Abstract: This invention relates generally to systems and methods for optimizing the performance and minimizing complications related to implanted sensors, such as pressure sensors, for the purposes of detecting, diagnosing and treating cardiovascular disease in a medical patient. Systems and methods for anchoring implanted sensors to various body structures are also provided.

Abstract: An implantable medical device receives a physiological signal indicative of circulatory blood volume and detects hypovolemia from that physiological signal. In one embodiment, an implantable pulmonary artery pressure (PAP) senses a PAP signal, and the implantable medical device detects hypovolemia from the PAP signal.

Abstract: A method of monitoring pressure within a medical patient, includes measuring an actual pressure in a medical patient in a first time period; measuring an indicator of the actual pressure in the first time period, wherein the indicator is derived from an electrical signal of the patient's heart; determining a correlative relationship between the actual pressure and the indicator, wherein both the actual pressure and the indicator are obtained in the first time period; measuring the indicator in a second time period; and determining the actual pressure in the second time period based on the correlative relationship obtained in the first time period and the indicator obtained in the second time period.

Abstract: A pressure sensor wire assembly measures pressure inside a body of a patient. The assembly comprises a pressure sensor element for measuring pressure and to generate a pressure sensor signal representative of the pressure, and a pressure sensor wire having the pressure sensor element at its distal portion, and adapted to be inserted into the body in order to position the sensor element within the body. A sensor signal adapting circuitry is an integrated part of the assembly, wherein the pressure sensor signal is applied to the adapting circuitry which is adapted to automatically generate an output pressure signal, related to the sensor signal, in a standardized format such that the measured pressure is retrievable by an external physiology monitor. The assembly further comprises an external pressure sensor to measure the pressure outside the patient's body and to generate external pressure values in dependence thereto.

Abstract: The present invention relates to a sensor guide wire (17) for intravascular measurements of physiological variables in a living body, having a proximal region (8), a distal sensor region (9) and a tip region (10). The sensor guide wire (17) further comprises a core wire member (11), a sensor element (14), which has a sensor portion (15), for measuring the physiological variable and to generate a sensor signal in response to said variable and a jacket (13), accommodating at least a part of said sensor element (14). The sensor portion (15), is sensitive to one or many of the physiological variables, pressure, temperature, and flow The core wire member (11) comprises two separate parts, a first core wire part (19) and a second core wire part (20), wherein a distal end (21) of said first core wire part (19) is attached to said jacket (13) proximally said sensor portion (15) and a proximal end (22) of said second core wire part (20) is attached to said jacket (13) distally to said sensor portion (15).

Abstract: Exemplary techniques and systems for interpolating left ventricular pressures are described. One technique interpolates pressures within the left ventricle from blood pressures gathered without directly sensing blood pressure in the left ventricle.

Abstract: Disclose herein is a method of measuring pressures in a coronary sinus. In one embodiment, the method includes: introducing a distal portion of a lead or tool into the coronary sinus, wherein the distal portion includes first and second pressure sensors and at least one selectably expandable member; expanding the at least one expandable member such that the first and second sensors are isolated from each other within the coronary sinus; and taking pressure measurements with the first and second sensors when isolated from each other.

Abstract: A tool and method of positioning and delivering medical devices and therapeutics within the pericardial space, as well as other body part or space. A needle is inserted into the chest through a sub-xiphoid puncture, and the pressure within the needle is monitored manometrically or otherwise sensed as the needle is advanced towards the pericardial space. By reading the pressure within the needle while it is advanced, the clinician is able to know that he or she is avoiding insertion of it into organs or spaces not intended to be the target location. In addition the retractable sharp edge allows the operator to access the space and cut tissue but do so safely by retracting the sharp edge.

Abstract: Provided is a canal type mini-apparatus insertable in an ear for diagnosing a disease. The canal type mini-apparatus includes a canal body and a protrusion body. The canal body is insertable in an ear and includes a bio-data detection unit at an end thereof The bio-data detection unit is configured to detect biological data from an inside of the ear for diagnosing a disease. The protrusion body is disposed at the other end of the canal body and including a data transceiving unit. The data transceiving unit is configured to control the bio-data detection unit and transmit/receive a signal to/from an analyzing device. When the canal type mini-apparatus is inserted in the ear, at least a portion of the protrusion body protrudes outward from the ear.

Abstract: The present invention provides for an improved combination sensor tip that includes an ultrasound transducer and a pressure sensor both disposed at or in close proximity to the distal end of the combination sensor tip. The present invention also provides for an improved connector to couple a guide wire to a physiology monitor that reduces torsional resistance when maneuvering the guide wire.

Abstract: Determining an index for assessing cardiac function. In an embodiment, a method includes receiving ventricular pressure data during an invasive cardiac procedure, wherein the received pressure data includes a diastatic ventricular pressure value, a minimum ventricular pressure value, and a predefined fiducial marker pressure value. An index value is calculated by comparing a first pressure difference to a second pressure difference. The first pressure difference represents the difference between the received diastatic ventricular pressure value and the received minimum ventricular pressure value. The second pressure difference represents the difference between the received fiducial marker pressure value and the received minimum ventricular pressure value. The index value is provided to a health care provider to assess early diastolic cardiac function.

Abstract: A catheter includes a flexible shaft having a length sufficient to access a patient's renal artery relative to a percutaneous access location. A treatment arrangement is provided at a distal end of the shaft and configured for deployment in the renal artery. The treatment arrangement includes an ablation arrangement configured to deliver renal denervation therapy. An occlusion arrangement is configured for deployment in the renal artery and for altering blood flow through the renal artery during or subsequent to renal denervation therapy delivery. A monitoring unit is configured for monitoring for a change in one or more physiologic parameters influenced by the renal denervation therapy. The monitoring unit is configured to produce data useful in assessing effectiveness of the renal denervation therapy based on the physiologic parameter monitoring.

Abstract: Methods and devices are disclosed that, in various embodiments and permutations and combinations of inventions, diagnose and treat Multiple Sclerosis or associated symptoms. In one series of embodiments, the invention consists of methods and devices for identifying patients whose Multiple Sclerosis or associated symptoms are caused or exacerbated, at least in part, by blockages of one or more of the patient's internal jugular veins (IJV) or azygous veins (AZV). In some instances, stenoses or other flow limiting structures or lesions in the patient's affected veins are identified. Further, in some instances the nature of such lesions and whether there is a significant disruption of blood pressure, or both, is ascertained. In some embodiments, methods and devices for applying one or more therapies to the blockages in the patient's IJV or AZV veins are provided.

Abstract: In a method for intermittently occluding the coronary sinus, in which the coronary sinus is occluded using an occlusion device, the fluid pressure in the occluded coronary sinus is continuously measured and stored, the fluid pressure curve is determined as a function of time, and the occlusion of the coronary sinus is triggered and/or released as a function of at least one characteristic value derived from the measured pressure values. The pressure increase and/or pressure decrease per time unit each occurring at a heart beat are used as characteristic values.

Abstract: An intravascular sensor delivery device for measuring a physiological parameter of a patient, such as blood pressure, within a vascular structure or passage. In some embodiments, the device can be used to measure the pressure gradient across a stenotic lesion or heart valve, such as a fractional flow reserve (FFR) across a stenotic lesion. The sensor delivery device has a distal sleeve configured to pass or slide over a standard medical guidewire. The sensor delivery device can be sized to pass over different sizes of guidewires to enable usage in coronary and peripheral arteries, for example. The sensing mechanism (sensor) can be a fiber optic pressure sensor, such as a MEMS-based FabryPerot fiber optic pressure sensor, for example, or could employ some other technology, e.g., MEMS capacitive or piezoresistive sensor.

Abstract: Methods and devices are disclosed that, in various embodiments and permutations and combinations of inventions, diagnose and treat Deep Vein Thrombosis or associated symptoms. In one series of embodiments, the invention consists of methods and devices for identifying patients whose Deep Vein Thrombosis or associated symptoms are caused or exacerbated, at least in part, by blockages of one or more of the patient's internal peripheral veins. In some instances, stenoses or other flow limiting structures or lesions in the patient's affected veins are identified. Further, in some instances the nature of such lesions and whether there is a significant disruption of blood pressure, or both, is ascertained. In some embodiments, methods and devices for applying one or more therapies to the blockages in the patient's peripheral veins are provided.

Abstract: In specific embodiments, a method for estimating a patient's central arterial blood pressure (CBP) for use with an implantable system, comprises (a) using an implanted sensor at a first site to obtain a first signal indicative of changes in arterial blood volume at the first site, the first site being along one or more peripheral arterial structures of the patient, (b) using an implanted sensor at a second site to obtain a second signal indicative of changes in arterial blood volume at the second site, the second site being a distance from the first site downstream along an arterial path of the peripheral arterial structure of the patient, and (c) using implanted electrodes to obtain a signal indicative of electrical activity of the patient's heart.

Abstract: A measurement system may comprise a sensor wire and a transceiver unit. The sensor wire may comprise an insertable portion configured to be inserted in a blood vessel of a patient's body and a sensor disposed within the insertable portion at a distal end of the sensor wire. The sensor is configured to measure a parameter when inserted inside the patient. The transceiver unit may comprise: a housing adapted to be connected to a proximal end of the sensor wire; and a first communication module within the housing adapted to wirelessly communicate by a communication signal with an external second communication module in order to transfer information to the external second communication module.

Abstract: The present invention provides for an improved combination sensor tip that includes a pressure sensor and a second sensor other than a pressure sensor, both disposed at or in close proximity to the distal end of the combination sensor tip. The present invention also provides for an improved connector to couple a guide wire to a physiology monitor that reduces torsional resistance when maneuvering the guide wire.

Abstract: A medical device for determining a respiratory effort having a pressure sensor to sense pressure signals, a housing having system components positioned therein, and a microprocessor positioned within the housing, wherein the microprocessor detects an inspiration and an expiration in response to the pressure signals, detects a breath in response to the detected inspiration and the detected expiration, and determines the respiratory effort in response to the detected breath.

Abstract: An embodiment of the invention is an in-vivo blood pressure sensor device including a strain transducer and flexible biocompatible material that carries the strain transducer. The flexible biocompatible material is configured to encircle the outside of a blood vessel when surgically installed. A preferred embodiment in-vivo blood pressure sensor device of the invention includes a strain transducer carried by a flexible biocompatible ring that is configured to be surgically installed to encircle a blood vessel. The device also includes passive circuitry encased in biocompatible material for sensing strain in the strain transducer and for providing data to an external reader. The passive circuitry is also configured to be surgically installed in a subject.

Abstract: Systems and methods provide for ambulatorily sensing pulmonary artery pressure from within a patient, and producing a pulmonary artery pressure measurement from the sensed pulmonary artery pressure. Power is ambulatorily provided within the patient to facilitate sensing of the pulmonary artery pressure and producing of the pulmonary artery pressure measurement. Acute pulmonary embolism is detected based on a change or rate of change in the pulmonary artery pressure measurement. An alert is preferably generated in response to detecting pulmonary embolism.

Abstract: Various techniques are provided for assessing the reliability of left atrial pressure (LAP) estimates made by an implantable medical device based on impedance values or related electrical values. In one example, various cardioelectric and cardiomechanical parameters are used to corroborate LAP estimation in circumstances where the LAP estimates deviate from an acceptable, satisfactory or otherwise healthy range. The cardioelectric parameters include, e.g.: ST elevation; heart rate (HR); heart rate variability (HRV); T-wave alternans (TWA); QRS waveform parameters; P-wave duration; evoked response (ER) parameters; and intrinsic PV/AV/VV conduction delays. The cardiomechanical parameters include, e.g.: heart rate turbulence (HRT); cardiogenic impedance signals; heart sounds; and non-LAP blood pressure measurements, such as aortic pressure measurements.

Abstract: An implantable medical device receives a physiological signal indicative of circulatory blood volume and detects hypovolemia from that physiological signal. In one embodiment, an implantable pulmonary artery pressure (PAP) senses a PAP signal, and the implantable medical device detects hypovolemia from the PAP signal.

Abstract: This invention provides a flexible antenna module for wireless energy transmission, which uses an antenna size controlling device to adjust the antenna's size to conform a living body's outer portion wearing the flexible annular antenna. An antenna energy transmission control module is provided to adjust the power for driving the flexible annular antenna according to the deformation of the flexible annular antenna. This invention can adjust both the antenna size to fit the individual and the power for driving the antenna. The individual can use the present antenna module under a comfortable, safe and reliable circumstance.

Abstract: A pressure sensor wire assembly measures pressure inside a body of a patient. The assembly comprises a pressure sensor element for measuring pressure and to generate a pressure sensor signal representative of the pressure, and a pressure sensor wire having the pressure sensor element at its distal portion, and adapted to be inserted into the body in order to position the sensor element within the body. A sensor signal adapting circuitry is an integrated part of the assembly, wherein the pressure sensor signal is applied to the adapting circuitry which is adapted to automatically generate an output pressure signal, related to the sensor signal, in a standardized format such that the measured pressure is retrievable by an external physiology monitor. The assembly further comprises an external pressure sensor to measure the pressure outside the patient's body and to generate external pressure values in dependence thereto.

Abstract: Rapid exchange guide unit comprising an elongated support member 3, and a guide wire member (11) provided with a guide wire lumen (13) having a distal guide wire opening (15) and a proximal guide wire opening (17), the guide wire lumen is arranged close to the distal end of said elongated support member, and is adapted to receive a guide wire. The rapid exchange guide unit further comprises at least one sensor (19) arranged close to the distal end of the elongated support member, and being adapted to measure a parameter in a living body, and to generate a sensor signal in dependence of the measured parameter. The sensor signal is applied to a signal processing unit adapted to process the sensor signal and to generate a processed sensor signal.

Abstract: A method is described for determining at least one patient-related parameter for monitoring a patient. A general population-related non-linear pressure/CSA relationship of the arterial vascular bed is used and the arterial pressure of the patient is measured to obtain a prediction of the cross sectional area (CSA) of the thoracic part of the aorta. The cross sectional area is measured, wherein at least one parameter of the general population-related non-linear pressure/CSA relationship is corrected by means of the measured cross sectional area to determine a patient-related non-linear pressure/CSA relationship such that the cross sectional area obtained with this patient-related pressure/CSA relationship is equal to the measured cross sectional area.

Abstract: The present invention relates to an improved medical device and method for accurately and reliably determining a cardiac status of a patient. An implantable medical device, IMD, comprises a sensor arrangement adapted to sense signals related to mechanical activity of the heart and an activity level sensor arrangement adapted to sense an activity level of the patient. Further, the IMD calculates a percentage of left ventricular diastolic time (PLVDT) for a cardiac cycle corresponding to a relation between a diastolic time interval and a cardiac cycle time interval using the determined systolic and diastolic time intervals or a percentage of left ventricular systolic time (PLVST) for a cardiac cycle corresponding to a relation between a systolic interval time interval and a cardiac cycle time interval. A cardiac status is determined based on the calculated PLVDT (or PLVST) and on an activity level of the patient.

Abstract: Various techniques are provided for calibrating and estimating left atrial pressure (LAP) using an implantable medical device, based on impedance, admittance or conductance parameters measured within a patient. In one example, default conversion factors are exploited for converting the measured parameters to estimates of LAP. The default conversion factors are derived from populations of patients. In another example, a correlation between individual conversion factors is exploited to allow for more efficient calibration. In yet another example, differences in thoracic fluid states are exploited during calibration. In still yet another example, a multiple stage calibration procedure is described, wherein both invasive and noninvasive calibration techniques are exploited. In a still further example, a therapy control procedure is provided, which exploits day time and night time impedance/admittance measurements.

Abstract: A method of determining respiratory effort in a medical device in which pressure signals are sensed to generate corresponding sample points, an inspiration and an expiration are detected in response to the sensed pressure signals, a breath is detected in response to the detected inspiration and the detected expiration, and the respiratory effort is determined in response to the detected breath.

Abstract: A catheter has a plurality of sensors and electrodes, wherein the sensors are arranged alternately and spaced apart from each other. A system for continuous measurement and mapping of physiological data may use such a catheter with a coupling unit for insulated coupling of the plurality of sensors with a measurement unit and a mapping unit for mapping values received from the sensors to a predefined matrix.

Abstract: A pressure sensing catheter having a pressure sensor and an antenna that is coupled to the pressure sensor, e.g., by a connector, are provided. The pressure sensor can be adapted to measure a pressure surrounding the catheter, and the antenna can be adapted to telemetrically communicate the measured pressure to an external device. In an exemplary embodiment, the antenna, pressure sensor, and/or connector are hermetically sealed, e.g., by the catheter and/or a coating, to prevent the antenna, pressure sensor, and connector from coming into contact with fluid, thereby allowing the catheter to be permanently implanted or otherwise used for long term use. Exemplary methods for manufacturing and using pressure sensing catheters are also provided.

Abstract: An intravascular sensor delivery device for measuring a physiological parameter of a patient, such as blood pressure, within a vascular structure or passage. In some embodiments, the device can be used to measure the pressure gradient across a stenotic lesion or heart valve. For example, such a device may be used to measure fractional flow reserve (FFR) across a stenotic lesion in order to assess the severity of the lesion. The sensor delivery device has a distal sleeve configured to pass or slide over a standard medical guidewire. Some distance back from the sensor and distal sleeve, the device separates from the guidewire to permit independent control of the sensor delivery device and the guidewire. The sensor delivery device can be sized to pass over different sizes of guidewires to enable usage in coronary and peripheral arteries, for example.

Abstract: A method of determining endothelial dependent vasoactivity of a subject, the method is effected by recording pressure-related signals of a plurality of locations adjacent to at least one blood vessel; extracting at least one parameter from the pressure-related signals; and using the at least one parameter to determine a change of at least one characteristic of the at least one blood vessel, the change being representative of endothelial functioning; thereby determining the endothelial dependent vasoactivity of the subject.

Abstract: Sensor wire assembly for measuring a physiological variable in a body, said assembly comprises a sensor element for measuring the physiological variable and to generate a sensor signal in response of said variable, and a guide wire having said sensor element at its distal end, and adapted to be inserted into the body in order to position the sensor element within the body. The assembly further comprises a sensor signal adapting circuitry, being an integrated part of said assembly, wherein the sensor signal is applied to the adapting circuitry that is adapted to automatically generate an output signal, related to the sensor signal, in a standardized format such that the measured physiological variable is retrievable by an external physiology monitor.

Abstract: A device for continuous, uninterrupted patient monitoring includes a portable, self-contained Patient Worn Hub (PWH) device. The PWH is a compact, lightweight patient monitoring device designed to remain with the patient for the duration of care. Parameter measurement devices connect to the PWH. Third party parameter measurement devices connect to the PWH via the use of a connection assembly that translates the information provided by the third party device to the protocol embedded within the PWH. The PWH is able to communicate with a bedside monitor via wired cables or wirelessly. Measured values are shown on external displays and/or on an optional integrated PWH touchscreen display. The PWH includes internal memory for storage of patient data and trends. The PWH optionally includes a docking station for providing operating and battery charging power.

Abstract: A medical system according to embodiments of the present invention includes at least one sensor configured to monitor physiological status of a patient and to generate sensor data based on the physiological status, a user interface device, a processor communicably coupled to the user interface device, the processor configured to: present via the user interface device an array of two or more possible input elements, the input elements each comprising a class of patients or a diagnosis and treatment pathway; receive a selected input element based on a user selection among the two or more possible input elements; acquire the sensor data and process the sensor data to generate physiological data; and present via the user interface screen the physiological data according to a template that is customized for the selected input element.

Abstract: In a method for intermittently occluding the coronary sinus, in which in an alternating manner the coronary sinus is occluded by an occlusion device and the occlusion is released, the curve of the fluid pressure occurring in the coronary sinus after the release of the occlusion is estimated by calculation and the time of the beginning of the next occlusion is determined as a function of the estimated pressure curve.

Abstract: Implantable systems, and methods for use therewith, for monitoring arterial blood pressure on a chronic basis are provided herein. A first signal indicative of electrical activity of a patient's heart, and a second signal indicative of mechanical activity of the patient's heart, are obtained using implanted electrodes and an implanted sensor. By measuring the times between various features of the first signal relative to features of the second signal, values indicative of systolic pressure and diastolic pressure can be determined. In specific embodiments, such features are used to determine a peak pulse arrival time (PPAT), which is used to determine the value indicative of systolic pressure. Additionally, a peak-to-peak amplitude at the maximum peak of the second signal, and the value indicative of systolic pressure, can be used to determine the value indicative of diastolic pressure.

Abstract: An implantable medical device, such as a sensor for monitoring a selected internally detectable physiological parameter of a patient, is attached to a fixation member that is deployable within the patient to position and orient the sensor to enable it to perform its function. The fixation member may be configured to lie in a single plane when deployed or may be tubular in shape. The attachment of the housing and fixation member includes providing the fixation member with a linear attachment strut that is non-circular in cross section and providing the housing with external members that define an elongate channel, non-circular in cross section and receptive to the attachment strut. The attachment strut can be inserted transversely into the channel and the external member can be crimped over the strut to secure the housing and fixation member together.

Abstract: A system and method of monitoring the fluid status of a patient. The system may include a patient monitor that receives blood pressure data. A first fluid model receives the blood pressure data, and a personalized fluid model is derived from the application of the blood pressure data to the first fluid model. An estimation of the patient's fluid status may be derived from the personalized fluid model. The method may include the steps of measuring a first blood pressure value, creating a personalized fluid model, measuring a second blood pressure value, applying the second blood pressure value to the personalized fluid model; and deriving an estimation of the fluid status of the patient.

Abstract: Certain embodiments of the present invention are related to an implantable monitoring device to monitor a patient's arterial blood pressure, where the device is configured to be implanted subcutaneously. The device includes subcutaneous (SubQ) electrodes and a plethysmography sensor. Additionally, the device includes an arterial blood pressure monitor configured to determine at least one value indicative of the patient's arterial blood pressure based on at least one detected predetermined feature of a SubQ ECG and at least one detected predetermined feature of a plethysmography signal. Alternative embodiments of the present invention are directed to a non-implantable monitoring device to monitor a patient's arterial blood pressure based on features of a surface ECG and a plethysmography signal obtained from a non-implanted sensor.

Abstract: In a method for the intermittent occlusion of a vein draining the organ system, in which the vein is occluded by an occlusion device, the fluid pressure in the occluded vein is continuously measured and stored, the behavior of the fluid pressure is determined as a function of time, and the occlusion of the vein is triggered and/or released as a function of at least one characteristic value derived from the pressure measurements, pressure is applied during the occlusion in a pulsating manner. The device for the intermittent occlusion of a vein, including an occlusion device, a pressure measuring device for continuously measuring the fluid pressure in the occluded vein, and a memory for storing the fluid pressure behavior as a function of time, and a pulsating device are provided for applying a pulsating pressure in the occluded vein.

Abstract: An implantable coronary perfusion monitoring device for in-vivo determination of a coronary perfusion index (CPI) indicative of the coronary perfusion of a heart has a time measurement unit to determine a blood pressure reflection wave measure t indicating the timely position in the heart cycle of the maximum of a reflected blood pressure wave and in a time period starting at a preset point of time in systole and ending at a local maximum of blood pressure following aortic valve closure and, a diastolic peak pressure measurement unit adapted to determine a diastolic peak blood pressure measure DPP related to diastolic aortic peak pressure and a systolic arterial pressure measurement unit adapted to determine a systolic arterial blood pressure measure SAP related to systolic arterial pressure, and a coronary perfusion index calculating unit adapted to determine said coronary perfusion index CPI as (t·DPP)/SAP.

Abstract: Systems and methods provide for ambulatorily sensing pulmonary artery pressure from within a patient, and producing a pulmonary artery pressure measurement from the sensed pulmonary artery pressure. Power is ambulatorily provided within the patient to facilitate sensing of the pulmonary artery pressure and producing of the pulmonary artery pressure measurement. Acute pulmonary embolism is detected based on a change or rate of change in the pulmonary artery pressure measurement. An alert is preferably generated in response to detecting pulmonary embolism.

Abstract: Implantable systems, and methods for use therewith, for monitoring arterial blood pressure on a chronic basis are provided herein. A first signal indicative of electrical activity of a patient's heart, and a second signal indicative of mechanical activity of the patient's heart, are obtained using implanted electrodes and an implanted sensor. By measuring the times between various features of the first signal relative to features of the second signal, values indicative of systolic pressure and diastolic pressure can be determined. In specific embodiments, such features are used to determine a peak pulse arrival time (PPAT), which is used to determine the value indicative of systolic pressure. Additionally, a peak-to-peak amplitude at the maximum peak of the second signal, and the value indicative of systolic pressure, can be used to determine the value indicative of diastolic pressure.

Abstract: A delivery system for fixation of an implant assembly having an intracorporeal device at a deployment site using an anchoring structure. This invention provides an implant assembly having an anchor for fixation within a vessel. The anchoring structure adapted to be delivered via a catheter.

Abstract: An enhanced pressure sensing system and method use an external diaphragm to address issues involved with accurate and prolonged measurement of fluid pressure, such as of blood flowing in a vascular structure. Some external diaphragms include a metallized layer or other highly impermeable layer to furnish a high degree of seal at least near to hermetic grade. As temperature of the intermediary fluid changes, the external diaphragm is able to move in a direction that minimizes differential pressure across the external diaphragm over an operational temperature range thereby reducing pressure change of the intermediary fluid due to change in temperature of the intermediary fluid. Relatively smooth hydrodynamic surfaces can be used as well as a bi-layer construction.

Abstract: Embodiments include a cardiac rhythm management system having a lead that includes an omni-directional pressure sensor that is configured to resist tissue in-growth and provide reliable and consistent pressure readings from within a patient's vasculature. Embodiments of the cardiac rhythm management lead may also include a variety of pacing and shocking electrodes.