sleeve to move further distally to the 
extended protruding position wherein portal sleeve distal end 230 
protrudes beyond the distal end 294 of the penetrating member as shown in 
FIG. 8. Simultaneously, barb 235 is carried along proximally with portal 
sleeve flange 232 and engages the lever 218 causing the lever 218 to 
rotate clockwise looking at FIG. 7 and to cam the protruding distal 
portion 216 of spring clip 208 into the hollow cavity defined within the 
penetrating member. Displacement of the protruding distal portion 216 of 
spring clip 208 into the penetrating member releases the safety shield 227 
allowing the safety shield 227 to move distally under the influence of 
springs 248' to protrude beyond the distal end 294 of the penetrating 
member 225 as shown in FIG. 8. The penetrating unit 224 including the 
penetrating member 225 and the safety shield 227 can then be withdrawn 
from the portal unit 222 leaving the portal sleeve 226 in place. 
From the above, it will be appreciated that the portal sleeve or cannula of 
the safety penetrating instrument of the present invention is movable 
proximally during penetration of an anatomical cavity wall and distally 
upon entering the anatomical cavity to trigger further distal movement or 
protrusion of the cannula, protrusion of a safety shield or probe, or 
protrusion of both the cannula and a safety shield or probe to function as 
safety members protecting the distal end of the penetrating member. By 
"safety member" is meant any structure movable distally relative to the 
penetrating member to protect the tip of the penetrating member within an 
anatomical cavity. Since in the safety penetrating instrument of the 
present invention one or both of a cannula and a safety shield or probe 
can be extended to protect the penetrating member tip, each can function 
as a safety member upon penetration of the safety penetrating instrument 
into an anatomical cavity. The cannula, whether or not it functions as a 
safety member, can be a portal sleeve, a needle open at both ends with 
fluid flow therethrough, a catheter or any other tubular component of a 
medical instrument. When the cannula is not triggered to protrude as a 
safety member, it is coupled with a safety member such as a tubular safety 
shield disposed between the cannula and a penetrating member, a safety 
probe fitted within a hollow penetrating member, or a component partly 
within and around the penetrating member and movable distally to protrude 
relative to the penetrating member to protect the distal end thereof when 
triggered. On the other hand, if the cannula does function as a safety 
member, it can be coupled with a protective sheath or probe that is not 
triggered to protrude or with any of the aforementioned safety members. 
Redundant safety can also be achieved by biasing the safety shield and/or 
penetrating member distally while allowing one or both to move proximally 
during penetration and triggering release of the safety member in response 
to distal movement of one or more of the cannula, the safety shield and 
the penetrating member upon entry into the anatomical cavity. 
Additionally, the triggered safety member protrusion can be combined with 
penetrating member retraction to provide separate modes of safety. 
In the embodiments shown, the distal end of the cannula, and the distal end 
of the safety shield or probe if provided, are aligned with a transverse 
dimensional transition in the penetrating member at the penetrating member 
distal end immediately prior to use in penetrating the anatomical cavity 
wall; and since the cannula is movable during penetration, the distal end 
of the cannula becomes displaced proximally relative to the penetrating 
member during penetration, triggering safety member protrusion when moving 
distally toward the aligned position upon entering the anatomical cavity. 
FIG. 9 shows an alternative distal configuration for safety penetrating 
instrument 20 wherein the distal end 30 of the portal sleeve or cannula 26 
is located proximally of the penetrating member distal end transition 95 
prior to use. In this configuration the portal sleeve distal end 30 will 
begin to move further proximally after the penetrating member 25 has 
penetrated the anatomical cavity wall to a predetermined depth X and will 
spring back to its original position proximal of the penetrating member 
distal end transition 95 upon entering into the anatomical cavity thereby 
triggering protrusion of the portal sleeve beyond the penetrating member 
distal end 94 to function as a safety member. 
Another distal configuration for safety penetrating instrument 20 is shown 
in FIG. 10 wherein the distal end 30 of the cannula or portal sleeve 26 is 
spaced distally of the penetrating member distal end transition 95 a 
predetermined distance X preferably corresponding to the distance between 
rail member forward and rear walls. In this configuration the portal 
sleeve distal end 30 will move proximally during penetration towards 
becoming aligned with the distal end transition 95 of the penetrating 
member 25 to ease penetration by providing a smooth profile and will 
spring back beyond the penetrating member distal end 94 upon entering into 
the anatomical cavity thereby triggering further distal movement or 
protrusion beyond the penetrating member distal end 94 by the cannula 26. 
FIG. 11 shows an alternative distal configuration for the safety 
penetrating instruments 120 and 220 (hereinafter described with reference 
to safety penetrating instrument 120) wherein the distal end 130 of the 
portal sleeve or cannula 126 is aligned with the penetrating member distal 
end transition 195 prior to use and the safety shield distal end 137 is 
spaced proximally of the portal sleeve distal end 130 a predetermined 
distance X preferably corresponding to the distance between rail member 
forward and rear walls. In this configuration the portal sleeve distal end 
130 will move proximally during penetration towards becoming aligned with 
the safety shield distal end 137 and will spring back into alignment with 
the penetrating member distal end transition 195 upon entering into the 
anatomical cavity thereby triggering protrusion beyond the penetrating 
member distal end 194 by the portal sleeve, safety shield or both the 
portal sleeve and safety shield. 
FIG. 12 shows another alternative distal configuration for the safety 
penetrating instruments 120 and 220 (hereinafter described with reference 
to safety penetrating instrument 120) wherein the distal end 137 of the 
safety shield 127 is aligned with the penetrating member distal end 
transition 195 prior to use and the distal end 130 of the portal sleeve or 
cannula 126 is spaced distally of the safety shield distal end 137 a 
predetermined distance X preferably corresponding to the distance between 
rail member forward and rear walls. In this configuration the portal 
sleeve distal end 130 will move proximally during penetration towards 
becoming aligned with the distal end transition 195 of the penetrating 
member 125 and the safety shield distal end 137 to ease penetration and 
will spring back beyond the penetrating member distal end 194 upon 
entering into the anatomical cavity thereby triggering protrusion beyond 
the penetrating member distal end 194 by the safety shield. 
Another alternative distal configuration for safety penetrating instruments 
120 and 220 (hereinafter described with reference to safety penetrating 
instrument 120) is shown in FIG. 13 wherein the distal end 137 of the 
safety shield 127 is aligned with the penetrating member distal end 
transition 195 prior to use and the distal end 130 of the portal sleeve or 
cannula 126 is spaced proximally of the safety shield distal end 137 a 
predetermined distance X to delay proximal movement of the portal sleeve 
126. In this configuration the portal sleeve distal end 130 will move 
proximally during penetration after the penetrating member 125 and safety 
shield 127 have penetrated the anatomical cavity wall to a depth 
approximately equal to the distance X. The portal sleeve 126 will spring 
back distally upon entering the anatomical cavity thereby triggering 
further distal movement or protrusion of the portal sleeve, the safety 
shield or both the portal sleeve and safety shield to serve as safety 
members. 
Yet another distal configuration for safety penetrating instruments 120 and 
220 (hereinafter described with reference to safety penetrating member 
120) is shown in FIG. 14 wherein distal ends 130 and 137 of both the 
portal sleeve 126 and the safety shield 127 are located proximally of the 
penetrating member distal end transition 195 a predetermined distance X. 
In this configuration, the portal sleeve 126 will begin to move proximally 
relative to the safety shield 127 and penetrating member 125 when the 
penetrating member 125 has penetrated into the anatomical cavity wall a 
distance approximately equal to X and will trigger protrusion of the 
portal sleeve, the safety shield or both upon moving back distally toward 
the distal end of the safety shield. 
The components of the safety penetrating instrument of the present 
invention can be made of any suitable, medical grade materials to permit 
sterilization for re-use or for single patient use. The components can be 
made of multiple parts of various configurations and materials to reduce 
cost. The portal unit can have various valves, stop cocks and seals in the 
housing to control fluid flow therethrough, and conventional detent 
mechanisms can be used to connect or latch the hub with the housing when 
the portal unit and the penetrating unit are assembled. The distal ends of 
the cannula and the safety shield or probe can be chamfered or blunt, 
smooth or roughened, or have any other configuration depending on the need 
for ease of penetration or increased resistance; and when a safety shield 
or probe is provided it can be mounted either by the portal unit or the 
penetrating unit depending on the desirability of being left in place with 
the cannula or withdrawn with the penetrating member. 
The penetrating member can be solid, hollow or partially solid and hollow, 
formed as single or multiple pieces, and fixedly mounted as shown or 
movable telescopically over a guide tube or the like. The distal end 94 of 
the penetrating member 25 can have any configuration desired for a 
particular procedure, for example, the pyramidal trocar configuration 
shown or a conical distal end (FIG. 15), a threaded distal end (FIG. 16), 
a multifaceted distal end (i.e., having greater than three facets as shown 
in FIG. 17), a blunt distal end (FIG. 18), a slanted distal end (FIG. 19) 
or a hollow needle configuration with fluid flow therethrough (FIG. 20). 
Additionally, the surface defining the distal end of the penetrating 
member can be irregular or smooth, continuous or perforated, provided with 
cutting features or having any combination of the above. If the 
penetrating member 25 is a hollow needle having a beveled end as shown in 
FIG. 20 or a curved Toohey-type distal configuration, the proximal edge of 
the opening at the distal end 94 of the needle is considered the 
transverse dimensional transition 95 and thus the cannula and/or safety 
shield distal end is aligned with the distal end of the needle when 
located adjacent the proximal edge. 
As mentioned previously, the safety member of the present invention can be 
a tubular member such as the cannula or a safety shield disposed between 
the cannula and penetrating member, or in the case of a hollow penetrating 
member, the safety member can be a probe disposed at least partially 
within the penetrating member and movable through one or more apertures 
formed at or near the distal end of the penetrating member. FIG. 21 shows 
a cannula 26 surrounding a hollow penetrating member 25 with a beveled 
distal end 94 and a cylindrical safety probe 27 in an extended protruding 
position to protect the distal end of the penetrating member. The safety 
probe 27 has a beveled distal end 37 and is preferably movable from the 
extended position shown to a retracted position where the beveled distal 
end 37 of the safety probe 27 is flush with the distal end 94 of the 
penetrating member 25. It will be appreciated that a coaxial extending 
mechanism can be fitted within the penetrating member to move the safety 
probe to the extended position or a flange can be carried at the safety 
probe proximal end and passed through a slot or opening in the penetrating 
member to be acted on by any of the extending mechanisms previously 
described. The safety probe distal end can have any configuration to 
protrude through single or multiple openings formed in the penetrating 
member distal end and can conform to the distal profile of the penetrating 
member or present a discontinuous surface. 
The rail member can have various configurations to engage the latch and be 
released by the trigger. Preferably, the rail member will have a 
configuration to serve as a stop or abutment for the operating member as 
exemplified herein by a U-shaped rail member. 
The locking and releasing mechanisms require only a latch for locking the 
safety member in the retracted position and a trigger for releasing the 
latch in response to distal movement of an operating member; and, thus, it 
will be appreciated that various mechanisms can be employed to produce the 
locking and releasing functions such as, for example, multiple movably or 
pivotally mounted cams or pawls. It will be appreciated that the locking 
and releasing mechanism can be designed and arranged in the housing or the 
hub in various ways to minimize the length of the housing or the hub and, 
therefore, the overall length of the housing and hub. Various locking and 
releasing mechanisms that can be simply modified for use in the safety 
penetrating instrument of the present invention are disclosed in 
applicant's pending applications Ser. Nos. 07/800,507, filed Nov. 27, 
1991, 07/805,506, filed Dec. 6, 1991, 07/808,325, filed Dec. 16, 1991, 
07/848,838, filed Mar. 10, 1992, 07/868,566 and 07/868,578, filed Apr. 15, 
1992, 07/929,338, filed Aug. 14, 1992, 07/845,177, filed Sep. 15, 1992, 
07,945,177, filed Sep. 15, 1992, 08/079,586, filed Jun. 22, 1993, 
08/195,512, filed Feb. 14, 1994, 08/196,029, filed Feb. 14, 1994, 
08/196,027, filed Feb. 14, 1994, 08/195,178, filed Feb. 14, 1994, 
08/237,734, filed May 4, 1994, 08/247,205, filed May 20, 1994, 08/254,007, 
filed Jun. 3, 1994 and 08/260,439, filed Jun. 15, 1994, the disclosures of 
which are incorporated herein by reference. The above applications 
disclose automatically retracting safety penetrating instruments such that 
modification of the locking and releasing mechanisms requires configuring 
the latches to lock a member in a retracted position rather than in an 
extended position. The above applications also disclose various bias 
arrangements useful with the safety penetrating instrument of the present 
invention. Other locking and releasing mechanisms that can be used in the 
safety penetrating instrument of the present invention are disclosed in 
applicant's copending patent application Ser. Nos. 08/279,170 and 
08/279,172, filed Jul. 22, 1994, the disclosures of which are incorporated 
herein by reference. 
One or more control buttons, such as the control buttons described in 
applicant's copending patent application Ser. No. 08/083,220, filed Jun. 
24, 1993, the disclosure of which is incorporated herein by reference, can 
be mounted next to any latch for manually disengaging the latch to prevent 
locking of the safety member in the retracted position, thereby converting 
the safety penetrating instrument to a standard safety shielded 
penetrating instrument without triggered protrusion. In addition, any 
latch can carry a secondary pawl or protrusion at a distal end for locking 
the safety member in the extended position and can then be released 
through the use of a control button as described above. 
It will also be appreciated that the safety penetrating instrument of the 
present invention permits use of strong bias springs to ensure movement of 
the safety member (whether it be the cannula, a safety shield or probe, or 
both) to the extended protruding position without increasing the force to 
penetrate. After penetration of the safety penetrating instrument into the 
anatomical cavity, the safety member acts as a shock absorber upon 
inadvertent contact with tissue which contact can be felt by the user and 
visually determined by movement of the handle. The distal bias for the 
cannula of the safety penetrating instrument need only be strong enough to 
allow slight movement of the cannula during penetration such that the 
force-to-penetrate can be minimized. The features of the various 
embodiments described above can be combined in any manner desired 
dependent upon the requirements and complexity of the safety penetrating 
instrument. 
Inasmuch as the present invention is subject to many variations, 
modifications and changes in detail, it is intended that all subject 
matter discussed above or shown in the accompanying drawings be 
interpreted as illustrative only and not be taken in a limiting sense.