Austin, Samuel Lynn (10821 FM 2709, Eustace, TX, 75124, US)
Davis, Albert (304 Arborcrest, Richardson, TX, 75080, US)
Keyes Jr., Charles R. (6359 CR 4511, Athens, TX, 75751, US)
Baker, Clyde (11254 South Palisade Rim Dr, South Jordan, UT, 84095, US)
Rogers, Danny Carpenter (P.O. Box 2656, Athens, TX, 75751, US)
Austin, Samuel Lynn (10821 FM 2709, Eustace, TX, 75124, US)
Davis, Albert (304 Arborcrest, Richardson, TX, 75080, US)
Keyes Jr., Charles R. (6359 CR 4511, Athens, TX, 75751, US)
Baker, Clyde (11254 South Palisade Rim Dr, South Jordan, UT, 84095, US)
| 1. | 01) ; original claims 1, 6,9,12,17 and 29 amended; original claims 2,22 and 30 cancelled ; new claims 3191 added; remaining claims unchanged (I I pages)] 1. A device for isolating a cardiac surgical site, comprising : a first finger having a longitudinal axis and a clinging accessory adapted to attach the first finger to a heart; a first joint positioned along the longitudinal axis such that the first finger may rotate about the longitudinal axis on a surface of the heart such that said rotation stretches the surgical site, and a first stopper disposed on the first finger for preventing undesired rotation of the first finger to isolate the surgical site. |
| 2. | Canceled. |
| 3. | The device of claim 1 further comprising a second finger having a clinging accessory adapted to attach the second finger to the heart. |
| 4. | The device of claim 3 further comprising a link coupling the first finger to the second finger. |
| 5. | The device of claim 1 wherein the first finger is cylindrical. |
| 6. | The device of claim 1 wherein the clinging accessory comprises a plurality of tines. |
| 7. | The device of claim 1 wherein the clinging accessory comprises a plurality of suction points. |
| 8. | The device of claim 1 wherein the clinging accessory comprises a rough textured surface. |
| 9. | The device of claim 1 wherein the first joint comprises a rotatable handle coupled in a sleeve. |
| 10. | The device of claim 9 wherein the first stopper is configured such that the rotatable handle comprises at least one notch and the sleeve has at least one cooperating rib. |
| 11. | The device of claim 9 wherein the first stopper is configured such that the rotatable handle comprises at least one rib and the sleeve has at least one cooperating notch. |
| 12. | The device of claim 3 further comprising a second joint disposed on the second finger adapted such that the second finger may rotate on a surface of the heart. |
| 13. | The device of claim 3 further comprising a second stopper disposed on the second finger for preventing undesired rotation of the second finger. |
| 14. | The device of claim 4 wherein the link comprises : a ball disposed between the first finger and the second finger adapted to secure attachment to a stabilizing member; a first attachment bar coupled between the first finger and the ball; and a second attachment bar coupled between the second finger and the ball. |
| 15. | The device of claim 4 wherein the link comprises: a first stabilizing member associated with the first finger; a second stabilizing member associated with the second finger ; and a retractor adapted to couple the first stabilizing member to the second stabilizing member. |
| 16. | The device of claim 9 wherein the handle comprises an 0ring groove adapted to secure an 0ring about an end of the handle. |
| 17. | A method of isolating a cardiac surgical site, comprising the steps of : disposing a first finger on a heart surface having a longitudinal axis ; clinging the first finger to the heart surface; disposing a second finger on the heart surface; clinging the second finger to the heart surface; rotating the first finger about the longitudinal axis to achieve selective isolation of a portion of the heart surface, and locking the first finger to prevent rotation. |
| 18. | The method of claim 17 further comprising the step of rotating the second finger to further achieve the selective isolation of the portion of the heart surface. |
| 19. | The method of claim 18 wherein the step of rotating the first finger and the step of rotating the second finger are accomplished at approximately the same time. |
| 20. | The method of claim 17 further comprising the step of compressing the first finger into the heart surface. |
| 21. | The method of claim 17 further comprising the step of lifting the first finger while maintaining the cling to the heart surface. |
| 22. | Canceled. |
| 23. | The method of claim 17 further comprising the step of locking the second finger to prevent rotation. |
| 24. | The method of claim 17 wherein either of said clinging steps comprises penetrating the surface of the heart. |
| 25. | The method of claim 17 wherein either of said clinging steps comprises applying suction to the surface of the heart via the first finger and the second finger. |
| 26. | The method of claim 17 wherein either of said clinging steps comprises applying the first or second fingers having a rough texture surface adapted to frictionally grip the surface of the heart. |
| 27. | The method of claim 17 further comprising the step of compressing the first finger and the second finger into the heart surface. |
| 28. | The method of claim 17 further comprising the step of lifting the first finger and the second finger from the heart while maintaining the cling to the heart surface. |
| 29. | A device for isolating a cardiac surgical site, comprising a first support means having a longitudinal axis and a clinging means for attaching the first support means to a heart; a second support means having a clinging means for attaching the second support means to the heart; a rotating means disposed on the first support means so that the first support means may rotate about the longitudinal axis on a surface of the heart; an attaching means for connecting the first support means to the second support means; and a locking means disposed on the first support means for preventing undesired rotation of the first support means. |
| 30. | Canceled. |
| 31. | A device for isolating a cardiac surgical site, comprising a first and second finger, each finger having a longitudinal axis and a clinging accessory adapted to attach to a heart, wherein at least one of the fingers may rotate about its longitudinal axis on a surface of the heart such that the rotation stretches a surgical site, and at least one of the fingers has a varying axial diameter with respect to its longitudinal axis. |
| 32. | The device of claim 31 further comprising a link coupling the first finger to the second finger, and a stabilizing member coupling to the link. |
| 33. | The device of claim 32 wherein the link comprises a ball disposed between the first finger and the second finger adapted to secure an attachment to the stabilizing member; a first attachment bar coupled between the first finger and the ball; and a second attachment bar coupled between the second finger and the ball. |
| 34. | The device of claim 32 wherein the stabilizing member comprises : a socket for coupling with the link, a flexible arm with a first end and a second end wherein the first end couples to the socket, a tightening device coupled to the flexible arm for fixing the position of the flexible arm, and a mounting device coupled to the second end of the flexible arm. |
| 35. | The device of claim 31 wherein at least one finger is cylindrically convex. |
| 36. | The device of claim 31 wherein at least one finger is cylindrically concave. |
| 37. | The device of claim 31 wherein at least one finger is camshaped. |
| 38. | The device of claim 31 wherein the clinging accessory comprises a plurality of tines, and each tine having a distal end and proximal end such that the proximal end is coupled to a surface of the finger. |
| 39. | The device of claim 38 wherein the tines are made entirely or in part of a material selected from the group consisting of stainlees steel, plastic and nylon. |
| 40. | The device of claim 38 wherein the distal end is hooked shaped. |
| 41. | The device of claim 38 wherein the tines are straight. |
| 42. | The device of claim 38 wherein the distal end has an enlarged spherical head. |
| 43. | The device of claim 38 wherein the length of each tine varies according to its radial position on a circumference of an outer surface of the respective finger. |
| 44. | The device of claim 31 wherein the clinging accessory comprises a rough textured surface. |
| 45. | The device of claim 31 further comprising a guard coupled to the first finger and the second finger. |
| 46. | The device of claim 45 wherein the guard has at least one element, wherein the element is longitudinally aligned with at least one finger such that the element partially covers the finger. |
| 47. | The device of claim 46 wherein the element has a crosssectional shape in the form of an arc. |
| 48. | The device of claim 46 wherein the guard further comprises a support coupled to at least one element such that at least one element is supported above the respective finger. |
| 49. | The device of claim 45 further comprising a spray tube coupled to the guard, wherein the spray tube comprises at least one spray nozzle positioned and directed so that fluids may be sprayed onto a surgical site. |
| 50. | The device of claim 49 further comprising a fluid supply controller coupled to the spray tube to regulate a flow of fluids. |
| 51. | The device of claim 50 further comprising a supply of fluids coupled to the fluid supply controller, wherein the supply of fluids are entirely or in part selected from the group consisting of saline solution, water, and air. |
| 52. | A device for isolating a cardiac surgical site, comprising at least one finger comprising a hollow cylinder with a plurality of openings therethrough, the at least one finger for engaging the surface of a surgical site, wherein the at least one finger may rotate on the surface of the site such that the surface of the site may be stretched. |
| 53. | The device of claim 52 further comprising a device for creating suction at the plurality of openings to facilitate engagement of the finger to the surface of the site. |
| 54. | The device of claim 52 wherein the respective openings are longitudinal slits radially spaced around a longitudinal axis of the hollow cylinder. |
| 55. | The device of claim 54 further comprising at least one cover partially surrounding a perimeter of the cylinder such that the plurality of openings are sealed when the finger is placed adjacent to the surface of the heart. |
| 56. | The device of claim 53 further comprising a second finger; a link coupling the at least one finger to the second finger ; and a stabilizing member coupling to the link. |
| 57. | The device of claim 56 wherein the link comprises a ball disposed between the first sleeve and the second sleeve adapted to secure attachment to a stabilizing member; a first attachment bar coupled between the first finger and the ball ; and a second attachment bar coupled between the second finger and the ball. |
| 58. | The device of claim 57 wherein the stabilizing member comprises a socket, a flexible arm with a first end and a second end where the first end couples to the socket, and wherein the second end couples to a tightening means and a mounting means. |
| 59. | A device to shield a heart stabilizer comprising a guard and a supporting member coupled to the guard such that the supporting member positions the guard over the heart stabilizer. |
| 60. | The device of claim 59 wherein the supporting member couples to the heart stabilizer such that the heart stabilizer supports the supporting member. |
| 61. | A device to shield a heart stabilizer, having at least one longitudinal member, comprising at least one element longitudinally aligned with the longitudinal member such that the element covers the longitudinal member. |
| 62. | The device of claim 61 wherein the element has a crosssectional shape in the form of an arc. |
| 63. | The device of claim 61 further comprising a supporting member coupled to the element such that the element is supported above the longitudinal member. |
| 64. | The device of claim 63 further comprising at least one spray tube coupled to the element, wherein the spray tube comprises at least one spray nozzle directed and positioned so that a flow of fluids may be sprayed onto a surgical site. |
| 65. | The device of claim 64 further comprising a fluid supply controller to regulate the flow of fluids. |
| 66. | The device of claim 64 wherein the fluids are selected entirely or in part from the group consisting of saline solution, water, carbon dioxide and air. |
| 67. | A device for cleaning a surgical site comprising a heart surface isolator and a spray tube comprising at least one spray nozzle directed at the surgical site so that a flow of fluids may be sprayed onto the surgical site. |
| 68. | The device of claim 67 further comprising a fluid supply controller to regulate the flow of fluids. |
| 69. | The device of claim 68 wherein the fluids are selected entirely or in part from the group consisting of saline solution, water, carbon dioxide and air. |
| 70. | A device for isolating a cardiac surgical site, comprising a first and second finger, each finger having a longitudinal axis and a clinging accessory adapted to attach to a heart, wherein at least one of the fingers may rotate about its longitudinal axis on a surface of the heart such that the rotation stretches a surgical site, and a guard coupled to the first finger and the second finger. |
| 71. | The device of claim 70 further comprising a link coupling the first finger to the second finger, and a stabilizing member coupling to the link. |
| 72. | The device of claim 71 wherein the link comprises a ball disposed between the first finger and the second finger adapted to secure an attachment to the stabilizing member; a first attachment bar coupled between the first finger and the ball; and a second attachment bar coupled between the second finger and the ball. |
| 73. | The device of claim 71 wherein the stabilizing member comprises : a socket for coupling with the link, a flexible arm with a first end and a second end wherein the first end couples to the socket, a tightening device coupled to the flexible arm for fixing the position of the flexible arm, and a mounting device coupled to the second end of the flexible arm. |
| 74. | The device of claim 70 wherein the guard has at least one element, wherein the element is longitudinally aligned with at least one finger such that the element partially covers the finger. |
| 75. | The device of claim 74 wherein the element has a crosssectional shape in the form of an arc. |
| 76. | The device of claim 74 wherein the guard further comprises a support coupled to at least one element such that at least one element is supported above the respective finger. |
| 77. | The device of claim 70 further comprising a spray tube coupled to the guard, wherein the spray tube comprises at least one spray nozzle positioned and directed so that fluids may be sprayed onto a surgical site. |
| 78. | The device of claim 70 further comprising a fluid supply controller coupled to the spray tube to regulate the flow of fluids. |
| 79. | The device of claim 70 further comprising a supply of fluids coupled to the fluid supply controller, wherein the supply of fluids are selected entirely or in part from the group consisting of saline solution, water, carbon dioxide and air. |
| 80. | A method of isolating a cardiac surgical site, comprising the steps of : guiding a first finger to a heart surface; clinging the first finger to the heart surface; guiding a second finger to the heart surface; clinging the second finger to the heart surface; and rotating at least one of the fingers about a longitudinal axis such that the rotation stretches a surgical site, and at least one of the fingers has a varying diameter. |
| 81. | The method of claim 80 further comprising the step of rotating the second finger to further achieve the selective isolation of the portion of the heart surface. |
| 82. | The method of claim 80 further comprising the steps of locking the first finger to prevent rotation. |
| 83. | The method of claim 81 further comprising the steps of locking the first finger and the second finger to prevent rotation. |
| 84. | The method of claim 80 wherein either of said clinging steps comprises frictionally engaging the surface of the heart. |
| 85. | The method of claim 80 further comprising the step of shielding the fingers. |
| 86. | The method of claim 80 further comprising the step of spraying the heart surface with a fluid mixture. |
| 87. | A method of isolating a cardiac surgical site, comprising the steps of : guiding a first finger to a heart surface; clinging the first finger to the heart surface using a suction force; guiding a second finger to the heart surface; clinging the second finger to the heart surface using a suction force; and rotating at least one of the fingers about its longitudinal axis such that the rotation stretches a surgical site. |
| 88. | The method of claim 87 further comprising the step of rotating the second finger to further achieve the selective isolation of the portion of the heart surface. |
| 89. | The method of claim 87 further comprising the steps of locking the first finger to prevent rotation. |
| 90. | The method of claim 88 further comprising the steps of locking the first finger and the second finger to prevent rotation. |
| 91. | The method of claim 87 further comprising the step of spraying the heart surface with a fluid mixture. |
FIELD OF THE INVENTION The invention relates generally to medical surgical devices, and more particularly to a device and method of stabilizing a surgical site during cardiac or cardiovascular surgery.
BACKGROUND OF THE INVENTION Heart disease and associated cardiovascular problems have become so common in the United States that over 400,000 open heart surgeries are performed each year. Traditionally, physicians would open the chest and stop the heart before performing a surgical procedure on the heart. However, medical practices have improved, and physicians now recognize that there are advantages to performing surgery on a beating heart. For example, performing surgery on a beating heart avoids the necessity to expose the heart to filters, oxygenators, tubes, and other devices. This decreases the trauma associated with stopping the heart, as well as avoids other dangers that stopping the heart poses to a patient. In addition, by avoiding the use of these devices, the physician can lower the expense of an operation. Furthermore, performing surgery on a beating heart lowers the risk of ischemic damage to heart and surrounding tissue.
Unfortunately, there are many difficulties and challenges which must be overcome to successfully perform surgery on a beating heart. For example, every time the heart beats, the heart moves. This makes it difficult to isolate a specific site on the heart for surgery. Furthermore, physicians typically must develop great skill and expertise to accommodate the movement of the heart with existing instruments which were designed for use with a heart that is stopped. Because of the increased demands of performing surgery on a beating heart, surgery on a beating heart often takes longer than surgery on a stopped heart. Fortunately, devices and methods are being developed which decrease the amount of time and
expertise it takes to identify and isolate a target vessel and thus, reduce the time it takes to perform open heart surgery.
One family of instruments which have been developed to facilitate surgery on a beating heart are known as cardiac immobilization devices (devices). A number of these devices function by attaching to the heart at two or more points. The points are then moved further apart, thus stretching the surface area of the heart about which surgery is to be performed (surgical site). The devices typically grip the heart surface by suction. Unfortunately, there are a number of disadvantages associated with these methods of isolating a surgical site.
Some cardiac immobilization devices often appear to be little more than steak tongs or clamps which have been slightly altered to attach to a heart surface. Other devices use flex links or rods to attach to a retractor and then use a metallic foot to stabilize the heart surface. Suction devices may comprise a plurality of suction cups, or may have at least one hollow cylinder with holes in it, which is then attached to a pump which pulls a vacuum at the holes.
Figure 1A (prior art) shows a cardiac immobilization device 130 attached to a heart surface 140. To perform open heart surgery, typically a chest retractor 110 is braced within a rib cage and used to maintain an opening in the chest wall 112 which provides access to the heart surface 140. A stabilizing member, such as a flexible arm assembly 120 is used to securely locate a cardiac immobilization device 130 upon the heart surface 140. Accordingly, the stabilizing member 120 is coupled to the retractor 110 via a clamp 126 and holds the cardiac immobilization device 130 in a predetermined position.
The flexible arm assembly 120 includes a flexible arm 124 which may be bent and twisted into various shapes and geometries to access different locations on the heart surface 140. At the end of the flexible arm 124 closest to the heart surface 140 is a socket 128 for attaching the flexible arm 124 to the cardiac immobilization device 130. At the other end of the flexible arm 124 is a handle 122 which when turned tightens a cable (not shown) within the flexible arm 124. The tightening of the cable makes the flexible arm 124 rigid and immobile. The tightening of the cable also tightens the socket 128, allowing the socket 128 to grip an object, such as a ball 132 (the ball 132 is part of the cardiac immobilization device 130).
The shown cardiac immobilization device 130 uses suction to attach to a surface of the heart 140. To attach the cardiac immobilization device 130 to the heart surface 140, the cardiac immobilization device 130 utilizes a foot plate 136 with holes thereunder (not shown) on which a vacuum is placed. The vacuum is maintained by air hoses 134 which are attached to an air pump (not shown) and the foot plate 136. Thus, the cardiac immobilization device 130 is held stationary on the heart surface 140 at the end of the flexible arm 124 of the flexible arm assembly 120 so that the heart surface 140 located within the foot plate 136 can be isolated.
One disadvantage of many tong type attachments is that they provide an uneven spread (the heart surface closest to the tong's hinge point is spread a smaller distance than the heart surface at the end of the tong).
There are also many disadvantages associated with using suction to isolate a surgical site. For example, many patients have a heart which is surrounded with fatty tissue. Since the fat surrounding the heart moves, when a physician uses a suction device to isolate a heart surface, the suction cups or suction holes attach to the fat (rather than the heart surface). The operative result of the device attaching to the fatty tissue is that the heart surface can still beat underneath the fatty tissue, which means that isolation and stabilization of the surgical site is poor.
Furthermore, the fatty tissue may be drawn into the device (at a hole, for example) by the suction, and may clog the suction device thereby stopping suction at the holes which are further along and at the end of the device. In addition, after attachment to the heart is made with a suction device, the ability to spread the heart surface is limited by the force of suction on the heart surface. Should the suction break, the device must be repositioned and reattached to the heart, which consumes time and is a nuisance to the physician. Furthermore, when strong enough suction is applied to the heart surface to achieve adequate spreading and to prevent slippage, the suction can cause blood to accumulate and clot just beneath the heart surface, a hematoma (this condition is also commonly referred to as a "heart hickie").
Therefore, what is needed is a device and method of isolating a surgical site for cardiac and cardiovascular surgery. The device should contact a minimal surface of the heart, accommodate the non-planar geometry of the heart, grip the heart
firmly, yet gently, and should be easy to apply to and to remove from a beating heart. The present invention provides such a device and method.
Blood in arteries can spew out from the anastomosis site during surgery, which reduces visualization for the surgeon. Periodically, blood must be manually removed by an assistant typically with a blower. The surgeon, therefore, must stop the procedure so that blood can be removed. What is needed, therefore, is a stabilization device integral with a blower device so that the blower could be operated remotely without interfering with the procedure.
SUMMARY OF THE INVENTION The present invention provides a device and method for isolating a heart surface, particularly, the surface of a beating heart during cardiovascular surgery.
The device utilizes rotation to attach to the heart surface and then spread the heart which isolates the spread portion of the heart for surgery.
Disclosed is a device for isolating a cardiac surgical site. The device generally comprises a first finger (which may be cylindridal) having a clinging accessory for attaching the first finger to a heart. Furthermore the device could comprise a second finger having a clinging accessory for attaching the second finger to the heart, a first joint disposed on the first finger so that the first finger may rotate on a surface of the heart such that said rotation stretches a surgical site, and a link for attaching the first finger to the second finger. In addition, a first stopper may be disposed on the first finger for preventing undesired rotation of the first finger to isolate the surgical site.
The accessory for attaching could comprise a plurality of tines, a plurality of suction points, or a rough textured surface such as a surface similar to sandpaper, for example. In addition, the first joint or a second joint (disposed on the second finger) could comprise a rotatable handle coupled in a sleeve. Furthermore, the first stopper or a second stopper (disposed on the second finger) could be configured such that the rotatable handle comprises at least one notch and the sleeve has at least one rib. Likewise, the first stopper or the second stopper (disposed on the second finger) could be configured such that the rotatable handle comprises at least one rib and the sleeve has at least one notch. The handle could comprise an O-ring groove for securing an O-ring about an end of the handle.
The link could comprise a ball and socket joint disposed"between tti"'e-rst finger and the second finger for providing multi-axis articulation of the first finger and the second finger, as well as a first attachment bar coupled between the first handle and the ball and socket joint, and a second attachment bar coupled between the second handle and the ball and socket joint. Conversely, the link could comprise a first ball and socket joint associated with the first handle, a second ball and socket joint associated with the second handle, and an attachment bar for coupling the first ball and socket joint to the second ball and socket joint.
More generally, the present invention provides a means for isolating a cardiac surgical site. The means for isolating comprises a first support means, such as a finger or a functional equivalent, having a clinging means for attaching the first support means to a heart, and a second support means, such as a second finger or a functional equivalent, having a clinging means for attaching the second support means to the heart. The means for isolating also includes a rotating means, such as a cylinder or a functional equivalent, disposed on the first support means so that the first support means may rotate on a surface of the heart, a locking means, such as a rib and notch, or a functional equivalent, disposed on the first support means for preventing undesired rotation of the first support means. An attaching means, such as a link or a functional equivalent, connects the first support means to the second support means.
There is also provided a shield or guard attached to the fingers so the clinging means will not catch sutures, gloves or tissues during the medical procedure. The shield may also have a sprayer for washing the surgical site.
In another embodiment, the present invention provides a method of isolating a cardiac surgical site. The method comprises disposing a first finger on a heart, clinging the first finger to the heart surface, disposing a second finger on a heart, clinging the second finger to the heart surface, and rotating the first finger for achieving selective isolation of cardiac tissue. The method may further comprise rotating the second finger, locking the first finger to prevent rotation, or locking the second finger to prevent rotation. The method may also provide that clinging comprises penetrating the surface of the heart, applying suction to the surface of the heart, or applying an abrasive surface for frictionally gripping the surface of the
heart. In addition, when applying a finger, the method may further comprise the step of compressing the finger onto the heart surface. Furthermore, the method could include the step of elevating the finger while maintaining its attachment to the heart surface.
The rotational action of the present invention allows the physician to overcome problems associated with fatty tissue on the heart surface, to adjust the spread of the heart surface during surgery, and to attach and detach the present invention from the heart quickly.
BRIEF DESCRIPTION OF THE DRAWINGS Other aspects of the invention, including specific embodiments, are understood by reference to the following detailed description taken in conjunction with the drawings in which: Figure 1A (prior art) shows a cardiac immobilization device attached to a heart surface; Figure 1 is an isometric view of one embodiment of a device according to the teachings of the present invention; Figure 2 shows a side view of the device shown in figure 1; Figure 3 is an exploded view of one arm of the device of figure 1; Figure 4 is a front view of the finger having tines attached to the holes: Figure 5 is a cut rear view of the handle taken along line 5-5 of figure 3; Figure 6 shows the sleeve in greater detail; Figure 7 is a cut side view of an arm in a locking position where the locking position is defined as the position of the device when the rib is set in a notch; Figure 8 illustrates the sleeve relative to the handle when the device is in a rotatable position; and Figure 9 is a flow diagram of one method of practicing the present invention.
Figure 10 is an isometric drawing of the present invention which includes a flexible arm assembly.
Figure 11a is a side view of another embodiment of the present invention. Figure 11b is an isometric drawing of the embodiment shown in figure 1 la.
Figure llc is a front view of the embodiment shown in figure lla.
Figure 12a is a side view of another embodiment of the present invention.
Figure 12b is an isometric drawing of the embodiment shown in figure 12a.
Figure 13a is a side view of another embodiment of the present invention.
Figure 13b is a portion of a front view of the embodiment shown in figure 13a.
Figure 14a is a side view of another embodiment of the present invention.
Figure 14b is an exploded view of figure 14a.
Figure 14c is a section view through fingers 1410 and 1412.
Figure 14d is a section view of fingers 1410 and 1412 adjacent to the surface of a heart.
Figure 15a is a front view of the fingers 10 and 12 (figure 2) with another embodiment of a clinging accessory.
Figure 15b is a front view of the fingers 10 and 12 (figure 2) with another embodiment of a clinging accessory.
Figure 15c is a front view of the fingers 10 and 12 (figure 2) with another embodiment of a clinging accessory.
Figure 15d is a front view of the fingers 10 and 12 (figure 2) with another embodiment of a clinging accessory.
Figure 15e is a front view of the fingers 10 and 12 (figure 2) with another embodiment of a clinging accessory.
Figure 16a is an isometric view of one embodiment of the present invention.
Figure 16b is an exploded isometric view of figure 16a.
Figure 16c is an isometric view of one embodiment of the present invention.
Figure 16d is an exploded isometric view of figure 16a.
Figure 17a is an isometric drawing of another embodiment of the present invention.
Figure 17b is a combination top view and schematic view of another embodiment of the present invention.
References in the detailed description correspond to like references in the figures unless otherwise indicated.
DETAILED DESCRIPTION The present invention provides devices and methods for isolating a heart surface, and particularly the surface of a beating heart, during cardiovascular surgery. The device attaches to the heart surface and then utilizes rotation to spread the heart and isolate the spread portion of the heart (surgical site) for surgery. The rotation action of the present invention allows the physician to overcome problems associated with fatty tissue on the heart surface, to adjust the spread of and tension on the surgical site during surgery,. and to attach and detach the device from the heart quickly. Other advantages and uses of the present invention will be apparent to those of ordinary skill in the art from the following description of the drawings.
Figure 1 is an isometric view of one embodiment of a device according to the teachings of the present invention. The device generally comprises a pair of stainless steel fingers 10,12 which are mounted in stainless steel handles 14,16.
Of course, the fingers 10,12 and the handles 14,16 may be made of any other material, such as plastics, rubber, other metals, or composite materials, for example. Furthermore, the fingers 10,12 and the handles 14,16 could be formed, cut or molded as a single unit. Stainless steel sleeves 20,22 fit over the handles 14, 16 and are held in place about the handles 14,16 by resilient 0-rings 24,26. The combination of a finger, a handle, a sleeve, and an O-ring is called an"arm."To couple two arms together, the sleeves, 20,22 are attached together by a link 18 which is shown in figure 1 as a ball and socket assembly, for example. the combination of both arms and link 18 is known as a finger assembly 36.
A link is any device or collection of devices used to associate a finger and a stabilization device, such as another finger. The link 18 of figure 1 comprises a stainless steel ball 17, which is weldedly coupled to each sleeve 20,22 by stainless steel attachment bars 19. The ball 17 is securely fastened in a socket 128 of the flexible arm assembly 120 shown in figure 1 a. Of course, other link devices may be used. For example, the link 18 could comprise an attachment bar alone. Likewise, stabilizing members may have a variety of designs, and these other designs may use other types of mechanical links to maintain a predetermined distance between the fingers.
Figure 2 shows a side view of the device illustrated in Sgurel"Finger"lOTias a plurality of fines 30 which function as a clinging accessory to attach the device to a heart surface. Accordingly, a clinging accessory provides a finger traction to a heart surface. Other clinging accessories (such as suction holes, suction cups, rough textured surfaces (such as sandpaper), barbs, or electrostatic attachment, for example) are well known in the art and may be adapted for use with the present invention. Also, the handle 14 has a knob 42 which extends higher than the sleeve 20 so that the physician may grasp and rotate the handle 14. The sleeve 20 has a plurality of notches 50, and the handle 14 has a rib 40 which fits securely inside of one notch 50. Accordingly, the combination of the rib 40 and a notch 50 together form a stopper which may be set to prevent rotation of the fingers 10,12 as discussed below. A better understanding of the form and function of the present invention may be gained by examining the devices'individual components and their interrelations.
Figure 3 is an exploded view of one arm of the device of figure 1. In figure 3, the finger 10 is seen to possess a plurality of holes 32 which accept the tines 30.
Although three holes 32 and three tines 30 are shown in figure 3, it should be understood that the finger 10 may have any number of holes 32 and a corresponding number of tines 30. The holes 32 are of sufficient depth so that the tines 30 may be attached therein with solder, glue or by other means. Although the finger 10 of figure 3 is shown to be cylindrical, it should be understood that a finger may have any geometry so long as it may attach to a heart surface and stretch a surgical site by rotating. Finger 10 also has an attachable portion 34 which fits securely in a cylinder 44 of the handle 14.
The handle 14 has a grippable knob 42 which is capable of being securely grasped and turned. Abutting the grippable knob 42 is the rib 40. At the other end of the handle 14 is a groove 48 which functions as an O-ring seat. The end of the handle 14 having the groove 48 is preferably shaped like a hemisphere to facilitate placing the O-ring 24 onto the groove 48.
Figure 4 is a front view of the finger 10 having tines 30 attached and holes 32. From figure 4 it is seen that the tines 30 have a hook shape which minimizes heart surface penetration and which facilitates the release of the tines from the
heart muscle. The tines are of a stiffness so that should a stretching'rotation" require the releasing of the tines from the heart surface, they may release without ripping the heart surface, and then re-penetrate the heart surface at a new location, if necessary. Also, it should be noted that the tines point generally in the direction of the grabbing rotation. Although four linear rows are shown in figure 4. the invention may have any number of rows which may include non-linear, or even apparently random, row formations. In one embodiment, the tines have a length of about one quarter inch. Of course, other methods of attachment are well known in the art. These include but are not limited to, rough textured surfaces such as sandpaper, barbs, electro-statics, and suction holes, for example.
Figure 5 is a cut rear view of the handle 14 taken along line 5-5 of figure 3.
From this view it can be seen that the grippable knob 42 extends both above and below the cylinder 44. The portion of the grippable knob 42 extending below the cylinder 44 forms a lip 46 which is of a width that matches the circumference of the sleeve 20 such that when the sleeve 20 fits over the cylinder 44 the outside of the lip 46 aligns with the outside of the sleeve 20. This view also illustrates that the rib 40 is of a width and size to accommodate the notch 50.
Figure 6 shows the sleeve 20 in greater detail. As shown, sleeve 20 has a plurality of notches 50. Although four notches are shown in figure 6, the sleeve 20 may have any number of notches 50 so that the rotation of the fingers may be held at varying degrees of rotation. In addition, one side of the sleeve 20 has a hole 54, or other surface preparation, for accepting the attachment bar 19 (of course, the sleeve 20 may have other apertures attached to it depending on the link 18 used; likewise, the sleeve 20 may be connected to a link via welding, which avoids the need for apertures or modifications). The O-ring 24 pushes against the handle 14 so as to apply tension to the sleeve 20 to securely force a rib 40 over notch 50, as described below. Accordingly, the sleeve 20 has a cylinder 56 which at the end opposite the notches 50 has a tapered lip 52 which is shaped to accept the O-ring 24 to minimize wear on the O-ring 24.
Figure 7 is a cut side view of an arm in a locking position where the locking position is defined as the position of the device when the rib 40 is set in a notch 50.
Also, when in the locking position, the sleeve 20 fits securely against the handle 14.
In the locking position, the 0-ring 24 in groove 48 exerts a force upon the sleeve 2U" to keep it in place abutting the handle 14. Furthermore, note that the rib 40 also abuts the sleeve 20, indicating that a notch 50 (not shown) is in position about the rib 40, forming a stopper.
Figure 8 illustrates the sleeve 20 relative to the handle 14 when the device is in a rotatable position. Here, it can be seen that the sleeve 20 is pushed against the O-ring 24, causing distortion of the O-ring 24. The separation of the sleeve 20 from the grippable knob 42 removes the notch 50 from the rib 40 and allows for the handle 14 to be rotated. Accordingly, as the handle 14 rotates so does the finger 10.
Then, depending on the direction of the rotation, the heart surface will either be stretched or compressed.
A three dimensional drawing of the present invention is illustrated in Figure 10 in which finger assembly 36 (figure 1) is mounted on a flexible arm assembly 190. Flexible arm assembly 190 includes a flex arm 191 which may be bent and twisted into various shapes to access different locations on the heart surface.
Socket 192 is on one end of flexible arm 191. Socket 192 mates with ball 132 (figure 1). At the other end of flex arm 191 is universal retractor mounting 194 and variable tension lock 195. Universal retractor mounting 194 mounts to chest retractor 110 (figure la). Variable tension lock 195 tightens a cable (not shown) within flex arm 191. This tightening causes flexible arm 191 to become rigid and immobile, and thus allows fingers 10 and 12 remain placed against the heart after placement.
One method of implementing the present invention uses the above disclosed device. Accordingly, figure 9 is a flow diagram of one embodiment of a method according to the present invention. First, the chest cavity is cut and opened and held securely in place, typically by a chest retractor, in an expose heart and place retractor step 90. As advances in open heart surgery are made, less intrusive means of exposing the heart for surgery will be developed and this method should in no way be read to limit its use to open chest cavities, or in the use of retractors.
Following the securing of the chest retractor, flex arm 191 with a finger 10 attached thereto (figure 10) is attached to the retractor in a fix flex arm step 91.
Next, finger 10 is placed about the area of the heart on which surgery is to be
performed in a finger placement step 92. Then, the finger 10 is attached to the heart in a finger attachment step 94 and in a make flex arm rigid step 95, the flex arm is made stiff, typically by tightening variable tension lock 195 (figure 10).
The fingers 10,12 may be placed together on the heart in a single finger placement step 92 and then attached to the heart in a single finger attachment step 94, or each finger 10,12 may be placed on the heart surface, and then attached to the heart surface independently of each other. In any event, the result is that the finger 10 lies on one side of the surgical site, and a second finger 12 lies generally on the opposite side of the surgical site. Optionally, to achieve better traction in a following rotation step, and thus better isolation of the heart surface, the fingers 10,12 may be gently pressed onto the heart (the fingers do not penetrate the heart surface).
Next, in a finger rotation step 96, at least one finger is rotated in a direction which increases the surface tension of the heart surface across the surgical site until a desired tension is achieved across the surgical site area. Once the desired tension is achieved on the heart surface, the tension is maintained by locking the device in that current state of rotation in a position locking step 98. Yet even better heart surface isolation may be achieved at this point by lifting the fingers 10,12 (and thus the isolated heart surface) slightly. Surgery may then be performed at the isolated surgical site on the heart as well as on any veins or arteries going to or from the surgical site. If necessary, during surgery, the handles may be rotated in either a gripping or releasing direction to increase or decrease the tension at the surgical site. Then, after the surgery is completed, the above detailed steps may be reversed and the device removed.
Figures 11-17 describe various examples and embodiments of the present invention. For brevity and clarity, a description of those parts which are identical or similar to those described in connection with other embodiments illustrated in FIGURES 1 through 10 will not be repeated. Reference should be made to the foregoing paragraphs with the following description to arrive at a complete understanding of these embodiments. It is understood that features of various examples and embodiments may be interchanged, combined or otherwise reconfigured.
Figure lla is a side view of finger assembly 201"In Figure"Ila, linger'210 is hidden from view by finger 212. Fingers 210 and 212 are similar to fingers 10 and 12 (figure 1), except that fingers 210 and 212 have a convex cylindrical shape.
The diameter of fingers 210 and 212 at end 202 is approximately the same as the diameter at end 204. The diameter of fingers 210 and 212 gradually increases from end 202, at point B, to a maximum diameter at point A. Point A is approximately at the longitudinal midpoint between end 202 and 204. The diameter of fingers 210 and 212 at point A is typically twice the diameter of fingers 210 and 212 at point B. However, the diameter of fingers 210 and 212 at point A could be any multiple of the diameter at point B.
Figure l lob is an isometric drawing of finger assembly 201 showing fingers 210 and 212 adjacent to the surgical site. In figure 11b, finger 210 is placed on one side of the surgical site 206 and finger 212 is placed on the other side of surgical site 206. In a method described previously in reference to an earlier embodiment, fingers 210 and 212 may be rotated in a direction which increases the surface tension of the heart surface across the surgical site. The surface tension of the heart surface is represented in figure 11b as arrows 220 through 238. As can be seen in figure 1 lob, arrows 224 and 234, which are approximately at the longitudinal midpoint of fingers 210 and 212, are significantly longer than arrows 220,228,230, and 238 which represent the relative surface tension are at the ends of fingers 210 and 212. This increase in surface tension at the center of the surgical site is due to the fact that a portion of finger 210 at the midpoint must travel a greater distance than the portion of finger 210 at ends 202 or 204 for the same amount of angular rotation.
This concept is illustrated in figure llc, which is a front view of finger 212.
Point B is a point at end 202 on the outer circumference of finger 212. Point A is also on the outer circumference of finger 212, but close to the longitudinal midpoint of finger 212 (figure lla). As illustrated in figure lie, when finger 212 is rotated about its longitudinal axis through an angle a, point B moves to point B'. Similarly, point A moves to A'. Point A moves more than point B. In fact, the greater the relative diameter of the circumferences, the greater the relative movement between
point A and point B along their respective circumferences. Tnis increa in movement causes a corresponding increase in surface tension. Thus, the surgeon can increase the surface tension in the middle of the surgical site. The relative distribution of surface tension is illustrated in figure 11b as arrows 220 through 238.
Figure 12a is a side view of finger assembly 201 with fingers 310 and 312.
In Figure 12a, finger 310 is hidden from view by finger 312. Fingers 310 and 312 are similar to fingers 10 and 12, except that fingers 310 and 312 have a concave cylindrical shape. The diameter of fingers 310 and 312 at end 302 is approximately the same as the diameter at end 304. In this embodiment, the diameter of fingers 310 and 312 gradually decreases from end 302, at point C, to a minimum diameter at point D. Point D is approximately at the longitudinal midpoint between end 302 and 304. The diameter of the fingers at point C could be any multiple of the diameter at point D, depending on the amount of relative surface tension desired and the material used.
Figure 12b is an isometric drawing of finger assembly 201 showing fingers 310 and 312 adjacent to the surgical site. In figure 12b, finger 310 is placed on one side of the surgical site 206 and finger 312 is placed on the other side of surgical site 206. In a procedure similar to the one described in the first embodiment, fingers 310 and 312 are be rotated in a direction which increases the surface tension of the heart surface across the surgical site. The surface tension of the heart surface is represented in figure 12b as arrows 320 through 338. As can be seen in figure 12b, arrows 324 and 334, which are approximately at the longitudinal midpoint of fingers 310 and 312, are significantly shorter than arrows 320,328,330, and 338 which represent the surface tension at the ends of fingers 310 and 312. This decrease in surface tension at the center is due to fact that the portion of finger 310 at the longitudinal midpoint travels a shorter distance than the portion at ends 302 or 304 for the same amount of angular rotation. The surgeon, therefore, can thus decrease the surface tension in the middle of the surgical site relative to the outside area of the surgical site.
In Figure 13a, fingers 410 and 412 have a camber on one side to form a cam shaped cross-section. The diameter of fingers 410 and 412 at end 402 is
approximately the same as the diameter at end 404. In this embbdimeht, the diameter of fingers 410 and 412 gradually increases from end 402, at point E, to a maximum diameter at point F. Point F is approximately at the longitudinal midpoint between end 402 and 404.
Figure 13b is a front view of finger 412. In this view, end 402 is shown as circle 406. Outline 408 represents the cross-sectional outline of finger 412 at approximately point F (figure 13a). As illustrated in figure 13b, the cross-sectional shape of finger 412 is that of a cam.
This embodiment allows the amount of surface tension to be vary, depending on the circumstances and the surgeon's preferences. If the surgeon feels that greater tension across the surgical site is important, the surgeon can position fingers 410 and 412 with camber side 410 down, facing the heart's surface. On the other hand, if the surgeon desires a more uniform amount of tension across the entire surgical site, the surgeon can keep camber side 410 up, away from the heart.
As explained previously, there are several disadvantages associated with using suction to isolate a surgical site. Regardless of the disadvantages, many surgeons may prefer to use suction to stabilize the heart. One of the primary disadvantages with using suction is that the horizontal surface tension of the heart must be maintained by a vertical suction force. As explained previously, there are disadvantages with using only a vertical suction force maintain a horizontal, surface tension.
This embodiment of the present invention overcomes many of the limitations of the prior art because it addition to the vertical suction force, this embodiment also increases the surface tension by using a horizontal rotating force.
Turning now to figure 14a, which is a side view of this embodiment. Because this is a side view, finger 1410 is hidden from view by finger 1412. In this embodiment, finger 1412 is partially surrounded by cylindrical cover 1418.
Figure 14b is an exploded view of figure 14a. Finger 1412 has longitudinal slits 1414 around its perimeter. Finger 1412 also has attachable portion 34 which, similar to the first embodiment, fits securely in cylinder 44 of the handle 14 (figure 3). However, in this embodiment, attachable portion 34 is hollow and has
connection 1420 at one end. Vacuum tube 1422 fits tightly over connection 14'20 such that a hermetic seal is created between vacuum tube 1422 and connection 1420. Similar to the first embodiment, sleeve 20 fits over cylinder 44 and is restrained by o-ring 24.
Figure 14c is a section view through fingers 1410 and 1412. Fingers 1410 and 1412 have hollow cylindrical openings 1426 and 1428 running longitudinally through their respective centers. Slots 1414 form a plurality of ribs 1416 and 1417 within in fingers 1410 and 1412. Also shown in figure 14c, are covers 1418 and 1419 which partially surrounds fingers 1410 and 1412. Each of covers 1418 and 1419 have a single large slit 1422 and 1424. Fingers 1410 and 1412 rotate within and relative to covers 1418 and 1419.
Figure 14d is a section view of fingers 1410 and 1412 adjacent to the surface of a heart. In operation, a vacuum pump (not shown) is attached to vacuum tube 1422 (figure 14b) which creates a low pressure in vacuum tube 1422. This low pressure is transferred through the hollow portion of attachment portion 34 to cylindrical openings 1426 and 1428. The low pressure causes a suction force in slits 1414 which allow fingers 1410 and 1412 to attach to heart surface through suction as shown in figure 14d. Finger 1410 can then be rotated with respect to finger 1412 and vice versa. This rotation causes a horizontal surface tension represented by arrows 1430 and 1432, and thus the surgical site can be stabilized by a lateral force -not a vertical force as in the prior art.
Various clinging accessories may be used to engage fingers 10,12,210,212, 310,312,410, and 412 to the surface tissue of the heart. The clinging accessory previously shown uses plurality of tines 30 in figures 1-4,7-8,11-13. As previously discussed, tines 30 are only one form of numerous clinging accessories available.
Other clinging accessories (such as suction holes, suction cups, rough textured surfaces (such as sandpaper), barbs, or electrostatic attachment, for example) may be used with any embodiment of the present invention. It is understood that as fingers are gently pressed against the heart, they do not penetrate the heart surface but instead engage the surface in a manner that enables manipulation of tissue without tissue damage.
Nylon, for instance, may be less traumatic to the heart tissue than the use
of tungsten carbide tines. Figure 15a is a front view of the fingers 10'and l2"tBguTe 2) where finger 10 is surrounded by a plurality of nylon hooks 1502 and figure 12 is surround by a plurality of nylon hooks 1504, similar to that used in a Velcro' fastening system. Hooks 1502 are approximately. 050 inches in length. Hooks 1502 are designed to minimize heart surface engagement. The hooks are of a stiffness so that should a stretching rotation require the releasing of the tines from the heart surface, they may release without ripping the heart surface, and then engage the heart surface at a new location, if necessary. Also, it should be noted that the tines point generally in the direction of the grabbing rotation.
Another embodiment of clinging accessory is illustrated in figure 15b, which employs a plurality of straight nylon bristles 1508 surrounding finger 12 and nylon bristles 1506 surrounding finger 10. Bristles 1506 and 1508 gently engage into the heart tissue.
Figure 15c is a front view of fingers 10 and 12 where the finger elements are surrounded by a plurality of nylon bristles 1510 and 1512, respectively. In this embodiment, bristles 1510 and 1512 have tiny balls at the protruding end of the bristles. These different embodiments have unique advantages and disadvantages and offer the surgeon more choices based on personal preferences. For instance, bristles 1508 and 1506 offer better traction than bristles 1510 and 1512. However, bristles 1510 and 1512 reduce trauma to the heart tissue.
Figure 15d is a cross section view of fingers 10 and 12 adjacent to heart tissue 1520. In this embodiment, a plurality of straight nylon bristles 1516 and 1514 are used as the clinging accessory, however bristles 1516 and 1514 use bristles of a progressively different degree of length. As illustrated in figure 15d, bristles 1516 and 1514 are longer on the top side of fingers 10 and 12 than the bristles on the bottom side. Thus, the shorter bristles are pointed towards heart tissue 1520.
Similarly, figure 15e is a cross section view of fingers 10 and 12 adjacent to fat tissue 1522 and heart tissue 1520. In this figure, the longer bristles of bristles 1516 and 1514 pointed down towards the heart tissue. This embodiment provides the surgeon with the option of varying the degree of engagement into the heart tissue.
Depending on the condition and location of the surgical site, heart tissue
1520 may be surround by fat tissue 1522 (figure 15e). On the other hand, ixfliittlie ör no fat tissue surrounds the surgical site, the surgeon can simple rotate fingers 10 and 12 so that the shorter bristles are adjacent to heart tissue 1520, as illustrated in figure 15d.
As discussed previously, the finger elements use clinging accessories to"grab" the tissue of the heart. The clinging accessories can be hooks, tines, bristles or other rough surfaces. These clinging accessories also tend to catch and snag sutures used by surgeons during the procedure. To avoid snagging sutures, gloves, and transplanted arteries, a suture guard may be positioned over the finger elements. Such a device is illustrated in figures 16a.
Figure 16a is an isometric view looking down upon finger assembly 36 as it is attached to suture guard 1602. Figure 16b is an exploded isometric view of figure 16a showing how suture guard 1602 fits between sleeve 20 and 22. Suture guard 1602 can be made of metal, plastic or any other acceptable material. Plastic is the preferred embodiment because it can be molded into intricate shapes easily, is lightweight, and it can be clear. Using clear plastic allows the surgeon to see through suture guard 1602, which allows the surgeon to see as much of the surgical site as possible. Figure 16c is an isometric view looking up at the bottom of finger assembly 36 when it is attached to suture guard 1602. Figure 16d is an exploded view of figure 16c.
Turning now to figure 16d, suture guard 1602 has fins 1604 through 1609 which are shaped to press against the outside perimeter of sleeves 20 and 22. This dual pressure against sleeves 20 and 22 restrains suture guard 1602 and prevents suture guard 1602 from slipping off sleeves 20 and 22. Suture guard 1602 also has plastic legs 1612 and 1614, which cantilever over fingers 10 and 12 to protect any sutures from tines 30.
Figure 17a is an isometric drawing of finger assembly 36 attached to an embodiment of the suture guard with a blower. In this embodiment, suture guard 1702 has spray tubes 1704 and 1706 along the inside edge of legs 1712 and 1714.
Spray tubes 1704 and 1706 have a plurality of openings or nozzles 1708. Spray tubes 1704 may be independent of legs 1712 or 1714 or they may be molded together, and thus become integral with legs 1712 and 1714. In another
embodiment, legs 1712 and 1714 could simply be hollow and Xläve a-plurålityRof nozzles 1708 along the inside surface.
Spray tubes 1704 and 1706 are hermetically joined with y-connection 1710 to pressure tube 1712. Pressure tube 1712 is a flexible plastic or rubber tube capable of delivering a pressurized fluid from a water/air supply (not shown) to spray tubes 1704 and 1706. The pressurized fluid exits through nozzles 1708.
Nozzles 1708 are positioned, or"aimed"at the surgical site such that when a fluid flows through them, a plurality of sprays 1714 are created which washes the surgical site.
Figure 17b is a combination top view and schematic view of suture guard 1702 attached to finger assembly 36. Finger assembly 36 is mounted on a flexible arm assembly 190, which includes a universal retractor mounting 194 and variable tension lock 195. As discussed previously, universal retractor mounting 194 mounts to chest retractor 110 (figure la). Pressured tube 1712 is shown running alongside of flexible arm assembly 190. It is important to note, that in another embodiment, pressured tube 1712 could also be incorporated into flexible arm assembly 190.
Attachment connection 1716 is either attached to or integral with universal retractor mounting 194. Attachment connection 1716 connects pressurized tube 1712 with attachment tube 1718. Pressurized tube 1718 is connected to water/air supply 1724. Between water/air supply 1724 and attachment connection 1716 is stop lock 1722 and metering valve 1720.
Water/air supply 1724, known in the art, can be a saline bag combined with a gas source, such as carbon dioxide. The gas in the source is kept under pressure.
Furthermore, there is a certain amount of head pressure in the saline if the saline is hangs above the surgical site. This combined pressure causes the fluid, which is a combination of gas and saline to flow through pressured tube 1718. Stop lock 1722 cuts off the fluid in the event that metering valve 1720 cannot control the flow of fluid through pressured tube 1718. Under normal circumstances, however, metering valve 1720 controls the flow of fluid through pressured tube 1718, and ultimately, to nozzles 1708 (figure 17a). Metering valve 1720 is a roller clamp valve and is well known in the art.
The fluid continues to move through pressurized tube 1718 to pressured tube
1712. Pressured tube 1712 joins spray tubes 1704 and 1706 and y-connector 1710 (figure 17a). As previously discussed, the fluid then moves through spray tubes 1704 and 1706, out nozzles 1708 in the form of a fine spray 1714 (figure 17a). The fine spray washes the surgical site.
Though the invention has been described with respect to a specific preferred embodiment, many variations and modifications will become apparent to those skilled in the art upon reading the present application. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.
Next Patent: CONCENTRICALLY EXPANSIBLE NEEDLE RETRACTOR