One innovative aspect of the subject matter described in this disclosure can be implemented as a tamper-resistant wearable band that may include a flexible strap including a first end and a second end and an irreversibly locking clasp (referred to herein as a clasp). The irreversibly locking clasp may include a housing, an inner anchor configured to anchor the first end of the flexible strap to the housing and a locking sled that is slideably coupled to the housing, wherein the inner anchor and the locking sled are configured to lock and immobilize the second end of the flexible strap. In some examples, the locking sled may include flexible pawls and/or gears configured to engage with teeth formed in the housing. In some other examples, the locking sled may be configured to travel in only one direction with respect to the housing. In still other examples, the flexible strap may be configured to move freely within the irreversibly locking clasp until the locking sled is fully inserted into the housing.

Another innovative aspect of the subject matter described in this disclosure can be implemented in another tamper-resistant wearable band that may include a flexible strap and an irreversibly locking clasp. The irreversibly locking clasp may include a base portion configured to anchor a first end of the flexible strap to the irreversibly locking clasp and a cover portion slideably coupled to the base portion and configured to selectively lock and immobilize a second end of the flexible strap. In some examples the irreversibly locking clasp may be configured to operate in a first state, wherein the flexible strap moves freely within the irreversibly locking clasp and operate in a second state, wherein the flexible strap is locked and immobilized within the irreversibly locking clasp. In some other examples, a position of the cover portion with respect to the base portion determines, at least in part, whether the irreversibly locking clasp is operating in the first state or the second state. In still other examples, the base portion may include a ramp configured to guide the flexible strap and fold in response to pressure from the cover portion and the cover portion may include strap teeth configured to lock and immobilize the second end of the flexible strap.

All of the methods and apparatuses described herein, in any combination, are herein contemplated and can be used to achieve the benefits as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the features and advantages of the methods and apparatuses described herein will be obtained by reference to the following detailed description that sets forth illustrative embodiments, and the accompanying drawings of which:

FIG. 1A shows a simplified view of a tamper-resistant wearable band, according to some examples.

FIG. 1B shows another simplified view of the tamper-resistant wearable band of FIG. 1B.

FIG. 2 shows an exploded view of the tamper-resistant wearable band of FIG. 1, according to some examples.

FIG. 3A shows a perspective view of one example of an inner anchor of a tamper-resistant wearable band as described herein.

FIG. 3B shows a second perspective view of the inner anchor of FIG. 2.

FIG. 4 shows an example of a locking sled of a tamper-resistant wearable band as described herein.

FIG. 5 shows an example of a housing of a tamper-resistant wearable band (shown transparent).

FIG. 6A shows a cut-away view of one example of a tamper-resistant wearable band similar to FIG. 1 in the first state (in which the clasp is not secured, so that the length of the strap may be adjusted).

FIG. 6B shows a section through the tamper-resistant wearable band of FIG. 6A in a second state, in which the locking sled is engaged with the inner anchor within the housing so that the clasp is irreversibly secured closed, preventing the strap from sliding in or out.

FIG. 6C illustrates the change in the angle of the ramp (or ramp members) between the first state (on the left) and the second state (on the right).

FIG. 7 shows an alternate cut-away view of the tamper-resistant wearable band of FIG. 1 with a clasp in the first (unsecured) state.

FIG. 8 shows a cut-away view of the tamper-resistant wearable band of FIG. 1 with a clasp in the second state, in accordance with some examples.

FIG. 9 shows an alternate cut-away view of the tamper-resistant wearable band of FIG. 1 with a clasp in the second (secured) state.

FIG. 10 shows a simplified view of a tamper-resistant wearable band, according to some examples.

FIG. 11 shows a cut-away view of an example of a tamper-resistant wearable band with a clasp in the first (unsecured) state, according to some examples.

FIG. 12 shows another simplified view of a tamper-resistant wearable band of FIGS. 10 and 11, according to some examples.

FIG. 13 shows a cut-away view of the tamper-resistant wearable band with a clasp in the second state, according to some examples.

FIG. 14A shows another example of a tamper-resistant wearable band in an unlocked configuration.

FIG. 14B is another view of the tamper-resistant wearable band of FIG. 14A in a locked configuration.

FIGS. 15A-15D illustrate components of a tamper-resistant wearable band similar to that of FIGS. 14A-14B. FIG. 15A shows an exploded view of the clasp of the tamper-resistant wearable band. FIG. 15B shows the housing of the clasp; FIG. 15C shows an example of an inner anchor including a ramp and one or more teeth positioned opposite the ramp; and FIG. 15D shows an example of a locking sled of the clasp.

FIGS. 16A-16B are sectional views through the tamper-resistant wearable band of FIGS. 14A and 14B. FIG. 16A shows the clasp in the unsecured configuration, in which the strap may move freely. FIG. 16B shows the clasp in the secured configuration in which the strap is locked in place.

FIG. 17 is a sectional view through a clasps of a tamper-resistant wearable band in a secured configuration, similar to that shown in FIGS. 14B and 16B.

DETAILED DESCRIPTION

Disclosed herein are various examples of a tamper-resistant wearable bands. These tamper-resistant wearable bands may be used to attach or affix any feasible device to any feasible part of a patient or subject's body. For example, the tamper-resistant wearable band may affix patient monitoring and/or tracking devices to a patient's arm (e.g., wrist) or leg (e.g., ankle). The tamper-resistant wearable bands described herein may affix, and/or may integrate, tracking devices in psychiatric or for prisoner/incarceration settings.

FIG. 1A shows a simplified view of a tamper-resistant wearable band 100, according to some examples. The tamper-resistant wearable band 100 may include an irreversibly locking clasp 110 and a strap 120. The clasp 110 may include an outer housing cover 111, a locking sled 112 and a strap anchor (not shown). The strap 120 may include a first end 121 and a second end 122.

The strap 120 may be flexible and formed from and/or include woven (including tightly woven) or non-woven polyester, polyamide, polyolefins, or laminated constructions such as polyolefin laminated fibers, or any other feasible material. The strap 120 may have a length that accommodates the tamper-resistant wearable band 100 to be worn around any desired appendage, or may be worn around a patient's neck, or around the patient's torso (e.g., trunk).

As mentioned, the strap may be formed of a woven metal or may include a woven, braided, and/or knit metal material. In some examples, the strap/brand may be formed of one or more laminations, including laminations of mixed materials, and/or a core material that is covered with one or more overlayers, including an extruded overlayer. Although in some examples the entire length of the strap or band is flexible, in some examples it may be beneficial to have regions that are more flexible and less flexible, including region that are relatively rigid (inflexible). For example, the band may be inflexible with just the securing portion or region being flexible. Alternatively or additionally, the band (e.g., strap) may have a constant thickness or in some examples may have a variable thickness, except within the clasp or securing portion or region.

The first end 121 of the strap 120 may be looped around the strap anchor and may be doubled back over itself as shown in region 130. In some examples, the first end 121 of the strap 120 may be mechanically attached to itself in the region 130. For example, the first end 121 may be attached to itself using adhesives, sewing, heat welding, ultrasonic welding, or any other feasible means. The strap anchor is described in more detail below in conjunction with FIGS. 2 and 3A-B.

The locking sled 112 may be slideably coupled to (e.g., may slide within) the outer housing cover 111. For example, the locking sled 112 may be inserted to a first position into the outer housing cover 111. In the first position, the locking sled 112 and the strap anchor may form a first path for the strap 120 that allows the second end 122 of the strap 120 to be inserted into the outer housing cover 111 and guided through the outer housing cover 111 until the second end 122 exits the outer housing cover 111. The first path for the strap 120 is described in more detail below in conjunction with FIGS. 6A-C and 7.

When the locking sled 112 is in the first position, the irreversibly locking clasp 110 is said to be in a first state that allows the strap 120 to be adjusted. That is, the strap 120 may be moved freely through the irreversibly locking clasp 110 to accommodate different sizes of arms, legs, and the like. Unlike some conventional wearable bands that are limited to discrete size adjustments, the clasp 110 allows a fully continuous size adjustment.

FIG. 1B shows another simplified view of the tamper-resistant wearable band 100. In this view, the locking sled 112 has been inserted and/or slid into a second position into the outer housing cover 111 of the irreversibly locking clasp 110. When the locking sled 112 is in the second position, the clasp 110 is said to be in a second state the locks and immobilizes the strap 120. In some examples, the strap 120 may withstand 300 pounds of force or more when immobilized. In the second position, the locking sled 112 and the strap anchor may form a second path for the strap 120. The second path for the strap 120 is described in more detail below in conjunction with FIGS. 8 and 9.

When the locking sled 112 is fully inserted into the outer housing cover 111, the exterior of the irreversibly locking clasp 110 may be relatively smooth. That is, the clasp 110 may have smooth corners, edges, and relatively thin seams. These exterior features of the clasp 110 may provide little or no elements that may be subject to attack by tools such as screw drivers, knives, pliers, or the like, thereby enhancing the tamper-resistant features of the tamper-resistant wearable band 100.

In some examples, the irreversibly locking clasp 110 may have overall dimensions of approximately 30 millimeters (mm)×30 mm×10 mm. Such dimensions may enhance the wearer's comfort.

FIG. 2 shows an exploded view 200 of the tamper-resistant wearable band of FIG. 1, according to some examples. In this view, the strap 120 is shown separate from the clasp 110. The irreversibly locking clasp 110 is shown exploded and may include the outer housing cover 111, the locking sled 112, and a strap anchor 210.

The outer housing cover 111 may include teeth 220 that are formed or molded into sides of an internal cavity. The locking sled 112 may include pawls 230 (or gears, rack, etc.) that may engage with the teeth 220. In some examples, the teeth 220 and the pawls 230 (e.g., gears) may enable the locking sled 112 to be inserted into (e.g., slideably coupled with), but not withdrawn from, the outer housing cover 111. In other words, the locking sled 112 may be held in place and restricted to travel in only one direction. Thus, after the locking sled 112 is inserted in the outer housing cover 111, the locking sled 112 may not be removed locking the tamper-resistant wearable band into place.

The outer housing cover 111 and the locking sled 112 may be composed of or from any feasible material, including polyoxymethylene, polycarbonate, polyethylene teraphalate, polybutylene teraphalate, polyamide, and polyphenylene ether. In some examples, the material for the outer housing cover 111 and the locking sled 112 may be strong and have a high elastic elongation. In some examples the clasp may be made entirely of metal or alternatively just a portion of the clasp (e.g., the outer shell region may be metal).

The strap anchor 210 may include a ramp 211 that, together with the outer housing cover 111 and the locking sled 112 may form a path for the strap 120 (path not shown) within the clasp 110. The paths for the straps are described in more detail below in conjunction with FIGS. 6A-9.

FIG. 3A shows a first view of the strap anchor 210 of FIG. 2. The strap anchor 210 may fit within the outer housing cover 111 of the irreversibly locking clasp 110 of FIG. 1. In some examples, the strap anchor 210 may provide a means for anchoring the first end 121 of the strap 120 to the clasp 110. The strap anchor 210 may include ramp 211 and an anchor bar 320. The first end of the strap is looped around the anchor bar 320 and may be secured to itself, e.g., by laser welding, or by some other permanent manner.

The ramp 211 may form, in part, a path for the strap within the irreversibly locking clasp 110. A ramp angle of the ramp 211 may affect the ease of the feeding of the strap 120 through the clasp 110. For example, a shallow ramp angle may enable the strap 120 to be easily fed through the clasp 110 but may extend or increase the size of the outer housing cover 111. On the other hand, a steep ramp angle may make the insertion and feeding of the strap 120 more difficult. In some examples, the ramp angle may be approximately 35 degrees. In some other examples, the ramp angle may be between 45 and 65 degrees.

In some examples, the ramp 211 may fold or deform when, for example, receiving a force or pressure. In some cases, the ramp 211 may be formed by teeth, fingers, or other projections.

The anchor bar 320 may provide a feature on the strap anchor 210 that the strap 120 can wrap around and form a loop. For example, the strap anchor 210 may include a slot 321 next to the anchor bar 320. The slot 321 may be wide enough to accommodate the width of the strap 120. FIG. 3B shows a second view of the strap anchor 210. As shown, the strap anchor 210 may include the ramp 211, the anchor bar 320 and the slot 321.

FIG. 4 shows a view of the locking sled 112 of FIG. 1, according to some examples. The locking sled 112 may include a first pawl arm 410, a second pawl arm 411, strap teeth 430, and outer surface 440. The first and second pawls arms 410, 411 may be flexible and engage with the teeth 220 of the outer housing cover 111 (teeth 220 and outer housing cover 111 not shown). In some examples, the first and second pawls arms 410, 411 may enable the locking sled 112 to be inserted into, but not withdrawn from, the outer housing cover 111. The strap teeth 430 may engage with (e.g., penetrate) and immobilize the strap 120 when the locking sled 112 is in the second position within the outer housing cover 111. In some cases, the strap 120 may be immobilized by friction between the strap teeth 430 and the ramp 211 (not shown). The strap teeth 430 may be metal or may be formed from any other feasible material. In some examples, the strap teeth 430 may have a 60 degree angle, although any feasible angle is contemplated. Furthermore, when the locking sled is in the second position, the outer surface 440 may be flush with an outer surface of the outer housing cover 111.

FIG. 5 shows an internal view of the outer housing cover 111 of FIG. 1. As shown, the outer housing cover 111 may include teeth 220 that can engage with the first and second pawl arms 410, 411 of the locking sled 112 (not shown).

FIG. 6A shows a cut-away view 600 of the tamper-resistant wearable band 100 of FIG. 1 in the first state, according to some examples. As shown, the irreversibly locking clasp 110 may include the outer housing cover 111, the locking sled 112, and the strap anchor 210. The first end 121 of the strap 120 may form a loop around the anchor bar 320 and may be mechanically attached to itself to close the loop.

The sliding lock 112 may be inserted into the outer housing cover 111 to a first position. While in the first position, the outer housing cover 111, the sliding lock 112, and the strap anchor 210 may form a first path 610 for the strap 120. For example, the ramp 211 and the sliding lock 112 may guide the second end 122 of the strap 120 within the outer housing cover 111. In the first state, the strap 120 may move back and forth freely within the outer housing cover 111. As shown, the strap teeth 430 may not engage with the strap 120.

FIG. 6B shows a section through the same wearable strap of FIG. 6A in a second state, in which the sliding lock 112 is fully engaged with the inner anchor so that the teeth 430 of the sliding lock 112 drive against the strap 120 and deform the ramp 211 from a first configuration in which the angle of the ramp (e.g., the angle of the outer surface of wedge-shaped outer edge forming the ramp) within the channel is increased, e.g., from a relatively low angle of between about 10 degrees to 40 degrees (e.g., less than 45 degrees, 40 degrees or less, 35 degrees or less, etc.) to a steeper angle of between about 45 degrees and 90 degrees (e.g., between about 50 and 90 degrees, between about 55 degrees and 90 degrees, 45 degrees or greater 50 degrees or greater, 55 degrees or greater, 60 degrees or greater, etc.). FIG. 6C illustrates the change in the effective angle 635, 635′of the ramp 211, 211′.

The change in configuration of the angle of the ramp may be achieved by deforming the ramp or ramp members, or by crushing the ramp or ramp members. The resulting increase in the angle allows the teeth to engage with the strap at an almost perpendicular angle and changes the path of the strap within the outer housing cover channel so that it turns with a much steeper angle within the outer housing cover channel, resulting in a dramatically stronger securement of the strap within the outer housing cover, particularly as compared to examples in which the ramp does not change configuration to increase the angle.

In general the ramp portion of the inner anchor may allow the second end 121 of the strap 120, which is initially loose, to be easily inserted into the channel of the outer housing cover, and be guided, by the ramp through the channel and out the second end of the outer housing cover, particularly when the sliding lock 112 is partially inserted into the outer housing cover, as shown in FIG. 6A. Thus, the inner anchor may guide the second end of the strap up over the ramp and out of the second end of the outer housing cover before being locked down by the sliding lock member 112, as shown in FIG. 6B.

FIG. 7 shows an alternate cut-away view 700 of the tamper-resistant wearable band 100 of FIG. 1 in the first state. The sliding lock 112 may be in the first position in the outer housing cover 111. The strap 120 may follow the first path 610 for the strap 120 and the strap teeth 430 may not yet engage the strap 120. The first and second pawl arms 410 and 411 may engage with teeth 220 of the outer housing cover 111.

FIG. 8 shows a cut-away view 800 of the tamper-resistant wearable band 100 of FIG. 1 in the second state, in accordance with some examples. The sliding lock 112 may be inserted into the outer housing cover 111 to a second position. While in the second position, the outer housing cover 111, the sliding lock 112, and the strap anchor 210 may form a second path 810 for the strap 120. For example, strap teeth 430 may fold or deform the ramp (not shown) and engage with and immobilize the strap 120 within the outer housing cover 111. In some examples, the sliding lock 112 may directly or indirectly provide pressure to the ramp thereby causing the ramp to fold. The second path 810 for the strap 120 may no longer smoothly transition up the ramp 211, but instead have an “S” shape while being bound by the strap teeth 430. In some cases, the second path 810 may have a reverse curvature. In some examples, the second path 810 for the strap 120 may form an 80-90 degree angle in the strap 120.

FIG. 9 shows an alternate cut-away view 900 of the tamper-resistant wearable band 100 of FIG. 1 in the second state. The sliding lock 112 may be in the second position in the outer housing cover 111. The strap 120 may follow the second path 810 for the strap 120 and the strap teeth (not shown) may engage and/or penetrate the strap 120.

FIG. 10 shows a simplified view of a tamper-resistant wearable band 1000, according to some examples. The tamper-resistant wearable band 1000 may include an irreversibly locking clasp 1010 and a strap 1020. The strap 1020 may include a first end 1021 and a second end 1022. The strap 1020 may be another example of the strap 120 of FIG. 1.

The irreversibly locking clasp 1010 may include a base 1011 and a cover 1012. The base 1011 may anchor the first end 1021 of the strap 1020. FIG. 10 shows the tamper-resistant wearable band 1000 in a first state that allows the strap 1020 to move freely and be adjusted back and forth through the clasp 1010.

FIG. 11 shows a cut-away view 1100 of the tamper-resistant wearable band 1000 in the first state, according to some examples. As shown, the irreversibly locking clasp 1010 may include the base 1011 and the cover 1012. The first end 1021 of the strap 1020 may be anchored or otherwise attached to the base 1011. In the first state, the base 1011 and the cover 1012 may form a first path 1120 for the strap 1020. Furthermore, in the first state the cover 1012 may be in a first position with respect to the base 1011. In some examples, the base 1011 may include a ramp 1130 that may form, at least in part, the first path 1120 for the strap 1020. Furthermore, the cover 1012 may include strap teeth 1140 that may not engage with the strap 1020 while the tamper-resistant wearable band 1000 is in the first state. Thus, while in the first state, the strap 1020 may move freely within the clasp 1010.

The cover 1012 may be slideably coupled to the base 1011. In some examples, the base 1011 and the cover 1012 may include one or more teeth and pawls (not shown) respectively, that enable the base 1011 and the cover 1012 to move and lock into a second position.

FIG. 12 shows another simplified view 1200 of the tamper-resistant wearable band 1000 of FIGS. 10 and 11, according to some examples. In this view, the cover 1012 has been moved into a second position with respect to the base 1011. The strap 1020 has the first end 1021 anchored by the base 1011 and the second end 1022 immobilized by the cover 1012. When the cover 1012 is in the second position, the tamper-resistant wearable band 1000 is said to be in a second state where the strap 1020 is locked and immobilized.

FIG. 13 shows a cut-away view 1300 of the tamper-resistant wearable band 1000 in the second state, according to some examples. As shown, the cover 1012 is in the second position forcing the strap teeth 1140 to engage and/or penetrate the strap 1020 and fold or deform the ramp 1130. In some examples, the cover 1012 may directly or indirectly provide pressure to the ramp 1130 thereby causing the ramp 1130 to fold or the effective angle of the ramp (the angle that the strap takes against the ramp) increasing from an initial angle to a larger angle. Thus, the base 1011 and the cover 1012 may form a second path 1310 for the strap 1020 while the tamper-resistant wearable band 1000 is in the second state. Therefore, in the second state the cover 1012 may be in a second position with respect to the base 1011. In some examples, the second path 1310 for the strap 1020 may have an “S” shape and/or a reverse curvature.

In some examples, the ramp may deform by introducing one or more projecting arms or teeth through the projection forming the ramp. Thus, although the ramp itself may not bend or deflect, the ramp deforms by adding additional ramping elements that have a larger effective angle. In some examples the additional ramp projections may be inserted through the ramp from the locking sled.

As mentioned above, these apparatuses may be used for any method, system or apparatus that may benefit from a tamper-resistant strap or band. For example, the apparatuses and methods described herein may be useful for securing a tracking and/or monitoring device to a subject (e.g., a patient) including a psychiatric patient, a penal subject, etc. These methods and apparatuses (e.g., devices, systems) can be used for coupling a tracking and/or monitoring device in any appropriate setting, including hospital ward, managed care facility, psychiatric ward, etc. these apparatuses may be used in a care setting and/or a residential setting, for example, for monitoring subjects with dementia, subjects who are intellectually and developmentally disabled (IDD), etc.

Any of the apparatuses described herein may be configured to include or be used with one or more monitoring and/or tracking components. See, e.g., U.S. Pat. No. 10,896,590, U.S. patent application publication no. U.S. 2021/0166544 and PCT/US2020/050548, herein incorporated by reference in their entirety. In any of these apparatuses, the apparatus may include an integrated tracking and/or monitoring device within, e.g., the irreversibly locking clasp. For example, the clasp may include a housing or chamber enclosing the tracking and/or monitoring components, including power (e.g., battery), control circuitry, wireless circuitry, and the like.

In any of these examples, the apparatus may include a patient identification tag that uses low energy Bluetooth technology. For example, a patient identification tag may include a body portion that is attached to the strap (or alternatively the clasp may for the body portion), The clasp and/or a separate body portion may include a Bluetooth low energy (BLE) RFID beacon device that can transmit a signal (e.g., a signal having a 360° range of about 10 to 20 feet from the device in some non-limiting examples). A battery and battery holder may also be included. The battery may be electrically connected to a BLE RFID beacon portion. Thus, in some examples the apparatus may include a patient identification tag that is integrated into the clasp, including integrated into a specific chamber within the clasp. For example the clasp may include (in the outer housing cover or within an inner anchor within the housing cover) a chamber holding a Bluetooth low energy circuit board for use as a patient identification tag; a flexible active circuit board may include a transmission component.

In general, any of these apparatuses may include a clasp that has more than one ramp/sled feature. For example an apparatus may include two ramp/sled features instead of one (as described above), which may allow for infinite adjustment from both ends using an infinite band or two entirely separate bands. Thus, these apparatuses may be configured as a bi-clasp.

FIGS. 14A and 14B illustrate another example of a tamper-resistant wearable band 1400, according to some examples. The tamper-resistant wearable band 1400 may include an irreversibly locking clasp 1410 and a strap 1420. The clasp 1410 may include an outer housing cover 1411, a locking sled 1412 and a strap anchor (not visible in FIG. 14A), The strap 1420 may include a first end and a second end. In FIG. 14A, the tamper-resistant wearable band 1400 is shown with the locking sled in a first configuration, not fully engaged with the outer housing, so that the second end of the strap 1422 can be moved relative to the clasps, to enlarge or reduce the diameter of the loop of the strap. Thus, the device may be freely tightened or loosened. Once the strap size is positioned at the desired diameter, the locking sled 1412 may be driven fully into the housing 1411 and locked in place, securing the strap, As shown in FIG. 14B. The portion of the second end of the strap 1422 extending out of the clasp may be cut or trimmed.

In this example, similar to that shown in FIGS. 10-13, the internal ramp is formed as part of an inner anchor (or inner anchor member) and has an angle of between about 30 and 45 degrees.

FIGS. 15A-15D illustrate the components of the irreversible locking clasp of FIGS. 14A-14B. For example, FIG. 15A shows an exploded view with the component parts disassembled, including an outer housing cover 1411 having a first open end 1433, an inner anchor 1410 and a locking sled 1412. FIG. 15B shows a slightly enlarged perspective view of the outer housing. In this example the outer housing is single piece that includes a smooth outer surface and an inner surface that may include one or more engagement surfaces for engaging and retaining either or both the inner anchor and the locking sled.

FIG. 15C shows an enlarged perspective view of the inner anchor member 1410. In this example the inner anchor includes a ramp having a first ramp angle and a strap retaining or anchoring bar 1442. The inner anchor member 1410 also includes a set of teeth 1630 that are positioned opposite from the ramp. When the inner anchor member is secured within the outer housing cover 1411 the ramp faces the second end opening and the teeth face away from the second end opening. The inner anchor member 1410 may also include one or more securements for engaging with the inner region of the housing cover. In any of these examples the apparatus also includes one or more attachments 1535 for securing to the locking sled 1412, in order to lock the locking sled in position when it is fully inserted into the outer housing cover 1411.

In the example shown in FIG. 15C the inner anchor integrates the teeth, ramp and anchoring bar; in some examples these features may be separate from each other (e.g., the inner anchor may be two or more separate or separable components. The inner anchor, and in particular the teeth 1630 may be formed of a metal and/or polymeric material that is relatively rigid. In the example shown in FIGS. 14A-14B and 15C, the inner anchor including the ramp, teeth and anchoring bar are formed of a metal such as zinc. In this example, zinc is particularly advantageous because it cannot hold an edge, but has otherwise desirable mechanical properties. The inability of zinc to maintain a sharp edge may be particularly useful for devices that are to be used in a carceral setting.

FIG. 15D shows an example of a locking sled as described herein. In FIG. 15D the locking sled 1412 includes a second ramp 1551, as well as an opening 1553 through which the strap may be passed. The locking sled may also include one or more gears 1561 that may engage with a rack or other structure within the outer housing cover to prevent the locking sled from withdrawing from the outer housing cover. In any of these examples the clasp is configured so that the strap may be held (by friction) within the clasp but may be adjusted to increase or decrease the loop size of the strap. A minimal amount of friction may hold the strap relative to the clasp while still allowing it to be adjusted by the application of minimal force. In the examples shown in FIGS. 14A-14B and 15A-15D the path taken by the strap through the inner anchor member and over and through the lock sled 1553 provides sufficient resistance (frictional resistance) to movement of the strap to prevent slipping, but allows for relatively easy readjustment of the strap.

FIGS. 16A-16B show a section through the apparatus of FIGS. 14A and 14B, respectively. In this example the apparatus includes the flexible strap 1420 having a first end 1421 and a second end 1422 that are secure by the irreversibly locking clasp. The irreversibly locking clasp includes an outer housing cover 1411 that is open at a first open end 1433 and a second open end 1434. The first end of the strap is attached to an inner anchor (e.g., to an anchoring bar 1442 of the inner anchor) and held within the outer housing cover. In this example the inner anchor also includes a ramp 1611 having a first angle 1635 forming a first path 1610 for the strap through the clasp. In the unengaged configuration the path 1610 allows the strap to pass freely and continuously through the clasp, including through an opening of the locking sled 1412. The locking sled 1412 is coupled to the outer housing cover 1411