FIELD OF THE INVENTION

The disclosed technology relates to intravascular diagnosis. More particularly, the disclosed technology relates to diagnosing the severity of stenosis in the vasculature of a patient.

BACKGROUND

Reduced blood flow due to atherosclerotic occlusion of vessels is a major cause of vascular diseases. Pressure measurements in arterial vessels and particularly in coronary arteries prior to treatment have been used for lesion characterization and treatment selection. More specifically, pressure gradient across a lesion has been clinically used as an indicator for lesion severity. Measurements made during and after treatment allow one to assess therapy efficacy. Existing equipment for monitoring intravascular measurements have multiple, separate parts and bulky monitors. There is, accordingly, continuing interest in improved monitoring equipment.

SUMMARY

The disclosed technology relates to diagnosing the severity of stenoses in the vasculature of a patient.

In one aspect of the disclosed technology, an apparatus for intravascular diagnosis includes a monitoring guidewire having a core wire and a sensor disposed in a distal region of the core wire, and a portable display unit configured to be disposed after a predetermined number of uses or after a predetermined duration of use. The portable display unit can include a processor and a display screen, where the portable display unit is capable of receiving communication from the monitoring guidewire, is configured to perform computations using the processor based on communications received from the monitoring guidewire, and is configured to display information on the display screen based on the computations.

In one embodiment, the portable display unit includes one or more batteries configured to power the portable display unit. In one embodiment, the one or more batteries can be rechargeable by a power source of the portable display unit and/or a power source external to the portable display unit.

In one embodiment, the portable display unit further includes one or more batteries configured to power the portable display unit for a predetermined duration of use, such that the portable display unit can be configured to be disposed after the one or more batteries are depleted. In one embodiment, the one or more batteries are non-rechargeable. In one embodiment, the portable display unit can be configured to be inoperable after a one uses.

In one aspect of the disclosed technology, the monitoring guidewire can be configured to be disposed after a single use.

In one embodiment, the portable display unit and the monitoring guidewire can communicate wirelessly. In one embodiment, the portable display unit includes a connector configured to establish a communicative connection with the monitoring guidewire. In one embodiment, the connector is configured to establish a mechanical connection with the monitoring guidewire to control the guidewire within a vasculature. In one embodiment, a torquer is configured to engage the monitoring guidewire to control the guidewire within a vasculature.

In one embodiment, the monitoring guidewire includes a housing surrounding the sensor, and the housing can be laser etched to provide flexibility for the housing. In one embodiment, the monitoring guidewire includes a flexible coil surrounding the sensor, with the coil having a relaxed portion over the sensor.

In one aspect of the disclosed technology, the sensor is a pressure sensor and communication from the monitoring guidewire includes measurements from the pressure sensor. The processor of the portable display unit is capable of computing fractional flow reserve based on pressure measurements from only the pressure sensor in the distal region of the core wire.

In one embodiment, the fractional flow reserve is a push-forward fraction flow reserve (“FFR”) computed as: FFR=(Psensor−Pra)/(Psaved−Pra), where:

Psavedare moving means over time of recorded pressure measurements proximal to a first stenosis,

Psensorare moving means over time of real time pressure measurements distal to the first stenosis, and

Prais a constant.

In one embodiment, Psavedare moving means over time of recorded pressure measurements proximal to the first stenosis and proximal to a second stenosis. In one embodiment, Psensorare moving means over time of real time pressure measurements distal to the first stenosis and proximal to a second stenosis. In one embodiment, Psensormoving means over time of real time pressure measurements distal to the first stenosis and distal to the second stenosis.

In one embodiment, the fractional flow reserve is a pull-back fraction flow reserve computed as: FFR=(Psaved−)/(Psensor−Pra), where:

Psavedare moving means over time of recorded pressure measurements distal to a first stenosis,

Psensorare moving means over time of real time pressure measurements proximal to the first stenosis, and

Prais a constant.

In one embodiment, Psensorare moving means over time of real time pressure measurements proximal to the first stenosis and distal to a second stenosis. In one embodiment, Psavedare moving means over time of recorded pressure measurements distal to the first stenosis and distal to a second stenosis. In one embodiment, Psensorare moving means over time of real time pressure measurements proximal to the first stenosis and proximal to the second stenosis.

In one embodiment, the portable display unit displays on the display screen the fractional flow reserve. In one embodiment, the portable display unit displays a graph of the pressure measurements.

In one embodiment, the portable display unit includes a communications port configured to receive communications that include pressure measurements.

In one embodiment, the fractional flow reserve is a pull-back fraction flow reserve computed as: FFR=(Psensor−Pra)/(Pport−Pra), where:

Pportare moving means over time of real-time pressure measurements received at the communications port,

Psensorare moving means over time of real-time pressure measurements from the pressure sensor disposed in the distal region of the core wire, and

Prais a constant.

In one embodiment, the portable display unit is configured with capability to compute fractional flow reserve in at least two ways: computing fractional flow reserve based on pressure measurements from only the pressure sensor disposed in the distal region of the core wire, and computing fractional flow reserve based on the pressure measurements from the pressure sensor and based on pressure measurements received at a communications port. In one embodiment, the portable display unit can be configured to automatically use one of the at least two ways of computing fractional flow reserve. In one embodiment, the portable display unit can be configured to automatically select one of the ways of computing fractional flow reserve when a condition is present and can be configured to automatically select another of the at least two ways of computing fractional flow reserve when the condition is absent. In one embodiment, the portable display unit can be configured to permit a user to manually select one of the at least two ways of computing fraction flow reserve.

In one aspect of the disclosed technology, an apparatus for intravascular diagnosis includes a monitoring guidewire having a core wire and a sensor disposed in a distal region of the core wire, and a handheld display unit configured to be disposed after a predetermined number of uses or after a predetermined duration of use. The handheld display unit can include a processor and a display screen, where the handheld display unit is capable of receiving communication from the monitoring guidewire, is configured to perform computations using the processor based on communications received from the monitoring guidewire, and is configured to display information on the display screen based on the computations. In one embodiment, the handheld display unit can be equal to or less than 30 cm×30 cm×30 cm in size.

In one aspect of the disclosed technology, an apparatus for intravascular diagnosis includes a monitoring guidewire having a core wire and a sensor disposed in a distal region of the core wire, and a portable display unit capable of receiving communication from the monitoring guidewire. The portable display unit includes a processor and display screen, and is configured to perform computations using the processor based on communications received from the monitoring guidewire and is configured to display information on the display screen based on the computations. The portable display unit has no capability of being turned off after the display screen is turned on,

These aspects and embodiments of the disclosed technology are exemplary and do not limit the scope of the disclosed technology, which will be apparent from a reading of the following detailed description and the associated drawings.

