Patent Application
20180049684
The invention generally relates to surgery and to collecting a liquid from the body. More specifically, the invention relates to improvements in housing and operating a lancet, which is a sharp edge or point for piercing the skin to draw blood. Further, the invention relates to an improved device for use in cutting, puncturing, or piercing the body or a specific portion thereof. Such piercing is by a lancet or similar instrument with a short, wide, double edged, pointed blade that cuts as the instrument is advanced longitudinally, or a blade that can repeatedly produce an incision of specific length, or an incision of specific length and of specific depth in body tissue. The invention further relates to a device employing a lancet blade that is actuated from a checked or inoperative position when released to an operative position by an energy storing resilient means. The invention is especially applicable to applying user-controlled variable suction or vacuum to skin area adjacent to and surrounding a pierced location.
To monitor and treat various diseases and conditions such as diabetes, taking a blood sample is required of many people, often numerous times during a single day. Instruments known as lancet devices provide a quick means for producing a sample of blood for analysis. A basic lancet device is a housing with a longitudinally slidable holder for a puncturing element at a forward or distal end thereof. Different styles of puncturing elements can be used, including needles and blades. For convenient reference, the puncturing element will be generally referred to as a blade without limiting the scope of puncturing elements included therein. The puncturing element holder or blade holder can receive and carry a disposable puncturing element or lancet blade with the blade extending forward. As an aid to initial placement of the lancet device on the user's skin, a nose or spacer element at the forward or distal end of the housing is suitably long to space the housing, lancet blade holder, and lancet blade from the user's skin when the spacer is pressed against the skin prior to triggering. The lancet device can be cocked to place the lancet device in a ready condition for the blade to be released or triggered to spring forward from the spacer and pierce the user's skin. A basic lancet device contains an actuator to drive the lancet blade forward. For example, a mechanical cocking element can compress a spring that will drive the lancet holder forward when released. The cocking element also may employ a checking element to lock the lancet holder in a checked position, awaiting release.
When released, the blade moves forward and pierces the user's skin. The tip of the blade will extend forward from the distal end of the spacer. A trigger element associated with the housing can be actuated to release the lancet holder from checked position; whereupon the spring will cause the lancet holder to shoot forward, rapidly sliding the lancet blade forward and through the open end of the spacer to pierce the user's skin where the open forward end of the spacer is pressed against the skin. The spring or other driving actuator allows the blade to pierce the user's skin and then withdraw. For example, a spring actuator may allow the blade to continue forward by inertia, beyond a position of neutral spring forces, such that after puncturing the user's skin, the blade springs back from its maximum forward position. The maximum forward extension beyond a location of neutral forces represents the depth of skin penetration. Thus, lancet devices of this type are able to pierce the user's skin so rapidly, and with controlled depth, that there is little discomfort, producing a drop of blood for sampling.
Variations in the features of lancet devices provide differences in performance. A lancet device can be constructed to apply vacuum to the piercing site by incorporating a vacuum chamber in the housing, behind the lancet holder. In such a lancet device, a spring-loaded piston can be checked in a forward position. When triggered to be released, the piston shoots backwards, thereby creating a vacuum or low pressure volume in the vacuum chamber. At the same time, the lancet blade is advanced to pierce the user's skin similarly to the previous description. However, this device differs because the vacuum is applied through the space to the pierced skin area surrounding the lancet. The vacuum is maintained due to the seal established between the forward end of the spacer and the user's skin. The trigger defines a vent hole that is covered by the user's finger during triggering operation. By moving his finger from the vent hole, the user can open the vent and dissipate the vacuum before attempting to remove the lancet device from the user's skin.
Some users have found that the fixed vacuum of such a lancet device is stronger than they wish to experience. Also, users who might like the advantages of a vacuum feature may find that the cost of the vacuum feature is too high. The basic lancet devices, without any vacuum pump, tend to be far more economical.
It would be desirable to achieve the economy of a basic lancet device while providing access to a vacuum feature, as desired. Maintaining a low cost in a medical device is widely important and desired, especially among frequent users of such a device.
It would be desirable to allow the user or patient to vary the degree of vacuum according to his own needs. In many cases, the user and the patient are the same person, who then can judge when vacuum is sufficient. In other cases, such as with a parent who assists his child, the parent is the user. The parent and child can determine between them how much vacuum is desired or needed.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, the method and apparatus of this invention may comprise the following.
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with the description, serve to explain the principles of the invention. In the drawings:
A core lancet device is an elongated housing that carries at its front end a longitudinally oriented holder for a puncturing element. Typically, the puncturing element is disposable and is easily installed and removed from the holder. Various types of puncturing elements can be used with a core lancet device, including needles and blades. For convenience of reference, the puncturing element sometimes will be referred to as a lancet blade, without limiting the scope of puncturing elements included therein. A driving actuator, which will be sometimes referred to as a spring, is associated with the holder to interact as a driving member after being appropriately cocked and then released. A cocking element of the core lancet device can cock the holder or driving actuator to a checked position. A triggering element can release the holder or driving actuator from checked position. The driving actuator operates such that when the holder is released from checked position, the actuator provides a driving force that rapidly moves the holder forward. When a lancet blade is mounted in the holder, the blade springs forward with the holder. A depth control mechanism is associated with the holder to allow the blade to penetrate a user's skin to a certain depth and then to withdraw. As an example of a depth control mechanism where a blade is driven forward by a spring, the blade might continue forward by inertia, going beyond a neutral position of the spring, and then spring back to a neutral position. The excess advancement due to inertia can be how the blade pierces the user's skin. The springing back to neutral position is how the blade can withdraw from the user's skin. Thus, the piercing is rapid and depth is limited, with the entire forward piercing and rearward withdrawal taking place so quickly that the eye may have trouble seeing it.
Typically a removable, hollow tubular spacer is attached as a front end of the core lancet housing, with the path of the blade aligned to pass through the centerline of the tubular shape. The length of the spacer is such that the blade does not extend out of the open forward end of the spacer, both when the holder is in neutral position and when the holder is checked position. However, the spacer is short enough that the blade will extend out of the open forward end of the spacer when the blade is released from cocked condition and springs forward beyond neutral location. The tubular spacer enables the user to press the core lancet device against his skin to pre-position the lancet device without contacting the blade. Some lancet devices include a depth control that alters the maximum extension of the blade beyond the spacer. The length of the spacer can accommodate adjustment of this type while protecting the user from premature contact with the blade.
Even after the user's skin has been pierced, it can be difficult to bring the drop of blood to the skin surface. Sometimes the user has to squeeze and rub the pierced skin area to bring out the blood sample. The present invention provides an enhanced lancet device that improves this situation by adding suction to the function of a core lancet device that was constructed without built-in provision for suction. An aspect of the invention is the discovery that a vacuum function can be added to a core lancet device to produce an enhanced lancet device, where the core lancet device was not equipped with its own vacuum function independent of an external housing. The invention adds a coordinated source of vacuum, suction, or low pressure air that is applied to a core lancet device over a selected span of time. Suction might be applied immediately prior to the skin piercing event in order to build up suction strength. Suction might be applied during the piercing event, itself, to preserve previously built up suction and to extract blood. Suction might be applied immediately after the piercing event to extract the sample of blood.
This invention is primarily directed to a core lancet device that is nested in an external vacuum housing. The term, “core,” refers to a lancet device or housing that is not especially configured to generate vacuum. Such a core lancet device is characterized by an absence of an internal vacuum chamber. A functional fit between parts can allow an external chamber to surround the core lancet with vacuum, other than at a forward nose near the holder for the lancet blade. The external vacuum establishes air seepage through the core lancet device from the forward nose, creating suction in proximity to a forward puncturing device or blade. The external vacuum chamber houses the core lancet except at the forward nose, which serves as a suction inlet point. Thus, in an enhanced lancet device, an external vacuum housing operates through a core lancet housing to draw suction in proximity of the lancet blade. When a spacer is attached to the forward nose, the suction inlet point is advanced to the front end of the spacer, which applies the suction to the user's skin where the lancet blade will pierce the skin. Thus, the open front of the spacer is an extension of the forward suction point. The internal low pressure air from the external housing and internal lancet housing draws in the higher pressure atmospheric air at the front nose of the lancet housing and around the lancet blade holder, creating external suction that is applied to the user's skin through the spacer.
In greater detail, the invention is an outer vacuum housing that contains a core lancet device or core lancet housing. The outer vacuum housing is substantially pressure sealed, other than through the core lancet housing. The core lancet housing serves as an inner housing contained within the outer vacuum housing so that the inner housing is substantially surrounded by low pressure or vacuum, other than at the front where the blade holder and lancet blade are located. The combined inner and outer housings provide variable vacuum or suction and, in use, apply it through a tubular spacer to a user's skin in the area that the lancet blade will pierce.
The front of the inner core lancet housing and the front of the external vacuum housing meet at a forward junction. The inner and outer housings can be fastened together at the junction. A suitable junction area of the core lancet housing is an outward facing cylindrical forward end that encircles the lancet holder. A suitable junction area of the outer housing is an inward facing cylindrical forward end that closely fits around the junction area of the core lancet device. The two junction areas are placed at the same end of the combined inner and outer housings and are aligned with the pathway for the lancet blade.
The two junction areas have complementary shapes to establish the junction at a perimeter around the position of the lancet blade holder so that the lancet blade can move forward to puncturing position without interference from the junction. The core lancet provides the inner side of the junction, while the external vacuum housing provides the outer side of the junction. The junction minimizes or eliminates vacuum leakage between the two mating structures.
A tubular spacer or shell is formed or attached to the front end of the enhanced lancet device, at the junction between the inner core lancet housing and the external vacuum housing. This junction encircles a suction point. The spacer or shell provides a lateral wall around the path of the lancet blade to bring suction forward, as needed, to apply suction to the user's skin in front of the cocked lancet blade. The spacer or shell is pressed against the user's skin to establish a known spacing to the cocked lancet blade. Then, when the trigger element releases the holder and blade, the blade advances on its path by a known distance that is sufficient for the blade to penetrate the user's skin. However, the known distance of blade travel is limited, so that penetration is sufficient for blood sampling but not needlessly deep into the user's skin. The spacer or shell provides both an application of suction to the penetration site and a limitation of how deep the blade can penetrate beyond the forward end of the spacer or shell.
According to the invention, a core lancet housing can serve as an inner housing that is nested within the outer or primary housing, with the exception that the blade holder and lancet blade are aligned with a passage to the outside. The outer housing serves as a vacuum chamber and cooperates with the inner core lancet housing to supply suction into the outside passage. The suction or vacuum is transmitted through the outside passage, which may laterally confine the suction through a tube or shell to reach a forward position at the user's skin. The tube or shell become sealed to apply suction against the user's skin when pressed against the user's skin, and as a result, the suction or vacuum then is applied to the user's skin at the location where the lancet blade will pierce it. The applied suction enhances extraction of a drop of blood for sampling. After use, typically the tubular spacer or shell is removed from the enhanced lancet device to gain access to the blade holder and the lancet blade is replaced. The spacer is reattached to prepare the enhanced lancet device for a next use. Several embodiments demonstrate the scope of this invention.
According to a first embodiment, the invention can be adapted for use with a core lancet housing of known configuration but lacking a vacuum feature. In such a version, an otherwise complete core lancet housing is nested inside a cavity within an external housing, which then is sealed against loss of vacuum other than through a portion of the lancet housing with outside access, such as within the junction. The sealed cavity provides a basis for applying suction or vacuum around substantially the entire lancet device, other than the junction. Reference to a sealed external housing or sealed cavity also allows for air access to the open tip of the spacer. Otherwise, the enhanced lancet device is sealed when pressed against the user's skin. The reference to a sealed external housing or sealed cavity also allows for discharge of air through an exit port from a source of suction to establish a zone of lower pressure in the cavity.
In order to provide vacuum to an internal nested lancet housing, the external housing is configured with a combination of vacuum resistant walls and access areas. The pre-existing controls of the core lancet housing are operated by limited deformation of the access areas. Access area covers and shrouds provide such desired deformation to allow operation of controls on the lancet housing. The access area covers sufficiently resist deformation under vacuum that a vacuum can be applied to a lancing location on the user's skin.
According to an alternate embodiment, the invention is adapted to a sealed primary housing that provides the functions and equipment of a lancet device. These are a sliding lancet carrier or holder, a resilient member such as a spring loaded against the sliding lancet holder, a cocking element for withdrawing the sliding lancet holder to withdrawn position, a check element for locking the sliding holder in withdrawn position, and a trigger element for releasing the lancet holder from withdrawn position to slide forward through a front opening, lancing the user's skin at the front opening. The invention is adapted to the primary housing by providing an access port and an external suction tube mounted to the port, enabling the user to draw a variable degree of vacuum within the sealed primary housing.
With reference to
An external housing 24 is sized to receive internal housing 10. According to this specific embodiment, the cocking element 16 protrudes above a proximal or rearward open end 26 of housing 24. A flexible cap 28 fits onto rearward end 26 of external housing 24 and over cocking element 16. A retention band 30 secures the cap 28 around housing end 26 and secures a seal between the housing 24 and cap 28. The cap can be attached to housing 24 by any of various means, including pressure, adhesive, threads, or twist-lock (bayonet), to name several examples. Flexibility of the cap allows the user to pull cocking element 16 rearward to cock lancet holder 12 to checked position. If necessary, cap 28 can be formed of stretchable material to accommodate sufficient rearward movement of cocking element 16.
Housing 24 receives trigger button 18 behind window 32. The window is formed or covered by a panel that is flexible enough to allow selective operation of the button. The material of window 32 may be a soft plastic that is applied to the housing 24 to seal the window. As examples, the window panel can be set into the window opening, bonded around the window opening, or overlaid on the window opening, which can include the application of a ring of plastic that fits snugly around the housing 24. Thus, the controls on the internal housing 10 are operable behind elastic, flexible, or otherwise accessible covers while the internal housing 10 is installed within the external housing 24.
At the forward, distal end 34 of housing 24, the spacer 20 is inserted into housing end 34. The spacer typically is a component of the internal core lancing device and fits snugly onto the distal end of internal housing 10. A seal 36 is applied to spacer 20 in a position to also seal with housing 24 at lower end 34.
A port 38 is in communication with the inside volume of housing 24. The port is sized to engage with an end 40 of a suction tube 42. The opposite end 44 of the suction tube is suitable for engagement with a source of suction. The invention contemplates that the user will apply suction by mouth, so that the degree of suction is instantaneously variable at the user's discretion.
According to
Several different core lancet housings are commercially available.
The internal housing 50 of
An external housing 62,
As shown in
In addition to the vacuum pump, the housing base 64 carries a processor chip 76 that enables blood sample data to be analyzed. The chip 76 is connected to reading wires 78 that sense the content of a blood sample produced by the lancet blade 14. The chip has communication ability to manage the blood data, to convey the reading via wireless means such as cellular, wi-fi, or Internet communication to a doctor, laboratory, recording device, or other chosen recipient. A battery 80 provides power to operate the chip 76 and vacuum pump 70, 72. A manual on/off switch 82 is exposed in an external wall of the housing base 64 to enable the user to selectively operate the supporting devices in the housing 62.
The cavity 68 also is configured to receive the core internal lancet housing 50. The internal lancet housing 50 fits snugly within the cavity 68 with cylindrical nose 60 supported within a close fitting outer cylindrical ring 84 at the forward end of the housing 62. Outer ring 84 provides a sufficient seal with nose 60 so that lower pressure or vacuum can be formed inside housing 62. The ring 84 can be a part of housing 62, or it can be a separate ring that is attached to housing 62, such as by threads. Ring 84 also might be only a partial ring that is closed by a supplemental segment of the cover 66, as described below.
As best shown in
When cover 66 is applied to base 64, the housing 62 is sealed against passage of air other than within the outer cylindrical ring 84 and preferably at cylindrical nose 60. When cylindrical nose 60 is contained and sealed in the outer cylindrical ring 84, suction can be drawn through nose 60 by seepage, as present. In this way, the ring 84 serves as a perimeter of a suction port. For example, cavity 68 will be at reduced air pressure due to the operation of pump 70, 72. One possible point of entry for air is at nose 60, around the edges of the lancet blade holder 52, which is within cylindrical ring 84. Any other likely point of entry for air, such as at the junction of nose 60 and ring 84, is likewise within the perimeter established by ring 84. These possible points of seepage are desirably located within suction port 84 to supply suction in proximity to the lancet blade 14.
The use of a core lancet housing 50 contributes to the successful availability of vacuum at the lancet blade 14. A core lancet housing is not especially sealed to contain its own vacuum. Instead, the core lancet housing becomes a transmitter of suction from the external housing 62 to the forward end of the internal lancet housing 50, such as to nose 60 on the lancet housing 50. Suction at nose 60 is in surrounding proximity to the lancet blade and can be further confined and directed by a spacer or shell 94 attached to ring 84.
The external housing 62 serves as the primary vacuum chamber and relies on limited transmission of higher pressure air only within the suction port surrounded by ring 84. This suction port is partially filled by the nose 60 of core lancet housing 50, leaving seepage through the core lancet housing 50 into the external housing 62 as the transmittal path for suction through the suction port within ring 84.
It would be desirable to further confine, contain, and guide this suction to apply it to a user's skin when the lancet blade has punctured the user's skin for the purpose of extracting a sample of blood. Suitably applied suction can aid in producing the sample of blood from the puncture. In order to apply suction to a user's skin, a vacuum shell 94 is attached around and in front of the outer cylindrical ring 84 of the external housing 62. As shown in
In the assembled enhanced lancet device 63 of
In greater detail, the sample collection strip 102 is positioned at the front of the vacuum shell 94 so that the user's skin surface supports the sample collection strip 102 for the lancet blade 14 to engage the sample collection strip 102 in the same thrust as the lancet blade pierces the user's skin. The vacuum shell 94 is configured to maintain the sample collection strip in the desired position. For example, the sample collection strip 102 can be shaped as a disk, and the vacuum shell 94 might define a circular shell portion 104 of similar outlined size and shape as the disk. To better retain the sample collection strip 102 in the desired location, a mount or fastener can be used. For example as shown in
Pin 106 is offset from the centerline of shell cylinder 98, although the offset preferably is smaller than or equal to the radius of the disk-shaped sampling strip 102. The center axis of the mounting pin 106 is represented by dashed line 110 in
According to the sampling method where the lancet blade passes through collection strip 102 and then pierces the user's skin, the lancet blade might sever a fleck of the collection strip 102 during advancement. It would be desirable to prevent forming such flecks and to avoid the accidental transfer of a fleck into the user's skin with the tip of the lancet blade. The chance of this sort of transfer is minimized by pre-forming a lancet passage 112 through the sampling strip 102 in the lancet blade's line of travel. A plurality of lancet blade passages 112 can be formed at equal spacing from central aperture 108, thus lying in a ring around aperture 108. The plurality of lancet blade passages 112 also may be separated by equal angles. By rotating the collection strip around aperture 108, any one of the passages 112 can be positioned in line with the lancet blade, in what can be termed the active area of the collection strip. Likewise, the passage 112 aligned with the blade can be called the active passage. Other passages 112, currently not in the active area, can be used to index the position of the collection strip so that the active passage 112 maintains alignment with the lancet blade. In
The desired alignment of the lancet blade 14 with the active passage 112 is made possible by knowing the offset represented by the separation of dashed lines 100 and 110, as well as by locating the sampling strip in a known rotational position to place an active passage 112 in alignment with the path of the lancet blade. The rotational position of an active passage 112 is readily controlled by an indexing device acting between the vacuum shell 94 and the sampling strip 102. For example, in
The illustrated sampling strip 102 is configured to have a plurality of sampling areas 116 equally spaced around central mounting aperture 108. For example, in the drawings a single sampling strip is divided into eight sampling sectors 116. Each sampling area 116 is configured with a pre-formed passage 112 in the proper location to align with the lancet blade when the sampling strip 102 is suitably rotated and indexed to place a selected sampling area 116 in the active position. The single sampling strip 102 then can be used as many times as there are sectors 116 by rotating the sampling strip on the mounting pin 106, placing one sector after another into the active indexed position that is aligned with the lancet blade.
The reading wires 78 can be positioned to contact the active sampling area 116. In
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be regarded as falling within the scope of the invention as defined by the claims that follow.
| Number | Date | Country | |
|---|---|---|---|
| 62377507 | Aug 2016 | US |
