Patent Application
20060095073
1. Field of the Invention
The present invention relates generally to the field of cardiovascular intervention, and more particularly to the field of devices and materials for inducing hemostasis in arteries during invasive procedures.
2. Summary of the Related Art
It is common in cardiac procedures to visualize arteries and veins with contrast medium. During heart catheterization and angiography for example, a surgeon will typically enter the cardiac system via the femoral artery in the groin. However, investigations via the femoral artery are especially difficult because of the high pressure against the artery wall. In a typical procedure, a surgeon will make a small incision in the femoral artery using a small diameter instrument. A guide is inserted into the incision and into the artery, and a catheter is threaded over the guide into the artery. Thereafter, the guide is removed and contrast medium is injected through the catheter into the artery.
After the investigation is completed, the catheter is withdrawn, leaving a wound in the femoral artery. Due to the high pressure within the femoral artery, the bleeding from the wound can be significant. A number of methods and devices have been developed to curtail this bleeding. For example, physicians may stem the bleeding manually by pressing at least one finger against a compressive bandage laid on the wound for about 20 minutes. This method is not satisfactory for a number of reasons. First, it is inconvenient for both patients and physicians and also requires valuable physician time. Furthermore, it is difficult for the physician to maintain a constant pressure for such a long period of time. Lastly, as these procedures are repeated many times a day, the repetitive strain on the hands of the physician will inevitably take its toll, potentially affecting the quantity of care made available to patients.
Several mechanical devices have also been proposed to curtail the bleeding from catheterization in the femoral artery. In general, the principle of these devices is the same: an external pressure is applied near the incision site in the femoral artery for about 20 minutes following completed catheterization. The pressure is to be set high enough to stop bleeding, but not so high that the blood flow is cut off down to the leg and foot.
However, although the devices themselves are designed to provide pressure against an incision site, the design and adaptability of these devices is limited. It can be appreciated that the cross-section of any portion of the human body, but most particularly the femoral region, is oval in shape. Accordingly, as the human body is not planar, there are 360 degrees of normal lines around any body surface. In spite of this fact, the existing art typically applies any pressure against the femoral incision in a downward direction. This direction is not necessarily perpendicular to the femoral artery, and thus any pressure placed on the artery will inevitably result in tangential and shearing forces that could cause discomfort to the patient and result in inadequate hemostasis and/or vascular complications.
Moreover, as the existing art is limited in its angular approach to applying pressure to the artery, the idiosyncrasies of individual patients can limit its effectiveness. These types of procedures are performed on individuals having 7% body fat as well as 37% body fat, and the accessibility of the femoral artery can vary greatly depending on each patient's body composition, shape, and muscle tone. The existing art does not include a method of ergonomically engaging the femoral artery in a manner that is adaptable for differing body shapes and sizes while maximizing patient comfort. There is a need in the art for such a device.
Accordingly, the present invention includes a device for inducing hemostasis in an artery. The device includes a base, a vertical member coupled to the base, a horizontal member slidably coupled to the vertical member, an angular selector slidably coupled to the horizontal member, a compression arm rotatably coupled to the angular selector, and a pressure pad coupled to the compression arm wherein the compression arm is selectively positioned along a horizontal axis, a vertical axis, and an angular position such that the pressure pad applies pressure to an artery. The device of the present invention may be used as a femoral artery clamp for post-catheterization of a wound site during cardiac procedures.
The horizontal member and angular selector include a number of locking mechanisms that are used to secure the device in position. The compression arm includes a compressor and a cam that are used in concert for providing an optimal force to drive the pressure pad. The compressor may include a spring mechanism for supplying a first amount of force, while the cam is adjustable for fine-tuning the amount of force from the compressor.
The pressure pad defines a number of surfaces that approximate the profile of a surgeon's hands, including both a convex portion and a planar portion for applying pressure in more than one place along the artery. The pressure pad is optionally constructed of a transparent material such that the physician can more easily see the contact site. The present invention also includes an area upon which a coagulant is placed accelerating hemostasis. The present invention also includes a method of inducing hemostasis in an artery using a mechanism.
The foregoing is intended as a summary of the novel and useful features of the present invention. Further aspects, features and advantages of the invention will become apparent from consideration of the following detailed description and the appended claims when taken in connection with the accompanying drawings.
The present invention is best described with reference to the drawings.
The device 10 is comprised generally of a base 12 defining a substantially planar surface. An anchor 13 is adapted for connecting a vertical member 14 to the base 12. A horizontal member 20 including a coupler 16 and a shaft 19 is coupled to the vertical member 14 by the coupler 16. On an opposite end, the horizontal member 20 is buttressed by a cap 26.
Returning to
It is noteworthy that even in the closed position, the first locking mechanism 18 does not prevent some movement of the horizontal member 20. On the contrary, should a patient move or be inadvertently shaken during a hemostatic procedure, the present invention is adapted to be reflexive and permit some movement for the patient's safety and comfort.
Returning now to
In any embodiment, the present invention functions by locking the third locking mechanism 32 in a selected port 33 such that the compression arm 30 will define an angle with respect to the horizontal member 20. The compression arm 30 may be locked in any position within a range of zero to 80 degrees with respect to the vertical member 14. Most preferably, the third locking mechanism is adapted to provide the compression arm 30 with a range from zero to sixty degrees with respect to the vertical member 14.
Referring now to
A pressure pad 44 is disposed at the end of the compression arm 30 for applying direct pressure to the wound site. The pressure pad 44 is coupled to the compression arm 30 such that it is rotatable along arrow C and about arrow A. The pressure pad 44 is also pivotable with respect to the compression arm 30 along arrow B. Thus, the pressure pad 44 is movable to some degree along arrows A, B, and C, and thus has a virtually limitless range of motion, making it readily adaptable to a number of surgical procedures.
The pressure pad 44 defines a first region 54 that is substantially convex in shape, and a second region 56 that is substantially planar in shape. In a preferred embodiment, the first region 54 accurately approximates the size of the fingers used by a physician to apply pressure to the arterial wall. It is noteworthy that both the first region 54 and the second region 56 are adapted to engage the arterial wall, thus providing multiple points of contact and dispersing the force supplied by the compression arm 30 over a greater surface area. In a preferred embodiment, the pressure pad 44 is made of a transparent material for allowing the physician to precisely place the device 10 over the wound site. In another preferred embodiment, the pressure pad 44 is coated with a coagulating material (not shown) that will accelerate the hemostatic process on contact with the wound site.
Further details of the compression arm 30 are visible in the exploded view of
In a preferred embodiment, the rod 40 has the series of markers 50, such as colored bands, to indicate the force being exerted by the spring 68. As the rod 40 is moved towards the compressor 36, the spring 68 is compressed, corresponding to a greater spring force. Thus, a physician can use the markers 50 to visually determine how much force is being applied by the spring 68, and accordingly how much pressure the pressure pad 44 is exerting on the arterial wound. In a preferred embodiment, the spring 68 is calibrated to exert a range of pressure ranging from zero to 20 pounds per square inch (psi). More preferably, the markers 50 will designate specified pressures ranging from 5 to 15 psi.
The rod 40 engages the cam 42, which is used for adjusting the footprint of the pressure pad 44. The pressure pad 44 is coupled to the second rod 72 about an axle 52 protruding from a base portion 74. A pin 76 also protrudes from the base portion 74 to keep the pressure pad 44 properly aligned with the second rod 72 and the compressor 36. The cam 42 is used to rotate the pressure pad 44 about line A, thus permitting a full 360 degrees of access to the wound site by the pressure pad 44. As previously noted, the pressure pad 44 is preferably made of a transparent material for allowing the physician to precisely place the device 10 over the wound site. In another preferred embodiment, the pressure pad 44 is coated with a coagulating material (not shown) that will accelerate the hemostatic process on contact with the wound site.
In a preferred embodiment, the device 10 of the present invention is utilized according to the method described herein. In a first step, the arterial wound is disposed on the base 12 in the manner shown in
As described above, the present invention includes a device for inducing hemostasis in an artery, also referred to as a femoral clamp in a specific embodiment involving the femoral artery. Through novel design and function, the present invention permits attending medical personnel to mechanically curtail bleeding from an artery in a precise and controllable manner. In particular, by applying the pressure in a direction perpendicular to the patient's wound site, the present invention reduces the time needed for closing the artery. Moreover, as the device employs a number of movable members and locking mechanisms to attain many degrees of freedom, it is readily adaptable to a range of body types, including the most and least muscular among us.
It should be apparent to those skilled in the art that the above-described embodiments are merely illustrative of but a few of the many possible specific embodiments of the present invention. Numerous and various other arrangements can be readily devised by those skilled in the art without departing from the spirit and scope of the invention as defined in the following claims.
