Method and apparatus for targeting material delivery to tissue

• US 6,549,803 B1
• Filed: 05/08/2000
• Issued: 04/15/2003
• Est. Priority Date: 05/08/2000
• Status: Expired due to Term

• Current Assignee: Brainlab AG
• Original Assignee: Image-Guided Neurologics Inc (Medtronic Plc)
• Inventors: Poston, Timothy, Raghavan, Raghu, Viswanathan, Raju R.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): QADERI, RUNA S
• Application Number:
  US09/566,478
• Time in Patent Office: 1,072 Days
• Field of Search: 600/407, 600/419, 600/420, 600/431, 600/412, 250/302, 324/307, 324/309, 424/9.3, 604/264, 382/128, 382/131
• US Class Current: 600/431
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2005/14292 Computer-based infusion planning or simulation of spatio-temporal infusate distribution
• CPC Class Codes: A61M 5/14 Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor

Abstract

Movement of material in an organism, such as a drug injected into a brain, is modeled by a uniformly structured field of static constants governing transport by moving fluid and diffusion within the fluid. This supports planning of material introduction, (e.g., infusion, perfusion, retroperfusion, injections, etc.) to achieve a desired distribution of the material, continuing real-time feedback as to whether imaged material is moving as planned and will be distributed as desired, and real-time plan modification to improve results.

Claims

1. A method for the interactive simulation of the movement of a first material in an organism, comprising:

(a) constructing a field of local physical quantities appropriate to motion, appearance and disappearance of said material in said organism, and

(b) constructing a field of a rate at which fluid flowing in said organism as a consequence of bodily processes or of an injection process moves at each position, thereby transporting said material, and

(c) constructing a model of a source from which said material enters said organism, with any pressure differential or flux rate that causes it to enter said organism, and

(d) computing a concentration field over time of said material, assuming a planned time course of said pressure differential or flux rate, and

(e) using said concentration field to implement control of concentration of said material by adjustment of the source from which said material enters said organism.

2. The method of claim 1 wherein the field of a rate at which fluid flowing in said organism as a consequence of bodily processes or of an injection process moves at each position is simulated and the field comprises at least one mechanism of movement selected from the group consisting of diffusion, flow, chemical creation or destruction of molecules, and absorption.

3. A method according to claim 2, where said organism is a patient or experimental subject, and said implemented control of the concentration optimizes resulting concentrations in different tissues according to target values therapeutically or scientifically chosen.

4. The method according to claim 3 wherein implemented control comprises minimizing resulting concentrations at tissue that is not targeted for therapy.

5. The method according to claim 4 wherein implemented control also comprises minimizing resulting concentrations at tissue that is not targeted for therapy.

6. The method to claim 3 wherein implemented control optimizes resulting concentrations at tissue targeted for therapy.

7. A method according to claim 2 where a field of diffusion tensor values and of rates of absorption, creation and destruction is constructed from scan data that, by appropriate scaling or other physically calibrated transformation, imply values for concentrations and/or motions of a material that has physical, chemical and biological properties different from those of the first material.

8. A method according to claim 2 where a field of diffusion tensor values and of rates of absorption, creation and destruction is constructed from magnetic resonance data that, by appropriate scaling or other physically calibrated transformation, imply values for concentrations and/or motions of a material that has physical, chemical and biological properties different from those of the first material.

9. A method according to claim 8 where predicted time courses of concentrations under the assumptions of a current plan and of suggested options are graphically displayed by the use of imagery.

10. The method according to claim 9 wherein the user controls a region or slice that displayed by the use of imagery.

11. The method according to claim 10 wherein the user controls optical properties relative to tissue regions and material concentrations are visualized.

12. A method according to claim 2 where the field of of rates of absorption, creation and destruction is constructed, by appropriate scaling or other physically calibrated transformation, from scan data recorded from a previous administration to the specific target region of that organism of material that has physical, chemical and biological properties sufficiently similar to those of the first material to be predictive of its transport properties.

13. A method according to claim 12 where comparison of a predicted concentration with real-time measurement of actual concentration is used to modify the field of local physical quantities to values and rates that predict a continuing change in concentration of said first material, and in pressure and edema.

14. A method according to claim 2 where the field of local physical quantities is constructed from scan data that permit segmentation of a region occupied by said organism into anatomical types, for which anatomical types of regions general diffusion tensor values and absorption rates are known.

15. The method according to claim 14 wherein said general local physical quantities are known from actual measurements on other organisms.

16. A method according to claim 1 where the field of local physical quantities is constructed from scan data that, by scaling or other physically calibrated transformation, imply values for concentrations and/or motions of a material that has physical, chemical and biological properties different from those of the first material.

17. A method according to claim 1 where the field of local physical quantities is constructed, by appropriate scaling or other physically calibrated transformation, from scan data recorded from a previous administration to the specific target region of that organism of material that has physical, chemical and biological properties sufficiently similar to those of the first material to be predictive of its transport properties.

18. A method according to claim 1 where the field of local physical quantities is constructed from scan data that permit segmentation of a region occupied by said organism into anatomical types, for which anatomical types of regions general diffusion tensor values and absorption rates are known.

19. The method according to claim 18 wherein said general diffusion values and absorption rates are known from actual measurements on other organisms.

20. A method according to claim 18 where comparison of a predicted concentration with real-time measurement of actual concentration is used to modify the field of local physical quantities to values and rates that predict a continuing change in concentration of said first material, and in pressure and edema.

21. A method according to claim 1 where the concentration field is computed by solving a finite differential equation constructed from a continuum model of some or all of the processes of transport, absorption, creation and destruction.

22. A method according to claim 21 where the concentration field is computed by the use of a multiplicity of processors acting in parallel, each handling a sub-region of the simulated volume, and using shared or separate memory of the field of local physical quantities.

23. A method according to claim 22 where said multiplicity of processors is embedded on a dedicated chip or assembly of chips are optimized for the computations required after the concentration field is computed.

24. A method according to claim 1 where the concentration field is computed by computing the motion of a number of simulated particles of said first material, with probability of motion in a particular direction controlled by a fluid velocity field and a diffusion tensor field and probability of absorption, creation or destruction controlled by other parts of the field of local physical quantities.

25. A method according to claim 24 where the concentration field is computed by the use of a multiplicity of processors acting in parallel, each processor handling a sub-population of one or more simulated particles, and at least some of said multiplicity of processors using shared or separate memory of the field of local physical quantities.

26. A method according to claim 25 where said computing of the concentration field is performed on a multiplicity of processors is embedded on a dedicated chip or assembly of chips.

27. A method according to claim 24 where a computer explores a range of possible planned time courses for pressure differential or flux rate and identifies certain options as more satisfactory than other planned time courses in terms of predetermined targets, and permits the user to implement an offered time course from among said certain options by an act of assent or selection in a user interface of software embodying the method.

28. A method according to claim 1 where target minimum or maximum concentrations and maximum pressures or extents of edema at particular locations are specified by the user, and a computer warns if said target minima or maxima are predicted to be unmet if a current planned time course of pressure differential or flux rate is executed or continued.

29. The method according to claim 1 wherein said material is a dissolved drug, dispersed drug, emulsified drug, a suspension of cells, or a suspension of nanodevices.

30. A method for the interactive simulation of the movement of a first material in an organism, comprising:

(a) constructing a field of local physical quantities appropriate to motion, appearance and disappearance of said material in said organism, and

(b) constructing a field of a rate at which fluid flowing in said organism as a consequence of bodily processes or of an injection process moves at each position, thereby transporting said material, and

(c) constructing a model of a source from which said material enters said organism, with any pressure differential or flux rate that causes it to enter said organism, and

(d) computing a concentration field over time of said material, assuming a planned time course of said pressure differential or flux rate, and

(e) using said concentration field to implement control of concentration of said material by adjustment of the source from which said material enters said organism, where the field of local physical quantities is constructed from magnetic resonance data that, by appropriate scaling or other physically calibrated transformation, imply values for concentrations and/or motions of a material that has physical, chemical and biological properties different from those of the first material to be predictive of its transport properties.

31. A method for providing a plan for the introduction of a first material to the tissue of a patient comprising:

providing an image of an interior volume of a patient, the image having more than one type of bodily composition within a field of view of the image,

assigning or determining values for at least two of said more than one type of bodily composition within said field of view, said values relating to at least one property selected from the group consisting of a) solvating ability, b) diffusivity, c) absorptivity, d) adsorptivity, e) degradation, f) production and g) transmissivity for a class of compounds or a specific compound,

selecting a position within the field of view for introduction of a first material,

selecting a rate of introduction of the first material at said position,

determining a pattern of movement over time of first material movement from said position based upon at least the rate of introduction and at least at least one property in said group,

comparing said pattern of first material movement to objectives for providing said first material to tissue within said patient, and

modifying at least one of a) said position, b) said rate of introduction, c) length of time of first material introduction, and d) physical properties of said first material.

32. A method for providing a plan for the introduction of a first material to the tissue of a patient comprising:

providing an image of an interior volume of a patient, the image having more than one type of bodily composition within a field of view of the image,

assigning or determining values for at least two of said more than one type of bodily composition within said field of view, said values relating to at least one property selected from the group consisting of a) solvating ability, b) diffusivity, c) absorptivity, d) adsorptivity, and transmissivity for a class of compounds or a specific compound,

selecting a position within the filed of view for introduction of a first material,

selecting a rate of introduction of the first material at said position,

determining a path of first material movement from said position based upon at least the rate of introduction and at least on of said at least one property,

comparing said path of first material movement to objectives for providing said first material to tissue within said patient, and

modifying at least one of a) said position, b) said rate of introduction, c) length of time of first material introduction, and d) physical properties of said first material.