EP1237617A2 - Dispositif et procede de massage cardiaque direct avec penetration invasive minimum - Google Patents
Dispositif et procede de massage cardiaque direct avec penetration invasive minimumInfo
- Publication number
- EP1237617A2 EP1237617A2 EP00992659A EP00992659A EP1237617A2 EP 1237617 A2 EP1237617 A2 EP 1237617A2 EP 00992659 A EP00992659 A EP 00992659A EP 00992659 A EP00992659 A EP 00992659A EP 1237617 A2 EP1237617 A2 EP 1237617A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- spring
- elongate members
- cannula
- tip
- strut
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/00234—Surgical instruments, devices or methods, e.g. tourniquets for minimally invasive surgery
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/00234—Surgical instruments, devices or methods, e.g. tourniquets for minimally invasive surgery
- A61B2017/00238—Type of minimally invasive operation
- A61B2017/00243—Type of minimally invasive operation cardiac
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B2017/00831—Material properties
- A61B2017/00867—Material properties shape memory effect
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/02—Surgical instruments, devices or methods, e.g. tourniquets for holding wounds open; Tractors
- A61B2017/0237—Surgical instruments, devices or methods, e.g. tourniquets for holding wounds open; Tractors for heart surgery
- A61B2017/0243—Surgical instruments, devices or methods, e.g. tourniquets for holding wounds open; Tractors for heart surgery for immobilizing local areas of the heart, e.g. while it beats
Definitions
- the present invention relates to medical devices for cardiac massage and, more particularly, to devices and methods for performing minimally invasive direct cardiac massage.
- CCM Open chest cardiac massage
- CCM closed cardiac massage
- CPR cardiopulmonary resuscitation
- balloon-type and shoe-type heart-engaging members described in the patents may be difficult to deploy in the potential space between the posterior surface of the rib cage and the pericardium.
- inflatable balloon members may lack sufficient rigidity to impart the necessary compressive force, rigid shoe-like members risk damage to the pericardium, and cup-shaped compressive members may compress so much of the heart volume that the end diastolic volume is compromised.
- the devices of the prior art do not appear to take into account potential fatigue of the materials used in the device. That is, the device requires deployment and use after a long period of storage which may overstress members that are pre-biased in their stowed configurations.
- an umbrella-like structure including a plurality of flexible spoke members is deployed from the distal end of a tubular cannula. The spoke members are biased to spring open and form the umbrella structure from a constrained position within the cannula.
- the present invention provides an improved minimally-invasive direct cardiac massager apparatus that utilizes a plurality of spring members expandable from a delivery cannula into an atraumatic heart contacting portion.
- the delivery cannula is sized to fit between two ribs so that the heart contacting portion may be deployed into the mediastinum space between the patient's rib cage and heart.
- the spring members are configured such that the heart contacting portion is relatively flat so as not to occupy excessive space between the rib cage and heart.
- the spring members are arranged in a circle and are biased outwardly so as to form a trumpet-like structure, and a biocompatible sheet is stretched across the spring members to provide a flexible heart contacting surface.
- the spring members are designed to be stowed within the delivery cannula in a stressed condition below the yield stress of the material, and are deployed into a relaxed, curved configuration.
- One aspect of the present invention is a medical device incorporating a spring that is alternately disposable in stowed and deployed configurations.
- the spring includes a plurality of elongate members each having a longitudinal axis, a bending strength, and a yield stress.
- the elongate members are arranged in substantial juxtaposition and are substantially parallel to one another.
- the spring has a spring bending strength to which the bending strengths of each of the elongate members contribute.
- the spring further has a relaxed state and a stressed state such that when disposed in one of the relaxed or stressed states the spring is in the stowed configuration, and when in the other of the relaxed or stressed states the spring is in its deployed configuration.
- the spring is disposed in its stressed state when in the stowed configuration.
- the spring is arcuate in the relaxed state and substantially straight in the stressed state.
- the medical device incorporating the spring preferably further includes a tubular cannula within which the spring is linearly displaceable.
- the cannula includes an open end wherein the spring extends from the open-end into the relaxed state/deployed configuration, and is located substantially within the cannula in the stressed state/stowed configuration.
- a flexible, biocompatible sheet may connect the springs in the relaxed state/deployed configuration, the sheet being disposed generally perpendicular to the axis of tubular cannula.
- the medical device incorporating the open-mouthed tubular cannula further includes a blunt tip member that is initially positioned to cover the open mouth of the tubular cannula to facilitate advancement of the cannula through an access incision.
- the blunt tip member is mechanically restrained so as not to contact either the springs or the sheet during transition of the springs from the relaxed state/deployed configuration to the stressed state/stowed configuration.
- each spring has the tip extending from the cannula open mouth that, in the relaxed state/deployed configuration, forms an angle of greater than 90 degrees with respect to a ray extending along the axis of the tubular cannula. More preferably, each spring forms an angle of greater than 180 degrees with respect to the axial ray.
- the medical device spring defines a base on one and a tip on the other end, wherein the tip is more flexible than the base.
- the elongate members each define a first end in the direction of the spring base and a second end in the direction of the spring tip. The second end of least one elongate member does not extend to the spring tip so that the spring tip is more flexible than the base.
- there are more than two of the elongate members and none of the second ends of the elongate members is coincident with another of the second ends.
- the elongate members may be generally flat in cross-section and may be juxtaposed with wide faces in contact to form a laminated spring structure.
- the present invention contemplates a medical device comprising springs as described above, wherein the elongate members are made of a material that is capable of exhibiting a stress-induced Martensitic phase.
- the elongate members may be made of a nickel-titanium alloy.
- the medical device is usable for performing minimally invasive direct cardiac massage, and further includes a handle, wherein a plurality of the springs extend from a distal end of the handle.
- the springs are initially disposed in their stowed configurations such that the plurality of the springs is sufficiently compact to allow least the distal portions thereof to be inserted into the mediastinum of a patient through a minimal access incision of less than one inch in length.
- springs are movable to their deployed configurations such that they will radially expand within the mediastinum. Distal portions of the springs will directly engage the patient's heart such that pressure will be exerted upon the heart when the handle of the device is advanced in the distal direction.
- the elongate members comprising each spring are formed of a superelastic metal alloy capable of exhibiting stress-induced martensite, however the springs move back and forth between their stowed and deployed configurations without exhibiting stress-induced martensite.
- each of the springs in the heart massaging device comprises a main strut having a first radius of curvature when in its deployed configuration and unconstrained, and a sub-strut having a second radius of curvature when in its deployed configuration and unconstrained. The ends of the sub-strut are attached to the main strut.
- the main strut may comprise a plurality of the elongate members each having a longitudinal axis, a bending strength, and a yield stress.
- the elongate members of the main strut are arranged in substantial juxtaposition and substantially parallel to one another.
- the sub-strut may comprise a single elongate member attached at either of its ends to the main strut.
- the sub-strut may comprise a plurality of single elongate members each having a longitudinal axis, a bending strength, and a yield stress.
- the plurality of single elongate members of the sub-strut are arranged in substantial juxtaposition and substantially parallel to one another. At least one of the elongate members of the sub-strut is attached to the main strut at either end of the sub-strut.
- the handle of the heart massaging device of the present invention includes a tube within which the springs are positioned while in their stowed configurations.
- the tube has a distal portion that is insertable into the thoracic cavity of the patient through a minimal access incision of less than one inch in length.
- the handle is relatively displaceable after the tube has been inserted into the patient so as to allow the springs to radially expand.
- the tube has an open mouth at its distal end, the device further including a blunt tip member initially positioned to cover the open mouth of the tube to facilitate advancement of the tube through the minimal access incision.
- an expandable medical device delivery cannula having a blunt insertion tip is provided.
- the delivery cannula includes an expandable medical device received in a contracted state within a lumen of the generally tubular cannula.
- the cannula lumen has an open distal end through which the medical device can be deployed into an expanded state and then subsequently retracted within the cannula lumen into the contracted state.
- the blunt insertion tip covers the open distal end of the cannula lumen during insertion of the cannula into a body cavity.
- a connecting shaft rigidly attached to the insertion tip extends proximally within the cannula lumen and is adapted to slide longitudinally therewithin.
- a deployment mechanism is provided on a proximal end of the tubular cannula and includes structure operable to deploy and retract the expandable medical device, and limit retraction of the connecting shaft with respect to the medical device during retraction of the medical device.
- the deployment mechanism includes a handle longitudinally displaceable with respect to the tubular cannula and directly coupled to the expandable medical device to enable 1 :1 displacement of the handle with respect to the medical device.
- the handle may be frictionally coupled to a proximal end of the connecting shaft to enable 1 :1 displacement of the handle with respect to the connecting shaft, unless displacement of the connecting shaft is limited by structure other than the handle that overcomes the frictional coupling between handle and connecting shaft.
- the structure that limits displacement of the connecting shaft is fixed with respect to the tubular cannula and includes a control housing and deployment button.
- Figure 1A is a schematic cross-section of a chest of a patient showing a minimally invasive direct cardiac massager of the present invention prior to insertion into the chest cavity;
- Figure 1 B is a view as in Figure 1A showing the heart massager after insertion through an intercostal space between the patient's ribs and prior to deployment;
- Figure 1C is a view as in Figure 1 B showing the heart massager after deployment within the space between the posterior side of the rib cage and pericardium;
- Figure 1 D is a view as in Figure 1C after use of the heart massager with the heart contacting portions of the device having been partially retracted back into an insertion cannula;
- Figure 1 E is a view as in Figure 1 D showing the complete retraction of the heart contacting portions and withdrawal of a blunt dissector tip prior to withdrawal of the heart massager from within the chest cavity;
- Figure 2 is a perspective view of the heart massager of the present invention showing the rear side of the deployed heart contacting portion;
- Figure 3 is a close-up perspective view of the rear side of the heart contacting portion in use on a heart
- Figure 4A is elevational view of the heart massager of the present invention with a heart contacting portion retracted within an insertion cannula;
- Figure 4B is an elevational view of the heart massager with the heart contacting portion deployed from within the cannula;
- Figure 5A is a sectional view of a distal length of the heart massager of the present invention showing the heart contacting portion deployed;
- Figure 5B is a sectional view of a control housing seen in Figure 5B;
- Figure 6 is a partial elevational view of a slotted deployment shaft used in the heart massager of the present invention
- Figure 7 is an elevational view of a connector shaft used in the heart massager of the present invention
- Figure 8A is a partial sectional view of the heart massager of the present invention with the heart contacting portion removed, and showing the position of the connecting shaft during retraction;
- Figure 8B is a partial sectional view of the heart massager as in Figure 8A, and showing the connecting shaft fully retracted prior to withdrawal of the heart massager from within the chest cavity;
- Figure 9 is a detailed sectional view of a distal portion of the heart massager of the present invention and showing strut members in their retracted, stressed positions;
- Figure 10 is an isolated elevational view of one of the struts of the heart contacting portion in its deployed condition
- Figure 11 is a detailed view of the strut of Figure 10.
- Figure 12 is a detailed view of an alternative strut having a single thick proximal member and a plurality of thin distal members;
- Figure 13 is a detailed view of an alternative strut having both thick and thin proximal members, the thin members extending to the distal tip;
- Figure 14 is a detailed view of an alternative strut having a single elongated member and a single reinforcing member;
- Figure 15 is a detailed view of an alternative strut having a plurality of reinforcing members, one of them being thicker than the others; and Figure 16 is a detailed view of an alternative strut having a plurality of same thickness reinforcing members.
- Figure 17a is a side view of an alternative strut having a distal closed-loop segment and a proximal portion formed of a plurality of individual leaves.
- Figure 17b is an enlarged view of the distal closed loop segment of the strut of Figure 17a.
- Figure 18 is a side view of the distal portion of a cardiac massage device of the present invention, in its deployed configuration, such device incorporating closed loop struts of the type shown in Figures 17a and 17b.
- Figure 19a is a partial, cut-away, side view of the device of Figure 18 showing the proximal portion of one of its struts in a non-deployed position (i.e., housed within the cannula 24).
- Figure 19b is a partial, cut-away, side view of the device of Figure 18 showing the proximal portion of one of its struts in a deployed position (i.e., following retraction of the cannula 24 and outward splaying of the struts)
- the present invention provides an improved minimally invasive direct cardiac massager which is both easier to use and less susceptible to breakage.
- a number of different configurations of the heart massager are shown herein, none of which should be construed as especially advantageous over the others.
- the heart massager of the present invention utilizes an improved spring strut design which has a relaxed curvilinear shape that is bent further than struts of the prior art, but which remains below the yield stress of the material when straightened out.
- Such a spring strut could be utilized in other medical implements for a similar benefit. Therefore, the present invention is not deemed to be limited to only a minimally invasive heart massager, as shown.
- a minimally invasive cardiac massage apparatus or heart massager 20 in accordance with the present invention, is schematically shown in use.
- the heart massager 20 comprises an elongate, generally tubular device which can be passed through a small aperture between ribs into proximity of the heart H.
- the ribs shown are indicated at R2-R6, and a distal end of the heart massager 20 can be seen passing through the intercostal space between ribs R4 and R5.
- a different approach could be used.
- the heart massager 20 has a blunt tip 22 covering the distal end of a tubular cannula 24.
- the blunt tip 22 preferably has a spherical surface to facilitate passage through the layer 26 of muscle and cartilage between the ribs, and preliminary incision through the layer 26 to facilitate this passage is shown.
- the blunt tip 22 has a width about the same as an adult finger, or more precisely between about 0.5 to 1.0 inches.
- the heart massager 20 further includes a cylindrical stop flange 28 extending outward from the cannula 24. The entire heart massager 20 has been advanced, as indicated by ⁇ rrow 30 in Figure 1A, into the position in Figure 1 B wherein the stop flange 28 abuts the exterior surface of the layer 26.
- the interference between the stop flange 28 and the layer 26 provides an indication to the surgeon that the heart massager 20 is properly inserted.
- the blunt tip 22 has passed into a cavity 32 between the ribs and heart H and is in slight contact with the pericardial layer surrounding the heart.
- a heart contacting portion 34 of the heart massager 20 is shown deployed into contact with the heart H. This deployment is accomplished by depressing a control button 36 and advancing a deployment shaft 38, as indicated by arrow 40.
- the specific details of the heart massager 20 will be described below, although it should be noted that the heart contacting portion 34 comprises a plurality of spring struts 42 surrounded by a protective cover 44 in direct contact with the heart H.
- the heart massaging operation takes place by periodically moving the heart contacting portion 34 toward and away from the heart H, as indicated by the dashed line position 46.
- the timing of the massage thrusts is determined by the physician or operator of the device, and is not the subject of the present invention.
- the heart massager 20 is retracted as seen in Figure 1 D. More specifically, the deployment shaft 38 is displaced proximally with respect to the cannula 24, as indicated by arrow 48. In doing so, the heart contacting portion 34 collapses through a mouth 50 of the cannula 24 in the direction of arrow 52. As will be described below, the blunt tip 22 is prevented from being collapsed inside the heart contacting portion 34.
- Figure 1 E illustrates the final retraction configuration of the heart massager 20 in which the heart contacting portion 34 is fully retracted within the mouth 50 of the cannula 24.
- the blunt tip 22 Prior to withdrawing the heart massager 20 from the patient's chest cavity, the blunt tip 22 is retracted to the position shown leaving a slight gap 54 between a taper 56 on the underside the tip and the mouth 50.
- the gap 54 helps ensure that tissue is not pinched between the blunt tip 22 and mouth 50, which might cause complications.
- the stop flange 28 has remained in contact with the layer 26 of muscle and cartilage between the ribs.
- the entire heart massager 20 is withdrawn from within the patient's chest cavity, as indicated by arrow 58.
- Figure 2 illustrates the heart massager 20 in perspective with the heart contacting portion 34 fully deployed so that the multiple struts 42 are visible.
- the struts 42 bend radially outward when advanced distally past the mouth 50 of the cannula 24.
- the distal-most tips of each strut 42 curls back upon the strut and the protective cover 44 wraps around each tip to provide a smooth, toroidal or nearly toroidal outer periphery 60.
- the protective cover 44 can be a variety of flexible, biocompatible materials, but is preferably a polyester fabric, such as a mesh available from Jelliff having the characteristics of: 160 mesh x 0.002 inch monofilament diameter x 104 ⁇ m mesh openings.
- a tether 64 attaches the protective cover 44 to one of the struts 42 at a location not shown.
- the heart massager 20 further includes a proximal handle 62 and a control housing 66 within which the control button 36 is operably mounted.
- the control housing 66 is rigidly affixed to the proximal end of the cannula 24 and includes a central aperture 68 through which the deployment shaft 38 slides.
- the deployment shaft 38 controls the movement of the heart contacting portion 34, by virtue of its rigid attachment to the proximal end of each strut 42, as will be explained below.
- FIG. 3 illustrates the distal end of the deployed heart massager 20 in use on a heart H. This view illustrates the preferred orientation of heart massager 20 at the lower apex of the left ventricle LV, or pumping chamber of the heart.
- Oxygenated blood from the left ventricle is urged upward through the aortic valve and ascending aorta AA to the arterial system of the body. Most importantly, oxygenated blood is immediately urged through the coronary arteries (CA), primarily during diastole, to perfuse the muscle tissue of the heart H itself, which is critical in cardiac arrest situations.
- CA coronary arteries
- Figure 3 best illustrates how the rounded, toroidal periphery 60 of the heart contacting portion 34 avoids damage to the heart H and surrounding tissue.
- the multiple spring struts 42 act as a buffer between the displacement motion of the heart massager 20 and the soft heart muscle.
- FIGS. 4A and 4B illustrate the heart massager 20 in its retracted (4A) and deployed (4B) states. In these views, the distal direction is to the left, while the proximal direction is to the right. These views illustrate the relative lengths of each of the components, especially emphasizing the short length of the cannula 24 extending distally from the control housing 66.
- FIG 4A the heart massager 20 is fully retracted so that the blunt tip 22 lies flush against the mouth 50.
- a pair of indicators can be seen on the deployment shaft 38. Specifically, a retraction indicator 70 is visible when shaft 38 is fully retracted, or retracted to at least a safe point, within the control housing 66.
- a deployment indicator 72 is used to alert the operator when the heart massager 20 is fully deployed. So, as seen in Figure 4B, the deployment indicator 72 is just visible on the right side of control housing 66 when the heart contacting portion 34 is fully deployed.
- FIGS 5A and 5B are cross-sections showing details of the inner workings of heart massager 20.
- a pair of diametrically opposed struts 42 are shown deployed from within the mouth 50 of the cannula 24. Only two struts 42 are shown, and they are simplified to more clearly illustrate their overall shape and interaction with the rest of the heart massager 20. It will be understood that Figures 9-16 show multiple variations of struts that can be used in place of those seen in Figure 5A.
- Each strut 42 includes a curled tip 80, a middle spring portion 82, and a base portion 84. The base portion 84 of each of the struts 42 is secured relative to the deployment shaft 38.
- the deployment shaft includes a strut mounting cylinder 86 at the left (distal) end around which the base portions 84 are secured.
- Each of the base portions 84 is secured to the cylinder 86 with a suitable adhesive, potting compound, sutures, or other similar expedient.
- the base portions 84 terminate adjacent to a flange 88 which acts as a manufacturing guide to assist in securing the strut base portions 84 with a potting compound (see 174 in Figure 9).
- One of the advantages of the present invention is the extremely curled tips 80 of each of the struts 42. These present a non-traumatic shape for the heart- contacting portion 34, further softened by their highly flexible nature.
- the tips 80 are curled back more than 90° from the distal direction along the cannula 24.
- the tips 80 are curled back more than 135°, more preferably more than 180°.
- the tips 80 are curled back between about 200° and 240°.
- an embodiment of the present invention, illustrated in Figures 17 and 18, includes tips that are bent completely back upon the strut, in a closed loop having a tip bend angle of 360°, and thus the preferred tip bend angle is thus between 180° and 360°.
- Figure 5A best illustrates the shape of the protective cover 44, which as mentioned, wraps around each of the curled tips 80 at a skirt portion 90.
- the protective cover 44 stretches between the diverging struts 42 in a planar trampoline portion 92 having a central aperture 94 through which a connecting shaft 96 extends.
- the blunt tip 22 is secured to the left (distal) end of the connecting shaft 96 and is larger than the aperture 94 so that it remains out in front of the trampoline portion 92.
- the plurality of struts 42 and protective cover 44 form an inverted-umbrella shape which is not entirely circular, but instead extends along chordal segments.
- the number of struts 42 must be sufficient to provide a fairly uniform pressing surface for massaging the heart H, yet not too numerous or else retraction of the struts into the introducer sheath becomes difficult or impossible. At a minimum there are three struts 42, although there are preferably at least eight struts 42 across which the protective cover 44 is secured, with a preferred range of between four and twelve struts 42. The greater the number of struts 42, of course, the more truly toroidal is the periphery 60 ( Figure 3) of the heart contacting portion 34.
- each strut 42 includes a base portion 84 secured to a strut mounting cylinder 86.
- the strut mounting cylinder 86 forms a distal end of the deployment shaft 38 which extends longitudinally through a bore in the control housing 66.
- the connecting shaft 96 on which left ( distal) end is secured the blunt tip 22, passes through a longitudinal bore formed within the deployment shaft 38.
- a portion of the connecting shaft 96 can be seen in Figure 5A through an elongated slot 98 formed in the deployment shaft 38.
- An annular guide sleeve 100 is secured to the connecting shaft 96 with a pin 102.
- the guide sleeve 100 has an inner throughbore sized to surround the deployment shaft 38, the guide sleeve being adapted to slide longitudinally with respect to the deployment shaft.
- the guide sleeve 100 is generally tubular with a maximum outer diameter smaller than the inner diameter of the cannula 24. Therefore, the guide sleeve 100 is adapted to slide longitudinally along the slot 98 with respect to the deployment shaft 38 and within the cannula 24.
- Figure 5B is an enlarged sectional view through the control housing 66 with the cannula 24 and deployment shaft 38 illustrated in phantom.
- the control button 36 is mounted within a dead-end cavity 104 of the control housing 66 having a depth greater than the control button to permit movement therein. More specifically, a cut out 106 on the control button 36 receives one end of a screw 108 fastened within a threaded bore 110 in the housing 66. The cut out 106 is elongated in a direction transverse to the longitudinal axis of the heart massager 20 to permit the control button 36 to be displaced with respect to the screw 108. A spring 112 positioned in the bottom of the cavity 104 biases the control button 36 in a direction out of the cavity. For purposes of explanation, movement of the control button 36 will be described as either in or out, with reference to the deadend cavity 104.
- the control button 36 defines a through bore 114 for receiving the deployment shaft 38 and guide sleeve 100 positioned thereon.
- the throughbore 114 defines a number of surfaces which interact with surfaces upon the deployment shaft 38 and guide sleeve 100 to control deployment of the heart contacting portion 34 as well as the relative movement of the connecting shaft 96 and blunt tip 22.
- a left-facing cam surface 120 defines an angle of approximately 45 degrees with respect to the longitudinal axis
- a sleeve stop 122 is oriented perpendicular with respect to the longitudinal axis and faces to the left (distally)
- a deployment stop 124 is also oriented perpendicular with respect to the longitudinal axis and faces to the right (proximally).
- the control housing 66 further includes a bore segment 126 on the left receiving the cannula 24 and terminating in a lip 128.
- a counter bore 130 located just to the right (proximally) of the cavity 104 terminates in a step 132 leading to a relief chamber 134, which in turn ends at an inner flange 136 closely receiving the deployment shaft 38.
- FIGS 6 and 7 illustrate the deployment shaft 38 and connecting shaft 96 in isolation.
- the deployment shaft comprises the aforementioned slot 98 terminating just to the right of a lock collar 140.
- the lock collar 140 projects outward from the shaft 38 and defines, on its right (proximal) end, a tapered retraction ramp 142, and on its left (distal) end a perpendicular deployment shoulder 144.
- the retraction indicator 70, deployment indicator 72, and strut mounting cylinder 86 are more clearly seen in Figure 6.
- the guide sleeve 100 can be seen to have, from left to right, a tapered first ramp 150 on its left (distal) end, a perpendicular retraction shoulder 152, a tapered second ramp 154, and a tapered safety ramp 156 on its right (proximal) end.
- the retraction shoulder 152 and second ramp 154 face each other across a neck 158 formed in the middle of the guide sleeve 100.
- Figure 7 also illustrates the fixed position of the blunt tip 22 with respect to the guide sleeve 100, the two elements being fastened by respective pins to the connecting shaft 96.
- the heart massager 20 is inserted as described above in a chest cavity of the patient and deployed from the retracted position shown in Figure 4A to the deployed position shown in Figure 4B.
- the device must be retracted back to the condition where the heart contacting portion 34 is within the cannula 24, and withdrawn from the chest cavity.
- Certain features of the present heart massager 20 prevent it from being prematurely deployed, and insure that the heart contacting portion 34 can be folded up within the cannula 24 without collapsing around blunt tip 22.
- retraction of the device will not cause the blunt tip 22 to pinch tissue against the mouth 50, as previously mentioned. The interaction of the various structural components to enable these functions will now be described.
- the heart massager 20 is seen in section with the heart contacting portion 34 removed for clarity.
- the blunt tip 22 is seen slightly spaced from the mouth 50, it need only be pressed inward to seat against the mouth, as seen in Figure 4A.
- the deployment shaft 38 is fully withdrawn to the right (proximally) so that the heart contacting portion 34 would be entirely disposed within the cannula 24. Further retraction is prevented by the contact between the lock collar retraction ramp 142 and the step 132 of the control housing 66. Additionally, the deployment shoulder 144 of the lock collar 140 abuts the deployment stop 124 on the control button 36.
- the operator depresses the control button 36 against the force of the spring 112 to disengage the deployment stop 124 from the deployment shoulder 144.
- the operator can then displaced the handle 62 to the left (distally) while holding the control housing 66 to cause the entire heart contacting portion 34 to emerge from the mouth 50 of the cannula 24.
- the first and second ramps 150 and 154 cam the guide sleeve 100 past the spring-loaded deployment stop 124.
- the axial width of the neck 158 is sized smaller than or equal to the distance across the sleeve stop 122 and deployment stop 124 to help prevent binding of the guide sleeve 100.
- FIG. 5A illustrates a dimension X representing the longitudinal "footprint" of the heart contacting portion 34.
- This dimension X is desirably minimized so that the heart contacting portion 34 can fully deploy within the cavity 32 between the ribs and heart, as shown in Figure 1C, without placing undue pressure on the heart or otherwise injuring surrounding anatomical structures.
- This dimension X is preferably between 1 and 5 cm, and more preferably is about 3 cm.
- Movement of the strut mounting cylinder 86 to the right begins to pull the struts 42 into the cannula 24. Again, friction between guide sleeve 100 and deployment shaft 38 tends to pull the connecting shaft 96 and blunt tip 22 to the right (in a proximal direction) as well.
- the control button 36 prevents the guide sleeve 100 from displacement to the right beyond the position shown in Figure 8A. More specifically, retraction shoulder 152 on the guide sleeve 100 abuts against the sleeve stop 122 on the control button 36.
- the safety ramp 156 cams the sleeve stop 122 inward, the tip stop ultimately being biased outward against the neck 158.
- the interaction between the retraction shoulder 152 and sleeve stop 122 restrains the guide sleeve 100, although the deployment shaft 38 is still free to slide within the guide sleeve. Restraining the guide sleeve 100 in this manner in turn restraints movement of the blunt tip 22, by virtue of their interconnection via the connecting shaft 96. As seen in Figure 8A, therefore, the blunt tip 22 remains spaced from the mouth 50 to permit complete and unobstructed collapse of the struts 42 within the cannula 24.
- Figure 8A also shows the retraction ramp 142 on the lock collar 140 approaching the control housing 66.
- the retraction ramp contacts the cam surface 120 provided on the left end of the control button 36 and forces the control button inward.
- This inward movement of the control button 36 disengages the sleeve stop 122 from the retraction shoulder 152, and releases the guide sleeve 100 for further movement to the right.
- the deployment shaft 38 and connecting shaft 96 end up in the positions shown in Figure 8B from continued movement of the deployment shaft to the right.
- the retraction ramp 142 contacts the step 132 with the guide sleeve 100 positioned within the relief chamber 134.
- the length between the mouth 50 and step 132 in conjunction with the length between the blunt tip 22 and guide sleeve 100 is such that the blunt tip 22 remains spaced from the mouth across the gap 54, previously described with respect to Figure 1E.
- the gap 54 is desirably between about 10-30 mm wide.
- FIG. 9 is a detailed view of the distal portion of the heart massager 20 with one embodiment of the struts 42 shown in the fully retracted positions. Only two diametrically opposed struts 42 are illustrated in isolation from the rest of the heart contacting portion 34 for the sake of clarity.
- each of the struts 42 has a distal or tip portion 80, a middle spring portion 82, and a base portion 84.
- Each of the struts 42 comprises a primary member 170 and a secondary member 172.
- the primary member 170 has a length extending between the strut flange 88 and the mouth 50 of the cannula 24, while the secondary member 172 is shorter and only extends from the strut flange to the approximate midpoint of the primary member.
- the primary member 170 and secondary member 172 have narrow rectangular cross-sections and are juxtaposed side-by-side, contacting along opposed flat surfaces.
- Figure 9 illustrates an anchoring sleeve 174 surrounding the base portions 84 of the struts 42 and holding them firmly against the strut mounting cylinder 86.
- a connecting sleeve 176 is provided for each strut 42 around both the primary member 170 and secondary member 172 at the location where the secondary strut terminates.
- the connecting sleeve 176 can be a variety of materials, but is preferably a ring welded to the ends of the secondary members 172 (seen below in Figures 19A and 19B), or may also be a biocompatible heat- shrink polymer, such as FEP.
- the primary member 170 is permitted to slip with respect to the secondary member 172 along their contact surfaces, except at the base portion 84 where the secondary member 172 is axially retained but allowed to flex outward.
- the bending stress imposed in the retracted configuration is apparent. That is, the curvilinear deployed struts 42 seen in Figure 5A are in their relaxed, un-stressed shapes. In contrast, as the struts 42 are retracted within the cannula 24 and straightened out, internal stresses are generated because of the extreme relaxed curvature, especially at the tips 80.
- the struts of the present invention are designed so that these stresses imposed in the retracted, or straightened, configuration do not exceed the yield stress of the material used. Because the stresses are below the yield point, the struts 42 reliably deploy in their intended shapes, and the possibility of fatigue failure is substantially eliminated.
- the parts of the structure subject to the highest stress are constructed of one or more thinner members to minimize the stress on the individual layers.
- the cladding serves to hold them together as a single unit. At the same time, however, the layers are permitted to slide relative to each other within the cladding.
- FIGS 10-16 illustrate a number of alternative strut configurations of the present invention that combine the desirable attributes of being highly curled for reduced trauma to the patient, stiff enough to perform adequate heart massage, and also configured so that the yield stress of the material is not exceeded when they are straightened out.
- each of the struts combines a number of strut members together to provide, in conjunction, these advantageous features.
- Figures 10 and 11 illustrate an exemplary embodiment of strut 200 comprising a plurality of individual strut members having progressively different lengths and juxtaposed against one another.
- the strut 200 includes a pair of primary strut members 202 extending the full length of the strut, and a series of progressively shorter secondary members 204a-d that are stacked in series against the primary strut members.
- the strut 200 can be functionally divided into a curled tip portion 206, a middle portion 208, and a base portion 210. Again, the base portion 210 attaches to a distal end of the deployment shaft 212, only partially shown in Figure 10.
- a connecting sleeve may be provided around part or all of the length of the primary and secondary members 202, 204, to hold them against one another but still permit slip therebetween.
- the secondary strut members 204 are sequentially stacked to the inside of the curvature of the strut 200, and gradually shorten in length in this direction.
- the first secondary strut member 204a lies against the primary strut member 202, terminates just short of the curled tip portion 206 and is the longest of the secondary strut members.
- Secondary strut member 204b is juxtaposed against and shorter than the first member 204a, and so on.
- the ends of each of the secondary strut members 204 are evenly spaced apart to provide a uniformly stepped configuration.
- each of the secondary strut members 204 are shown having approximately the same thickness, or cross-sectional size. This arrangement results in a spring portion 208 that is stiffest toward the base portion 210 and becomes gradually more flexible toward the curled tip portion 206. In other words, the spring stiffness decreases in a linear step function from the base portion 210 toward the tip portion 206.
- the struts 200 will be pressed against the heart and tend to spread apart further, or bend to the left as seen in Figures 10 and 11.
- the spring portion 208 must be sufficiently stiff to perform the massaging function, but the tip portion 206 has to be extremely flexible to be curled into the non-traumatic orientation shown and then be straightened out without exceeding the yield stress of the material.
- the strut 200 provides these advantages by virtue of the stepped configuration of the strut members. Those of skill in the art will understand that varying the cross-sectional size and/or shape of any of the strut members, or their respective lengths, may be desirable to change the spring characteristics of the strut 200.
- the extreme curl of the tip portion 206 forms the toroidal or pseudo-toroidal periphery 60 that insures the heart massager 20 will not damage or catch on any surrounding anatomical structures, especially the heart. Because the cross-sectional size of the strut 200 is reduced to a minimum at the tip portion 206, the area moment of inertia is likewise reduced. Indeed, the strut 200 is designed to have an area moment of inertia in the tip portion 206 that ensures that the yield stress is not exceeded when the tip portion is flattened or straightened out.
- each of the secondary strut members 204a-d are permit to slide with respect one another, and with respect to the primary strut members 202, so as not to superimpose each of their area moments of inertia in bending.
- the stress in each of the primary and secondary strut members is independent of the stress in the others.
- Figure 12 illustrate an alternative strut 220 having a relatively large proximal member 222 and a plurality of smaller distal members 224.
- One of the distal members 224 in shown positioned on the inside of the curve of the proximal member 222, while the other two are shown to the outside.
- the strut 220 has a curled tip portion 226, a middle portion 228, and a base portion (not shown).
- the middle portion 228 has a constant stiffness in bending along the proximal member 222, and has increased flexible in the region of the distal members 224.
- a connecting sleeve may be provided around the three distal members 224, to hold them against one another but still permit slip therebetween.
- Figure 13 illustrates a still further strut 230 having a pair of primary strut members 232 and a single secondary member 234 which is larger in cross-section than the primary members.
- the secondary member 234 is provided to the inside of the curve of the strut 230, while the primary members 232 extend the full length of the strut to the outside of the curve.
- the primary members thus define a curled tip portion 236, while the combination of the primary and secondary members define a spring portion 238.
- Figures 14-16 illustrate, respectively, alternative struts 250, 260, and 270, all of which comprise multiple members that separate in a mid portion of the strut.
- the strut 250 of Figure 14 includes a single primary member 252 and a single support or reinforcing member 254 disposed to the inside of curve of the primary member.
- the primary member 252 has a generally constant cross-section in a proximal region, but tapers down to a narrower cross-section in a tip portion 256.
- the strut 260 of Figure 15 comprises a single primary spring member 262 and a plurality of reinforcing members 264. One of the reinforcing members extends the full length of the strut 260 and defines the curled tip portion 266.
- the reinforcing members 264 are stacked to the inside of the curve of the primary spring member 262 and have varying lengths.
- the strut 270 in Figure 16 includes a plurality of strut members having approximately the same cross-sectional size, one of which extends the entire length of the strut to define the fip portion 272. The remaining strut members terminate at different locations to the inside of the curve of the strut.
- the struts are designed to have sufficient stiffness to perform the heart massaging function, but also have a minimum area moment of inertia at their tips to avoid exceeding the yield stress from straightening out the highly curled, non-traumatic tip portion.
- the struts described herein can be made from a variety of biocompatible materials that provide the required strength and elastic properties.
- the struts are made from a Nickel-Titanium (e.g., Nitinol) alloy having super-elastic properties in a region of the stress-strain curve below the transition from an austenitic phase to a martensitic phase. That is, certain Nickel-Titanium alloys exhibit a stress-induced martensitic (SIM) phase change at predetermined stress levels. This allows additional strain before yield occurs.
- SIM stress-induced martensitic
- the present invention provides struts that remain below the stress-induced martensite point of the material, such as the SIM point if SIM alloys such as nickel-titanium alloys are used.
- Other materials that can be used include stainless steel, Elgiloy, and even certain composites.
- the at least some of the struts described herein can be formed from a shape memory alloy exhibiting a Martensitic to Austenitic phase transition at a predetermined temperature, for instance a temperature less than or equal to 32° C. Therefore, the struts exhibit one shape at a normal ambient room temperature of around 25 °C and undergo a Martensitic to Austenitic phase transition and attendant shape change when inserted into a body cavity having a temperature of around 37°C.
- a further embodiment of a strut 280 is seen in Figures 17A and 17B.
- the strut 280 comprises a primary member 282 that extends substantially the length of the strut to a distal tip 284, and a secondary member 286 that extends on both sides of the primary member. More specifically, secondary member 286 extends along one face of the primary member 282 from a proximal end 288 of the strut 280 to the distal tip 284, wraps around in a closed loop 290, and continues adjacent the opposite face of the primary member back to the proximal end 288. The primary member 282 terminates short of the distal tip 284. The closed loop is seen in greater detail in figure 17B.
- FIG 18 an embodiment of the cardiac massage device 294 of the present invention incorporating the closed loop struts 280 is seen in Figure 18.
- Figure 17A also illustrates a reinforcing member 300 that is disposed on the inside curve of the closed loop strut 280.
- the reinforcing member 300 facilitates bending of the strut 280 and helps maintain stresses in the strut below the yield port of the material.
- a preferred connection between a reinforcing member 310 and a primary, multi-layer strut 312 of the present invention is seen in Figures 19A and 19B.
- the reinforcing member 310 is welded at either end to small rings or bands 314a, 314b disposed around the strut 312.
- the band 314a on the left or proximal end of the reinforcing member 310 is fixed axially with respect to the strut 312.
- the band 314b on the right or distal end of the reinforcing member 310 is permitted to slide with respect to the strut 312. Therefore, as seen in Figure 19B, when the strut 312 is deployed, the band 314b is permitted to slide with respect thereto.
- the reinforcing member 310 flexes with respect to the curvature of strut 312 such that a space 316 therebetween appears.
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Surgery (AREA)
- Heart & Thoracic Surgery (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Surgical Instruments (AREA)
- Percussion Or Vibration Massage (AREA)
Abstract
L'invention concerne un dispositif médical doté d'un ressort comprenant plusieurs membres allongés sensiblement juxtaposés de sorte qu'ils sont sensiblement parallèles. Le ressort est alternativement déployé et replié pendant l'utilisation du dispositif et se trouve dans un état détendu ou tendu. Le ressort peut être arqué dans son état détendu et déployé, et, en règle générale, linéaire dans son état tendu et replié. Les membres allongés peuvent être configurés de sorte que chacun contribue à la force globale de tension du ressort sans qu'aucun ne soit tendu au-delà de sa propre limite d'élasticité, lorsque le ressort est dans son état tendu. Les membres allongés peuvent avoir une section plate et définir ensemble une structure stratifiée. Un des membres allongés peut se terminer tout près de l'extrémité distale du ressort, de sorte qu'il est plus flexible à l'extrémité que sur la base proximale. Ledit dispositif peut être un instrument de massage cardiaque comprenant plusieurs ressorts déployés à partir d'une extrémité d'une canule tubulaire pour prendre ensemble une forme d'ombrelle inversée, une texture étant étirée sur l'ensemble du groupe d'éléments. Les membres allongés peuvent être en nitinol. La tension maximum imposée à chacun d'eux est inférieure à celle qui provoquerait une modification de la phase martensitique.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US46019599A | 1999-12-13 | 1999-12-13 | |
US460195 | 1999-12-13 | ||
PCT/US2000/042636 WO2001041695A2 (fr) | 1999-12-13 | 2000-12-07 | Dispositif et procede de massage cardiaque direct avec penetration invasive minimum |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1237617A2 true EP1237617A2 (fr) | 2002-09-11 |
Family
ID=23827730
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP00992659A Withdrawn EP1237617A2 (fr) | 1999-12-13 | 2000-12-07 | Dispositif et procede de massage cardiaque direct avec penetration invasive minimum |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1237617A2 (fr) |
AU (1) | AU4519401A (fr) |
CA (1) | CA2395146A1 (fr) |
WO (1) | WO2001041695A2 (fr) |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE531172C2 (sv) | 2007-05-16 | 2009-01-13 | Rhinomed Ab | Vibrationsanordning avsedd att användas i kroppskaviteter, företrädesvis i näshålan |
WO2013087886A1 (fr) | 2011-12-16 | 2013-06-20 | Chordate Medical Ag | Dispositif pour stimulation d'hypothalamus |
WO2013087892A1 (fr) | 2011-12-16 | 2013-06-20 | Chordate Medical Ag | Stimulation double |
JP6134735B2 (ja) | 2011-12-16 | 2017-05-24 | コーデイト・メディカル・アクチエボラーグChordate Medical AB | Ans刺激 |
EP2790569B1 (fr) | 2011-12-16 | 2018-01-10 | Chordate Medical AB | Système de détection de pression et procédé |
WO2013087885A1 (fr) | 2011-12-16 | 2013-06-20 | Chordate Medical Ag | Dispositif pour traitement de céphalées |
EP2641580B1 (fr) | 2012-03-20 | 2020-06-03 | Chordate Medical AB | Dispositif de vibration électroactive |
CN104203192B (zh) | 2012-03-20 | 2016-12-14 | 考地特医疗Ab公司 | 用于振动刺激的振动模式 |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4909789A (en) * | 1986-03-28 | 1990-03-20 | Olympus Optical Co., Ltd. | Observation assisting forceps |
US5632746A (en) * | 1989-08-16 | 1997-05-27 | Medtronic, Inc. | Device or apparatus for manipulating matter |
US5163949A (en) * | 1990-03-02 | 1992-11-17 | Bonutti Peter M | Fluid operated retractors |
US5683451A (en) * | 1994-06-08 | 1997-11-04 | Cardiovascular Concepts, Inc. | Apparatus and methods for deployment release of intraluminal prostheses |
US5978714A (en) * | 1997-06-06 | 1999-11-02 | Zadini; Filiberto | Epicardial percutaneous device for electrical cardiac therapy |
-
2000
- 2000-12-07 CA CA002395146A patent/CA2395146A1/fr not_active Abandoned
- 2000-12-07 WO PCT/US2000/042636 patent/WO2001041695A2/fr active Search and Examination
- 2000-12-07 AU AU45194/01A patent/AU4519401A/en not_active Abandoned
- 2000-12-07 EP EP00992659A patent/EP1237617A2/fr not_active Withdrawn
Non-Patent Citations (1)
Title |
---|
See references of WO0141695A3 * |
Also Published As
Publication number | Publication date |
---|---|
CA2395146A1 (fr) | 2001-06-14 |
WO2001041695A3 (fr) | 2002-01-10 |
AU4519401A (en) | 2001-06-18 |
WO2001041695A2 (fr) | 2001-06-14 |
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