276 results about "Intracranial pressure" patented technology

Systems and methods for assessment of tissue properties, noninvasively, by acquiring data relating to at least one aspect of intrinsic and/or induced tissue displacement, or associated biological responses, are provided. Data relating to tissue displacement and associated biological changes may be acquired by detecting acoustic properties of tissue using ultrasound interrogation pulses, preferably in a scatter or Doppler detection mode. Based on this data, tissue properties are assessed, characterized and monitored. Specific applications for systems and methods of the present invention include non-invasive assessment and monitoring of intracranial pressure (ICP), arterial blood pressure (ABP), CNS autoregulation status, vasospasm, stroke, local edema, infection and vasculitus, as well as diagnosis and monitoring of diseases and conditions that are characterized by physical changes in tissue properties. Methods and systems for localizing physiological condition(s) and/or biological response(s), such as pain, by targeting and selectively probing tissues using the application of focused ultrasound are also provided.

Methods and systems for long term monitoring of one or more physiological parameters such as respiration, heart rate, body temperature, electrical heart activity, blood oxygenation, blood flow velocity, blood pressure, intracranial pressure, the presence of emboli in the blood stream and electrical brain activity are provided. Data is acquired non-invasively using ambulatory data acquisition techniques.

A telemetry method and apparatus using pressure sensing elements remotely located from associated pick-up, and processing units for the sensing and monitoring of pressure within an environment. This includes remote pressure sensing apparatus incorporating a magnetically-driven resonator being hermetically-sealed within an encapsulating shell or diaphragm and associated new method of sensing pressure. The resonant structure of the magnetically-driven resonator is suitable for measuring quantities convertible to changes in mechanical stress or mass. The resonant structure can be integrated into pressure sensors, adsorbed mass sensors, strain sensors, and the like. The apparatus and method provide information by utilizing, or listening for, the residence frequency of the oscillating resonator. The resonant structure listening frequencies of greatest interest are those at the mechanical structure's fundamental or harmonic resonant frequency. The apparatus is operable within a wide range of environments for remote one-time, random, periodic, or continuous/on-going monitoring of a particular fluid environment. Applications include biomedical applications such as measuring intraocular pressure, blood pressure, and intracranial pressure sensing.

Systems and methods for determining ICP based on parameters that can be measured using non-invasive or minimally invasive techniques are provided, wherein a non-linear relationship is used to determine ICP based on one or more variable inputs. The first variable input relates to one or more properties of a cranial blood vessel and/or blood flow, such as acoustic backscatter from an acoustic transducer having a focus trained on a cranial blood vessel, flow velocity in a cranial blood vessel, and the like. Additional variables, such as arterial blood pressure (ABP), may be used in combination with a first variable input relating to one or more properties of a cranial blood vessel, such as flow velocity of the middle cerebral artery (MCA) to derive ICP using a non-linear relationship. Methods and systems for locating target areas based on their acoustic properties and for acoustic scanning of an area, identification of a target area of interest based on acoustic properties, and automated focusing of an acoustic source and/or detector on a desired target area are also provided. Acoustic transducer assemblies are described.

Systems and methods for assessing a physiological parameter of a target tissue wherein a pulse of focused ultrasound is applied to a target tissue site thereby inducing oscillation of the target tissue. By these systems and methods, a property of an acoustic signal emitted from the oscillating target tissue is measured and related to a physiological property of the tissue. Specific applications for systems and methods of the present invention include the assessment and monitoring of intracranial pressure (ICP), arterial blood pressure (ABP), CNS autoregulation status, vasospasm, stroke, local edema, infection and vasculitus, as well as diagnosis and monitoring of diseases and conditions that are characterized by physical changes in tissue properties.

Communication systems and methods for dynamically controlling the power wirelessly delivered by a remote reader unit to separate sensing device, such as a device adapted to monitor a physiological parameter within a living body, including but not limited to intraocular pressure, intracranial pressure (ICP), and cardiovascular pressures that can be measured to assist in diagnosing and monitoring various diseases. The communication method entails electromagnetically delivering power from at least one telemetry antenna within the reader unit to at least one telemetry antenna within the sensing device, and controlling the power supplied to the sensing device within a predetermined operating power level range of the sensing device.

A system for measuring and converting to an observer intelligible form an internal physiological parameter of a medical patient. The invention allows transcutaneous telemetry of the measured information intracranial pressure via a system which includes a patient implanted sensor module and a processing and display module which is external of the patient and optically coupled to the sensor module via an external coupling module. A sensor within the implanted module transduces the measured information and a near infrared (NIR) emitter transmits this telemetry information when interrogated by the complementary external coupling module. Alternately, a set of tuned inductor-crystal circuits versus inductor-crystal comprised in part of a cylindrical crystal oscillator whose resonant frequency is sensed by a dipper circuit arrangement is provided. Power for the sensor module is derived inductively through rectification of a transcutaneously-applied high-frequency alternating electromagnetic field which is generated by a power source within the external coupling module, in concept much like a conventional electrical transformer. A computer within the processing and display module calculates the parameter value from the telemetry signal and represents this data either in numerical, graphical, or analog format.

An intracranial pressure (ICP) within a patient's skull can be determined by observing a vessel in the patient's eye, desirably in the red and/or infrared (IR) spectrum, while causing the pressure inside the eye to increase. On or about the time the observed vessel collapses in response to increasing the pressure inside the eye, the pressure inside the eye is determined. The ICP can then be determined as a function of the pressure inside the eye. Desirably, the vessel being observed is the central retinal vein of the eye.

The invention relates to systems and methods for assessing blood flow in single or multiple vessels and segments, for assessing vascular health, for conducting clinical trials, for screening therapeutic interventions for effect, for assessing risk factors, for evaluating intracranial pressure and for analyzing the results in a defined manner. The invention enables direct monitoring of therapies, substances and devices on blood vessels, especially those of the cerebral vasculature. Relevant blood flow parameters include mean flow velocity, systolic acceleration, and pulsatility index. Measurement and analysis of these parameters, and others, provides details regarding the vascular health of individual and multiple vessels and a global analysis of an individual's overall vascular health. The invention is applicable as both a system and method for monitoring and improving the design, performance, marketing and use of vascular stents. In particular, the invention enables DVA-assisted stenting procedures, including both pre-operative and post-operative management.

A whole-body mathematical model (10) for simulating intracranial pressure dynamics. In one embodiment, model (10) includes 17 interacting compartments, of which nine lie entirely outside of intracranial vault (14). Compartments (F) and (T) are defined to distinguish ventricular from extraventricular CSF. The vasculature of the intracranial system within cranial vault (14) is also subdivided into five compartments (A, C, P, V, and S, respectively) representing the intracranial arteries, capillaries, choroid plexus, veins, and venous sinus. The body's extracranial systemic vasculature is divided into six compartments (I, J, O, Z, D, and X, respectively) representing the arteries, capillaries, and veins of the central body and the lower body. Compartments (G) and (B) include tissue and the associated interstitial fluid in the intracranial and lower regions. Compartment (Y) is a composite involving the tissues, organs, and pulmonary circulation of the central body and compartment (M) represents the external environment.

The present invention provides a method, system, and apparatus to monitor cardiovascular signals such as arterial blood pressure (ABP), pulse oximetry (POX), and intracranial pressure (ICP). The system can be used to calculate and monitor useful clinical information such as heart rate, respiratory rate, pulse pressure variation (PPV), harmonic phases, pulse morphology, and for artifact removal. The method uses a statistical state-space model of cardiovascular signals and a generalized Kalman filter (EKF) to simultaneously estimate and track the cardiovascular parameters of interest such as the cardiac fundamental frequency and higher harmonics, respiratory fundamental frequency and higher harmonics, cardiac component harmonic amplitudes and phases, respiratory component harmonic amplitudes and phases, and PPV.

Embodiments of the present invention relate to a system and method for monitoring intracranial pressure. Embodiments of the present invention include emitting an electromagnetic wavelength into forehead tissue of a patient and detecting characteristics of the electromagnetic wavelength after the electromagnetic wavelength has been scattered by the tissue. The characteristics may include variations in the electromagnetic wavelength corresponding to a pulse. Further, embodiments of the present invention include analyzing the variations to identify venous pulsations, and determining whether intracranial pressure is elevated in the patient based on a correlation between the venous pulsations and levels of intracranial pressure.

A method and apparatus for assessment of hemodynamic and functional state of the brain is disclosed. In one embodiment, the method and apparatus includes non-invasive measurement of intracranial pressure, assessment of the brain's electrical activity, and measurement of cerebral blood flow. In some embodiments, the method and apparatus include measuring the volume change in the intracranial vessels with a near-infrared spectroscopy or other optical method, measuring the volume change in the intracranial vessels with rheoencephalography or other electrical method, and measuring the brain's electrical activity using electroencephalography.

In certain aspects, the present invention relates to CPR devices that are designed to limit the rise in intrathoracic pressure when performing CPR compressions (e.g., chest, thorax, etc.) so as to minimize increases in intracranial pressure resulting from such compressions and elevated ITP. Exemplary CPR devices of the invention generally include one or more pressure sensors and a control system configured to adjust or alert for the need to adjust the amplitude and duration of CPR compressions so as to prevent a rise in ITP above a certain threshold amount, thereby controlling the rise in ICP during CPR. Methods of controlling a rise in ICP during CPR are also provided.

A system for reducing the damaging effects of radiant energy, blast, or concussive events includes applying pressure to at least one jugular vein to reduce the egress of blood from the cranial cavity during or before the incidence of the imparting event. Reducing blood outflow from the cranial cavity increases intracranial volume and/or pressure of the cerebrospinal fluid to reduce the risk of traumatic brain injury and injuries to the spinal column. Reducing blood outflow further increases the intracranial pressure and volume, and thereby increases the pressure and volume of the cochlear fluid, the vitreous humor and the cerebrospinal fluid to thereby reduce the risk of injury to the inner ear, internal structure of the eye and of the spinal column. In addition, increasing intracranial pressure and volume reduces the likelihood of brain injury and any associated loss of olfactory function

The invention relates to systems and methods for assessing blood flow in single or multiple vessels and segments, for assessing vascular health, for conducting clinical trials, for screening therapeutic interventions for effect, for assessing risk factors, for evaluating intracranial pressure and for analyzing the results in a defined manner. The invention enables direct monitoring of therapies, substances and devices on blood vessels, especially those of the cerebral vasculature. Relevant blood flow parameters include mean flow velocity, systolic acceleration, and pulsatility index. Measurement and analysis of these parameters, and others, provides details regarding the vascular health of individual and multiple vessels and a global analysis of an individual's overall vascular health. The invention can track the onset, progression and treatment efficacy in an individual experiencing increased intracranial pressure, or can help identify underlying vulnerabilities of the vascular system to normal pressures, associated with and manifested as hydrocphalus or dementia.

Tools and techniques for the rapid, continuous, invasive and/or noninvasive measurement, estimation, and/or prediction of a patient's intracranial pressure. In an aspect, some tools and techniques can predict the onset of conditions such as herniation and/or can recommend (and, in some cases, administer) a therapeutic treatment for the patient's condition. In another aspect, some techniques employ high speed software technology that enables active, long term learning from extremely large, continually changing datasets. In some cases, this technology utilizes feature extraction, state-of-the-art machine learning and/or statistical methods to autonomously build and apply relevant models in real-time.

Systems and methods are described for noninvasively assessing an intracranial pressure of a patient. Some embodiments include providing a simulation model with a measured arterial blood pressure of the patient. Some embodiments further include providing the simulation model with a measured cerebral blood flow velocity of the patient. The simulation model correlates arterial blood pressure values, cerebral blood flow velocity values, and intracranial pressure values. Some embodiments further includes determining an intracranial pressure of the patient based on the simulation model. Some embodiments further includes creating an output data set indicative of the determined intracranial pressure.