AU2015227481B2 - Compression belt system for use with chest compression devices - Google Patents

Abstract

COMPRESSION BELT SYSTEM FOR USE WITH CHEST COMPRESSION DEVICES Abstract The invention concerns a system for performing chest compressions on a patient, said system comprising: a housing (6); a drive spool (42) operably attached to the housing (6), the drive spool (42) including a key shaped aperture; a belt (3) suitable for compressing the chest of the patient; a motor for rotating the drive spool (42), the motor disposed within the housing (6) and operably attached to the drive spool (42); and a key (66) for removably securing the belt (3) to the drive spool (42), the key (66) shaped to securely engage the drive spool aperture.

Description

2015227481 17 Sep 2015 1

Compression Belt System for Use with Chest Compression Devices . Held .of theJnvsiitions

The inventions described below relate to emergency medical, devices and methods and die res uscitation of cardiac arrest patients.

Cardiopulmonary resuscitation (CPR) is a well-known and valuable method of first aid used to resuscitate people who have suffered from cardiac arrest. CPR requires repetitive chest compressions to squeeze the heart and the thoracic cavity to pump blood through the body. Artificial respirati on, s uch as moath-to-mouth breathing or a bag mask apparatus, is used to supply air to the. Iuugs. When a first did ptovidei performs manual client compression effectively, blood flow in the body is about 25% to 50% of normal blood Sow. However, even experienced paramedics cannot maintain adequate chest compressions for more than a few minutes. Hightower, etai-Decay In Quality Of Chest Compressions Over Time. 26 Aon- Emerg. Med 300 (Sep. 1995), Thus, CPR is not often successful at sustaining or reviving flic patient Nevertheless, if chest compressions could be adequately maintained, then cardiac arrest victims could be sustained for extended periods of time. Occasional reports of extended CPR efforts (45 to 90 minutes) have been reported, with the victims eventually being saved by coronary bypass surgery. See Tovar, et al.( Successful Myocardial Revascularisation and Neurologic Recovery. 22 Texas Heart J. 271 ¢1995).

In efforts to provide better Mood flow and increase the effectiveness of bystander resuscitation efforts, various mechanical devices have been proposed for performing CPR. In one variation of such devices, a belt is placed around tee patient's chest and the belt is used to effect chest compressions. Oar own patents, Molienauer et al, Resuscitation device having, arootoc driven beitio constricr/comtiress the chest. U.S. Patent 6,142,962 (Nov, 7, 2000); Sherman, et aL, CPR Assist Device with Pressure Bladder Feedback. U.S. Patent 6,616,620 (Sep. 9,2003); Sherman et al., Modular CPR assist device. U.S. Patent 6,066,106 (May 23, 2000); and Sherman et at. Modular CPR assist device. U.S. Patent 6,398,745 (jrun, 4, .2002), and our application 09/866,377 filed os May 25, 2001, show chest compression devices teat compress a patient’s chest with a belt. Each of these patents is hereby incorporated by reference in their entirety.

Since seconds count during an emergency, any CPR device should be easy to use and facilitate rapid deployment of the device on the patient. Our own devices are easy to deploy quiddy and do increase the patient’s chances of survival. Nevertheless, a novel compression belt cartridge has been designed to facilitate deployment, use aid maintenance of chest compression devices. 2 2015227481 17 Sep 2015

Object

It is the object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages, or at least provide a useful alternative.

Summary

Accordingly, the present invention provides a system for performing chest compressions on a patient, said system comprising: a housing; a drive spool operably attached to the housing, the drive spool including a key shaped aperture; a belt suitable for compressing the chest of the patient; a motor for rotating the drive spool, the motor disposed within the housing and operably attached to the drive spool; and a key for removably securing the belt to the drive spool, the key shaped to securely engage the drive spool aperture.

There is also disclosed herein a method of performing chest compressions on a patient, said method comprising the steps of: providing a system for performing chest compressions comprising: a housing; a drive spool operably attached to the housing; a means for rotating the drive spool, said means for rotating disposed within the housing and operably attached to the drive spool; a compression belt cartridge comprising: a belt removably attached to the drive spool, the belt suitable for compressing the chest of the patient, the belt having a first portion and a second portion; a first liner sleeve disposed around the first portion of the belt, the first liner sleeve attached to the first portion of the belt; a second liner sleeve disposed around the second portion of the belt, the second liner sleeve attached to the second portion of the belt; a compression pad attached to the first portion of the belt and disposed within the first liner sleeve;

AH26(10492047_1):MSL 3 2015227481 17 Sep 2015 placing the patient on the housing; wrapping the first and second portions of the belt at least partially around the chest of the patient such that the belt is capable of compressing the chest of the patient; and rotating the drive spool to tighten the belt to compress the chest.

The devices and methods shown below provide for a belt cartridge for use in devices that perform chest compressions. The cartridge has a belt, a compression pad attached to the belt, a cover plate through which the belt is threaded, a belt spline for attaching the belt to a drive spool of a belt drive platform, and belt guards rotatably attached to the cover plate. During use, the cover plate and belt guides are removably attached to the housing of the belt drive platform. In turn, the belt extends out of the housing and is secured around the patient.

The belt itself is a single band of material that has a non-uniform width. The belt has two portions, with each portion of the belt having shared pull-straps that are narrow, a load direction section that is wide and a trapezoid-shaped transition section between the pull straps and load distribution sections. The transition sections of the belt are provided with reinforcing plates that strengthen the belt. The load distribution sections of the belt are provided with hook and loop fasteners so that the belt can be secured around the patient. In addition, a peg in the center of one load distribution section fits into a corresponding eyelet in the other load distribution section, thereby providing a means for registering the belt with the center of the patient’s sternum. The compression pad is disposed beneath the load distribution sections and facilitates chest compression.

The cover plate is provided with curved extensions such that the belt cartridge fits within only selected belt drive platforms. The cover plate is also provided with snap latches and hooks so that the cover plate attaches securely to the belt drive platform in a pre-determined orientation. Crossbars and reinforcing beams are provided to the cover plate so that cover plate may be made from a thin, lightweight plate of plastic. The entire chest compression cartridge is low cost, lightweight and disposable.

The belt cartridge is attached to the belt drive platform via the cartridge cover plate. The belt itself is attached to a drive spool via a belt spline. The belt spline fits into a slot provided in the drive spool. The spline is provided with bosses or catches and the slot is provided with a corresponding shape so that the spline fits securely into the slot. A guide plate disposed around

AH26(10492047_1):MSL 4 2015227481 17 Sep 2015 one end of the drive spool slot serves as a guide for inserting the spline. After the spline is inserted into the slot, the guide plate is adjusted to further secure the spline within the slot.

Once the spline and belt are secured to the drive spool, the cover plate is attached to the housing of the belt drive platform.

Snap latches and hooks provided on the cover plate fit into corresponding detents and apertures in the housing of the belt drive platform so that the cover plate is secured to the housing. Belt guards disposed on the lateral ends of the cover plate are then closed around spindles disposed on the belt drive platform. The belt guards further secure the cover plate to the belt drive platform and protect the patient, rescuer and belt during use. In addition to the belt guards, labels are provided on the housing, cover plate and belt to indicate to the user the correct method of attaching the cartridge to the belt drive platform and on the correct method of wrapping the belt around the patient.

The safety mechanisms include a breakable link, liner socks, belt guards and a rapid-release connector. The breakable link is attached near the transition section of the belt. The breakable link prevents an unsafe amount of tension from developing in the belt by breaking at a pre-selected load threshold. The liner socks protect the patient from friction and contain the breathable link. The liner socks cover the belt so that the belt slides against the liner socks and not against the patient. If the link breaks, then the link remains inside a sock. The belt guards protect foreign objects from entering the belt drive platform. Thus, articles of clothing, tools, fingers, other body parts, or other foreign objects are less likely to interface with the belt drive platform. Similarly, the patient and rescuer are less likely to be injured by the device since the belt guards protect the moving parts of the belt drive platform. The rapid-release connector allows the belt to be removed safely even during compressions. The rapid release connector is placed on the load distribution sections of the belt. The connector is a combination of hook and loop fasteners and a peg disposed within an eyelet.

Brief Description of the Drawings

Preferred embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings wherein:

Figure 1 shows the chest compression belt fitted on a patient.

AH26(10492047_1):MSL 5 2015227481 17 Sep 2015

Figure 2 shows a bottom view of a chest compression device that uses a belt to perform compressions.

Figure 3 shows a top (anterior) view of a belt cartridge used with a belt drive platform.

Figure 4 shows a bottom (posterior) view of a belt cartridge used with the belt drive platform.

Figure 5 shows a superior view of a belt cartridge used with the belt drive platform.

Figure 6 shows the belt used in the belt cartridge of Figures 3 through 5.

Figure 7 shows a close-up view of the cover plate used in the belt cartridge of Figures 3 through 5.

Figure 8 illustrates a method of attaching the compression belt to the drive spool.

Figure 9 shows a close-up view of the spline, the belt and the drive spool.

Figure 10 illustrates a method of attaching the belt cartridge to the belt drive platform.

Figure 11 illustrates a method of attaching a belt guard to a spindle of the belt drive platform.

Figure 12 shows a close-up view of the compression belt cartridge.

Figure 13 shows a cross-section of the belt, liner socks and breakable link.

Figure 14 shows the belt attached to the breakable link.

AH26(10492047_1):MSL 2015227481 17 Sep 2015 6 figure 15 shows another cross-section of the breakable Sink.

Detailed Descriptionofthc inventions

Figure 1 shows the chest compression' belt fittest! on a patient l A chest compression device 2 applies compressions with the belt 3» which has a right belt portion 3R and a left belt portion 3L, The chest compression device 2 iudutks a belt drive platform 4 and a compression belt cartridge 5 (which includes the beli). The belt drive platform includes a housing δ upon which the patient rests, a means for tightening the belt, a processor and a user interface disposed on the housing. The means for tightening the belt includes a motor, a drive train (dutch, brake rnid/or gear box) and a drive spool upon which the belt spools during use. Various other mechanisms may be used to tighten rite belt, including the mechanisms shown in Laeh et a!., Resuscitation Method atirfAtiparatus· U.S. Patent 4,774,1.60 (Sep. 13,198S) and in Kelly et ah, Chest Compression Apparatus for Cardiac Arrest. U.S. patent 5,738,637 (Apr, 14,1998), The entirety of these patents is hereby incorporated by reference.

In vise, the patient is placed on the housing and the belt is placed under the patient’s axilla (armpits), wrapped around the patient's chest, and secured. The means for tightening the belt then tightens the belt repedtiyely to perform chest compressions,

The compression belt 3 shown in Figure i is provided with a structure that aids in performing compressions effectively and efficiently. Specifically, the belt is shaped like a dottble-Waded oar.

The wider load distribution sections Ιέ and 17 of the belt are secured to each other over the patient’s chest and apply the bulk of the compressive load during use. The narrow pall straps 18 aid 19 of the belt are spooled onto the drive spool of die belt drive platform to tighten the belt during use. The vraperoi d-shaped transition sections 26 and 21 reinforce the belt and transfer force from the pull straps to the load distribution sections evenly across the width of the load distribution sections. The narrow end of a trapezoid faces the pull strap and the wide end of a trapezoid faces a corresponding load distribution section.

The pull straps 18 aad 19 of the belt are narrow so that the chest compression device may perform compressions more efficiently, thus saving battery power and prolonging the ability of the device to perform compressions. The narrow pull straps of the belt reduce the mass of the belt aud reduce the torque necessary to tighten the belt around the patient's chest, particularly when the mesas for tightening the belt tightens the belt by spooling it around a drive spool. In addition, by using narrow pull straps, the belt may fit within a narrow channel beam in the belt drive platform. This reduces the weight and size of the belt drive platform and increases die strength of the platform by allowing a narrower channel beam (see item 45 of Figure 2) to be used with the platform.

The load distribution sections 16 and 17 of the belt are wider than the puli straps to allow the chest compression device to perform compressions mote effectively and more safely. The wider portions of the belt compress more cf the chest, increasing blood flow and thus performing 2015227481 17 Sep 2015 7 compressions more effectively, la addition, the wider portions of the belt allow more force to be applied to the patten! by evenly distributing pressure on the patient's chest, thus increasing blood flow while making chest compressions safer for the patient.

The transition sections 20 and 21 of (he belt transfer the tension from the pull snaps to the load distribution sections and reinforce the belt Thus, the transition sections narrow along the lateral portioned'the belt

The right load distribution section 16 and left load distribution section 17 of the belt are provided with hook and loop fasteners so that the belt may be secured to the patient's chest (Securing the right and left load distribution sections to each other secures tile belt around the patient’s chest) Preferably, the hook side of the book and loop fastener Is located on the anterior load distribution section cf the belt (in this illustration, the left side Is anterior to and superficial to the right load distribution section) so that the hooks do cot contact carpet or other materials when the belt Is open and splayed on the ground, though the hook and loop fasteners may be located anywhere on the load distribution sections of the bel t. A handle 32 (more clearly shown in Figure 2) is provided on the left end of the belt to aid in placing and removing tire belt. The handle and user interface arc located on the same side of the belt drive platform to make applying and removing the belt an ergonomic motion.

An eyelet 33 is provided in the left bad distribution section of the belt and a corresponding registration peg 34 is provided in the right load distribution section of the belt (The peg, cyciet and hook and loop fasteners may be disposed on either load distribution section.) To secure the belt to the patient, tire left load distribution section is l aid over the right load distribution section and the eyelet is aligned with the peg. (The peg fits within the eyelet.) The eyelet and peg assist the rescuer to properly register the load distribution sections with respect to each other and die patient, and thereby properly position the belt on the patient The eyelet and peg ate also long relative to the superior/iftferior direction of die patient and are located in the center of Use assembled load distribution sections. Thus, the eyelet and peg help the rescuer place the center of the load distribution sections over the center of the patient’s sternum, to addition, since the right and left load distribution sections tend to pull away from each other when the belt is tensioned, the peg and eyelet further secure the load distribution sections of the belt to each other by resisting shear forces that tend to pull the sections apart.

In addition, the peg and eyelet enable the mater to repentably release the belt and then secure the belt around die patient such that the belt has tile same length each time the belt is secured around the patient (During use the rescuer may need to release the belt and re-secure the belt around the patient without replacing the cartridge.) Since the belt maintains the same length, the chest 2015227481 17 Sep 2015 8 compression device is mud more likely to achieve the same depth of chest compressions after the belt has been re-secured as compared to before the belt has been re-secured.

The combination of hook and loop fasteners and die eyeletipeg fastener provides for a means for securing the belt aioimd the patient The same combination allows a rescuer to rapidly gad easily release the belt The rescuer may release the belt, even during compressions, by grasping the left end of the belt and lifting the left load distribution section ftom the right load distribution section. Tims, the securing mechanism is also an emergency release mechanism. To further enhance safety, the eyelet may be provided with an electrical contact switch, optical sensor or other electrical or mechanical means for determining whether tire peg is inserted into the eyelet. Thus, a ehest compression device with the appropriate software or hardware can sense whether the peg is frilly inserted into the eyelet. If the peg is not in the eyelet, then the chest compression device will not perform compressions. The system will alert the operator if proper registration is not detected so that the operator may re-fit the belt

Figure 2 shows a bottom view of the belt drive platform 4 and shows the housing 6, a bell: cartridge 5 attached to the housing and a means for tightening the belt disposed within the belt drive platform. The means tor tightening the belt may comprise a drive sped 42 attached to the belt and to a motor. The dri ve spool is shown in phantom to indicate its position beneath the cover plate. The motor and associated components are located within the belt drive pisiform.

The belt drive platform is provided with a control system that controls how the bell is wrapped around the drive spool For example^ the drive spool is controlled so that some of the belt is left wrapped around the drive spool between compressions. When the means for tightening has loosened tire belt around the patient, just before beginning the next compression, a length of the belt corresponding to one revolution of the drive spool is left wrapped around the drive spool. Thus, the belt will maintain its curled shape, reducing the chance of causing folds in the belt during compressions and increasing the efficiency of spooling the belt around fire drive spool.

The housing serves as a support for the patient. Handles 43 provide for easy transport of the housing and of the patient while on the housing. The belt cartridge has a cover plate 44 that fits within a channel beam 45 in the belt drive platform, thus securing (be belt cartridge 41 to the belt drive platform 4. Labels 46 ate placed on the housing and cover plate to indicate the proper alignment of the cover plate. The cover plate is secured to and aligned within the channel beam by the use of retainer dips or snap latches 47,48,49 and 50 which fit between corresponding paired bosses or detents in the housing. Tabs integrally formed with the snap latches extend into slots disposed in the housing of the belt drive platform. The cover plate is also aligned and secured within the channel beam by the ase c£ hooks 51,52,53 and 54 which fit into corresponding apertures in the 2015227481 17 Sep 2015 9 housing. I» addition, (he cover plate is also provided with additional labeling 55 to provide warnings, manufacturer infomtation, trademarks or advertising.

Figures 3, 4 and 5 show the Mi cartridge 41, The Mi cartridge is disposable so that there is no need to dean the belt, or other elements of die cartridge, after use. Thus, the belt cartridge reduces the exposure of subsequent patients and users to bodily fluids or other contaminants. If necessary, die cartridge may be replaced while the patient is still on the belt drive platform, in addition, since the belt cartridge is disposable the belt may be made of materials that readily conform to the shape of an individual patient, bat have a shorter service life.

The cartridge includes a belt 3, a compression pad 65 attached to the belt, a belt dip, key or spline 66 for attaching the belt to a drive spool, a cover plate 44 and belt guards 67 and 68 rotatably attached to the cover plate via hinges 69 and 70. The belt guards are removably secured over spindles that arc attached to the belt drive platform. A liner, sleeve or sock is disposed over the belt, as shown in Figure 5, The belt is threaded through slots 71 and 72 disposed in the belt guards 67 and 68. With regard to the belt 3, die right portion 3R and the left portion 3L of the belt share pull straps IS and 15 and each have a load distribution section 16 and 17 and a transition section 20 and 21. Each load distribution section of the belt Is provided with hook and loop fasteners so that rite belt may be secured around the patient's chest. Additionally, as described above, an eyelet 33 is provided in the left load distribution section and a corresponding peg 34 is provided in the right load distribution section (see Figure 5). Preferably, the puli strap sections comprise a single strap.

The pud straps of the belt are secured to the dri ve spool of the belt drive platform with the spline 66, which is attached to the pull straps of the belt. The spline fits within a slot provided in the drive spool. When the drive spool rotates, the pull straps spool around the drive spool. The compression belt then tightens and is pulled onto the patient’s chest, thereby accomplishing compressions.

The puli straps 18 and 19 of the belt are threaded through the belt guards 67 and 68 which are rotatably attached to the cover plate 44. The belt guards and cover plate are fashioned from a lightweight but strong plastic. The cover plate and belt guards are designed to allow the belt cartridge to be removably attached to die belt drive platform and to protect die belt during use. Specifically, the cover piate is provided with snap latches 47,48,49 and 50 that fit between corresponding paired basses or detents on the housing. Integral Safe extend from die snap latches and fit into corresponding slots in the housing. The cover plate is aiso provided with hooks 51,52,53 and 54 that fit into corresponding apertures in the bousing of the belt drive platform. The snap latches and hooks are designed so that the cover piate is removably attached to the belt drive platform without the use of tools. The snap latches and hooks may have a variety of shapes and forms. The snap latches and hooks may also be asymmetrical with respect to the cover plate, thus making it possible to lit the 2015227481 17 Sep 2015 10 cover plate on the belt drive platform In only one orientation. To increase the ease of use of die cartridge, the cover plate is provided with labels 46 to indicate the desired orientation of the cover plate with respect to the belt drive platform.

Below the load distribution sections of the belt is a compression pad 65 that affects the distribution of compression force and assists in performing chest compressions. An example of a chest compression pad may be found in oar application 10/192,771, filed July 10,2002. la one embodiment the compress ion pad is a three-sectioned Madder filled with foam. The compression pad is located on the belt so that it is centered over the patient's chest when the belt Is in use, The compression pad is disposed below the load distribution sections of the belt and is removably attached to the belt with double-stick ape, hook and loop fasteners or comparable fastening means. The compression pad is also disposed inside the liner sock.

Additional safety features may be provided wife die compression belt cartridge 41. For example, spreader bars or reinforcing plates S7 tnav be attached to the transition sections of the belt with stitches 88, (The reinforcing plates may be attached to fee transition sections of the belt by any suitable method,) The reinforcing plates reinforce the transition sections of the belt and help prevent the transition and load distribution sections from twisting, bending, folding or otherwise deforming with respect to fee pull straps, except in regard to the ability of the belt to wisp around fee patient's chest. The reinforcing plates are made of a hard plastic or other noa-resilient. though flexible material.

The belt also may be provided with one or more breakable couplings or breakable links 89 on one or both sides of the load distribution or belt transition sections. The breakable link 89 or links are interposed between sequential portions of the belt such that the belt separates if a link breaks. The link is designed to break at a predetermined tension, If the belt experiences an unsafe amount of tension, teen a link breaks, the belt; separates and fee patient is thereby protected from excessive forces. What constitutes an unsafe amount of tension or excessive force varies, depending on tee patient and the device and belt used, but is in the range of about 200 pounds to about 500 pounds as measured in fee area of fee belt to the side of the patient. Preferably, tee link is designed to break under about 300 pounds of tension as measured in fee area of fee belt to the side of fee patient, la addition, the link may be designed to reattach to itself or to a clip or other mating fastener after failure. Thus, in fee event of {ink failure, the belt may be re-attached quickly and compressions may be restarted with minimal delay.

To prevent the load distribution sections from twisting relative to fee other sections of the bel^ the links may be designed to also serve as swivel joints, or the belt may be provided wife additional swivel joints along the belt The swivel joints connect the pull straps to fee belt transition 2015227481 17 Sep 2015 11 sections. The swivel joints aBow (he load distribution sections to twist relative to the pull straps, about the longitudinal axis of the belt, without twisting the pull straps themselves.

Another safety feature is a liner sock 90 for the belt (see Figure 5). The liner sock surrounds the portions of the pull straps , as well as the compression pad, that contact the patient thereby protecting the patient from friction as the belt moves during compressions. The finer socks are attached to the belt guards around the belt guard slots so that hair, otter body parts or other foreign objects cannot become caught in the belt guard slots. On foe other end, foe socks are disposed around and are attached to the load distribution sections of the belt

In use, tire belt spline is inserted into the drive spool of foe belt drive platform. The cover plate of the cartridge U then insetted into the channel beam of foe belt drive platform and fixed into place via the hooks and snap latches. The belt is wrapped around the patient, with foe load distribution sections secured over the patient’s chest Thus, foe chest compression device performs compressions by repetitively tightening the belt.

Figure 6 shows foe belt 3 used in the belt cartridge of Figures 3 through 5. When laid out, the belt has the shape of a double-sided oar or paddle. As descri bed above in reference to Figures 3 through S, foe right portion 3R and the left portion 31. of foe belt each have a load distribution section 16 and 17, a transition section. 20 and 21 and puli straps 18 and 19. The puli straps are narrow with respect to the load distribution sections, The load distribution sections are disposed opposite each other, and each, load distribution section of the belt is provided with hook and loop fasteners 96 so that foe belt may be secured to the patient’s chest. An eyelet 33 is provided in the left load distribution section and a corresponding peg 34 is provided in foe right load distribution section to furfoer secure the belt around the patient. (The peg and eyelet may comprise a variety of shapes and sizes; for example, the peg may be a post and tire eyelet a round grommet) In addition, a spline 66 is attached to the belt by any suitable manner. The spline fits within a slot provided in the drive spool of foe belt drive platform. Thus, when the drive spool rotates, foe puli straps will spool around the drive spool.

The transition sections 20 and 21 of foe belt are disposed opposite each other and are provided with corresponding thin (1/16 inch) reinforcing plates 97 and 9b of flexible plastic that reinforce the belt. (The plates may comprise different materials and may be thicker or thinner, or even of varying thickness, depending on foe material used and foe desired stiffness of foe transition sections; however, plates with a thickness of about 1/4 inch or less are preferred) The reinforcing plates mitigate the effects of stress concentrations in the belt, stress voids in foe belt, belt creasing, belt wadding and other problems caused by using a compression belt that has a non-uniform width. The reinforcing pistes are attached to the transition sections cef the belt and the shape of foe reinforcing plates conforms to foe shape of foe transition sections of foe belt (The reinforcing plates may be attached to the transition sections by any suitable means and may be located above, below or 2015227481 17 Sep 2015 12 within the transition sections.) The reinforcing plates also bend to conform to the shape of the patient’s torso Airing compressions. As the plates bend around the patient, the heading stiffness of the plates along the other axes of the piates increases. To provide smooth compressions along the patient’s chest, one or more edges cf the reinforcing piates may be bent outwards and away from the patient (like ski tips)..

The belt material of the pull straps, the load distribution sections and the transition sections to a constant thickness of about 0.010 indies and is made of a custom, fiber-reiuforced material that can be manufactured by a number of belt manufacturers. Our belt is a material made from unidirectional layers of high-strength fibers held together with a resin. (The fibers are Spectra 2000 fibers available from Allied Signal!, Inc., but raay also be carbon, Kevlar™ and other fibers.) Our custom belts do not stretch or break under heavy loads, and are resistant to bodily fluids, aging, humidity and temperature.

The belt may also be made of a flat metal or rounded metallic cable, nylon, sail cloth or other strong and flexible materials. The belt material may also include layers of additional materials such m Tyvek™ (high-density, spun bonded polyethylene) or Teflon™ (polytetrafluoroethykne) directly bonded to the primary belt material.

The custom belts used with the belt cartridge have 4 laminated layers if fibers oriented at 0, 90,6 and -£» degree angles with respect to the long axis of the belt Placing at least some of the layers obliquely with respect to the long axis df the belt improves belt performance and longevity. The resin holding the fibers together is about 60¾ to 70% of the volume of die material. An additional layer is laminated on tea outside of the belt to improve water resistance and lessen friction during use. A belt designed with laminated fibers at different orientations with respect to the long axis of the bell is less likely to stretch during compressions. The above belt has an average stiffness of about 77,000 pounds per inch per one-inch length, of belt, as measured along the longitudinal axis of the belt, and thus dees not si retch during compressions.

The belt (or cable) may be pre-conditioned before distribution or sale. The cartridge and belt may be disposed on a test platform and the cartridge and belt tested before being sold. This process pie-conditions the belt Pre-conditioning the belt deforms the belt to tile shape of the spool shaft, which allows for more efficient spooling of the belt during compressions, Preconditioning also helps prevent Site belt from deforming during use. Thus, preconditi oned belts will perform consistently during use. In addition, the belt is at least partially spooled around the drive spool during storage so that the pull straps are set to tire shape of the drive spool prior to use.

The overall belt and belt cartridge are sired and dimensioned to be used with. 95% of all body sizes. (Only extremely small or large patients may have difficulty benefiting from a device that includes the compression belt cartridge.) The pull stops are about 2 Inches wide (along the superior- 2015227481 17 Sep 2015 13 inferior dimension of fee patient, as indicated by the direction of arrows 99} and about 40 inches long (along fee medial-lateral dimension of fee patient, as indicated by the direction of arrows .100). The load distribution sections of thus belt are about 8 inches wide and about 12 inches long. The transition sections of the belt are about 6 inches long and taper gradually between fee pull straps and a load distribution section; tiros, the transitioa sections haw a trapezoidal shape. AH sections of fee belt material ha ve a constant thickness of about 0.010 laches, with a tolerance of 0.001 indies. The belt may be thinner to reduce the wei ght of fee cartridge and the overall device, though the belt may be as thick as 0,23 indies, B ecause fee bel t is thin, fee overall weight of a compression device is kept to a minimum. Using a thin belt also spools less material onto a drive spool during use. This reduces fee overall diameter of the drive spool plus belt material, thereby reducing fee amount of torque necessary to operate fee ches t compression device. Thus, using a thin belt also saves energy, thereby increasing fee life of a battery used to power a chest compression device.

Figure 7 shows a close-up view of fee cover plate 44 used in fee belt cartridge of Figures 3 through 5. As already described, fee cover plate is designed to allow fee belt cartridge to be removably attached to the belt drive platform and to protect the belt during use. Specifically, fee cover plate is provided with books SI and 52 thatfrt within apertures provided in the housing. The cover plate is also provided with soup latches 47 and 4S which fit securely between corresponding paired bosses or detents feat extend from slots disposed in the housing. Tabs Integrally formed with the snap latches extend into the slots when fee cover plate is secured to the housing.

To reduce weight, the cover plate is fashioned from a thin plate of plastic. To increase strength, the cover plate is provided with intersecting reinforcing ribs 106 (also shown in Figure 3) feat reinforce fee cover plate and help the cover plate to resist the force of compressions. Additional aluminum reinforcement braces 187 (also shown in Figure 3) are provided to further reinforce the cover plate. The reinforcement braces span fee height of fee cover plate to provide the cover plate with additional strength. The reinforcement braces also brace fee channel beam, thereby protecting the belt drive platform from deforming under high forces.

The cover plate is provided with opposing curved extensions 188 and 189 so feat fee cover plate fits precisely wife!» fee belt drive platform. The curved extensions, as well as fee overall size and dimensions of the cover plate, prevent the belt cartridge from bang used with devices not designed to receive the belt cartridge. Thus, fee cover plate also helps ensure that the cartridge will be used safely.

Rotatably attached to fee curved extensions of fee cover piste me belt guards 67 and 68 that protect the user, belt drive pkiform and belt, when fee chest compression device is in use The belt guards are removably secured around the spindles during use. The belt guards are Wider than the belt, 2015227481 17 Sep 2015 14 and the pell straps are threaded through slots 71 and 72 disposed in die belt guards. Thus, during use, the belt slides within the belt guards and over the spindles* The spindles, ia him, rotate within the belt drive platform. The spindles also rotate underneath the belt guards, sliding against the belt guards where the belt guards are disposed against the spindles.

On each end of the cover plate, fingers or pawls 110 and 111 hook around corresponding catches or ratchets 112 and 113, The ratchets are attached to corresponding lunges 69 and 70, though may be attached to the corresponding belt guards. The pawls are attached to the cover plate and prevent the belt guards from curling away from the cover plate. However, a user may (preferably without tools) apply a force sufficient to pull the ratchets away from the pawls as fits hinges rotate, thereby allowing belt guards more freedom to rotate outwardly, away from the cover plate. The user may also re-engage the pawl and ratchet so that die belt gaards are once again prevented from curling outwardly.

The various components of the belt cartridge may be differently oriented with respect to each other. For example, die compression pad may be disposed beneath die liner sock instead of inside the l iner sock. In other embodiments, if the geometry of the belt drive platform changes, then the compression belt cartridge may be changed accordingly. For example, if the drive spool is located to one side of the belt drive platform, then the spline would be located outside die belt guards (instead of between them) and tile rest of the cartridge would be adjusted to fit to die housing and belt drive platform. The belt may have other shapes; for example, the belt may have more than one narrow region. (If the belt drive platform uses more than one drive spool then the belt may have more than one set of pull straps.) In addition, other means for tightening the belt may be used, such as multiple motors and drive spools, pistons, scissors mechanisms or other mechanical actuators.

Figures 8 through 11 illustrate devices and methods for operabty inserting the beit cartridge into the housing of the belt drive platform. Figure 8 illustrates a user 124 inserting the belt spline 66 into the slot 125 in tire drive spool 42, The user sets aside the cover plate 44 and inserts toe front end 127 of the spline into the drive spool slot 125 in the direction indicated by arrow 128. The user then fits the back end 129 of the spline into s guide slot 130 disposed in a guide plate 131, which serves to farther secure (he spline in place, and secures rise back end of the spline Into the drive spool slot. The user (hen secures the cover plate over the channel beam 45. After securing the cover plate in the channel beam, the belt guards 67 and 6S attach to opposing rods, tollers or spindles 132 fixed to the s ides of the belt drive platform. The spindles decrease friction as die belt travels along the spindles.

Figure 9 shows a ctoae-up view of the spline 66, the guide plate 131 and the drive spool slot 125, The spline is provided with a particul ar shape so that the spline wSi fit more securely within the drive spool slot. The shape of the spline also discourages the use of splines not designed by the 2015227481 17 Sep 2015 15 manufacturer and discourages placement of the spike b an incorrect orientation. Thus, the spline is keyed to the drive spool slot.

Specifically, the spline 6<5 b provided in the form of a rectangular rod or bar made of a bard plastic or a metal. The front end 127 of the spline is provided with a protruding foot, boss or catch 143 shaped to fit into the front end 144 of the drive spool slot likewise, the hack end 129 of the spline is provided with a second protruding foot, boss or catch 145 shaped to fit into the bade end 14$ of the drive spool slot (The spline may have other shapes to accommodate differently shaped slots in the drive spool,)

The drive spool slot is provided with corresponding recesses 147 and 148 to accommodate the front and back catches on the spline respectively, Thus, tire spline resembles a key and can function In a similar manner with respect to the use of the died: compression device. In addition to the catches, slots and recesses shown, the spline is further held in place with one or mote detents in the belt drive platform that engage the front or back catches on the spike. The detents also servo a® catches inside the belt drive platform that prevent die drive spool from relating when the spline is not inserted in Ore drive spool slot Thus, the device will not operate unless the spline is correctly inserted into the drive spool slot. In addition, dhe float end of die spline engages an electromechanical switch when inserted into the slot When the spline engages toe switch, a signal is generated (or interrupted) that informs the control system that the clip is present and properly engaged. Additionally, the belt drive platform may be provided with hardware or software that detects whether tire spline is correctly inserted and informs the user of incorrect insertion and prompts the user to re-insert the spline if the spline is not correctly inserted.

The spline, coyer plate or belt drive platform may be provided with a means for ensuring that a particular compression belt cartridge will only be used once (that is, used on only one patient during one rescue attempt). For example, the spline may be provided with a breakaway or deformable tab that, on insertion into die drive spool slot, renders rite spline unusable after the spline has been removed from the spool shaft slot Additionally, the spline may have a means for identifying whether the spline was produced by an approved manufacturer or whether the spline previously had been attached to the drive spool slot of a belt drive platform. Pent example, an RF identification tag or other wireless communication mechanism could be attached to the spline, wherein rite RF tag transmits data corresponding to a unique identifying number. A magnetic strip may also be attached to the spline that stores a unique identifying number. A given belt drive platform will operate only if the identifying number corresponds to a number provided to the platform by the manufacturer and only if that number has not been used with the belt drive platform in tbs past If fire belt drive platform is connected to a network, then any belt drive platform connected to the network may be programmed to recognize when a particular belt cartridge has been used with any other belt drive platform. 2015227481 17 Sep 2015 16

Moreover, the belt drive platform may be programmed to alter the Identifying number on the spline, thereby rendering the cartridge unusable with any other belt drive platform. If this feature is implemented, the belt drive platform may be accompanied by an over-ride feature that allows a used cartridge to be used again. Thus, In the unusual situation where multiple heart attack victims are encountered or where a used cartridge is die only available cartridge, the cartridge may be used again.

To further secure the spline within the drive spool slot, a collar or guide plate 13! is provided around one or both ends of the drive spool 42. The guide plats is provided with a guide plate slot 139 through which the back end of the spline is inserted. After the spline is inserted, the guide plate is adjustable to firtniy secure the spline within the drive spool slot, A user may manually move tee guide plate sufficiently to insert the spline into and remove tee spline front tee slot,

The guide plate may ire spring loaded mid pushed into tee wall of the. channel beam to make room for inserting the spline, or the guide plate may be rotated (or rotated and pushed) to secure the back end of the spline within the drive spool slot If tee guide plate is spring loaded, the spring comprises a means for providing a biasing force to tee guide plate; however, other means for biasing the guide plate may be used, such as a flexible tab. In any case, tee guide plate may be disposed in relation to the drive spool such that the spline may not be inserted into or removed from tee drive spool slot unless tee guide plate or the drive spool is moved. This ensures that the spline will remain secured to the drive spool during use and during storage (while the drive spool is rotating and while the drive spool is stationary).

In use, tee spline is inserted into the drive spool slot as shown by arrows 149 and ISO. When the drive spool rotates, the belt 3 wraps or spools around the drive spool, thereby tightening tee belt As the belt is tightened the patient’s chest Is compressed. The patient’s chest is decompressed as tee drive spool rotates in the opposite direction, thereby allowing the belt to unwind and relax. After use, the process of inserting tee belt may be reversed to detach tee belt cartridge from tee belt drive platform. Tims, the belt cartridge may be replaced after each vise of the belt drive platform. Preferably, all of the attachment mechanisms are releasable, as described above, so that the operator can replace the belt without the use of special tools.

Figure 10 illustrates a method of attaching tee belt cartridge to tee housing of tee belt drive platform. The belt cartridge cover piste 44 is attached to the channel (established by beam 45) in tee belt drive platform. Labels 46 allow tee user to easily align the cover plate within tee channel beam. Hooks S3 on the cover plate fit into corresponding apertures 158 in tee belt drive platform. Belt guards ¢7 are removably disposed around spindles 132. (The spindle is shown in phantom to indicate its position underneath the belt guard and within the belt drive platform). In addition, snap latches 47 fit within paired detents teat extend from tee edges of slots 159 in tee belt drive platform. Tabs extending from tee snap latches fit within tee slots themselves. 2015227481 17 Sep 2015 17

The labels include an arrow 160 disposed in a recess 161 in the belt drive platform and an arrow 162 disposed in a recess 163 on the cover plate 44, The cover plate is correctly aligned within the channel beam when the arrow on the belt drive platform is pointing at the arrow cat the cover plate. The hooks and snap latches on the cover plate then fit within corresponding apertures and slots within the belt drive platform.

The snap latches are designed so that an audible elide is heard when a snap latch is fully inserted into a corresponding slot. The snap latches may be designed so that they bend as they fit between die detente. When fully inserted, a flange on the end of the snap latch slips with respect to the detents, making an audible click when the flange strikes the edge of the slot. In addition, the hooks and snap latches may bo aligned so that the belt cartridge only fits in one orientation with respect to the belt drive platform. For example, the snap latches or hooks may he spaced asymmetrically with respect to cover plate so that if the cover plate is incorrectly oriented die cover plate will not fit into the channel beam.

Figures 11 shows s method of attaching a belt guard 68 to a spindle 132 of the belt drive platform 4. The cover plate 44 has already been secured to the belt drive platform, though the hinges 76 allow the belt guard to rotate with respect to the belt drive platform and cover plate. The belt guards are provided wi th a hook-shape so that they securely attach around the spindles 132 fixed to the belt drive platform. The user may secure the belt guards around the spindles, as indicated by arrow 173.

In use, the belt guards protect the patient, rescuer, belt, belt cartridge and belt drive platform. The belt guards prevent foreign objects from entering the belt drive platform and becoming caught in the channel beam. Thus, a user’s fingers or clothes, patient's clothes or body parts, or debris located near the site of emergency cannot enter the belt drive platform and damage the patient, the rescuer or the various parts of either the belt drive platform or the belt cartridge.

Figure 12 shows a dose-up view of the compression belt cartridge 41, Instructions 174 on how to deploy the compression belt cartridge or the belt drive platform are prints! on the outer surface of the belt 3, belt liner, cover plate, compression pad or any other component of the compression belt cartridge. Specifically, indicia including pictorial instructions and written instructions (including Braille) show the rescuer how to correctly secure the compression belt around the patient.

Markings 175 on the outside of the belt liner indicate when the belt straps have been twisted. The markings may be lines that are oblique or skew to the longitudinal axis of the belt or belt liner, but may also be areas of solid adorn cm one side of the belt or belt liner, Preferably, less than the entire surface of one side rtf the belt liner is painted or marked. (Excessive ink, dye, transfer or adhesive elements, such as stickers, cause the liner to become too stiff, thereby significantly 2015227481 17 Sep 2015 18 iacreasing the chances that the belt liner will wear prematardy.) The markings 175 may also serve as a means for identifying the manufacturer; for example, the markings may show the manufacturer name or other advertising information.

In addition, markings are provided to show a rescuer how to correctly align fee compression belt and the belt drive platform with the patient. A yellow or other brightly colored orientation line is disposed along the superior edge of the load distribution sections of compression belt, parallel to the longitudinal axis of the compression belt When the compression belt is correctly placed on the patient fee yellow line will line up with the patient’s axilla (armpits). Furthermore, fee yellow line also lines up with a corresponding yellow strip disposed on the housing of the twit drive platform. Thus, a rescuer can easily visual»*© when fee belt and belt drive platform are correctly oriented wife respect to fee patient and to each other, (Other marking schemes may also be used in relation to other anatomical landmarks such that the placement of the orientation lines may be varied.)

Similarly, fee alignment peg or the load distribution section indicates few fee patient should be aligned cm the center of the belt drive platform and that the load distribution sections should be aligned or the center of the patient’s chest. Thus, when the belt is placed correctly, the peg lies over the center of fee patient’s sternum, Preferably, the peg is tong relative to fee superior-inferior direction such thBt the longitudinal axis of the peg lies directly over and parallel to a superior-inferior line in the center of the patient's sternum.

The instructions, alignment arrows and cartridge components are color coded (or otherwise uniquely marked) to be easier to read and understand, or to indicate the purpose of the instructions. For example, fee eyelet 33 and peg 34 are colored yellow (or otherwise uniquely colored or marked) to indicate that they mate. The belt cartridge also may be provided with colored warning or instruction labels 176 (multiple colors and color schemes may be used). Examples of warning or instruction labels include: “Align the armpits onto fee yellow line," “LifeBand straps 90 degrees to platform,” “Do itot cut,” “Do not twist” or “Single patient use do trot reuse,” Bach warning may be assigned a different color, such as ted, blue, Mack and gray.

The devices and methods shown above in reference to the figures may be modified. For example, the spline may be a hemisphere and attach to a corresponding hemisphere on fee drive spool. The slot in the dri ve spool may extend through the drive spool and fee belt threaded through the slot The spline may also be provided with arms feat clip around fee drive spool and thereby secure fee spline to fee drive spool. The spline may be provided wife magnets, a collar, detents or other latching features to ensure feat fee spline remains attached to the drive spool during use. In the case of a magnet, fee wrapped portion of the belt around fee drive spool holds the belt: so place when fee load becomes large. 2015227481 17 Sep 2015 19

The hook and loop fasteners may be replaced with buckles. The cartridge may fee provided with a processor and a speaker, with the processor programmed to gi ve audio instructions to the user, in addition, other means for tightening She bcltmay be used, such as multiple motors and drive spools, pistons, scissors mechanisms or other mechanical actuators,

Similarly, the drive spool or drive spools may have different shapes, if so, then the connection between the pull straps and the drive spool may have to be altered to accommodate the new drive spool shape. For example, &amp; drive spool may have a conical shape and the puli straps replaced with puli cables or with puli straps made of a materia! without resin, hi this case, the belt or cables may be fixedly attached to the drive spool.

Figures 13 through 15 show close-up views of the belt 3, the breakable link 89 and the liner socks 182 and 183 surrounding the portions 3R and 3L of the belt that contact the patient and also shows the breakable link 89, (The peg 34, eyelet 33, spline 66 and various sections of the belt 16,17, 18,19,2d and 23 are shown for reference. The compression pad and cover plate are act shown in Older to more clearly show the belt liner.) Tire loosely fitted liner socks protect the patient from friction. The belt generates friction along the surface of the patient as the belt repetitively compresses the patient’s chest. Without some means for reducing the friction, the belt would likely cause injury during compressions, such as abrasions, contusions or other compression-related injuries. In addition, friction increases the energy required to operate the compression device and thereby reduces battery 1 ife. The liner socks protect the patient and increase energy efficiency by allowing the belt to easily slide along the liner, with the liner only mo ving slightly against the patient's chest, (Some bunching of the liner socks may occur during compressions.)

The liner socks are tubes of Tyvek™ (high-density, spun bonded polyethylene) that are attached to the belt cartridge to form sobks around the right 73 and left 3L portions of the belt (The liner socks may comprise other materials that are water resistant and have a similar coefficient of friction to Tyvek191, T etlon™ or like substances. The liner socks may also have multiple layers of material*, that is, socks within socks.) The left sock 1821$ attached to the left fecit guard $8 at one end and to the left load distribution section 37 of the belt at the other end. A hole in the left sock allows the peg 34 to be inserted into the eyelet 33. The left sock is attached to the belt at any point near the free end of the load distribution section. Tfee right sock 183 is attached to Die right belt guard 67 at one etid and to the right load distribution section 16 of the belt at the other end. The right sock is attached to the belt at any point near file free end of the right load distribution section. The right sock wraps around die compression pad 65 and surrounds the breakable link.

The breakable link 89 is a cylinder made of aluminum or other su itable material. The central portion 190 of the cylinder has a smaller diameter than the end portions 191 and 192 of the cylinder. Since the link will break at the thinnest portion of the cylinder, the amount of force required to break 2015227481 17 Sep 2015 20 different Multiple links may be provided on either side of the belt Preferably, one link Is provided on each side of die belt relative to die patient

The link Is designed to break in the presence of excessive tension (over about 209 pounds to about 500 pounds on one side of the patient, and preferably at about 300 pounds). The breakable link breaks cleanly under excessive tension and experiences little plastic deformation before breaking. Thus, if the belt experiences excessive tension, die link will break, the belt will separate and the patient will be protected from excessive forces.

To attach die 1 ink to die belt, the belt is separated Into two sections and corresponding flaps 18S and 1¾ near opposing ends of each section are folded over themselves to form pockets in each belt section. The pockets are held k place by stitches 187. A pin 188 is disposed within each pocket and held in place by the stitches. The pins are exposed in the area of holes 189 that are provided in a corresponding end of each pocket. The holes provide space to receive the ends of the link and allow the piss to be threaded through apertures provided in the link. (The unexposed portions of the pins are shown in phantom to indicate their position inside the pockets and inside the link.) Thus, a pin connects a section of the belt to the link and the belt sections are thereby connected to each other via the link. Ore link is designed so that the center of the link will break, thereby separating the belt, before the pins or any other part of the link will break.

Figure 15 shows another cross-section of the breakable link. The breakable link 89 is an aluminum cylinder, The central portion .19ft of tire cylinder has a smaller diameter than the end portions 191 and 192 of the cylinder. Since the link will break at the thinnest portion of the cylinder, the amount of force required to break the Usk is precisely controlled by seeing the ctoss-secciottai area of the smallest part of the centra! portion 190 of die cylinder. The material used to make the link also controls the force required to break the link. Different materials will break at different levels of force depending on a number of factors, including the cross sectional area of the link, the type of alloy used, whether the link is heat treated, the type of surface finish provided and die like.

Each end portion of the cylinder is provided with a hole 193 to accommodate the pins. The holes are drilled from etcher side of the cylinder with a conical drill. The conical drill creates opposing ridges 194 In the carter of each hole. A pin contacts the link in the area of the ridges so that the pin is loaded at a point. This orientation prevents excessive forces from developing in directions oilier than in the direction the link is intended to break, lire combination of die conical holes and the pins permit the link to bend or break only m tire direction the link is intended to break. To further reduce bending or shear forces, die pins and/or the link are coated with Teflon.™ (poiytotrafluoroeihyle.tie) so that the pins may wobble with minimal friction within the link holes.

The breakable link has a length of 0.942 inches, has a radius of 0.310 inches at the cud portions and a radius of 0.0S8 inches at the thinnest central portion. The end portions of the link are 2015227481 17 Sep 2015 21 the link is precisely controlled by setting the radius of the central portion 190 of the cylinder, if the link 89 breaks under tension then the two remaining ends of the link remain within the sock. The liner sock thus reduces the chance that a broken link will Lash out and cause injury to the patient or bystanders. la addition, a separate bag or sleeve 184 may be attached to the belt near either end of the link. The bag surrounds the breakable link and contains the link in the event that the link breaks.

The link or Jinks attached to the belt may be provided with additional features. For example, a link may be additionally designed to serve as a swivel joint. The swivel joint link connects the pail Straps to the belt transition sections of the belt. The swivel joint link allows the load distribution sections to twist relative to the pull straps, about the longitudinal ants of the belt, without twisting the pull straps themselves. {The pall straps are sufficiently stiff that they do not twist during use.) Tire swivel joint link helps prevent the device from malfunctioning as a result of the pall straps becoming twisted and helps prevent the link from breaking due to shear forces or twisting forces, is otto devices, separate swivel joints are provided and attached to the belt as described above, For these devices the swivel joint and the link may be connected to each other, but may also be disposed at separate locations on rise Mi

In addition, a link, or swivel link may be designed to be re-engaged (or to be re-attached to the belt) if one or more links do separate. For example, the Jink or swivel link may J>e attached to the belt with a clip that fails at a pre-determined force, but that can be re-attached to the belt. Similarly, the swivel link may bo provided in two pieces joined by a joint that separates at a pre-determined force, but that can he re-attached to each other. (Other re-attachable links or swivel link designs may also be used.) Thus, in the event of a i/nk failure during chest compressions, the entire belt cartridge need not ho replaced. Instead, the problem that caused the Mure can be addressed, the failed link or links quickly re-engaged or re-attached and chest compressions fhen resumed. The re-attached link will fail at the same force as the force required to cause the link to origi nally fail.

The detachable link may comprise a detachable device operabjy connected to a force sensor, pressure sensor or strain gauge. The detachable device is highly resistant to breaking under force, but the detachable device will separate when the force sensor, pressure sensor or strain gauge measures an excessive force. Such a detachable device may be designed so (hat a user may reattach die link to itself or to the belt, thereby allowing the user to restart compressions quickly.

Figure 14 shows the belt 3 attached to the breakable link 89, The breakable link is located on the belt in a place where the belt tension most closely corresponds to rite actual load on the patient Thus, foe breakable link R9 is located between the pull straps and foe trausidoa-section of foe belt.

The breakable link may be located elsewhere on the belt, though foe link would have to be adjusted io break at a different amount of belt tension since the tension and sheer forces ο» the link would be 2015227481 17 Sep 2015 22 0.3 10 inches long each and the centra! portion of the link is 0.322 inches long. The thinnest centra! portion of the link is 0.042 inches long (and is part of the overall 0322 inch length of the central section). An aluminum link of these dimensions wiil break when about 300 pounds of fores is applied along the long axis IPS of the l ink. The dimensions of the link may be varied to vary the force required to break the link, preferably about 300 pounds for the detachable device and belt cartridge shown in Figures 3 through 5. In addition to aluminum, the link may be made of a variety of materials, including other metals (such as steel or magnesium), polymers, composites or fibers. However, the link must predictably break when exposed to a given force applied m a given direction.

Other devices and methods may also be used to increase the safety of using a belt to perform chest compressions. For example, other forms of reducing the coefficient of friction of the belt may be used. The liner, belt or patient may be provided with a layer of friction-reducing material. For example, a layer of Teflon™ may be placed between the belt and the liner sock, between the belt and the compression pad or between the belt and the patient. {The layer of friction-reducing material decreases the chance that die patient will be injured during chest compressions and increases the energy efficiency of chest compressions.) Thus, one or more liner sheets can replace or be used in addition to the liner socks to prevent injury to the patient. The coefficient of friction of the belt may also be reduced by super-cooling the belt A lubricating substance, such as tale powder or a liquid may placed between the patient and the belt, but means for preventing the lubricant from entering the belt dri ve platform should also be provided.

Additionally, the belt and belt cartridge may be provided in different sizes to accommodate differently sized patients. The belt and belt cartridge described herein is sized to accommodate about 95% of the popuiatioa Thus, if one «nailer belt size and one larger belt size sue available, then the three belt sizes will accommodate the vast majority of ail patient sizes (though a range of belt sizes is possible). Another design scheme uses one size of bet; and cartridge and provides detachable belt extensions to increase the size of the belt- A belt extension is a length of belt having similar properties to the belt on the cartridge. A suitable fastener, such as a hook and loop fastener or a detachable link, connects the belt extension to the belt on the cartridge.

When multiple belt sizes are available the belt may be provided with markings that allow the rescuer to measure the length of the belt with respect to the patient The user then manually eaters the size of the belt into the belt drive platform through a user interface in the belt drive platform. To accommodate the new bdt size the device’s software alters how the device performs chest compressions. Thus, the device will perform chest compressions consistent with medical guidelines, regardless of the size of the bdt or the size of the patient (to the design limits of the device).

In other devices, the belt cartridge is provided with an identifying code, pinout or other identifier that automatically inputs the size of the belt into the belt drive platform. The device 2015227481 17 Sep 2015 23 changes how it performs chest, compressions (in terms of how much belt slack is taken up by the means for tightening) based on the size of the belt In the case of belt extensions, the new belt length is manually entered into the processor, though the belt extension may be provided with a switch or other identifying mechanism that automatically inputs the new overall belt length into (he processor. Again, the belt drive platform’s software accordingly alters how the device performs chest compressions.

In addition, other means for tightening the belt may be used to drive the belt, such as multi pie motors and drive spools, pistons, scissors mechanisms or other mechanical actuators. Moreover, the belt drive platforms or housings containing such means may have a variety of shapes and sizes, so long as the belt and belt cartridge are designed to attach to a particular belt drive platform and to means for tightening the belt

While the preferred embodiments of toe devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. Other embodiments and configurations may be devised without departing from the spirit of the inventions and (its scope of the appended claims,

Claims (9)

1. A system for performing chest compressions on a patient, said system comprising: a housing; a drive spool operably attached to the housing, the drive spool including a key shaped aperture; a belt suitable for compressing the chest of the patient; a motor for rotating the drive spool, the motor disposed within the housing and operably attached to the drive spool; and a key for removably securing the belt to the drive spool, the key shaped to securely engage the drive spool aperture.

2. The system of claim 1, further comprising a rotation prevention detent in the drive spool that prevents the drive spool from rotating when the key is not inserted in the drive spool aperture.

3. The system of claim 1, further comprising: an RF identification tag secured to the key for enabling operation of the system.

4. The system of claim 3, wherein the RF identification tag further comprises a unique identifying number and operation of the system is only enabled if the unique identifying number corresponds to an authorized number.

5. The system of claim 3, wherein the RF identification tag further comprises a unique identifying number and operation of the system is only enabled if the unique identifying number has not previously been used with the system.

6. The system of claim 5, further comprising: an override to enable operation of the system with a unique identifying number that has previously been used.

7. The system of claim 1, further comprising; means for removably engaging the key to the drive spool that renders the key unusable after it has properly engaged the drive spool and been removed from the drive spool.

8. The system of claim 3, further comprising: a control system; wherein the RF identification tag further comprises a unique identifying number and operation of the system is only enabled if the unique identifying number corresponds to an authorized number stored in the control system.

9. The system of claim 8, wherein the control system alters the unique identifying number when the key engages the drive spool.