Abstract:
Penetrator assemblies that include an outer penetrator and a removable inner trocar. In some of the penetrator assemblies, the removable inner trocar has a handle including a surface with a series of discs formed along a longitudinal axis, and the outer penetrator has a flange operable to engage an insertion site proximate the bone marrow. Some of the penetrator assemblies include a connector having a recess extending toward the cutting tip and through which a longitudinal axis of the outer penetrator extends, the recess configured to receive a portion of a shaft to enable rotation of the penetrator assembly by a powered apparatus or power drill.

Description:
RELATED APPLICATION 
     This application is a divisional application of U.S. patent application Ser. No. 10/449,476, filed May 30, 2003, now U.S. Pat. No. 7,699,850 and entitled “Apparatus and Method to Access the Bone Marrow”, which claims priority to U.S. Provisional Patent Application Ser. No. 60/384,756, filed May 31, 2002, and entitled “Apparatus and Method to Provide Access to Bone Marrow” 
     This application is copending to patent application entitled “Apparatus and Method to Provide Emergency Access To Bone Marrow”, Ser. No. 10/449,503, filed May 30, 2003; and copending to patent application entitled “Apparatus and Method to Access the Bone Marrow for Oncology and Stem Cell Applications”, Ser. No. 10/448,650, Filed May 30, 2003, which claims priority from the same provisional application. 
    
    
     TECHNICAL FIELD 
     The present invention is related in general to a medical device to access the bone marrow and specifically to an apparatus and method for penetrating the bone marrow with a powered drill and inserting a penetrator or needle. 
     BACKGROUND OF THE INVENTION 
     Every year, millions of patients are treated for life-threatening emergencies in the United States. Such emergencies include shock, trauma, cardiac arrest, drug overdoses, diabetic ketoacidosis, arrhythmias, burns, and status epilepticus just to name a few. For example, according to the American Heart Association, more than 1,500,000 patients suffer from heart attacks (myocardial infarctions) every year, with over 500,000 of them dying from its devastating complications. 
     An essential element for treating all such emergencies is the rapid establishment of an intravenous (IV) line in order to administer drugs and fluids directly into the circulatory system. Whether in the ambulance by paramedics, or in the emergency room by emergency specialists, the goal is the same—to start an IV in order to administer life-saving drugs and fluids. To a large degree, the ability to successfully treat such critical emergencies is dependent on the skill and luck of the operator in accomplishing vascular access. While it is relatively easy to start an IV on some patients, doctors, nurses and paramedics often experience great difficulty establishing IV access in approximately 20 percent of patients. These patients are probed repeatedly with sharp needles in an attempt to solve this problem and may require an invasive procedure to finally establish an intravenous route. 
     A further complicating factor in achieving IV access occurs “in the field” e.g. at the scene of an accident or during ambulance transport where it is difficult to see the target and excessive motion make accessing the venous system very difficult. 
     In the case of patients with chronic disease or the elderly, the availability of easily-accessible veins may be depleted. Other patients may have no available IV sites due to anatomical scarcity of peripheral veins, obesity, extreme dehydration or previous IV drug use. For these patients, finding a suitable site for administering lifesaving drugs becomes a monumental and frustrating task. While morbidity and mortality statistics are not generally available, it is known that many patients with life-threatening emergencies have died of ensuing complications because access to the vascular system with life-saving IV therapy was delayed or simply not possible. For such patients, an alternative approach is required. 
     SUMMARY OF THE INVENTION 
     In accordance with teachings of the present invention, an apparatus and method for gaining rapid access to the bone marrow is provided. 
     In one embodiment of the invention an apparatus for penetrating a bone marrow is provided that includes a housing and a penetrator assembly. The penetrator assembly is operable to penetrate the bone marrow, having a removable inner trocar and an outer penetrator. A connector operable to releasably attach the penetrator assembly to a drill shaft is included. The drill shaft is operable to connect the penetrator assembly to a gear assembly. The gear assembly is operable to engage and rotate the drill shaft. A motor operable to engage the gear assembly and drive the penetrator into the bone marrow by rotation of the drill shaft and a power supply and associated circuitry operable to power the motor are also included. 
     In another embodiment of the invention an apparatus for penetrating a bone marrow is provided that includes a housing and a penetrator assembly, operable to penetrate the bone marrow. A connector operable to releasably attach the penetrator assembly to a drill shaft, the drill shaft operable to connect the penetrator assembly to a reduction gear assembly is included. A reduction gear assembly operable to engage and rotate the drill shaft and a motor operable to engage the reduction gear assembly and drive the penetrator into the bone marrow by rotation of the drill shaft are also included. A power supply and associated circuitry operable to power the motor are also provided. 
     In one embodiment of the invention a penetrator assembly operable to provide access to a bone marrow comprising an outer penetrator and a removable inner trocar operable to penetrate the bone marrow is provided A connector operable to releasably attach the penetrator assembly to a power drill is also included. 
     In another embodiment of the invention a penetrator assembly operable to provide access to a bone marrow comprising an outer penetrator and a removable inner trocar operable to penetrate the bone marrow is provided. The inner trocar includes a handle, the handle including a grasping means that allows a user to grasp and manipulate the device. The outer penetrator includes a handle, the handle including a grasping means, and also includes a flange operable to engage an insertion site proximate the bone marrow. A connector operable to releasably attach the penetrator assembly to a power drill is also provided. The inner trocar is operable to releasably engage the connector. 
     In one embodiment of the current invention a method of accessing a bone marrow is provided that includes inserting a penetrator assembly into the bone marrow by means of a powered apparatus, detaching the powered apparatus from the penetrator, removing an inner trocar from an outer penetrator of the assembly and attaching a right angle connector to the outer penetrator. 
     In another embodiment of the current invention a method of accessing a bone marrow is provided that includes inserting a penetrator assembly into the bone marrow by means of a powered apparatus, detaching the powered apparatus from the penetrator, removing an inner trocar from an outer penetrator of the assembly and attaching an adapter suitable to convey medications or fluids to the bone marrow. 
     In yet another embodiment of the current invention a method of manufacturing an apparatus operable to penetrate a bone marrow is provided that includes manufacturing a housing having a connector operable to releasably attach a penetrator assembly to a drill shaft, a drill gear assembly, a gear assembly operable to engage and rotate the drill shaft, a motor operable to engage the gear assembly and drive a penetrator assembly into the bone marrow and a power supply and associated circuitry operable to power the motor and manufacturing a penetrator assembly operable to releasably attach to the connector. 
     In a further embodiment of the current invention, a kit for use in penetrating a bone marrow in an extremity is provided that includes a carrying case, an apparatus for penetrating the bone marrow including a housing and penetrator assemblies operable to penetrate the bone marrow, a removable inner trocar and an outer penetrator forming portions of at least one of the penetrator assemblies, at least one connector operable to releasably attach the penetrator assemblies to a drill shaft, a gear assembly operable to engage and rotate the drill shaft, a motor operable to engage the reduction gear assembly and drive at least one of the penetrator assemblies into the bone marrow and a power supply and associated circuitry to power the motor and a strap operable to immobilize the outer penetrator to a site in an extremity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete and thorough understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein: 
         FIG. 1A  is a schematic drawing showing an isometric view of one embodiment of the present invention; 
         FIG. 1B  is a schematic drawing showing an isometric view of one embodiment of the present invention; 
         FIG. 2A  is a schematic drawing showing an isometric view of one embodiment of the present invention; 
         FIG. 2B  is a schematic drawing showing an isometric view of one embodiment of the present invention; 
         FIG. 3A-C  illustrates a side and cross-sectional view of one embodiment of the present invention; 
         FIG. 4A-C  illustrates various-alternate embodiments of a reduction gear mechanism that may be included in an embodiment of the present invention; 
         FIG. 5A-C  illustrates one embodiment of a penetrator assembly of the present invention; 
         FIGS. 6A-C  illustrate various alternate embodiments of a penetrator assembly connector of the present invention; 
         FIG. 7A  illustrates one embodiment of a penetrator assembly of the present invention; 
         FIG. 7B  illustrates a cross-sectional view of one embodiment of a penetrator assembly of the present invention; 
         FIG. 7C  illustrates one embodiment of an inner trocar in cross section of the present invention; 
         FIG. 7D  illustrates one embodiment of an outer penetrator in cross section of the present invention. 
         FIG. 7E-G  illustrate examples of release mechanisms of the present invention. 
         FIG. 8A  illustrates one embodiment of a tip of a penetrator assembly of the present invention; 
         FIG. 8B  illustrates one embodiment of a tip of a penetrator assembly of the present invention; 
         FIG. 9  illustrates one embodiment of a kit to access the bone marrow of the present invention; and 
         FIG. 10  illustrates one embodiment of a connector to attach to an outer penetrator of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Preferred embodiments of the invention and its advantages are best understood by reference to  FIGS. 1A-10  wherein like numbers refer to same and like parts. 
     Various examples of an apparatus operable to access the bone marrow in accordance with the present invention are shown generally in  FIGS. 1A and 1B  at  10 . Apparatus  10  as shown in  FIGS. 1A and 1B  generally includes housing  12  and penetrator assembly  14 . Housing  12  includes handle  16  that is sized and contoured to fit the hand of an operator. Handle  16  may include on/off switch  22  and safety  24 . Penetrator assembly  14  includes outer penetrator  18 , inner trocar (not expressly shown) and penetrator assembly connector  20 . 
       FIGS. 2A and 2B  illustrate an alternate embodiment of the present invention. Apparatus  10   a  generally includes housing  12  and penetrator assembly  14   a . Housing  12  includes handle  16  that is sized and contoured to fit the hand of an operator. Handle  16  may include an on/off switch  22 . Penetrator assembly  14   a  includes outer penetrator  18 , inner trocar (not expressly shown) and penetrator assembly connector  20 . Penetrator assembly  14   a  may include penetrator shield  26 . An outer penetrator may include either a trocar, a needle, a cannula, a hollow tube, a drill bit or a hollow drill bit. 
       FIGS. 3A and 3B  illustrate yet another embodiment of the present invention. Apparatus  10   b  generally includes housing  12  and a penetrator assembly (not expressly shown). Housing  12  includes handle  16  and on/off switch  22 . Penetrator assembly may include penetrator (not expressly shown) and a connector, for example a pentagonal connector  20  as shown in  FIG. 3A . As shown in  FIG. 3B , housing  12  encloses motor  30 , power supply  32 , for example four or more AA batteries, motor connecting wires  34  between power supply  32  and motor  30  and switch connecting wires  36  between on/off switch  22  and power supply  32 . The power supply to the apparatus may be any suitable number of AA batteries or any other type of battery, a source of direct current, a source of alternating current or a source of air or gas power. The motor may be reciprocating or rotational. Thruster bearing  45 , for example a washer, may be located adjacent to housing  12  where drill shaft  40  exits housing  12 . Thruster bearing  45  prevents the thrust or penetration force of drilling from being placed on gear assembly  38  as penetrator is drilled into bone.  FIG. 3C  shows one embodiment of the invention where drill shaft  40  may be separated into two interdigitating pieces at  42  in order to allow the two ends of drill shaft  40  to slide in and out as bone is penetrated to avoid applying excessive force to a gear assembly. 
     In  FIG. 3B  gear assembly  38  is coupled to motor  30 . Gear assembly  38  may be a reduction gear assembly such as that shown in  FIG. 3B  that functions to reduce the revolutions per minute (RPMs) between the motor and drill shaft  40  and to increase drill shaft torque. Depending on the type of motor employed in the invention, gear assembly may or not be of the reduction type. 
     By way of example and not limitation, a reduction gear assembly, for example a worm gear assembly is shown in more detail in  FIG. 4A  and may include first connector  43  that connects shaft  44  of motor  30  to worm gear  46 . Worm gear  46  may engage spur gear  47 . Reduction gear assembly  38  may be used to decrease the RPMs between the motor and penetrator assembly to provide an optimum RPM at the point of insertion of penetrator assembly into bone. Reduction gear assembly  38  may also be used to increase the torque of drill shaft and drilling power. 
       FIG. 4B  illustrates one embodiment of reduction gear assembly  38  wherein a first spur gear  47  engages a second spur gear  49 .  FIG. 4C  illustrates an alternate embodiment of reduction gear assembly  38  wherein spur gear  47  is offset from mitered gear  48  that may be preferable in some embodiments of the present invention. Other gears may be used in a reduction gear assembly, for example a planetary gear (not expressly shown) that may be used alone or in combination with a worm gear or a spur gear. In one embodiment of the current invention, gear assembly may be any suitable gear arrangement and is not limited to a reduction gear assembly. 
       FIGS. 5A-5C  illustrate one embodiment of a penetrator assembly  55  operable to penetrate a bone marrow, having a removable inner trocar  50  and an outer penetrator  52 . Also shown in  FIG. 5A  is a penetrator shield  26  that may be used to shield penetrator assembly  55  from inadvertent engagement and also serves to preserve needle sterility. In some embodiments outer penetrator  52  may be a type of needle or cannula.  FIG. 5B  illustrates outer penetrator  52  may include a male connecting piece  56  operable to engage a complementary female connecting piece  54  of inner trocar  50 . Adjacent to male connecting piece  56  is connecting piece locking mechanism  58  that locks into position on female connecting piece  54 . Alternatively outer penetrator may include a female connecting piece suitable to engage a complementary male connecting piece of an inner trocar Luer lock attachment  57  is coupled to male connecting piece  56  for connection to an intravenous tubing or syringe after the outer penetrator is positioned in the bone marrow. Male connecting piece  56  and female connecting piece  54  may also be of the luer-lock type. Inner trocar  50  includes stylet  53  that keeps outer penetrator  52  from getting plugged with debris created during drilling. Stylet  53  acts in combination with cannula portion  51  of outer penetrator. Outer penetrator  52  may include flange  60  that abuts or interfaces the skin of an insertion site and may be used to stabilize a penetrator assembly at the time of insertion. Penetrator assembly  55  may include various types of connectors, such as connector  62  that may be used to connect penetrator assembly  55  to a powered drill. Connector  62  may be pentagonal as shown in  FIGS. 5A and 5C . 
     In one embodiment, the invention may include a specialized connector between the penetrator assembly and a powered drill. The connector performs at least two functions, a connecting function and a releasing function. The connecting function may be performed by various mechanisms such as a pentagonal male-female fitting or various lock-and-key mechanisms such as one that may include a combination or series of grooves and ridges or bars that match and interlock on a connector. 
     The releasing function may be performed by an O-ring connection, a magnetic connector, a chuck release mechanism, or a ball and detent mechanism with and without a spring. In one embodiment the releasing function may occur by means of a trigger mechanism whereby a trigger comes in contact with a holding mechanism and releases a penetrator or needle. In another embodiment a connecting mechanism may also include a trigger or retractable shield rod that slides up and contacts a holding mechanism or clamp that breaks away and releases a penetrator or needle after contact (not expressly shown). 
       FIGS. 6A-C  illustrate alternate embodiments of connectors operable to releasably attach penetrator assembly  55  to powered drill apparatus  10 .  FIG. 6A  illustrates penetrator assembly connector  62  wherein connector  62  is formed to fit into a connector receptacle  64  and releasably lock into place. In this example, connector  62  and connector receptacle  64  are pentagonal shaped. Advantages of this embodiment may be the ease of attachment and removal of penetrator assembly  55  from powered drill apparatus  10 . Penetrator assembly connector  62  may be formed from metal or plastic. 
       FIG. 6B  illustrates an alternate embodiment of penetrator assembly connector wherein a female pentagonal receptacle  65  is operable to engage pentagonal connecting piece  66  attached to powered drill apparatus  10 .  FIG. 6C  illustrates a further embodiment of a penetrator assembly connector wherein penetrator assembly connector  68  is a proprietary design having a pattern of ridges or bars  70  that engage a matching pattern of slots  71  on a connecting receptacle  72 . Example penetrator assembly connectors may include any type of lock and key design or a pentagonal design. Penetrator assembly connectors of any type may be held in place by either a magnet, an O-ring connector or a ball and detent mechanism with or without a spring (not expressly shown). 
     In one embodiment, the penetrator assembly may include an outer penetrator such as a cannula, needle or hollow drill bit which may be of various sizes. Needles may be small (for pediatric patients), medium (for adults) and large (for over-sized adults). Penetrator, cannulas or needles may be provided in various configurations depending on the clinical purpose for needle insertion. For example, there may be one configuration for administering drugs and fluids and an alternate configuration for sampling bone marrow or for other diagnostic purposes although one needle configuration may be suitable for both purposes. Needle configuration may vary depending on the site chosen for insertion of a needle. 
       FIGS. 7A-7D  illustrate one embodiment of a penetrator assembly  80  that includes a removable inner trocar  82  and an outer penetrator  84 .  FIG. 7B  illustrates a cross-sectional view of one embodiment of a penetrator assembly having a removable inner trocar  82  and an outer penetrator  84 . Outer penetrator  84  includes flange  86  and flange groove  88 . Flange  86  may be used to stabilize penetrator assembly  80  against the skin of an insertion site. Flange groove  88  is operable to engage plastic penetrator cover  94 . The surface of outer penetrator may include a series of discs formed along a longitudinal axis, a series of ridges or some other grasping means. This surface allows an operator to grasp the outer penetrator with two fingers and easily disengage the inner trocar  82  from outer penetrator  84 . Outer penetrator  84  includes a penetrator cannula  96  that is hollow when stylet  100  is removed. 
     In  FIG. 7C  inner trocar  82  includes handle  98  that may have a surface such as a series of discs formed along a longitudinal axis of the trocar, or a series of ridges or some other grasping means. Handle  98  allows an operator to easily grasp and manipulate inner trocar  82  and disengage it from outer penetrator  84 . Inner trocar  82  also includes stylet  100 . Stylet  100  exits an end of penetrator cannula  96  when inner trocar  82  is inserted into outer penetrator  84  Stylet  100  includes a cutting tip and is operable to penetrate bone marrow. In one embodiment of the invention, inner trocar  82  may include metal disc  95  to allow a magnetic connection between penetrator assembly and powered drill. Receptacle  97  may also engage a penetrator assembly male-type connector piece operable to connect penetrating assembly to a powered drill, or any other suitable connector. 
       FIGS. 7E-7G  illustrate example release mechanisms that may be coupled to a connector and included in penetrator assembly  80 .  FIG. 7E  illustrates one embodiment of a magnetic release mechanism where magnetic disc  70  is included in inner trocar  82 . In this embodiment magnetic disc  70  is at the base of open area or receptacle  97 . In alternative embodiments a magnetic disc could be included with a pentagonal connector or a lock and key connector or any other suitable connector. 
       FIG. 7F  illustrates another embodiment of a release mechanism where O-ring  72  is included in trocar  98  as part of a connector. In this embodiment O-ring  72  is in the wall of receptacle  97 . O-ring  72  is able to engage a lock and key connector, a pentagonal connector or any other suitable connector. 
       FIG. 7G  illustrates yet another embodiment of a release mechanism using ball and detent mechanism  74 . In this embodiment ball and detent mechanism  74  is in the wall of receptacle  97 . Ball and detent mechanism  74  is able to engage a lock and key connector, a pentagonal connector or any other suitable connector. 
       FIG. 8A  illustrates an embodiment of an outer penetrator needle  110  and inner stylet  112 . Cutting tip  114  of outer penetrator needle  110  and tip of inner stylet  112  are operable to penetrate bone marrow. In one embodiment of the invention the outer penetrator needle and the inner stylet are ground together as one unit in the manufacturing process to ensure that the two pieces are an exact fit and act as a single drilling unit. 
       FIG. 8B  illustrates another embodiment of an outer penetrator needle  96  and an inner stylet  100 . Cutting tip  102  of inner stylet  100  is operable to penetrate bone marrow. Inner stylet may also include a longitudinal groove  104  that runs along the side of stylet  100  that allows bone chips and tissue to exit an insertion site as a penetrator assembly is drilled deeper into bone. Outer penetrator or needle  96  includes cutting tip  106  that facilitates insertion of outer penetrator or needle  96  and minimizes damage to outer penetrator or needle  96  as penetrator assembly  55  is inserted into bone marrow. In one embodiment of the invention the outer penetrator needle and the inner stylet are ground together as one unit in the manufacturing process to ensure that the two pieces are an exact fit and act as a single drilling unit. 
       FIG. 9  illustrates one embodiment of kit  120  to penetrate bone marrow. Kit  120  includes apparatus  10  for penetrating bone marrow, alternative sizes of penetrator assemblies  122 , and strap  124  suitable to immobilize an outer penetrator on an extremity during insertion of penetrator assembly  122 . Carrying case  125  is also included. 
     Once an outer penetrator or needle is inserted into a bone, it may be connected to a source of intravenous fluids or medication.  FIG. 10  illustrates an example of a connector that may be used to connect the outer penetrator of a penetrator assembly to tubing  130 , for example an intravenous tubing for providing intravenous fluids or medications to a person. Outer penetrator  84  is inserted into the bone marrow of an extremity. Right angle connector  132  is then used to connect intravenous tubing  130  to outer penetrator  84 . Right angle connector has the advantage of allowing tubing to be connected to an outer penetrator or needle at an angle that will not kink or pinch off the lumen of the tubing. Other connectors or adapters may also be used to connect an outer penetrator to an intravenous tubing, another kind of tubing or to a syringe for use in providing medication or fluids to a person or for use in withdrawing a sample of blood from the bone marrow. 
     A method for providing access to the bone marrow includes using a powered drill, capable of reciprocal or rotational motion, to insert a penetrator assembly that includes an outer penetrator and an inner trocar into a bone marrow cavity. The powered drill is then released from the penetrator assembly and the inner trocar is grasped and removed from the outer penetrator. A connector present on the end of the outer penetrator, for example a luer lock connector, is then available for attachment to either an adapter, such as a right angle connector or directly to an intravenous tubing or syringe. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alternations can be made herein without departing from the spirit and scope of the invention as defined by the following claims.