| 摘要 |
The present invention provides a transthoracic drug delivery device that utilizes pressure to determine the precise location of the distal tip of the delivery tube of the device to insure that therapeutic substances are ejected into the myocardium and not dissipated in unintended tissue locations. In one embodiment the drug delivery device comprises a pressure sensing tube mounted in parallel to a drug delivery tube wherein the tubes are staggered so that the pressure tube extends beyond the delivery tube. When the myocardium is penetrated by the tubes, advancement into the heart and penetration into the left ventricle by the pressures sensing tube results in a pressure increase that indicates to the physician that the drug delivery tube, by its placement relative to the pressure sensing tube is still in the myocardium and, thus, prepared to deliver the drug. In another embodiment, a steerable syringe is provided so that multiple sites in the myocardium can be treated with a therapeutic substance with only one penetration into the heart. Once the delivery tube of the syringe penetrates the left ventricle, its distal tip can be deflected back toward the endocardial surface and the tube withdrawn proximally to cause penetration of the tip into the myocardium. A pressure sensor mounted to the tube indicates, by a measured drop in pressure that the myocardium has been penetrated. The therapeutic substance is ejected into the myocardium and the device is then backed out of the tissue by advancing the syringe in a distal direction. The deflectable tip can be adjusted to a different deflection angle and the delivery tube rotated to make available a circular array of points that may be accessed by the syringe.
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