687 results about "Hemodynamics" patented technology

A minimally invasive, implantable monitor and associated method for chronically monitoring a patient's hemodynamic function based on signals sensed by one or more acoustical sensors. The monitor may be implanted subcutaneously or submuscularly in relation to the heart to allow acoustic signals generated by heart or blood motion to be received by a passive or active acoustical sensor. Circuitry for filtering and amplifying and digitizing acoustical data is included, and sampled data may be continuously or intermittently written to a looping memory buffer. ECG electrodes and associated circuitry may be included to simultaneously record ECG data. Upon a manual or automatic trigger event acoustical and ECG data may be stored in long-term memory for future uploading to an external device. The external device may present acoustical data visually and acoustically with associated ECG data to allow interpretation of both electrical and mechanical heart function.

Apparatus and method to perform therapeutic treatment and diagnosis of a patient's vasculature through the use of an intravascular device having an optical fiber disposed therein. In an embodiment of this invention, the apparatus includes a therapeutic guidewire and at least one optical fiber disposed through the therapeutic guidewire, the optical fiber capable of providing diagnostic information before, during, and after the therapeutic treatment. In an embodiment, diagnostic information includes vessel and blood characteristics such as hemodynamic characteristics, hematological parameters related to blood and blood components, and thermal parameters of the vasculature.

Computational methods are used to create cardiovascular simulations having desired hemodynamic features. Cardiovascular modeling methods produce descriptions of blood flow and pressure in the heart and vascular networks. Numerical methods optimize and solve nonlinear equations to find parameter values that result in desired hemodynamic characteristics including related flow and pressure at various locations in the cardiovascular system, movements of soft tissues, and changes for different physiological states. The modeling methods employ simplified models to approximate the behavior of more complex models with the goal of to reducing computational expense. The user describes the desired features of the final cardiovascular simulation and provides minimal input, and the system automates the search for the final patient-specific cardiovascular model.

A noninvasive patient-specific method is provided to aid in the analysis, diagnosis, prediction or treatment of hemodynamics of the cardiovascular system of a patient. Coronary blood flow and pressure can be predicted using a 3-D patient image-based model that is implicitly coupled with a model of at least a portion of the remaining cardiovascular system. The 3-D patient image-based model includes at least a portion of the thoracic aorta and epicardial coronaries of the patient. The shape of one or more velocity profiles at the interface of the models is enforced to control complex flow features of recirculating or retrograde flow thereby minimizing model instabilities and resulting in patient-specific predictions of coronary flow rate and pressure. The invention allows for patient-specific predictions of the effect of different or varying physiological states and hemodynamic benefits of coronary medical interventions, percutaneous coronary interventions and surgical therapies.

Methods and apparatus provide realistic training in endovascular and endoluminal procedures. One embodiment includes modeling accurately the tubular anatomy of a patient to enable optimized simulation. One embodiment includes simulating the interaction between a flexible device and the anatomy and optimizing the computation. One embodiment includes replicating the functionality of therapeutic devices, e.g. stents, and simulating their interaction with anatomy. One embodiment includes computing hemodynamics inside the vascular model. One embodiment includes reproducing visual feedback, using synthetic X-ray imaging and / or or visible light rendering. One embodiment includes generating contrast agent injection and propagation through a tubular network. One embodiment includes reproducing aspects of the physical environment of an operating room by simulating or tracking, such as C-arm control panel, foot pedals, monitors, real catheters and guidewires, etc. One embodiment includes tracking instrument position and mimicking haptic feedback experienced when manipulating certain medical devices.

A non-invasive method of characterizing burn injuries using near infrared spectroscopy is described. In the method, a beam of light is emitted into the burnt tissue portion at two or more different tissue depths. The spectra are then compared using multivariate analysis to determine diagnostic regions of the spectra. This information is used to categorize the burn. In some cases, the diagnostic regions correspond to wavelengths related to the hemodynamics of the tissue portion. The spectra can also be repeated over time, thereby allowing trends and changes in the spectra to be measured. This data is in turn used to categorize the burn as either a superficial burn, partial thickness burn, deep partial burn or a full thickness burn. Once the burn has been categorized, the clinician can intervene as needed to treat the burn.

A method of treating hemodynamic disfunction by simultaneously pacing both ventricles of a heart. At least one ECG amplifier is arranged to separately detect contraction of each ventricle and a stimulator is then activated for issuing stimulating pulses to both ventricles in a manner to assure simultaneous contraction of both ventricles, thereby to assure hemodynamic efficiency. A first ventricle is stimulated simultaneously with contraction of a second ventricle when the first fails to properly contract. Further, both ventricles are stimulated after lapse of a predetermined A-V escape interval. One of a pair of electrodes, connected in series, is placed through the superior vena cava into the right ventricle and a second is placed in the coronary sinus about the left ventricle. Each electrode performs both pacing and sensing functions. The pacer is particularly suitable for treating bundle branch blocks or slow conduction in a portion of the ventricles.

Described herein are devices and methods for improving the hemodynamic function of a patient. In particular, a first device adapted to reshape an atrio-ventricular valve is used in combination with a second device configured to further alter the blood flow through the valve. The first device is typically an implant positioned in the subvalvular space of a ventricle. The second device may be an annuloplasty implant, a non-annulus valve apparatus implant, a ventriculoplasty implant, or a cardiac rhythm management device.

Apparatus and surgical methods establish temporary suction attachment to a target site on the surface of a beating heart for analyzing electrical signals or hemodynamic responses to applied signals at the target sites for enhancing the accuracy of placement of cardiac electrodes at selected sites and for enhancing accurate placement of a surgical instrument maintained in alignment with the suction attachment. A suction port on the distal end of a supporting cannula carries surface-contacting electrodes and provides suction attachment to facilitate temporary positioning of the electrodes in contact with tissue at the target site, and a clamping and release mechanism to facilitate anchoring a cardiac electrode on the moving surface of a beating heart at a selected site. Analyses of sensed signals or responses to applied signals at target sites promote epicardial mapping of a patient's heart for determining optimum sites at which to attach cardiac electrodes.

A method for monitoring the progression of the hemodynamic status of a patient by tracking autonomic tone. For example, the method may be applied to patients suffering from heart failure, diabetic neuropathy, cardiac ischemia, sleep apnea and hypertension. An implantable or other ambulatory monitor senses a pulse amplitude signal such as a vascular plethysmography signal. Variations of the signal amplitude on a scale greater than the heartbeat to heartbeat scale are indicative of variations in autonomic tone. A significant reduction in pulse amplitude and pulse amplitude variability are indicative of a heart failure exacerbation or other disease state change. This information may be used to warn the patient or healthcare providers of changes in the patient's condition warranting attention.

A system and method for estimating vascular flow using CT imaging include a computer readable storage medium having stored thereon a computer program comprising instructions, which, when executed by a computer, cause the computer to acquire a first set of data comprising anatomical information of an imaging subject, the anatomical information comprises information of at least one vessel. The instructions further cause the computer to process the anatomical information to generate an image volume comprising the at least one vessel, generate hemodynamic information based on the image volume, and acquire a second set of data of the imaging subject. The computer is also caused to generate an image comprising the hemodynamic information in combination with a visualization based on the second set of data.

An electronic monitoring device includes an electronic processor (520) having at least one signal input for body monitoring, and a memory (530) holding instructions for the electronic processor coupled to the electronic processor so that the electronic processor is operable to isolate a cardiac signal including cardiac pulses combined with other cardiac signal variations, and the electronic processor further operable to execute a filter (730) that separates a varying blood flow signal from the cardiac pulses and to output information (790) based on at least the varying blood flow signal. Other devices, sensor assemblies, electronic circuit units, and processes are also disclosed.

The fluid delivery system includes a pressurizing device for delivering injection fluid under pressure, a low pressure fluid delivery system, and a pressure isolation mechanism. The pressure isolation mechanism includes a first lumen associated with the pressurizing device, a second lumen associated with the low pressure fluid delivery system, and a pressure isolation port. The first valve is in a normally open position permitting fluid communication between the first lumen and the second lumen and movable to a closed position when fluid pressure in the first lumen reaches a predetermined pressure level. The first valve isolates the pressure isolation port from the first lumen in the closed position. A second valve is associated with the second lumen and regulates fluid flow through the second lumen. The second valve may be a disk valve defining one or more passageways in the form of slits through the body of the disk valve.

Approaches to rank potential left ventricular (LV) pacing vectors are described. Early elimination tests are performed to determine the viability of LV cathode electrodes. Some LV cathodes are eliminated from further testing based on the early elimination tests. LV cathodes identified as viable cathodes are tested further. Viable LV cathode electrodes are tested for hemodynamic efficacy. Cardiac capture and phrenic nerve activation thresholds are then measured for potential LV pacing vectors comprising a viable LV cathode electrode and an anode electrode. The potential LV pacing vectors are ranked based on one or more of the hemodynamic efficacy of the LV cathodes, the cardiac capture thresholds, and the phrenic nerve activation thresholds.

The invention relates to automatically adjusting an acquisition protocol for dynamic medical imaging, such as dynamic CT, MRI or PET imaging. The protocols are adjusted based on anatomic and dynamic models (10, 12, 14) which are individualized or fitted to each patient based on a scout scan (6, 8). The adjustment can compensate for changes in the patient due to patient motion (e.g. breathing or heartbeat) or flow of contrast or tracing agent during the sequence. This ensures that changes in the reconstructed images are indicative of pathological changes in the patient and not caused by patient motion or changes in scanning parameters or timing. The dynamic model can be a motion model (12) used to predict the motion of anatomic / physiologic features, typically organs, during scanning, or a haemodynamic model (14) used to predict flow of the contrast agent allowing for precise timing of the scanning sequence.

A system for non-invasively monitoring at least one hemodynamic vascular parameter of an individual is disclosed. The system comprises (a) at least two infrared detectors being positionable in a spaced apart configuration against a region of a skin of the individual above at least one blood vessel, each of said at least two infrared detectors being for individually collecting infrared spectral data from said region of the skin, said infrared spectral data corresponding to a volume of blood present within said at least one blood vessel; and (b) a processing unit being in communication with said at least two infrared detectors, said processing unit being for independently processing said infrared spectral data collected by each of said at least two infrared detectors so as to yield information pertaining to the at least one hemodynamic vascular parameter of the individual.

The patterns of contraction and relaxation of the heart before and during left ventricular or biventricular pacing are analyzed and displayed in real time mode to assist physicians to screen patients for cardiac resynchronization therapy, to set the optimal A-V or right ventricle to left ventricle interval delay, and to select the site(s) of pacing that result in optimal cardiac performance. The system includes an accelerometer sensor; a programmable pace maker, a computer data analysis module, and may also include a 2D and 3D visual graphic display of analytic results, i.e. a Ventricular Contraction Map. A feedback network provides direction for optimal pacing leads placement. The method includes selecting a location to place the leads of a cardiac pacing device, collecting seismocardiographic (SCG) data corresponding to heart motion during paced beats of a patient's heart, determining hemodynamic and electrophysiological parameters based on the SCG data, repeating the preceding steps for another lead placement location, and selecting a lead placement location that provides the best cardiac performance by comparing the calculated hemodynamic and electrophysiological parameters for each different lead placement location.

A method is provided for measuring the volume, the composition and the movement of electroconductive body fluids, based on the electrical impedance of the body or a body segment, especially for performing electromechanocardiography (ELMEC) or impedance cardiography (IKG) measurements for determining hemodynamic parameters. According to the method, an alternating measuring current of at least one frequency is introduced into the body, and the impedance and temporal variations thereof of essentially the same body segment through which the alternating measuring current flows are measured for at least two different measuring lengths (L, L2, L3, L4, L5), essentially in the longitudinal direction of the body.

Luminal endoprosthesis formed of a multi-layer braided framework. The framework is devoid of any cover layer, and formed of a plurality of stabilized layers of biocompatible metal wires which are interlaced, forming a lattice, a plurality of wires of a given layer being integrated in the lattice of the adjacent layers. The mechanical characteristics of an outermost layer is so that when in place, the layer applies against a vessel wall, the other layers extending substantially along cylindrical surfaces distinct from the outermost layer so as to form a multi-layer mat which affects the haemodynamic of a flow of blood passing along or through this mat and preventing a growing of plaque.

Method and system for computation of advanced heart measurements from medical images and data; and therapy planning using a patient-specific multi-physics fluid-solid heart model is disclosed. A patient-specific anatomical model of the left and right ventricles is generated from medical image patient data. A patient-specific computational heart model is generated based on the patient-specific anatomical model of the left and right ventricles and patient-specific clinical data. The computational model includes biomechanics, electrophysiology and hemodynamics. To generate the patient-specific computational heart model, initial patient-specific parameters of an electrophysiology model, initial patient-specific parameters of a biomechanics model, and initial patient-specific computational fluid dynamics (CFD) boundary conditions are marginally estimated. A coupled fluid-structure interaction (FSI) simulation is performed using the initial patient-specific parameters, and the initial patient-specific parameters are refined based on the coupled FSI simulation. The estimated model parameters then constitute new advanced measurements that can be used for decision making.

A pacing system for providing optimal hemodynamic cardiac function for parameters such as contractility (peak left ventricle pressure change during systole or LV+dp / dt), or stroke volume (aortic pulse pressure) using system for calculating atrio-ventricular delays for optimal timing of a ventricular pacing pulse. The system providing an option for near optimal pacing of multiple hemodynamic parameters. The system deriving the proper timing using electrical or mechanical events having a predictable relationship with an optimal ventricular pacing timing signal.

An embodiment of the invention includes a device, system and method for determining the characteristics of deep tissue. The novel method includes measuring blood flow rate and oxygenation characteristics of the tissue, and determining oxygen metabolism of the tissue as a function of the measure blood flow rate and measure oxygenation. The blow flow rate characteristics are measured as a function of light fluctuations caused by the tissue, while the oxygenation characteristics are measured as a function of transmission of light through the tissue with respect to the wavelength of light. The tissue may be layered tissue, for example, a portion of a brain. The tissue characteristics may be measured during times of varying levels of exercise intensity.

An apparatus and method to perform therapeutic treatment and diagnosis of a patient's vasculature through the use of an intravascular device having an optical fiber disposed therein. In an embodiment, the apparatus includes an intravascular device to perform a therapeutic treatment and at least one optical fiber disposed through the intravascular device. The optical fiber is configured to provide diagnostic information before, during, and after the therapeutic treatment. In an embodiment, diagnostic information includes vessel and blood characteristics such as hemodynamic characteristics, hematological parameters related to blood and blood components, and thermal parameters of the vasculature.