1. A data transmission system, comprising a transmitter and a receiver, wherein the transmitter is arranged to send data bursts with a duty cycle of less than 5% at transmission timing points, the transmitter comprising a pseudo-random signal generator which governs the time delay between successive timing points and a local oscillator which controls the time of data transmission, and wherein the receiver comprises a corresponding pseudo-random signal generator and local oscillator, and wherein power is applied to the receiver substantially only corresponding in time to the timing of the data bursts.
2. A system as claimed in claim 1, wherein the transmitter is arranged to send data bursts with a duty cycle of less than 1%.
3. A system as claimed in claim 1, wherein the transmitter and receiver each include a power source comprising a non-rechargeable battery.
4. A system as claimed in claim 1, wherein each pseudo-random signal generator comprises a maximal length feedback shift register.
5. A system as claimed in claim 1, wherein each data burst comprises a header section and a data section, and wherein the header section for a sub-set of the data bursts comprises a sequence which is unique to the header, thereby to enable receiver to obtain bit timing information.
6. A system as claimed in claim 1, wherein each data burst comprises a header section and a data section, and wherein the header section for a sub-set of the data bursts comprises data defining the time period to the next message.
7. A system as claimed in claim 5, wherein the header comprises address data which identifies the transmitter to the receiver.
8. A system as claimed in claim 7, wherein the address data is used in combination with the pseudo-random signal generator to generate a modified pseudo random sequence.
9. A system as claimed in claim 1, wherein the transmitter is for attachment to a shoe, and comprises an accelerometer and a processing unit, the processing unit integrating the detected acceleration over time to obtain instantaneous speed values which are transmitted in the data bursts.
10. A system as claimed in claim 9, wherein the receiver is for wearing on the wrist of the user of the system.
11. A system as claimed in claim 1, wherein each local oscillator comprises a 32768 Hz quartz oscillator.
12. A system as claimed in claim 6, wherein the header comprises address data which identifies the transmitter to the receiver.
13. A system as claimed in claim 12, wherein the address data is used in combination with the pseudo-random signal generator to generate a modified pseudo random sequence.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for determining functional significance of an arterial stenosis or lesion in a patient comprising:
determining an area of interest an arterial network of the patient;
obtaining a CT scan of the patient during an angiogram procedure, resulting in data on the area of interest;
using the data obtained from the CT scan to calculate an arterial input function (AIF) for the area of interest;
using the data obtained from the CT scan to determine contrast distribution and transluminal attenuation gradient (TAG) for the area of interest;
calculating transluminal attenuation flow encoding (TAFE) using contrast distribution, TAG, and AIF; and,
modeling flow velocity using TAFE.
2. The method of claim 1 further comprising augmenting the calculation of TAFE with data related to characteristics of the scanner used to obtain the CT scan.
3. The method of claim 1 further comprising programming a non-transitory computer readable medium to execute the method.
4. The method of claim 1 further comprising bringing the patient to a rest condition before obtaining the CT scan of the patient during the angiogram.
5. The method of claim 4 further comprising calculating the coronary flow velocity for the area of interest for the patient at the rest condition.
6. The method of claim 1 further comprising bringing the patient to a stressed condition before obtaining the CT scan of the patient during the angiogram.
7. The method of claim 6 further comprising calculating the coronary flow velocity for the area of interest for the patient at the stress condition.
8. The method of claim 1 further comprising obtaining a CT scan of the patient during an angiogram with the patient at rest and obtaining a CT scan of the patient during an angiogram with the patient under stress.
9. The method of claim 6 further comprising calculating flow rate for the patient at rest and under stress.
10. The method of claim 7 further comprising calculating coronary flow reserve for the area of interest as a ratio of Qstress to Qrest.
11. A method for determining functional significance of an arterial stenosis or lesion in a patient comprising:
determining an area of interest an arterial network of the patient;
obtaining a CT scan of the patient during an angiogram procedure, resulting in data on the area of interest;
using the data obtained from the CT scan to calculate an arterial input function (AIF) for the area of interest;
using the data obtained from the CT scan to determine contrast distribution and transluminal attenuation gradient (TAG) for the area of interest;
calculating transluminal attenuation flow encoding (TAFE) using contrast distribution, TAG, and AIF;
modeling flow velocity using TAFE;
using the coronary flow velocity to determine inflow and outflow rate and boundary conditions for the area of interest;
determining 3D arterial lumen geometry;
performing CFD modeling for the area of interest using the boundary conditions, inflow and outflow rates, and the 3D arterial lumen geometry;
calculating a pressure gradient for the area of interest using the CFD model; and,
using the pressure gradient to determine a loss coefficient for the area of interest.
12. The method of claim 11 further comprising augmenting the calculation of TAFE with data related to characteristics of the scanner used to obtain the CT scan.
13. The method of claim 11 further comprising programming a non-transitory computer readable medium to execute the method.
14. A method for determining functional significance of an arterial stenosis or lesion in a patient comprising:
determining an area of interest an arterial network of the patient;
obtaining a CT scan of the patient during an angiogram procedure, resulting in data on the area of interest;
using the data obtained from the CT scan to calculate an arterial input function (AIF) for the area of interest;
using the data obtained from the CT scan to determine contrast distribution and transluminal attenuation gradient (TAG) for the area of interest;
calculating transluminal attenuation flow encoding (TAFE) using contrast distribution, TAG, and AIF;
modeling flow velocity using TAFE;
using the coronary flow velocity to determine inflow and outflow rate and boundary conditions for the area of interest;
determining 3D arterial lumen geometry;
performing CFD modeling for the area of interest using the boundary conditions, inflow and outflow rates, and the 3D arterial lumen geometry;
calculating a pressure gradient for the area of interest using the CFD model;
using the pressure gradient to determine a loss coefficient for the area of interest;
measuring brachial pressure;
calculating an absolute arterial pressure; and,
calculating fractional flow reserve at rest for the patient.
15. The method of claim 14 further comprising augmenting the calculation of TAFE with data related to characteristics of the scanner used to obtain the CT scan.
16. The method of claim 14 further comprising programming a non-transitory computer readable medium to execute the method.
17. A system for determining functional significance of an arterial stenosis or lesion in a patient comprising:
a CT scanner configurable to obtain patient specific data related to an area of interest of an arterial network of the patient;
a non-transitory computer readable medium programmed for:
determining an area of interest an arterial network of the patient;
obtaining the patient specific data on the area of interest;
using the patient specific data obtained from the CT scan to calculate an arterial input function (AIF) for the area of interest;
using the patient specific data obtained from the CT scan to determine contrast distribution and transluminal attenuation gradient (TAG) for the area of interest;
calculating transluminal attenuation flow encoding (TAFE) using contrast distribution, TAG, and AIF; and,
modeling flow velocity using TAFE.
18. The system of claim 17 further comprising obtaining patient specific data during an angiogram with the patient at rest and obtaining patient specific data during an angiogram with the patient under stress.
19. The system of claim 18 further comprising calculating flow rate for the patient at rest and under stress.
20. The system of claim 17 further comprising calculating coronary flow reserve for the area of interest as a ratio of Qstress to Qrest.
21. The system of claim 17 further comprising:
using the coronary flow velocity to determine inflow and outflow rate and boundary conditions for the area of interest;
determining 3D arterial lumen geometry;
performing CFD modeling for the area of interest using the boundary conditions, inflow and outflow rates, and the 3D arterial lumen geometry;
calculating a pressure gradient for the area of interest using the CFD model; and,
using the pressure gradient to determine a loss coefficient for the area of interest.
22. The system of claim 21 further comprising:
measuring brachial pressure;
calculating an absolute arterial pressure; and,
calculating fractional flow reserve at rest for the patient.