543 results about "Av conduction" patented technology

A method of assessing the cardiac arrhythmia risk in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. In one embodiment, the method comprises the steps of: (a) collecting at least one QT and RR interval data set from the subject; (b) separating fluctuations from slow trends in said at least one QT and RR interval data set; (c) comparing said QT and RR fluctuations to one another and (d) generating from the comparison of step (c) partial measures of risk of cardiac arrhythmia in said subject. A greater difference between QT and RR fluctuations indicates greater risk of cardiac arrhythmia in said subject. The data sets are collected in such a manner that they reflect almost exclusively the conduction in the heart muscle and minimize the effect on the data sets of rapid transients due to autonomic nervous system and hormonal control.

The disclosure provides methods and apparatus of left ventricular pacing including automated adjustment of a atrio-ventricular (AV) pacing delay interval and intrinsic AV nodal conduction testing. It includes—upon expiration or reset of a programmable AV Evaluation Interval (AVEI)—performing the following: temporarily increasing a paced AV interval and a sensed AV interval and testing for adequate AV conduction and measuring an intrinsic atrio-ventricular (PR) interval for a right ventricular (RV) chamber. Thus, in the event that the AV conduction test reveals a physiologically acceptable intrinsic PR interval then storing the physiologically acceptable PR interval in a memory structure (e.g., a median P-R from one or more cardiac cycles). In the event that the AV conduction test reveals an AV conduction block condition or if unacceptably long PR intervals are revealed then a pacing mode-switch to a bi-ventricular (Bi-V) pacing mode occurs and the magnitude of the AVEI is increased.

The disclosure provides methods and apparatus of left ventricular pacing including automated adjustment of a atrio-ventricular (AV) pacing delay interval and intrinsic AV nodal conduction testing. It includes—upon expiration or reset of a programmable AV Evaluation Interval (AVEI)—performing the following: temporarily increasing a paced AV interval and a sensed AV interval and testing for adequate AV conduction and measuring an intrinsic atrio-ventricular (PR) interval for a right ventricular (RV) chamber. Thus, in the event that the AV conduction test reveals a physiologically acceptable intrinsic PR interval then storing the physiologically acceptable PR interval in a memory structure (e.g., a median P-R from one or more cardiac cycles). In the event that the AV conduction test reveals an AV conduction block condition or if unacceptably long PR intervals are revealed then a pacing mode-switch to a bi-ventricular (Bi-V) pacing mode occurs and the magnitude of the AVEI is increased.

Methods and process for detection of myocardial ischemia involve detection and analysis of changes in electrical conduction velocity within the heart to monitor changes in the condition of the cardiac muscle and indicate possible ischemia. Conduction velocity slows considerably when oxygen supply to the heart is reduced. Analysis of electrical conduction velocity can be used to verify the occurrence of myocardial ischemia in a more reliable manner. Changes in conduction velocity may be monitored based on conduction time between electrodes positioned in the left and right ventricles of the heart. The electrodes may be endocardial or epicardial electrodes. In general, the techniques may involve launching a stimulation waveform at one electrode and sensing a local cardiac depolarization at another electrode to assess conduction time.

In accordance with the present invention, a cardiac device is provided comprising a first electrode for sensing an electrical pulse in an atrium, a second electrode for sensing an electrical pulse in an atrium, a microcontroller coupled to the first electrode and the second electrode for determining time between the first and second pulses, and an electrode for stimulating a chamber of a heart wherein the stimulation is based on the first and second pulses.

The invention provides an independently researched and developed continuous dynamic blood pressure monitoring device and method based on pulse wave transit time (PWTT) and pulse wave transit velocity (PWV). According to the device, an electrocardiosignal collecting module (104) is arranged on a main case (101) in a wristwatch form, a pulse wave signal collecting module (103) is arranged at the position, corresponding to the wrist radial artery, of a wristband (102), and the electrocardiosignal collecting module (104) and the pulse wave signal collecting module (103) are in signal connection with a control module (105). The device and algorithm can obtain pulse waves in real time, the problem that in-vitro heart pulse waves are inconvenient to obtain is solved, the method for rapidly and accurately obtaining the cardiac ejection time point is provided, and the method is an important part of continuous dynamic blood pressure monitoring.

A method of operating a cardiac pacing device that optimizes the mechanical heart rate using coordinated potentiation therapy while maximizing the opportunity for intrinsic AV conduction to occur. The method may include adjusting the timing of extra stimulus intervals during coupled or paired pacing to promote AV conduction and to effect changes in rate according to certain embodiments of the invention. Other embodiments may include adjusting the atrial pacing rate to achieve a desired target rate consistent with AV conduction. A mode switch to a dual-chamber pacing mode may be provided according to certain embodiments of the invention to ensure a ventricular rate that meets or exceeds a minimum mechanical rate.

The invention relates to a blood pressure noninvasive measuring method. The method comprises the following steps: 1) arranging a pulse sensing device on an examinee, wherein the pulse sensing device is used for measuring the pulse wave of the examinee and is connected to a single chip microcomputer detection apparatus; 2) setting two measuring points in any pulse wave transmission path from the heart of the examinee to the finger tip of the examinee, wherein the distance of one measuring point to the heart is greater than that of the other measuring point; 3) uploading the measured values of the pulse sensing device in the above measuring points to the single chip microcomputer detection apparatus to acquire two pulse wave measuring curves; and 4) acquiring a blood pressure measuring value according to a wave peak or trough conduction time difference in a same period in the two pulse wave curves. According to the method of the invention, the two pulse signals of any two points from the heart to the finger tip are directly measured, and the blood pressure value is obtained based on the linear relation between the pulse wave conduction time and the arterial blood pressure.

The invention discloses a high-frequency minimally invasive surgery instrument for vascular melt closed cutting, which comprises a claw beam assembly with the diameter of 10-12mm/5-8mm and a control grip assembly, wherein a fast plugging mechanism is arranged between the claw beam assembly and the control grip assembly; the claw beam assembly can be exchanged; the claw beam assembly comprises clamping forceps, a fork frame, a claw beam, a lock drum/conductive ring, a jaw steering thumb wheel, a clamping opening/closing drive mechanism, a cutter drive mechanism and a disposable control mechanism; and the control grip assembly comprises a grip housing, a clamping forceps control mechanism, a cutter control mechanism, a current/signal switch and conduction device, a claw beam assembly exchange/lock mechanism, and a cutting safety mechanism. The high-frequency minimally invasive surgery instrument has the beneficial effects that the disposable using method for exchanging the claw beam is adopted; the purposes of reducing the surgery cost and preventing a patient from being threatened by cross infection are achieved, and the high-frequency minimally invasive surgery instrument is positively significant for the development of the minimally invasive medical career in China.

A conduction breaking device includes a movable member accommodated in an accommodation chamber of a case. A cutter portion projects from an advancing side of the movable member in the moving direction. A gas generator is arranged on the trailing side of the movable member in the moving direction. A conduction member extends to connect a pair of external connection portions and includes a pair of base portions and a breakable portion. The base portions are located in the side wall of the case and extend along the moving direction of the movable member. The breakable portion is shaped to connect the base portions to each other and to block the advancing side of the movable member in the moving direction. Step portions are formed in the breakable portion. Engaging portions that are engageable with the step portions are formed in the case.

An implantable medical device operates to promote intrinsic ventricular depolarization according to a pacing protocol. The medical device operates to promote intrinsic conduction by providing elongated AV intervals or operating in an atrial based pacing mode. Conduction checks to determine if AV conduction is present are performed on a graduated or progressive scale to facilitate intrinsic emergence.