A system includes a processor circuit configured to receive a first set of data. The first set of data includes two pressure measurements and a flow measurement from the vasculature of a patient obtained while the sympathetic nervous system of the patient is not under stimulation. The processor circuit calculates a blood flow resistance value based on the first set of data. The processor circuit then receives a second set of data. The second set of data also includes two pressure measurements and a flow measurement from the vasculature of the patient obtained while the sympathetic nervous system of the patient is stimulated. The processor circuit calculates another blood resistance value based on the second set of data. The processor circuit then compares the two blood flow resistance values to determine whether a denervation procedure would be effective to mitigate the nerve system's response to stimulation. The processor circuit outputs to a screen display metrics obtained from the measurement procedure.

A system includes a processor circuit in communication with an anatomical measurement device. The anatomical measurement device receives a metric associated with a sympathetic response of a patient. The sympathetic nervous system of the patient is then stimulated. The anatomical measurement device then receives another metric associated with a sympathetic response of the patient while the sympathetic nervous system is stimulated. The processor circuit then provides an output based on the comparison.

A system includes a processor circuit in communication with an anatomical measurement device. The anatomical measurement device receives a metric associated with a sympathetic response of a patient. The sympathetic nervous system of the patient is then stimulated. The anatomical measurement device then receives another metric associated with a sympathetic response of the patient while the sympathetic nervous system is stimulated. The processor circuit then provides an output based on the comparison.

A method of manufacturing a lead. The method includes providing a supporting tube, and disposing a conductive strip on an outer surface of the supporting tube such that the conductive strip extends in an axial direction along a length of the supporting tube. The method also includes mounting a chip having a first conductive contact pad and a second conductive contact pad to the supporting tube such that the first conductive contact pad is in contact with the conductive strip. The method further includes fitting an electrode to the supporting tube such that the electrode is in contact with the second conductive contact pad, and coupling a conductor to each end of the supporting tube such that each conductor is in contact with the conductive strip. The method also includes covering at least one of the chip and the conductors with a sheath to provide the lead.

A method of manufacturing a lead. The method includes providing a supporting tube, and disposing a conductive strip on an outer surface of the supporting tube such that the conductive strip extends in an axial direction along a length of the supporting tube. The method also includes mounting a chip having a first conductive contact pad and a second conductive contact pad to the supporting tube such that the first conductive contact pad is in contact with the conductive strip. The method further includes fitting an electrode to the supporting tube such that the electrode is in contact with the second conductive contact pad, and coupling a conductor to each end of the supporting tube such that each conductor is in contact with the conductive strip. The method also includes covering at least one of the chip and the conductors with a sheath to provide the lead.

A method of authorizing a limited use intravascular device can include determining if the intravascular device is in communication with a clinical system; determining if the intravascular device is authorized for clinical operation without providing the clinical system access to intravascular device data stored on the intravascular device; and providing an authorization signal to the clinical system. An intravascular device can include a flexible elongate member including a sensing component at a distal portion and a connector at a proximal portion, the connector including: a memory component configured to store a parameter value; a processing component; and a charge storage component configured to power the memory component and/or the processing component; wherein the processing component is configured to determine if the flexible elongate member is authorized for clinical operation using the parameter value without providing the parameter value to a clinical system.

The invention relates to a system for determining blood flow within a blood vessel (18). A fluid infusion unit (4, 10, 11) continuously infuses a fluid into the blood vessel, and a temperature values determining unit (14, 21) determines simultaneously a first temperature value at a first location and a second temperature value at a second location such that the first temperature value is indicative of the temperature of the fluid and the second temperature value is indicative of the temperature of a mixture of the fluid and the blood. The blood flow is determined based on the measured first and second temperature values and the infusion rate. This kind of determining the blood flow leads to an increased accuracy and is less cumbersome than known techniques requiring a movement of a temperature sensor for measuring temperatures at different locations.

Systems for determining fractional flow reserve are disclosed. An example system may include a pressure sensing guidewire for measuring a first pressure, a second pressure sensing medical device for measuring a second pressure, and a processor coupled to the pressure sensing guidewire and coupled to the second pressure sensing medical device. The processor may be designed to generate a plot of the magnitude of the second pressure over time, identify one or more time intervals of the plot that have a slope less than zero, determine a mean of the second pressure, and calculate the ratio of the first pressure to the second pressure when (a) the second pressure is less than or equal to the mean of the second pressure and (b) during the one or more time intervals when the slope of the plot is less than zero.

According to one embodiment, a tissue penetrating device includes an elongate shaft having a proximal end, a distal end, and a lumen extending there between. A first needle is disposed within the lumen of the elongate shaft and is extendable therefrom between a first configuration and a second configuration. In the first configuration, the first needle is disposed within the elongate shaft's lumen and is substantially aligned with an axis of the lumen. In the second configuration, the first needle extends distally of the elongate shaft's distal end and bends away from the lumen's axis. A second needle is disposed within a lumen of the first needle and is extendable therefrom when the first needle is positioned in the first configuration and when the first needle is positioned in the second configuration. The second needle may be extended from the first needle to penetrate tissue of a patient.

According to one embodiment, a tissue penetrating device includes an elongate shaft having a proximal end, a distal end, and a lumen extending there between. A first needle is disposed within the lumen of the elongate shaft and is extendable therefrom between a first configuration and a second configuration. In the first configuration, the first needle is disposed within the elongate shaft's lumen and is substantially aligned with an axis of the lumen. In the second configuration, the first needle extends distally of the elongate shaft's distal end and bends away from the lumen's axis. A second needle is disposed within a lumen of the first needle and is extendable therefrom when the first needle is positioned in the first configuration and when the first needle is positioned in the second configuration. The second needle may be extended from the first needle to penetrate tissue of a patient.