Patent Publication Number: US-2022226017-A1

Title: Biosensor inserters and methods with reduced medical waste

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 63/140,190, filed Jan. 21, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety for all purposes. 
    
    
     FIELD 
     The present disclosure relates to a biosensor inserter configured to insert a biosensor, which can be part of continuous analyte monitoring. 
     BACKGROUND 
     Continuous glucose monitoring, such as with a continuous glucose monitor (CGM) has become a routine sensing operation, particularly for sensing in diabetes care. By providing real-time glucose monitoring that provides glucose concentrations over time, therapeutic actions, such as insulin introduction, may be applied in a timely manner and the glycemic condition may be better controlled. 
     During a CGM operation, a biosensor of a transmitter and sensor assembly is inserted subcutaneously and is continuously operated in an environment surrounded by tissue and interstitial fluid (ISF). The biosensor is inserted under the skin and provides a signal to a transmitter of the transmitter and sensor assembly, and that signal can be indicative of a patient&#39;s blood glucose level, for example. These sensor measurements may be made intermittently and automatically many times throughout the day (e.g., every few minutes or other suitable interval). 
     The transmitter of the transmitter and sensor assembly is adhered to the outer surface of a user&#39;s skin, such as on the abdomen, on the back of the upper arm, or at another suitable location, while the biosensor is inserted through the skin so as to contact ISF. This skin insertion process may be referred to as “insertion.” Devices for carrying out this biosensor insertion may be referred to as “biosensor inserters.” 
     Biosensor inserter designs may be complicated and costly to manufacture. Moreover, some biosensor inserters are discarded as medical waste following their use. 
     SUMMARY 
     In some embodiments, a biosensor inserter configured to insert a biosensor is provided. The biosensor inserter includes a push member including a receiver, a contact member translatable relative to the push member, and a trocar holder configured to receive a trocar assembly including a trocar therein, the trocar holder is configured to be insertable into and removable from the receiver. 
     In further embodiments, a biosensor inserter is provided. The biosensor inserter includes a push member having a push element and a receiver; a trocar holder including a sheath portion, wherein the trocar holder is received in the receiver; a contact member configured to telescope relative to the push member; a transmitter carrier configured to support a transmitter and sensor assembly during insertion of the biosensor; a pivot member configured to pivot on the transmitter carrier; and a trocar assembly supported by the pivot member during insertion and retraction, the trocar assembly receivable in the sheath portion upon retraction. 
     In yet further embodiments, a method of using a biosensor inserter to insert a biosensor into a user is provided. The method includes providing the biosensor inserter comprising: a push member including a receiver, a trocar holder inserted in the receiver, the trocar holder including a sheath portion, a contact member translatable relative to the push member, and a trocar assembly including a trocar having a biosensor therein; contacting the contact member to skin of the user; pushing on the push member to cause insertion of the trocar and biosensor into the skin; continuing to push the push member to retract the trocar assembly into the sheath portion, while leaving the biosensor implanted; and removing the trocar holder and trocar assembly from the receiver. 
     Other features, aspects, and advantages of embodiments in accordance with the present disclosure will become more fully apparent from the following detailed description, the claims, and the accompanying drawings by illustrating a number of example embodiments. Various embodiments in accordance with the present disclosure may also be capable of other and different applications, and its several details may be modified in various respects, all without departing from the scope of the claims and their equivalents. Thus, the description is to be regarded as illustrative in nature, and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings are to be regarded as illustrative in nature, and not as restrictive. The drawings are not necessarily drawn to scale. Like numerals are used throughout the drawings to denote like elements. 
         FIG. 1  is a side-perspective view of a biosensor inserter including a removable trocar holder in accordance with one or more embodiments provided herein. 
         FIG. 2  is a partial exploded side view of a biosensor inserter including a removable trocar holder holding a trocar assembly in accordance with one or more embodiments provided herein. 
         FIG. 3A  is a cross-sectioned, perspective side view of a biosensor inserter illustrated in an extended configuration used when inserting the trocar and biosensor in accordance with one or more embodiments provided herein. 
         FIG. 3B  is a perspective side view of a trocar assembly including a trocar and a biosensor in accordance with one or more embodiments provided herein. 
         FIG. 3C  is an enlarged, cross-sectioned, partial side view of a trocar assembly illustrating the biosensor transitioning into a side groove of the trocar in accordance with one or more embodiments provided herein. 
         FIG. 4  is a cross-sectioned side view of a biosensor inserter illustrated in a first extended position where the trocar and biosensor would be inserted into the skin of the person in accordance with one or more embodiments provided herein. 
         FIG. 5  is a cross-sectioned side view of a biosensor inserter illustrated in a retracted position with the trocar assembly coupled to the removable trocar holder in accordance with one or more embodiments provided herein. 
         FIG. 6  is a cross-sectioned side view of a biosensor inserter illustrated with the trocar and trocar holder being removed from the remainder of the biosensor inserter in accordance with one or more embodiments provided herein. 
         FIG. 7  is a cross-sectioned, exploded side view of a biosensor inserter illustrated with the trocar and trocar holder removed from the remainder of the biosensor inserter in accordance with one or more embodiments provided herein. 
         FIG. 8  illustrates a flowchart of a method of using a biosensor inserter to insert a biosensor in a user in accordance with embodiments provided herein. 
     
    
    
     DETAILED DESCRIPTION 
     A biosensor inserter is configured to implant (insert) a biosensor of a transmitter and sensor assembly into the skin of a person. In conventional biosensor inserters, a trocar assembly is used as part of the biosensor inserter wherein the trocar thereof aids in the insertion of the biosensor into the person. Once the biosensor insertion process is performed, the trocar assembly and trocar is retracted and generally remains inside of the biosensor inserter. Because blood may contaminate the trocar and biosensor inserter, conventional biosensor inserters are treated as a biohazard and are disposed of as medical waste, much like sharps. 
     Embodiments of the present disclosure operate to reduce the amount of medical waste generated by these biosensor inserters upon being used. This is accomplished by isolating the trocar assembly and trocar from the remaining part of the biosensor inserter. In one or more embodiments described herein, a biosensor inserter is provided that has parts thereof that are designed to be recycled, while other components are removable and are treatable as medical waste. Thus, the amount of medical waste is dramatically reduced, and the amount of recyclable material is increased. In accordance with some embodiments of the disclosure, after performing the insertion process with the biosensor inserter, a trocar holder carrying the trocar assembly is separated from the recyclable components by having the trocar assembly and trocar enclosed in a sheath portion of the removable trocar holder. Thus, after removal, the trocar holder and trocar contained therein can be discarded as medical waste. The remaining portions of the biosensor inserter can be recycled. 
     For example, in some embodiments, the biosensor inserter may include a push member configured to be pushed by a user (the person receiving the biosensor or another person), a contact member configured to contact the person&#39;s skin, and transmitter carrier that holds a transmitter and biosensor assembly during insertion of the biosensor. As the push member is pushed by the user, the transmitter carrier is translated toward a user&#39;s skin and the trocar and biosensor are inserted therein during a first portion of a stroke of the biosensor inserter. Continuing to push on the push member retracts the trocar, leaving the biosensor implanted in the user&#39;s skin. 
     In one or more embodiments, the push member includes a trocar holder that is registerable in a receiver of the push member and that is configured to contain the trocar assembly in a sheath portion after the insertion process is completed, wherein the trocar holder and trocar can be removed from the push member as a unit and discarded as medical waste. The push member, inner insertion/retraction mechanism, and contact member can be treated as recyclable material, since they would not be exposed to blood, nor would they contain any sharps. The largest volume of material is contained in the push member, inner insertion/retraction mechanism, and the contact member, thus only a small amount of material is considered medical waste, namely the trocar holder and trocar assembly. A trocar may also be referred to as an insertion portion. 
     In some embodiments, a skirt portion of the contact member, that is configured to be in contact with the person&#39;s skin, can be removable and can be removed and discarded as medical waste if it, has been contaminated by blood. Otherwise, it can be recycled. 
       FIGS. 1 through 3C  illustrate various views of an embodiment of the biosensor inserter  100  including a push member  102  configured to be pushed by the user to cause insertion of the biosensor  314  (shown in  FIG. 3B-3C ) and a contact member  104  that is translatable (e.g., capable of telescoping) relative to the push member  102 . Contact member  104  is configured to be in contact with the user&#39;s skin during biosensor insertion process. In the depicted embodiment, the push member  102  includes a receiver  107 , which can be a pocket or other suitable opening. One type of mechanism  310  ( FIG. 3A ) of the biosensor inserter  100  is shown, which is operational to insert a trocar  212 T of a trocar assembly  212  along with the biosensor  314  ( FIGS. 3B-3C ) and then retract the trocar assembly  212  and trocar  212 T. 
     Further, biosensor inserter  100  includes a trocar holder  105  configured to hold the trocar assembly  212  after use so that it can be properly disposed of. The trocar holder  105  may provide a secondary function of providing a guide for the proper alignment of the trocar assembly  212  during insertion. For example, a body  312 B ( FIG. 3B ) of the trocar assembly  212  may have a shape, such as rectangular cross-sectional shape shown, that is similar to, but slightly smaller than an internal shape of an internal channel (e.g., hollow interior  205 I— FIG. 2 ) formed in the sheath portion  205 S of the trocar holder  105  such that the body  312 B of the trocar assembly  212  can slide in the hollow interior  205 I, but not rotate or tilt therein. The trocar holder  105  is configured to be insertable into, and removable from, the receiver  107 . Thus, the trocar holder  105  and trocar assembly  212  are removable (can be removed from) from the receiver  107  of the push member  102  and safely discarded as medical waste after use. 
     Again referring to the trocar assemblies  212  shown in  FIGS. 2 and 3B and 3C , the body  312 B of the trocar assembly  212  can include wings  212 W extending laterally therefrom. The wings  212 W ride in the slots  220  formed in sides of the sheath portion  205 S of the trocar holder and can snap past one or more retention features  220 R upon retraction of the trocar assembly  212 . Thus, the slots  220  formed in sides of the sheath portion  205 S are configured to receive wings  212 W of the trocar assembly  212 . The one or more retention features  220 R can be configured to secure the trocar assembly  212  to the sheath portion  205 S. Further, the one or more retention features  220 R can comprise a narrowed portion of a slot  220  formed in one or more sides of the sheath portion  205 S that are configured to receive wings  212 W of the trocar assembly  212 . As shown in  FIG. 3A , forks  316 F of the pivot member  316  engage the wings  212 W of the trocar assembly  212  to drive same and cause biosensor insertion and thereafter retraction. In particular, the pivot member  316  comprises a forked end including forks  316 F with a first fork and a second fork that can straddle the sheath portion  205 S of the trocar holder  105 , wherein each fork  316 F can include an open-ended groove configured to receive the wings  212 W therein. 
     Receiver  107  may be a pocket formed in a top portion of the push member  102  in some embodiments. For example, as shown in  FIG. 2 , the receiver  107  can be formed in a top and/or side(s) of the push member  102 . As shown, the grasping portion  105 G of the trocar holder  105  is configured to be grasped by a thumb and finger of the user. Any suitable surface feature  105 F or features that enhance gripping of the trocar holder  105  can be added to the side surfaces of the grasping portion  105 G, such as by adding a raised portion (e.g., raised rib) as shown. Optionally one or more indented portions or other grip feature may be provided to enhance gripping. Additionally, as shown in  FIGS. 2 and 3A , retention features may be added to the trocar holder  105 , such as to grasping portion  105 G. Retention features in this embodiment can comprise holes  205 H formed in tabs of the sides of the gripping portion  105 G as shown. The holes  205 H can register with pilots  305 P ( FIG. 3A ) formed on the body portion of the push member  102 . 
       FIG. 2  further illustrates the sheath portion  205 S of the trocar holder  105  in more detail. Trocar holder  105  includes the sheath portion  205 S extending from the grasping portion  105 G. Sheath portion  205 S includes a hollow interior  205 I that can receive a portion of the trocar assembly  212  therein. After the insertion of the biosensor  314 , the trocar assembly  212  is retractable by pivot member  316  into the hollow interior  205 I of the sheath portion  205 S, similar to what is shown in  FIGS. 2  and  FIG. 5 . 
     As shown, the sharp end of the trocar  212 T can be retracted so that it is located fully inside of the hollow interior  205 I so that the sharp end is sheathed and this contact therewith is minimized. This is achieved by the pivoting of the pivot member  316  as shown in  FIG. 5 , which moves the wings  212 W of the trocar assembly  212  up in the slots  220  past the retention features  220 R and effectively locks the wings  212 W into the retention area  220 A (See  FIG. 2 ) of the trocar assembly  212  where the wings  212 W are held securely so that the trocar assembly  212  cannot fall out of the sheath portion  205 S. 
     As the trocar assembly  212  is captured within the hollow interior  205 I, the user can squeeze the opposing side tabs  105 T of the grasping portion  105 G sufficiently to move the holes  205 H past the pilots  305 P and thus remove the trocar holder  105  along with the trocar assembly  212 . Thus, the material considered medical waste can be isolated away from the remaining recyclable portion. The trocar holder  105  along with the trocar assembly  212  can then be disposed as medical waste. Similarly, in a separate step, the skirt  104 S can also be removed and disposed of as medical waste, if contaminated. Skirt  104 S may be part of the contact member  104  and may slip over, or otherwise be removably fastened to, the upper portion  104 U of the contact member  104 . 
       FIGS. 3A and 4-7  illustrate the mechanism  310  of the biosensor inserter  100 . In some embodiments, the pivot member  316 , which contacts and operatively drives the trocar assembly  212 , is restrained from pivoting as the transmitter carrier  318  translates toward a user&#39;s skin during a first portion (insertion portion) of the stroke of the biosensor inserter  100 , but is allowed to pivot once delatched after the biosensor  314  is implanted in a user&#39;s skin. Once delatched, the pivot member  316  may pivot in a second portion of the stroke of the biosensor inserter  100 , which causes the retraction (the retraction portion of the stroke) of the trocar assembly  212  and leaves the biosensor  314  inserted into the user&#39;s skin. Thus, the pivot member  316  does not pivot in the first portion of the stroke, and does pivot in a second (retraction) portion of the stroke. The transmitter carrier  318  is translatable relative to the contact member  104  and is configured to support a transmitter and sensor assembly  330  during insertion of a biosensor  314  ( FIG. 3B ). The transmitter carrier  318  may include an aperture  319  configured to receive the sheath portion  205 S therein during insertion. Other suitable mechanisms for insertion and retraction may be used. 
       FIGS. 3A and 4-7  further illustrate cross-sectional side views of a biosensor inserter  100  shown in various portions of the stroke in accordance with one or more embodiments provided herein. The contact member  104  includes an upper portion  104 U and a skirt  104 S at the lower end. Lower end, which may be part of skirt  104 S, may contact a user&#39;s skin during insertion and retraction of the trocar assembly  212  to implant a biosensor  314 . Contact member  104  further includes a latch  104 L, which has a latch surface (lower latch surface) that once passed by via motion of a latch end  316 L of the pivot member  316  will allow the pivot member  116  to rotate ( FIG. 5 ). The pivot member  316  can be configured to pivot on the transmitter carrier  318 , such as about pivot  318 P. 
     For example, pivot  318 P may include laterally extending features (e.g., posts) formed on the pivot member  316  that interface with holes or recesses formed in first and second side supports of transmitter carrier  318  (see  FIG. 3A ) to form a pivot axis. Thus, the pivot member  316  is pivotable about the pivot axis and pivots on the pivot of  318 P formed by transmitter carrier  318  and pivot member  316 . 
     A pivot location of the pivot  318 P can be formed between the latch end  316 L and the opposite end of pivot member  316  containing the forks  316 F. Other suitable laterally extending features may be used to form the pivot  318 P, and other pivot mechanisms may be used, such as a removable axle, or the like. 
     Latch  104 L may be formed as an opening in the sidewall of the contact member  104 . The latch  104 L can comprise a circumferentially disposed surface of a width that can be wider than the latch end  316 L of the pivot member  316 . Up until when the latch end  316 L passes by the latch  104 L, the pivot member  316  is restrained from rotation about pivot  318 P. As shown, latch  104 L is part of a vertically extending cutout that may be closed at its lower end by skirt  104 S. Once past the latch  104 L, the pivot member  316  may rotate. 
     As shown in  FIGS. 3A-7 , push member  102  may include a push element  102 P, which can be a rigid member that extends downwardly (as oriented in  FIG. 3A ) from the underside of push member  102  and includes a contact end that engages with pivot member  316 . Push element  102 P engages with pivot member  316  and causes rotation (pivoting) thereof as well as translation of the transmitter carrier  318 . Transmitter carrier  318  can be received within the contact member  104  and can have a transmitter and sensor assembly  330  coupled thereto. Transmitter and sensor assembly  330  includes the transmitter electronics and radio that can be used to communicate measured analyte values and/or other data received from the implanted biosensor  314  to a reader, smartphone executing a suitable application, or other apparatus for processing and displaying analyte values, including trends. Transmitter and sensor assembly  330  further includes a biosensor  314  coupled thereto, which has a reading end that is received inside of the trocar  212 T and is inserted with the aid of the trocar  212 T and after which the trocar  212 T is removed and the biosensor  314  remains implanted in the person. 
     In operation, the transmitter and sensor assembly  330  can be detachably coupled to the transmitter carrier  318 . Transmitter and sensor assembly  330  can include an adhesive layer to adhere the transmitter and sensor assembly  330  to the user&#39;s skin upon retraction of the trocar assembly  212 . Any suitable mechanism that allows detachment of the transmitter and sensor assembly  330  from the transmitter carrier  318  may be used, such as a pressure sensitive adhesive, a slight interference fit, a low-release force retention mechanism, or the like. 
     In some embodiments, the push member  102 , contact member  104 , pivot member  316 , and/or transmitter carrier  318  may be formed from a biodegradable and/or recyclable material (e.g., a recyclable plastic, a biodegradable paper product, bamboo, etc.). In particular, in some embodiments, recyclable plastics may be used for the above-listed components, including, but not limited to, polyethylene terephthalate (PET), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyvinyl chloride, polypropylene, polystyrene, and the like. 
     In more detail, the transmitter carrier  318  is axially translatable relative to the contact member  104  and is configured to support the transmitter and sensor assembly  330  during insertion of the biosensor  314 . In particular, the transmitter and sensor assembly  330  may include transmitter electronics  336 , a power source (not shown), and a biosensor assembly that includes the biosensor  314 . 
     The transmitter and sensor assembly  330  may include transmitter electronics  336  ( FIG. 3B ) that may include an analog front end for biasing the biosensor  314  and for sensing current that passes through the biosensor  314 , such as an operational amplifier or amplifiers, current sensing circuitry, processing circuitry such as an analog-to-digital converter for digitizing current signals, memory for storing digitized current signals, a controller such as a microprocessor, microcontroller or the like for possibly computing analyte concentration values based on measured current signals, and transmitter circuitry for transmitting analyte concentration values to the external device (e.g., a smart phone or another suitable external reader device configured to store and/or displaying analyte concentrations). 
     In some embodiments, the biosensor  314  used within the transmitter and sensor assembly  330  may include two electrodes and the bias voltage may be applied across the pair of electrodes. In such cases, current may be measured through the biosensor  314 . In other embodiments, the biosensor  314  may include three electrodes such as a working electrode, a counter electrode, and a reference electrode. In such cases, the bias voltage may be applied between the working electrode and the reference electrode, and current may be measured through the working electrode, for example. The biosensor  314  may include an active region including one or more chemicals that undergo an analyte-enzyme reaction with the products they detect. The enzyme can be immobilized on one or more electrodes to provide a reaction (e.g., redox reaction) with the analyte and generate a current at the electrodes. Example chemicals include glucose oxidase, glucose dehydrogenase, or the like for measuring glucose as an analyte. In some embodiments, a mediator such as ferricyanide or ferrocene may be employed at the active region. In general, any analyte that may be detected and/or monitored with a suitable biosensor and for which suitable chemistry exists may be measured, such as glucose, cholesterol, lactate, uric acid, alcohol, or the like. An analyte is defined herein as a component, substance, chemical species, or chemical constituent that is measurable in an analytical procedure. 
     An example of the biosensor  314  can be any suitable implantable sensor that can be implanted in the skin of a user, such as a strand-shaped sensor shown in  FIGS. 3B-3C  that is able to be received inside of a side groove  332  formed lengthwise in the trocar  212 T of the trocar assembly  212  and that is able to sense an analyte concentration of an interstitial fluid under the skin. 
     Trocar  212 T of trocar assembly  212  may be made, for example, from a metal such as stainless steel, or a non-metal such as plastic. Other suitable materials may be used. In some embodiments, trocar  212 T may be have a lengthwise formed side groove  332  formed from, but not limited to, a round C-channel tube, a round U-channel tube, a stamped sheet metal part folded into a U-profile in cross-section, a molded/cast metal part with a U-channel profile in cross-section, or a solid metal cylinder with an etched or ground channel causing a U-shapes cross-section. Other trocar shapes may be used that allow insertion and retraction, while leaving behind the implanted biosensor  314 . 
     Body  312 B of trocar assembly  212  may be formed from a suitable plastic, for example, such as, but not limited to, acrylonitrile butadiene styrene (ABS), polycarbonate, nylon, acetal, polyphthalamide (PPA), polysulfone, polyethersulfone, polyetheretherketone (peek), polypropylene, high-density polyethylene (HDPE), and low-density polyethylene (LDPE). Other suitably rigid materials may be used. 
     As best shown in  FIG. 3B and 3C , the biosensor  314  is received in the side groove  332  of the trocar  212 T, that extends along the length of the trocar  212 T, and transitions into a passage  334  formed in the threaded portion  331 , and then passes laterally out of passage  334  to connect to the transmitter electronics  336  such as an electrical circuit board, or other like electronic component including, coupled to, or configured to couple to other electronics of the transmitter and sensor assembly  330 . Thus, upon insertion and then retraction of the trocar  212 T in and from the user&#39;s skin, the biosensor  314  can remain in place by being removed from passage  334  and the side groove  332 . 
     In operation, the trocar assembly  212  can be drivable by being contacted by the forks  316 F of the pivot member  316  in an insertion stroke to insert the biosensor  314  into the user&#39;s skin. In particular, trocar assembly  212  is drivable by the wings  212 W of the body  312 B being received in the open-ended grooves formed in the forks  316 F of the pivot member  316 . Further, the body  312 B may include a rectangular portion that is received in a like rectangular portion of the hollow interior  205 I. As discussed above, the rectangular portions may interface and provide an anti-rotation support. 
     As best shown in  FIG. 3A , contact member  104  may be configured to be concentric with push member  102  and may be telescopic therewith. In some embodiments, contact member  104  may include a first alignment feature such as a vertically extending groove or recess, and transmitter carrier  318  may include a second alignment feature, such as a vertically extending finger tab, that interfaces with the first alignment feature. Such alignment features may hold contact member  104  and transmitter carrier  318  in rotational alignment to prevent rotation there between, such as during the insertion and retraction portions of the stroke. Push member  102  and contact member  104  may be oval or oblong as shown, or optionally circular, elliptical, or any other suitable shape in transverse cross-section. In some embodiments, push member  102  and contact member  104  may not be concentric. 
     Operation of the biosensor inserter  100  is now described with reference to  FIGS. 4-7 , which illustrate cross-sectional side views of the biosensor inserter  100  during various portions of the stroke of the insertion method operative to insert a biosensor  314  in accordance with embodiments provided herein. In addition,  FIG. 8  illustrates a flowchart of a method  800  of using a biosensor inserter  100  to insert a biosensor  314  in accordance with embodiments provided herein. 
     To begin the insertion method  300  of  FIG. 8 , a needle cover (not shown) can be removed from threaded portion  331  of trocar assembly  212  of the biosensor inserter  100 . The biosensor inserter  100  is placed in contact with the skin surrounding a desired insertion site of a user, such as on an upper arm, an abdomen region, or another suitable location. 
     To begin insertion, a force  108  is applied to the push member  102  by a user so as to cause the push member  102  to translate relative to the contact member  104  and move toward the insertion site. Movement of push member  102  over the contact member  104  causes push element  102 P to contact the pivot member  316 , which causes transmitter carrier  318  and pivot member  316  to translate and move toward the insertion site with the latch end  316 L moving linearly relative toward the latch  104 L along the wall. 
     During this first portion of the stroke of the method  800 , pivot member  316  is prevented from pivoting via the contact of the latch end  316 L with the wall of the contact member  104 . Thus, transmitter carrier  318  and coupled transmitter and sensor assembly  330  translate toward the insertion site. 
     As shown in  FIG. 4 , transmitter carrier  114  and transmitter and sensor assembly  330  continue to move toward the insertion site and trocar  212 T makes contact and enters insertion site of the skin, and a bottom surface of transmitter and sensor assembly  330  contacts the skin around the insertion site. In some embodiments, bottom surface of transmitter and sensor assembly  330  may adhere (e.g., via an adhesive material) to the user&#39;s skin surrounding the insertion site. The trocar  212 T and biosensor  314  enters the insertion site where biosensor  314  can make contact with interstitial fluid in the subcutaneous region. The biosensor  314  can be placed 4 mm to 6 mm into the skin, for example, although other depths may be used. 
     As shown in  FIG. 5 , following insertion of the biosensor  314  (including adhesion of the transmitter and sensor assembly  330  to the skin around the insertion site), the push member  102  continues to move relative to the contact member  104  in a second portion of the stroke. When the latch end  316 L of the pivot member  316  moves past the latch  104 L at the start of the second portion of the stroke, the pivot member  316  is allowed to pivot via the pushing by push element  102 P, rotate under latch  104 L about pivot  318 P and into cutout portion  338 . The pivoting causes the retraction of the trocar assembly  212  in the second portion of the stroke. 
     During the retraction, pivot member  316  pivots on the transmitter carrier  318  due to the force  108  applied by push element  102 P on pivot member  316 . As this occurs, trocar assembly  212  retracts from the insertion site and moves away from transmitter and sensor assembly  330 , which is adhered to the user. As the push member  102  continues to move relative to the contact member  104  toward the insertion site, push element  102 P continues to press against pivot member  316 . Eventually, as shown in  FIG. 5 , pivot member  316  pivots sufficiently for trocar assembly  212  to be completely removed from the user&#39;s skin and leaves the implanted biosensor  314  therein. As the push member  102  is continued to be pushed further, the trocar assembly  212  is retracted along slots  220  and past retention feature  220 R. Additionally, the trocar assembly  212  is retracted into the sheath portion  205 S of the trocar holder  105  and securely held thereby. 
     Biosensor inserter  100  then may be removed, leaving transmitter and sensor assembly  330  in place, with the bottom surface of transmitter and sensor assembly  330  adhered to the user&#39;s skin at the insertion site and biosensor  314  in contact with interstitial fluid of the user. 
     Before or after removal of the biosensor inserter  100 , the trocar holder  105  with the trocar assembly  212  contained and held therein can be removed, such as shown in  FIG. 6 . The trocar assembly  212  is secured in the trocar holder  105  and can be discarded therewith as medical waste. 
     In some embodiments, the push member  102 , contact member  104 , pivot member  316 , and transmitter carrier  318  are formed of recyclable or biodegradable material, and these components may be recycled or composted. Thus, it should be recognized that biosensor inserters  100  of the present disclosure dramatically reduce the amount of medical waste and increase the amount of recyclable or biodegradable material. 
       FIG. 7  illustrates an exploded view of various components of the biosensor inserter  100 . 
     Referring now to  FIG. 8 , an embodiment of a method  800  of using a biosensor inserter (e.g., biosensor inserter  100 ) to insert a biosensor (e.g., biosensor  314 ) into a user is described. The method  800  comprises, in block  802 , providing the biosensor inserter (e.g., biosensor inserter  100 ) comprising: a push member (e.g., push member  102 ) including a receiver (e.g., receiver  107 ), a trocar holder (e.g., trocar holder  105 ) inserted in the receiver, the trocar holder including a sheath portion (e.g., sheath portion  205 S), and a contact member (e.g., contact member  104 ) translatable relative to the push member, and a trocar assembly (e.g., trocar assembly  212 ) including a trocar (e.g., trocar  212 T). 
     The method  800  further comprises, in block  804 , contacting the contact member (e.g., contact member  104 ) to skin of the user, and in block  806 , pushing on the push member (e.g., push member  102 ) to cause insertion of the trocar (e.g., trocar  212 T) and biosensor (e.g., biosensor  314 ) into the skin. The pushing (force  108 ) causes the transmitter carrier (e.g., transmitter carrier  318 ) to translate relative to the contact member. 
     Further, the method  800  comprises, in block  808 , continuing to push the push member (e.g., push member  102 ) to retract the trocar assembly (e.g., trocar assembly  212 ) into the sheath portion (e.g., sheath portion  205 S), while leaving the biosensor (e.g., biosensor  314 ) implanted. Finally, the method  800  comprises, in block  810 , removing the trocar holder (e.g., trocar holder  105 ) and trocar assembly (e.g., trocar assembly  212 ) from the receiver (e.g., receiver  107 ). Following removal, the trocar holder  105 , and trocar assembly  212  may be discarded as medical waste, along with the skirt  104 S, if contaminated with blood. The remainder of the biosensor inserter  100  can be recycled. 
     The foregoing description discloses only example embodiments. Modifications of the above-disclosed apparatus and methods, which fall within the scope of this disclosure, will be readily apparent to those of ordinary skill in the art.