94 results about "PR interval" patented technology

The presence or absence of a suction condition in an implantable blood pump is determined at least in part based on a parameter related to flow, such as a parameter related to thrust on the rotor of the pump. A local extreme of the parameter representing the minimum flow during ventricular diastole in an earlier interval is used to establish a threshold value. A value of the parameter representing the minimum flow during ventricular diastole in a later interval is compared to this threshold. If the comparison indicates a substantial decline in the minimum flow between the earlier and later intervals is associated with a suction condition. During the absence of a suction condition, the threshold is continually updated, so that the system does not indicate presence of a suction condition if the flow decreases gradually.

A biological information processing apparatus obtains a pulse wave signal indicating a pulse wave of a subject, and acceleration measured according to body motion of the subject and calculates an amount of body motion of the subject using the acceleration. By using at least one of the body motion amount and the acceleration, the apparatus approximates a heart rate of the subject and sets a parameter to be used for detection of a pulse interval using the heart rate. Then, the apparatus detects each pulse interval using a pulse waveform indicated by the pulse wave signal and the parameter.

An electronic hand hygiene compliance system and award indicator that provides realtime reporting of the percent number of hand hygiene events against a programmed target number of hand hygiene events for a given functional area over a given period of time, yeilding hand hygiene compliance. The system keeps up to date compliance for an established group interval until the data is written over by compliance data for the same group interval the following day. In addition, a random hand hygiene event can be identified for a given functional area during a given period of time to trigger an alarm for encouraging hand hygiene activity for a given dispenser or group of dispensers.

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.

A pulse wave signal is registered and an occurrence of human limb movements detected during sleep using a pulse wave sensor and an accelerometer. The values of RR intervals and respiratory rate are measured at preset time intervals Δt_i based on pulse wave signal. Mean P₁, minimal P₂, and maximal P₃ values of RR intervals, the standard deviation of RR intervals P₄, average respiratory rate P₅ and average number of limb movements P₆ are determined based on the above measured values. Function value F(Δt_i) is determined thereafter as:

F(Δt_i)=−K₁P₁−K₂P₂−K₃P₃+K₄P₄+K₅P₅+K₆P₆,

where K₁-K₆ are weight coefficients characterizing the contribution of the corresponding parameter to function value F(Δt_i); whereat the onset and termination of sleep phase favorable to awakening is determined by increments of function F(Δt_i).

The present invention is a cardiac rhythm-monitoring device, which allows patients to perform a preliminary screening for supraventricular arrhythmia. The device detects beat-to-beat heart rhythms (i.e. the R-R interval between individual heart beats) and performs a screening test to determine if there are indications of arrhythmia. The test looks for variance in the R-R interval that is outside of the normal range, either using a pre-constructed chart based upon general population studies to determine the normal range of variance or using normal distribution analysis of the patient's own heart rhythm to determine the normal range of variance for determining irregular heartbeats, and if there are multiple irregularities within the sensed time frame, the patient is warned of potential supraventricular arrhythmia. By sensing both electrical impulses form the heart and mechanical responses to the heartbeat, the device may augment its analysis.

The invention is directed to techniques for providing cardiac resynchronization therapy by synchronizing delivery of pacing pulses to the left ventricle with intrinsic right ventricular depolarizations. An implantable medical device measures an interval between an atrial depolarization and an intrinsic ventricular depolarization is measured. In various embodiments, the intrinsic ventricular depolarization may be an intrinsic right or left ventricular depolarization. The implantable medical device delivers pacing pulses to the left ventricle to test a plurality of pacing intervals. The pacing intervals tested may be within a range around the measured interval between the atrial depolarization and the intrinsic ventricular depolarization. One of the pacing intervals is selected based on a measured characteristic of an electrogram that indicates ventricular synchrony. For example, the pacing interval may be selected based on measured QRS complex widths and/or Q-T intervals. The implantable medical device paces the left ventricle based on the selected pacing interval.

An active implantable medical device, in particular a defibrillator/cardioverter, with a sophisticated discrimination of atrial fibrillations. This device is able to deliver therapy for defibrillation, cardioversion, and/or ventricular and/or atrial antitachycardiac pacing stimulation; sense the ventricular and atrial activity; identify a suspicion of and confirm the presence of episodes of tachycardia in the activity thus sensed; analyze the stability of detected RR intervals and the stability of the associated PR intervals; and, in the event of a detection of stable RR intervals and unstable PR intervals, discriminate between atrial fibrillation with fast ventricular rhythm and atrial fibrillation with ventricular tachycardia, and to control delivery of a differentiated therapy according to one case or the other. A bi-tachycardia discrimination also can be made.

Rate responsive pacing is limited in an atrial based pacing mode by the AV interval in order to avoid or minimize ventricular encroachment of atrial pacing. The AV or VA interval is used to permit rate responsiveness; modulate rate responsiveness or to determine a dynamic upper sensor rate.

A hearing prosthesis configured for delivery of stochastic stimulation to a recipient. The hearing prosthesis comprises a sound pickup component configured to receive a sound signal having at least one pitch; a stochastic stimulation generator configured to generate a stochastic sequence of stimulation pulses having first and second inter-pulse intervals distributed stochastically throughout the sequence within controlled limits, the first inter-pulse interval based on the at least one pitch; and at least one stimulation channel to deliver the sequence of electrical stimulation pulses to the recipient.