This invention relates to a medical apparatus for producing a controlled skin incision. More particularly, this invention relates to a disposable medical apparatus for producing a consistent incision of a particular depth and length on the skin by a slicing action rather than a puncturing action to cause bleeding. Still more particularly, this invention relates to an internal mechanism with a safety trigger that applies a constant force and displacement to a connected load for incising without the use of a preloaded spring component.

Description of prior art

Lancets and other devices that puncture or incise living tissue to take a sample of bodily fluid are well known in the art. One common medical device is a heel stick device that is generally used on infants to take a sample of the infant's bodily tissue. Using a heel stick device, a small incision is created on the patient's skin to draw a blood sample. Typically, the heel is chosen for this incision because the skin at the heel is the least sensitive and the capillary blood sampled from that area is adequate for the intended blood tests. Blood drawn using this procedure is used to perform a variety of tests such as general chemistries and liver function tests, complete blood counts, bedside glucose monitoring, and blood gas analysis. More commonly, a heel stick procedure is used for newborn screening tests such as those for hypothyroidism (underactivity of the thyroid gland), PKU (Phenylketonuria), Galactosemia, and sickle cell disease. Early detection of these diseases in newborns can greatly increase the odds of the infant's survivability.

Commercially available semi-automated incision devices are currently adopted in the medical industry for the purpose of carrying out the heel stick procedure. These mechanical lancet devices are typically single-use for hygiene reasons and are normally designed with a whole variety of built in safety features such as a retractable blade, a pre-actuation safety latch mechanism and a post- actuation safety latch mechanism. When the device is being prepared for use, the entirety of the blade should be safely contained within a housing. Ideally, the blade should only be exposed outside the housing when making an incision and then retract safely back into the housing. This ensures that users of the device do not accidentally cut themselves during the handling of the device while also greatly reducing the patient's anxiety as the blade will effectively be shielded from sight during the entire procedure. In most designs, once the blade has safely retracted, the triggering mechanism will either be latched to or locked in the housing to ensure that the device can not be reused. This safety feature contributes to the ease of disposal of the used devices and greatly reduces the risk of spreading deadly blood transmitted diseases.

One particular problem with heel stick devices is that these devices must be able to deliver a repeatable skin incision of a controllable length and depth. The incising stroke must produce a smooth cut as jagged cuts in the skin tend to cause more pain to the patient as well as taking a longer period to heal. A smooth cut also reduces the risk of the formation of a scar on the skin. The depth of the controlled cut is of utmost importance especially when the device is to be used on newborns. The Clinical and Laboratory Standards Institute (CLSI) recommends that the depth of the incision should not exceed 2.0 mm whilst the maximum length of the incision should be 2.5 mm or less. This standard is essentially a precaution to ensure that the calcaneus of the newborn will be not damaged during the procedure while ensuring that sufficient blood is drawn for the abovementioned blood tests and thus reducing the need for further incisions. Device manufacturers tend to utilize a wide variety of spring-like mechanisms to generate a constant controlled force and displacement on the incising blade. A US Patent Number 7,316,698, issued on January 8, 2008 to Edward L. Galloway et. al, describes an incision device where one end of the spring mechanism is connected to a sliding lid of a housing and the other end is positioned in the interior of the housing. When the sliding lid of is pressed downwards into the housing, the spring is compressed to store energy. Once the controllable load limit of the spring is exceeded, the spring releases the stored energy in a horizontal direction, pushing against a carriage element which is connected to the blade. The introduction of this force onto the carriage element drives the motion of the blade out of the housing, through the skin and back into the housing.

US Patent Number 5,527,333, issued on June 18, 1996 to Ben H. Nikkels et. al, describes a slicing blood sampling device that uses an "S" shape spring mechanism with the incising blade coupled at one end. A safety mechanism located in the housing prevents a triggering mechanism from actuating the spring unless a predetermined amount of force is applied downwards on the triggering mechanism. Once the triggering mechanism overcomes a safety restraint in the housing, the triggering mechanism moves in a downward motion causing the spring to extend. The extending spring then causes the coupled blade to proceed along a predetermined incision path. When the triggering mechanism is fully toggled, the fully extended spring recoils back to its original shape thus retracting the coupled blade back into the housing.

US Patent Number 6,010,519, issued on January 4, 2000 to James A. Mawhirt et. al, describes an incision device with a safety tab connected to a triggering mechanism, and a spring mechanism that is placed in a pre-actuated position against a pivot arm which is coupled to an incising blade. Once the safety tab is removed, the triggering mechanism can be pushed against the pivot arm which in turn compresses a spring to store energy in the spring. When the triggering mechanism is fully toggled, the spring releases the stored energy. This released spring exerts a force on the pivot arm causing the arm to travel in an opposite horizontal direction moving a coupled blade along a predetermined path.

The above described prior art devices possess a single pre-actuation safety mechanism either in the form of a removable safety tab, a safety trigger in the housing or a spring mechanism that requires a prerequisite amount of triggering force. If this single safety mechanism fails, either due a manufacturing defect or error, these devices may be actuated unintentionally. In prior art, the incising motion of the coupled blade is either automatically triggered by the release of a spring's stored energy once a stored limit has been exceeded or by the force applied to the spring via the triggering mechanism. Hence, the force and timing of the cut may not be consistent as these parameters will depend on the material properties of the spring and/or the pressure applied to the triggering mechanism. An important commercial consideration for these devices is their ease of assembly. Devices which involve a greater number of components or are more complex to assemble generally require a more costly production process.

In view of the above, it is the objective of the invention to provide a commercially viable, disposable incision device that is capable of producing a smooth and consistent controlled cut with multiple built in pre-actuation and post actuation safety mechanisms.

Summary of Invention

The above and other problems are solved and an improvement in the art is made by an incision apparatus in accordance with this invention. A first advantage of an incision apparatus in accordance with this invention is that the action of triggering the device also primes and releases the blade. This facilitates easy manufacture and assembly and prevents premature release of the blade. A second advantage of an incision apparatus in accordance with this invention is that the priming and releasing of the blade are performed in a single movement by the user. This reduces the number of parts needed to produce the incision apparatus and provides a consistent cut regardless of the force applied by user. A third advantage of an incision apparatus in accordance with this invention is that the incision apparatus does not require priming during assembly. Thus manufacturing, packaging, and transportation costs are reduced.

In accordance with embodiments of this invention, an incision apparatus is configured in the following manner. An incision apparatus for one time use and safe disposal has a housing having a first side and a second side. A slot is defined through the first side of the housing, and an opening is defined through the second side of the housing. A holder has a first body pivotally mounted within the housing. The holder also has a second body that holds a blade with a sharp edge for incising tissue. This second body holds the blade in a first position prior to use, allows the blade to extend through the slot along a predefined path during use and move to a second position inside the housing after use. A resilient element extending from the first body is in a first position prior to use and moves to a second position to cause the first body to pivot.

A flexible arm connecting the first body to the second body has a first state in which the flexible ami stores sufficient energy to cause the second body to move, this causes the blade to extend through the slot. The flexible arm also has a second state in which the flexible arm is substantially flexed, storing enough energy to move the second body from a position where the blade extends through the slot to the second position of the second body inside the housing. The flexible arm further has a third state in which the flexible arm stores insufficient energy to cause the second body to move.

A guide is defined in the housing that forces the second body to move along a predefined path from the first position to the position where the blade extends through the slot. An actuator is movable between a first position in which the actuator extends through the opening in the housing and is in contact with the resilient element in the first position and a second position in which the actuator is retracted into the housing causing the resilient arm to move to the second position. When a force is applied to the actuator, the force causes the resilient element to move from the first position to the second position imparting sufficient force to the resilient element to rotate the first body. The resilient element expends force to rotate the first body. As the first body rotates, a force is imparted on the flexible arm. The imparted force causes the flexible arm to change from the first state to the second state, thereby causing the second body to move along the predefined path from the first position to the position where the blade extends through the slot with sufficient force to incise the tissue. The flexible arm imparts further force on the second body to change from the second state to the third state and this moves the second body to the second position inside the housing. A stopping element holds the second body in the second position within the housing after the flexible arm changes to the third state. In some embodiments, the stopping element can comprise of a blocking rail situated on the internal side of the wall of the housing. In accordance with some embodiments of this invention, an incision apparatus may further include a first tab on a first side of the second body and a second tab on the second side of the second body. These first and second tabs cooperate with a guide to cause the second body to move along a predefined path from the first position in the body to the position where the blade extends through the slot. The incision apparatus may further cooperate with a support rail on the internal side of the wall to support the holder within the housing.

In accordance with further embodiments of this invention, the guide has a first rail defined on a first internal side of the housing and a second rail defined on a second internal side of the housing. These rails are configured to securely hold the first and second tabs in place along the first and second rails as the second body moves along the predefined path. In accordance with still further embodiments of this invention, the guide has a first cam defined on a first internal side of the housing forming a first slotted pathway. This causes the first tab of the second body to be securely held in the first slotted pathway to guide the second body along the predefined path during use. Further, the guide has second cam defined on a second internal side of the housing forming a second slotted pathway. This causes the second tab of the second body to be securely held in the second slotted pathway to guide the second body along the predefined path during use. In accordance with yet further embodiments of this invention, the stopping element is an extension of the guide that cooperates with the first and second tabs to prevent the second body from being moved to the first position inside the housing.

In accordance with embodiments of this invention, the incision apparatus has a blocking element that prevents the second body from moving along the predefined path until the flexible arm imparts sufficient energy to overcome the blocking element. Further, this blocking element may comprise a blocking rail situated on the internal side of the wall of the housing.

In accordance with further embodiments of this invention, the blocking element is an extension of the guide that causes the second body to move in a direction that causes the flexible arm to compress before allowing the second body to move along the predefined path.

In accordance with embodiments of this invention, the incision apparatus has a first locking element that prevents the first body from rotating about the pivot prior to use. The incision apparatus also has a release element that releases the second locking element when the force is applied to the actuator.

In accordance with further embodiments of this invention, the first locking element has a contact extending outward from an internal wall of the housing proximate the first body. The first locking element also has a nib extending outward from a surface of the first body that rests upon the contact to prevent the first body from rotating.

In accordance with still further embodiments of this invention, the first locking element has a projection extending outward from a surface of the actuator that is positioned to contact the nib on the second body when the force is applied to the actuator to dislodge the nib from the contact which allows the first body to rotate. In accordance with yet further embodiments of this invention, the contact has a sloped surface that facilitates dislodging of the nib from the contact by the projection.

In accordance with other embodiments of this invention, the incision apparatus has a second locking element that holds the actuator in the second position when the force is applied to the actuator.

In accordance with further embodiments of this invention, the second locking element has a projection extending from edge of the actuator and a slot defined in an internal side of the housing configured to receive the projection and securely hold the projection in place.

In accordance with yet further embodiments of this invention, the incision apparatus has a pair of rails on the internal side of the wall that define a trough for receiving the projection to guide the actuator from the first position to the second position.

In accordance with embodiments of this invention, the incision apparatus has an indentation defined in an external surface of the first end of the housing surrounding the slot. This indentation is configured to receive a heel of an infant in a position for performing an incision.

In accordance with embodiments of this invention, the flexible arm has a C- shaped spring with a first end affixed to the first body and a second end affixed to the second body.

In accordance with further embodiments of this invention, the incision apparatus has a support extending between the first body and a portion of the C- shaped spring to form a Y-shaped connector.

In accordance with some embodiments of this invention, the blade element is integral to the holder. In accordance with other embodiments, the holder is injection molded around the blade element. In further embodiments, the blade element may be secondarily affixed onto the holder by means of heat staking.

In accordance with some embodiments of this invention, an incision apparatus is used in the following manner: a user places the first side of the housing having a slot proximate skin tissue and pushes on the actuator. The actuator, in turn, applies a force to the actuator protruding from a housing to move the actuator from a first position to a second position. A resilient element of the holder inside the housing moves from a first position to a second position in response to the actuator moving from the first position to the second position. Sufficient force is imparted to the resilient element to rotate a pivotally mounted first body connected to the resilient element inside the housing in response to moving the resilient element from the first position to the second position and this force is expended to rotate the first body about the pivot. The force is imparted to a flexible arm connected to the first body in response to rotating the first body and the flexible arm changes from a first state, in which the flexible arm stores sufficient energy to cause the second body to move to cause the blade to extend through the slot, to a second state in which the flexible arm is substantially flexed storing enough energy to move the second body from a position where the blade extends through the slot to the second position of the second body responsive to imparting the force to the flexible. The flexible arm changing states causes the second body to move along the predefined path from a first position inside the housing to a position where the blade extends through the slot with sufficient force to incise the tissue. Further, the energy stored by the flexible arm is imparted on the second body and changes the flexible arm from the second state to a third state in which the flexible arm stores insufficient energy to cause the second body to move in response to the flexible arm changing to the second state and moving the second body to a second position inside the housing. The second body is held in the second position within the housing in response to the flexible arm changing to the third state. In accordance with some particular embodiments, the first body is locked in a first position prior to applying of the force on the actuator. Further embodiments release the first body locked in the first position in response to applying the force to the actuator. In yet other embodiments, the actuator is locked in a second position in response to moving the actuator to the second position.

In accordance with further embodiments, second body is blocked from moving along the predefined path until the flexible arm imparts sufficient energy to overcome a blocking element.

In accordance with yet further embodiments, an indentation is placed in an external surface of a first end of the housing surrounding the slot. This indentation is configured to receive a heel of an infant in a position for performing an incision over the heel of the infant prior to applying the force to the actuator.

Description of drawings

The above and other features and advantages of an incision apparatus in accordance with this invention are described in the detailed description given below and the following drawings:

Figure 1 illustrating an embodiment of an incisor device in accordance with one embodiment of this invention;

Figure 2 illustrating an exploded view of components of the incisor device shown in Figure 1 ; Figure 3 illustrating a first half of a housing of an incisor device in accordance with another embodiment of this invention;

Figure 4 illustrating a second half of a housing of the incisor device in accordance with the other embodiment of this invention;

Figure 5 illustrating a view of a first side of a holder in accordance with incisor device shown in Figure 1 ;

Figure 6 illustrating a view of a second side of a holder in accordance with incisor device shown in Figure 1 ;

Figure 7 illustrating a bottom side view of an actuator in accordance with the incisor device shown in Figure 1 ;

Figures 8-14 illustrating cross sectional views of one half of an incisor device in accordance with an embodiment of this invention during various stages of use; and

Figure 15 illustrating a flow diagram of a process of using an incisor device in accordance with the embodiment shown in Figures 8-14.

Detailed Description

This invention relates to a medical apparatus for producing a controlled skin incision. More particularly, this invention relates to a disposable medical apparatus for producing a consistent incision of a particular depth and length on the skin by a slicing action rather than a puncturing action to cause bleeding. Still more particularly, this invention relates to an internal mechanism with a safety trigger that applies a constant force and displacement to a connected load for incising without the use of a preloaded spring component. For clarity, the same element shown in multiple drawings is given the same reference numeral throughout this description.

Figure 1 illustrates a heel stick 100 that is one embodiment of an incisor device in accordance with this invention. Heel stick 100 includes housing 110 that has a first end 130 and a second end 125. In the shown embodiment, housing 110 is made of two portions 1 15 and 120 that are bound together. However, one skilled in the art will recognize that housing 110 may be one integral piece or made of any number of pieces without departing from this invention. Preferably, housing 110 is made of made of plastic. However, other material may be used to make housing 110 without departing from this invention.

Figure 2 illustrates an exploded view of heel stick 100 to show all of the internal components of heel stick 100. Heel stick 100 includes first and second portions 115 and 120 of housing 110; actuator 220; and holder 225. Preferably, all of these components are made of plastic that is injection molded. However, other materials and methods of manufacture may be used without departing from this invention. First and second portions of housing 110 are affixed to one another to form a cavity and are described in detail below with respect to Figures 3 and 4. Actuator 220 extends out of the cavity though opening 255 defined in second end 125 of housing 110 and is described in detail below with respect to Figure 7. Holder 225 is pivotally affixed to opposing internal side of housing 110, has an incising instalment such as a blade attached, and is described in more detail below with respect to Figures 5 and 6.

Figures 3 and 4 illustrate the internal sides of housing portion 115 and 120. In this embodiment, housing portion 115 includes supports 265-269 that extend outward from the interior sidewall either proximate to or from end walls of portion 115. Housing portion 120 includes cavities that are recessed into the interior sidewall either proximate or in the exterior end walls. Each of cavities 465-469 (Figure 4) is mated to one of supports 265-269 to affix portions 115 and 120. The portions may then be affixed together by an adhesive epoxy or other method. The mating of cavities 465-469 (Figure 4) to supports 265-269 aligns portions 115 and 120 to assure that the internal components are correctly aligned inside heel stick 100 to assure that the incisions made by each heel stick 100 produced are consistent. Further, housing portion 115 can incorporate lip 370 along the edges. Lip 370 is mated together with recess 470 along the edges of housing portion 120. This mating of lip 370 to recess 470 aligns the internal components of heel stick 100. One skilled in the art will recognize that the portions may be affixed and/or aligned in other manners without departing from this invention. Each portion 115 and 120 includes an opening on first end 130 that forms slot 250 when the portions are joined. Slot 250 is an opening defined in first end 130 of housing 1 10 through which an incising instrument extends to make the incision. On the surface of first end 130, each of portions 115 and 120 have an indenture defined around the opening used to form slot 250. When the portions are joined to form housing 110, indentation 360 (Figure 3) on the first end of housing 110 is formed by the indentures in portions 1 15 and 120. Indentation 360 (Figure 3) is formed to receive the heel of a typical infant and to position the heel such that an incision made by heel stick 100 is of a desired depth and length. Further, in this embodiment, the indentures may have inwardly curved surfaces to help define the shape of indentation 360 to receive a heel.

Receptacle 240 protrudes out from the interior side wall of each of portions 115 and 120. Receptacle 240 is configured to receive a mated extension on holder 225 to provide a pivot about which holder 225 rotates. Rails 350, 351 , 352, 450, 451 , 452 (Figures 3 and 4) are defined protrusions that extend out of internal sidewalls of portions 115 and 120. In this embodiment, rails 350, 450, cooperate with tabs 535 (Figure 5) protruding from opposing sides of holder 225 to define a guide path for a second body connected to an incising device to make a cut of a defined depth and width in a defined pattern. In accordance with this embodiment, the defined pattern of the incision is a "check mark" type shape. However, the rails may be arranged in another manner to make different patterns without departing from this invention. At an end of each rail 350, 450 proximate slot 210, stop elements 355, 455 (Figure 3 and Figure 4) may extend away from the main axis of the rail. Stop elements 355, 455 cooperate with a reflexive arm in holder 225 to hold the second body of holder 225 in a second position inside housing 110 after heel stick 100 has been used to prevent the incisor instrument from protruding through slot 210 and prevent heel stick 100 from being reset for additional use. Further, additional rail 352 can be added to aid in supporting the holder 225 while in the first position and second position; and during rotation of holder 225 inside heel stick 100. Stopper rail 351 may also be added to prevent holder 225 from moving back to the first position from the second position after heel stick 100 has been used.

Extensions 230 are wings that extend outward from the internal surface of portions 115 and 120 proximate second opening 255. A nib 550 (Figure 5) on holder 225 is held in place by extensions 230 to prevent holder 225 from rotating prior to use. A force is applied to the nib to force the nib over extensions 230 to allow holder 225 to rotate. To facilitate the nib overcoming extensions 230, extensions 230 may be flexible and/or include sloped surfaces that are in contact with the nib. As shown, nib 550 can also be tapered to cooperate with extensions 230 in dislodging nib 550 from extensions 230. Proximate opening 255, each portion 115 and 1 16 include one or more guide troughs 245, 246 defined by a pair of rails that cooperate with actuator 220 to guide the movement of actuator 220 between a first and second position during use. In some embodiments, guide troughs 245 are defined in the sidewall of the portions 115, 120 to receive projections 610-613 extending (Figure 7) out of the side the actuator 220. This prevents dislodgement of the actuator from opening 255 before use and slope 244 allows easy assembly of the actuator 220. In some embodiments, one or more of guide troughs 246 may include slots 260, 261 defined in the sidewall of the portion to receive a projection 610-613 extending out of the side of actuator 220 to hold actuator 220 in place after use. Figures 5 and 6 illustrate holder 225. Holder 225 includes a first body 505. First body 505 has a first surface, a second surface, a first side, a second side, a first end, and a second end. Axle 560 extends outward from the first and second surface of first body 505 and inserts into receptacles 240 of first and second portions 115 and 120 of housing 110 to pivotally mount first body 505 inside housing 110.

Resilient element 510 extends outward from the second end of body 505. Resilient element 510 is a flexible extension that may flex between a first position in which resilient element 510 stores insufficient energy to rotate first body 505 and a second position in which resilient element 510 stores sufficient energy to cause first body 505 to rotate from a first position to a second position. In operation, resilient element 510 cooperates with actuator 220 as described below to move between the first and second positions.

Nib 550 is a protrusion that extends out of a first side of first body 505. Nib 550 is configured to rest upon extensions 230 (Figures 3 and 4) prior to use to prevent first body 505 from rotating about the pivot. Nib 550 and extensions 230 are designed such that nib 550 may be dislodged from extensions 230 in response to a sufficient force being applied to nib 550. Nib 550 may have a sloped bottom edge to facilitate the dislodging of nib 550 from extensions 230. Flexible arm 520 is a flexible element that extends out of a second side of first body 505 connecting first body 505 to second body 525. In Figures 5 and 6, flexible arm 520 is curved and forms a C-shaped spring. In some embodiments, a second arm 521 may extend between flexible arm 520 and the second side of first body 505 to form a Y-shaped connector providing support. However, other configurations may be used without departing from this invention. In accordance with this invention, flexible arm 520 is in a first state in which flexible arm 520 stores sufficient energy to cause second body 525 to move which in turn causes incising instrument 530 to extend through slot 210 prior to use. During use, flexible arm 520 is in a second state in which flexible arm is substantially flexed and stores enough energy to move second body 525 from a position where incising instrument 530 extends through slot 210 to a second position inside housing 110. After use, flexible arm 520 is in a third state in which flexible arm 520 stores insufficient energy to cause second body 525 to move. The states of flexible arm 520 are described in more detail below with regards to operation of heel stick 100.

Second body 525 is a plastic body having a first side, a second side, a first end, a second end, a first surface and a second surface. Incision instrument 530 is a blade or other instrument having a cutting edge that is affixed to second body 525 in a manner in which a cutting edge extends outward from the first end of second body 525 to expose the cutting edge. As shown, incision instrument 530 is press fit on a mounting 540 in a recessed portion of one side of second body 525. However, incision instrument may be affixed to second body 525 in other manners, including, but not limited to, injection molding second body 525 around incision instrument 530. Tabs 535 are protrusions on each side of the first and second surfaces of the second body 525 that extend outward from the first and second surfaces of second body 525 and cooperate with guides in housing 110 to make second body move along a predefined path in operation.

Figure 7 illustrates a bottom side view of actuator 220 of the embodiment shown in Figure 1. Actuator 220 may move from a first position in which a portion of actuator 220 extends out from opening 250 to a second position in which actuator is substantially inside housing 110. Actuator 220 includes cavity 605 defined in a bottom side of actuator 220. Cavity 605 includes indentation 620 that receives an end of resilient element 510 to guide resilient element 510 between a first position and a second position. Projection element 615 is a protrusion that extends outward from the inner surface of cavity 605. Projection element 615 contacts nib 550 and/or extensions 230 to apply a force to nib 550 as actuator 220 moves from the first position to the second position. The force dislodges nib 550 from extensions 230 which in turn allows first body 505 to rotate. Further, projection element 615 may include assisting arm 616 that aids in dislodging the nib 550 from extensions 230 which in turn allows first body 505 to rotate.

Projections 610-613 extend outward from external sides of actuator 220. As shown, projections 610-613 extend from flexible legs defined in the side of actuator 220. Projections 610-613 are positioned such that projections 61 1 , 613 insert into slots 245 to lock actuator 220 in the first position to avoid dislodging actuator 220. Projections 610-613 insert into slots 260, 261 to lock actuator 220 in the second position after a force has been applied. Furthermore, projections 610- 613 may fit into guide troughs 246 to guide actuator 220 from the first position to the second position when the force is applied. Further, channel 630 can be positioned within cavity 605 opposite projection element 615 to allow holder 225 to have more clearance during movement. The operation of heel stick 100 in use will now be described using a flow diagram of process 1200 shown in Figure 15 with reference to Figures 8-14 showing cross sectional views of an embodiment of heel stick 100 in accordance with this invention. Prior to use, heel stick 100 is in a configuration as shown in Figure 8. Preferably, the shown configuration is the configuration in which heel stick 100 is assembled. As shown in figure 8, actuator 200 is in a first position in which a significant portion of actuator 220 extends out of opening 250 of housing 110. In this configuration, resilient arm 510 of first body 505 is in a first position in which resilient arm 510 has insufficient energy to cause first body 505 to rotate. To further prevent body 505 from rotating about the pivot, nib 550 is engaged by extensions 230.

In this configuration, flexible arm 520 is in a first state in which flexible arm 520 stores sufficient energy to cause second body 525 to move causing incising instrument 530 to extend through slot 210. Tabs 535 are engaged pathway 710 holding second body 525 in a first position within housing 110.

Process 1200 then begins in step 1205 by placing heel stick 100 proximate the heel of the infant to be incised. To facilitate properly positioning heel stick 100, the infants heel may be placed in indentation 230. At this point in process 1200, heel stick 100 is configured as shown in Figure 8. Once in place, a user depresses actuator 220 into housing 110 in step 1210. By depressing actuator 220, a force is applied to the actuator 220 moving actuator 220 from the first position to a second position. In the second position, actuator 220 is substantially retracted into housing 110. The movement from the first position to the second position may be guided by projections 610-613 moving through troughs 245,246 on the internal sidewalls of portions 115 and 120 of housing 110. Moving from the first position to the second position causes projection element 615 to dislodge nib 550 from extensions 230 to allow first body 505 to freely rotate in step 1215. The movement of actuator 220 also causes resilient element 510 to compress as resilient element 510 moves from the first position to the second position in step 1220. In the second position, resilient element 510 stores energy through its compression, which generates sufficient force to rotate first body 510. After step 1220, heel stick 100 is in the configuration shown in Figure 9. After actuator 220 moves to the second position, projections 610-613 are engaged by slots 260,261 to lock actuator 220 in the second position in step 1225. When actuator 220 is locked in place, resilient element 510 decompresses. The decompression of resilient element 510 imparts the stored energy to first body 505 causing first body 505 to rotate from a first to second position in step 1230. The rotation of first body 505 imparts energy to flexible arm 520 changing flexible arm 520 from a first state to a second state in step 1235.

In the second state, flexible arm 520 is substantially flexed and stores enough energy to move second body 525 from a position where incising instrument 530 extends through slot 210 to a second position inside housing 110. As flexible arm 520 is changing from the first to second state, energy is also imparted to second body 525 that causes a blocking element in guide path 710 to be overcome in step 1240. In step 1245, second body 525 moves along the predefined path as tabs 535 move along guide path 710 after the blocking element is overcome as is shown in Figure 10.

Movement of second body 525 along the predefined path extends incision instrument 530 through slot 210 in a predefined swing path and with sufficient force to make a cut of predefined depth and length in a predefined pattern determined by the predefined path in step 1250 as shown in Figures 1 1 , 12 and 13. When incision instrument 530 is extended though slot 210, flexible arm 520 reaches the second state and tabs 535 dislodge from an end of pathway 710. At this point, flexible arm 520 is freed and begins to recoil which causes flexible arm 520 to expend the stored energy and change from the second state to a third state in step 1255. In the third state, flexible arm 520 is relaxed and stores insufficient energy to cause second body 525 to move. The imparted energy moves second body 525 from a position in which incision instrument 530 extends though slot 210 to a second position inside housing 110 in which incision instrument 530 is completely retracted into housing 110 in step 1260. The movement of second body 525 moves tabs 535 away from pathway 710. In step 1265, an extension of cam guides 710 and stopper 355, 455 prevents the tabs of second body 525 from re-entering pathway 710. Thus, securing incision instrument 520 inside housing 110 in step 1265 as shown in Figure 14. Process 1200 then ends.

The above is a description of embodiments of an incision device in accordance with embodiment of this invention. It is expected that those skilled in the art will design alternative embodiment of a incision device that infringe on this invention as set forth in the following claims.