Abstract:
An isolated heart or heart-lung preparation in which essentially normal pumping activity of all four chambers of the heart is preserved, allowing for the use of the preparation in conjunction with investigations of electrode leads, catheters, ablation methods, cardiac implants and other medical devices intended to be used in or on a beating heart. The system can be designed to be used within a Magnetic Resonance Imaging (MRI) unit or a X-ray computed tomography (CT) scanner. The preparation may also be employed to investigate heart and lung functions, in the presence or absence of such medical devices. In order to allow comparative imaging visualizations of either or simultaneously the heart and/or lung structures and devices located within the chambers of the heart or vessels or bronchi within the lungs, a clear perfusate such as a modified Krebs buffer solution with oxygenation is circulated through all four chambers of the heart and thus the coronary and/or pulmonary vasculatures. A ventilator with intubation tube can be used to inflate/deflate the lungs and/or provide oxygen to the isolated organs. The preparation and recordings of the preparation may be used in conjunction with the design, development and evaluation of devices for use in or on the heart and/or lungs, as well as for use as an investigational and teaching aid to assist physicians and students in understanding the operation of the cardiopulmonary system.
Abstract:
A medical device system including at least a first implantable medical device and a second implantable medical device is configured to establish by a control module of the first implantable medical device whether the second implantable medical device is present in a patient and self-configure an operating mode of the control module in response to establishing that the second implantable medical device is present.
Abstract:
A fixation member of an electrode assembly for an implantable medical device includes a tissue engaging portion extending along a circular path, between a piercing distal tip thereof and a fixed end of the member. The circular path extends around a longitudinal axis of the assembly. A helical structure of the assembly, which includes an electrode surface formed thereon and a piercing distal tip, also extends around the longitudinal axis and is located within a perimeter of the circular path. The tissue engaging portion of the fixation member extends from the distal tip thereof in a direction along the circular path that is the same as that in which the helical structure extends from the distal tip thereof. The electrode assembly may include a pair of the fixation members, wherein each tissue engaging portion may extend approximately one half turn along the circular path.
Abstract:
An implantable pacemaker system includes a housing having a proximal end and a distal end. A control electronics subassembly defines the housing proximal end, and a battery subassembly defines the housing distal end. A distal fixation member extends from the housing distal end for fixing the housing distal end at an implant site. A pacing extension extends from the housing proximal end and carries a pacing cathode electrode. The pacing extension extends the pacing cathode electrode to a pacing site that is spaced apart from the implant site when the pacemaker is deployed in a patient's body.
Abstract:
A fixation member of an electrode assembly for an implantable medical device includes a tissue engaging portion extending along a circular path, between a piercing distal tip thereof and a fixed end of the member. The circular path extends around a longitudinal axis of the assembly. A helical structure of the assembly, which includes an electrode surface formed thereon and a piercing distal tip, also extends around the longitudinal axis and is located within a perimeter of the circular path. The tissue engaging portion of the fixation member extends from the distal tip thereof in a direction along the circular path that is the same as that in which the helical structure extends from the distal tip thereof. The electrode assembly may include a pair of the fixation members, wherein each tissue engaging portion may extend approximately one half turn along the circular path.
Abstract:
This disclosure describes implantable medical leads that include a lead body and an electrode. A width of the electrode as measured along a longitudinal direction of the lead varies about the perimeter of the lead. The uneven width of the electrode may bias a stimulation field in a particular direction, e.g., a radial or transverse direction relative to the longitudinal axis of the lead. Electrodes with an uneven width may be useful for controlling the direction of propagation of the stimulation field in order to, for example, avoid phrenic nerve stimulation during LV pacing or neck muscle stimulation during vagal neurostimulation.
Abstract:
A relatively compact implantable medical device includes a fixation member formed by a plurality of fingers mounted around a perimeter of a distal end of a housing of the device; each finger is elastically deformable from a relaxed condition to an extended condition, to accommodate delivery of the device to a target implant site, and from the relaxed condition to a compressed condition, to accommodate wedging of the fingers between opposing tissue surfaces at the target implant site, wherein the compressed fingers hold a cardiac pacing electrode of the device in intimate tissue contact for the delivery of pacing stimulation to the site. Each fixation finger is preferably configured to prevent penetration thereof within the tissue when the fingers are compressed and wedged between the opposing tissue surfaces. The pacing electrode may be mounted on a pacing extension, which extends distally from the distal end of the device housing.
Abstract:
An implantable medical device includes ventricular and atrial portions, and a flexible leadlet that extends therebetween. An open channel of the atrial portion, formed along a core thereof, is sized to receive the leadlet therein, when the leadlet is folded over on itself. An interventional medical system includes the device and a delivery tool; a tubular sidewall of the tool defines a lumen and has a tether extending therein. A slot formed in the sidewall extends proximally from an open end thereof, coincident with a distal opening of the lumen. When the atrial portion is contained within the lumen, a segment of the leadlet extends alongside the atrial portion; another segment of the leadlet, being folded over on itself, proximal to the atrial portion, has the tether engaged therewith. The slot may allow passage of the leadlet therethrough, when the atrial portion is positioned for deployment through the distal opening.
Abstract:
Methods and systems of making a medical electrical lead type having a set of tines. A system for implantation of a lead medical electrical lead in contact with heart tissue, comprises an elongated lead body; a set of curved tines mounted to and extending from a distal end of the lead body, the tines having a length (dD) and an effective cross sectional area, and a delivery catheter. The delivery catheter encloses the lead body and has a distal capsule portion enclosing the tines. The tines exerting a spring force against the capsule and provide a stored potential energy. The delivery catheter has an elastic, not stiff and low column strength ejection means for advancing the lead and tines distally from the capsule and fixating the tines within the heart tissue, the controllable and the stored potential energy of the tines together provide a deployment energy. The tines when so fixated in the tissue provide a fixation energy. The deployment energy and the fixation energy of the tines are equivalent.
Abstract:
Method and systems of determining adequacy of fixation of a medical lead type having a fixation helix are disclosed. The lead of the medical lead type is placed at a desired location within a patient's body and the fixation helix is screwed into tissue at that location. One or more parameters, associated with the lead, are measured at the location. Based upon the measured one or more parameters, determining a number of turns that the helix is embedded into the tissue at the location.