MECHANICAL CLUTCH FOR MRI

• US 20150253397A1
• Filed: 02/02/2015
• Published: 09/10/2015
• Est. Priority Date: 03/10/2014
• Status: Active Grant

• Current Assignee: Aspect Imaging Ltd.
• Original Assignee: Aspect Imaging Ltd.
• Inventors: RAPOPORT, Uri
• Granted Patent: US 9,568,571 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F16D 7/02 of the friction type
• CPC Class Codes: F16D 7/048 with parts moving radially between engagement and disengagement F16D7/10 takes precedence
• CPC Class Codes: G01R 33/34092 RF coils specially adapted for NMR spectrometers
• CPC Class Codes: G01R 33/3628 Tuning/matching of the transmit/receive coil
• CPC Class Codes: G01R 33/3642 Mutual coupling or decoupling of multiple coils, e.g. decoupling of a receive coil from a transmission coil, or intentional coupling of RF coils, e.g. for RF magnetic field amplification
• CPC Class Codes: G01R 33/385 using gradient magnetic field coils
• CPC Class Codes: Y10T 29/4984 Retaining clearance for motion between assembled parts

Abstract

A mechanical clutch for preventing damage to a capacitor of an MRI device. The clutch prevents the application of excessive torque via the tuning rods of the gradient coil of the MRI device. The mechanical clutch allows the tuning rods to slip (disengage) when the capacitor reaches the end of its adjustment range.

Claims

1. A mechanical clutch (100) engaging the rotation of a first and a second rotatable shafts;

said mechanical clutch comprises;

an outer element (110) having a first main longitudinal axis (111) with distal and proximal ends, further having, in a plain perpendicular to said longitudinal axis on said distal end, a substantially cylindrical bore (112);

said outer element is connected, in said proximal end, with said first shaft;

said cylindrical bore comprises at least one semi-flexible member (113) (SFM) comprising at least one aperture (114);

said SFM is configured to reversibly transition from a relaxed configuration (RC) (113A) to a tensed configuration (TC) (113B);

said member;

an inner element (120), having a second main longitudinal axis (121) with distal and proximal ends;

said inner element is connected, in said proximal end, with said second shaft;

said inner element comprises in said distal end a cylindrical protrusion (122) having a third main longitudinal axis (124);

said cylindrical protrusion is configured to rotatably accommodate within said cylindrical bore;

said protrusion comprises at least one bulge (123) perpendicular to said third longitudinal axis bulging from said cylindrical protrusion shell;

said at least one bulge having a distal and a proximal end;

said distal end is in contact with said cylindrical protrusion;

wherein said SFM is in said TC when said proximal end of said bulge is reversibly accommodated within said aperture and in said RC when said proximal end of said bulge is located outside said aperture;

wherein said SFM is configured to temporarily collapse outwardly when in said TC;

wherein said clutch ceases to engage said rotation of said first and said second rotatable shafts when said SFM collapse outwardly.

2. The mechanical clutch of claim 1, wherein said inner element and said outer element are either (a) MRI safe materials;

(b) plastic;

(c) thermoplastic;

or (d) any combination thereof.

3. The mechanical clutch of claim 1, wherein said mechanical clutch is selected from a group of clutches consisting of:

ratcheting clutch, synchronous clutch, overload clutch, and any combination thereof.

4. The mechanical clutch of claim 1, wherein said member is in said relaxed configuration when the torque applied by said second shaft is below a predetermined value and in said tensed configuration when said torque equals or above said predetermined value.

5. The mechanical clutch of claim 4, wherein at least one of the following is being held true (a) said predetermined value is adjustable;

(b) said mechanical clutch automatically reengages when said torque returns to less than said predetermined value.

6. The mechanical clutch of claim 1, wherein at least one of the following is being held true (a) said mechanical clutch requires manual reengaging;

(b) said reengaging occurs by transitioning said bulge from said aperture;

(c) said clutch has backlash-free torque transmission;

(d) said first shaft is at least one capacitor and said second shaft is at least one tuning rod of a resonance coil of an MRI;

(e) and combination thereof.

7. A mechanical clutch (100) engaging the rotation of a first and a second rotatable shafts;

said mechanical clutch comprises;

an outer element (110) having a first main longitudinal axis (111) with distal and proximal ends, further having, in a plain perpendicular to said longitudinal axis on said distal end, a substantially cylindrical bore (112);

said outer element is connected, in said proximal end, with said first shaft;

said cylindrical bore comprises at least one semi-flexible member (SFM) (113) comprising at least one aperture (114);

said SFM is configured to reversibly transition from a relaxed configuration (RC) (113A) to a tensed configuration (TC) (113B);

said member;

an inner element (120), having a second main longitudinal axis (121) with distal and proximal ends;

said inner element is connected, in said proximal end, with said second shaft applying Torque (Tx);

said inner element comprises in said distal end a cylindrical protrusion (122) having a third main longitudinal axis (124);

said cylindrical protrusion is configured to rotatably accommodate within said cylindrical bore;

said protrusion comprises at least one bulge (123) perpendicular to said third longitudinal axis bulging from said cylindrical protrusion shell;

said at least one bulge having a distal and a proximal end;

said distal end is in contact with said cylindrical protrusion;

wherein said SFM is in said TC when said proximal end of said bulge is reversibly accommodated within said aperture and in said RC when said proximal end of said bulge is located outside said aperture;

wherein said SFM is configured to temporarily collapse outwardly when in said TC;

wherein said clutch ceases to engage said rotation of said first and said second rotatable shafts when said SFM collapse outwardly;

wherein said proximal end of said bulge is accommodated within said aperture when said Tx is above a predetermined torque value (PTV) and said proximal end of said bulge is located outside said aperture when said Tx equals or is lower than said PTV.

8. The mechanical clutch of claim 7, wherein said mechanical clutch is made of either (a) MRI safe materials;

(b) plastic;

(c) thermoplastic;

or (d) any combination thereof.

9. The mechanical clutch of claim 7, wherein at least one of the following is being held true (a) said first shaft is at least one capacitor and said second shaft is at least one tuning rod of a resonance coil of an MRI;

(b) said PTV is adjustable;

(c) said mechanical clutch is selected from a group of clutches consisting of;

ratcheting clutch, synchronous clutch, overload clutch, and any combination thereof;

(d) said mechanical clutch automatically reengages when said PTV returns to less than said predetermined value;

(e) said mechanical clutch requires manual reengaging;

(f) said reengaging occurs by transitioning said bulge from said aperture;

(g) any combination thereof.

10. The mechanical clutch of claim 7, wherein at least one of the following is being held true (a) said first shaft is connected to said outer member through a Cardan joint configured to change the angle of said Tx applied by said second shaft;

(b) aid clutch has backlash-free torque transmission;

(c) said Tx drops immediately when said mechanical clutch disengages;

(d) said first shaft is connected to said outer member through a Cardan joint configured to change the angle of said Tx applied by said TR; and

any combination thereof.

11. The mechanical clutch of claim 7, wherein said first rotating shaft has a limit of torque it can receive (Ty).

12. The mechanical clutch of claim 11, wherein said Tx<

Ty.

13. A mechanical clutch (100) engaging the rotation of at least one capacitor (140) and a tuning rod of a resonance coil of an MRI (TR) (130);

said mechanical clutch comprises;

an outer element (110) having a first main longitudinal axis (111) with distal and proximal ends, further having, in a plain perpendicular to said longitudinal axis on said distal end, a substantially cylindrical bore (112), said outer element is connected, in said proximal end, with said at least one capacitor;

said cylindrical bore comprises at least one semi-flexible member (SFM) (113) comprising at least one aperture (114);

said SFM is configured to reversibly transition from a relaxed configuration (RC) (113A) to a tensed configuration (TC) (113B);

said member;

an inner element (120), having a second main longitudinal axis (121) with distal and proximal ends;

said inner element is connected, in said proximal end, with said TR applying Torque (Tx);

said inner element comprises in said distal end a cylindrical protrusion (123) having a third main longitudinal axis (124);

said cylindrical protrusion is configured to rotatably accommodate within said cylindrical bore;

said protrusion comprises at least one bulge (123) perpendicular to said third longitudinal axis bulging from said cylindrical protrusion shell;

said at least one bulge having a distal and a proximal end;

said distal end is in contact with said cylindrical protrusion;

wherein said SFM is in said TC when said proximal end of said bulge is accommodated within said aperture and in said RC when said proximal end of said bulge is located outside said aperture;

wherein said SFM is configured to temporarily collapse outwardly when in said TC;

wherein said clutch ceases to disengage said at least one capacitor with said TR when said SFM collapse outwardly;

wherein said proximal end of said bulge is reversibly accommodated within said aperture when said Tx is above a predetermined torque value (PTV) and said proximal end of said bulge is located outside said aperture when said Tx equals or is lower than said PTV.

14. The mechanical clutch of claim 13, wherein said mechanical clutch is made of either (a) MRI safe materials;

(b) plastic;

(c) thermoplastic;

or (d) any combination thereof.

15. The mechanical clutch of claim 13, wherein at least one of the following is being held true (a) said PTV is adjustable;

(b) said mechanical clutch is selected from a group of clutches consisting of;

ratcheting clutch, synchronous clutch, overload clutch, and any combination thereof (c) said mechanical clutch automatically reengages when said PTV returns to less than said predetermined value;

(d) said mechanical clutch requires manual reengaging;

(e) reengaging occurs by transitioning said bulge from said aperture;

(f) said capacitor is connected to said outer member through a Cardan joint configured to change the angle of said Tx applied by said TR; and

any combination thereof.

16. The mechanical clutch of claim 13, wherein at least one of the following is being held true (a) said clutch has backlash-free torque transmission;

(b) said Tx drops immediately when said mechanical clutch disengages; and

any combination thereof.

17. The mechanical clutch of claim 13, wherein said at least one capacitor has a limit of torque it can receive (Ty).

18. The mechanical clutch of claim 17, wherein said Tx<

Ty.

19. A mechanical clutch (100) engaging a first and a second rotatable shafts;

comprises;

an outer housing (120) having a first main longitudinal axis with distal and proximal ends, further having, in a plain perpendicular to said second axis, a substantially cylindrical bore, said outer housing is connected, in said proximal end, with said second shaft;

an inner element (110) configured to rotetably accommodate within said outer element, having a first main longitudinal axis with distal and proximal ends, connected, in said distal end, with said first shaft, characterized, in a plain perpendicular to said first axis, by a substantially cylindrical cross-section having a defined diameter, D_I;

wherein said inner element comprises at least one bulge protruding said diameter D_I, said bulge is characterized by a proximal base located within diameter D_I and distal end perturbing outside diameter D_I;

wherein said outer housing further comprising at last one semi-flexible member configured to reversibly transition from a relaps configuration, whereat said bulge in and a tensed configuration by a predefined torque (T_X);

wherein said member comprises at least aperture configure to reversibly accommodate said bulge'"'"'s distal end;

wherein the orientation of said bulge in respect to said member'"'"'s opening is rotetably transformable from at least one first eclipsed orientation, where the bulge'"'"'s distal portion is located within said opening, to at least one second non-eclipsed phase;

wherein said member is configured to temporarily collapse outwardly when said bulge is in its eclipsed configuration;

wherein at said eclipsed orientation, the rotation of both said first and said second shafts is synchronically engaged; and

further wherein at said at least one second non-eclipsed phase, said first and said second shafts are disengaged.

20. A method for manufacturing a mechanical clutch for engaging the rotation of a first and a second rotatable shafts (400);

said method comprises steps of;

a. obtaining (410);

i. an outer element having a first main longitudinal axis with distal and proximal ends, further having, in a plain perpendicular to said longitudinal axis on said distal end, a substantially cylindrical bore, said cylindrical bore comprises at least one semi-flexible member (SFM) comprising at least one aperture;

said SFM is configured to reversibly transition from a relaxed configuration (RC) to a tensed configuration (TC);

said member;

ii. an inner element, having a second main longitudinal axis with distal and proximal ends;

said inner element is connected, in said distal end to a cylindrical protrusion having a third main longitudinal axis;

said protrusion comprises at least one bulge perpendicular to said third longitudinal axis bulging from said cylindrical protrusion shell;

said at least one bulge having a distal and a proximal end;

said distal end is in contact with said cylindrical protrusion;

b. rotatably accommodating said protrusion within said cylindrical bore (420);

c. connecting said first shaft to said proximal end of said outer element (430); and

,

d. connecting said second shaft to said proximal end of said inner element (440);

said second shaft is applying torque (Tx);

wherein said SFM is transitioning from said RC to said TC when said protrusion rotates and said proximal end of said bulge changes its location from outside said aperture to within said aperture;

wherein said SFM is temporarily collapsing outwardly when transitioning to said TC;

wherein said clutch is ceasing to engage said rotation of said first and said second rotatable shafts when said SFM collapse outwardly;

wherein said proximal end of said bulge is accommodating within said aperture when said Tx is above a predetermined torque value (PTV) and said proximal end of said bulge is locating outside said aperture when said Tx equals or is lower than said PTV.

21. The method according to claim 20, additionally comprising at least one step selected from a group consisting of (a) manufacturing said mechanical clutch from either (i) MRI safe materials;

(ii) plastic;

(iii) thermoplastic; and

any combination thereof;

(b) manufacturing said mechanical clutch with an reengaging mechanism selected from a group consisting of;

manual, automatic, and any combination thereof;

(c) selecting at least one capacitor for said first shaft and at least one tuning rod of resonance coil of an MRI for said second shaft;

(d) and any combination thereof.

22. A method for manufacturing a mechanical clutch for engaging the rotation of at least one capacitor with a tuning rod of at least one resonance coil of an MRI (TR) (400);

said method comprises steps of;

a. obtaining (410);

i. an outer element having a first main longitudinal axis with distal and proximal ends, further having, in a plain perpendicular to said longitudinal axis on said distal end, a substantially cylindrical bore, said cylindrical bore comprises at least one semi-flexible member (SFM) comprising at least one aperture;

said SFM is configured to reversibly transition from a relaxed configuration (RC) to a tensed configuration (TC);

said member;

ii. an inner element, having a second main longitudinal axis with distal and proximal ends;

said inner element is connected, in said distal end to a cylindrical protrusion having a third main longitudinal axis;

said protrusion comprises at least one bulge perpendicular to said third longitudinal axis bulging from said cylindrical protrusion shell;

said at least one bulge having a distal and a proximal end;

said distal end is in contact with said cylindrical protrusion;

b. rotatably accommodating said protrusion within said cylindrical bore (420);

c. connecting said at least one capacitor to said proximal end of said outer element (430); and

,

d. connecting said TR to said proximal end of said inner element (440);

wherein said SFM is transitioning from said RC to said TC when said protrusion rotates and said proximal end of said bulge changes its location from outside said aperture to within said aperture;

wherein said SFM is temporarily collapsing outwardly when transitioning to said TC;

wherein said clutch is ceasing to engage said rotation of said at least one capacitor and said TR when said SFM collapse outwardly;

wherein said proximal end of said bulge is accommodating within said aperture when said Tx is above a predetermined torque value (PTV) and said proximal end of said bulge is locating outside said aperture when said Tx equals or is lower than said PTV.

23. The method according to claim 22, additionally comprising a step of manufacturing said mechanical clutch from either (a) MRI safe materials;

(b) plastic;

(c) thermoplastic;

(d) any combination thereof.

24. The method according to claim 22, additionally comprising at least one step selected from a group consisting of (a) manufacturing said mechanical clutch with an reengaging mechanism selected from a group consisting of:

manual, automatic, and any combination thereof;

(b) determining said PTV; and

any combination thereof.

25. The method according to claim 22, wherein said reengaging mechanism is reengaging only when said TX is below said PTV.

26. A method for operating a mechanical clutch for engaging the rotation of a first and a second rotatable shafts (500);

said method comprises steps of;

a. obtaining (510);

i. an outer element having a first main longitudinal axis with distal and proximal ends, further having, in a plain perpendicular to said longitudinal axis on said distal end, a substantially cylindrical bore, said cylindrical bore comprises at least one semi-flexible member (SFM) comprising at least one aperture;

said SFM is configured to reversibly transition from a relaxed configuration (RC) to a tensed configuration (TC);

said member;

ii. an inner element, having a second main longitudinal axis with distal and proximal ends;

said inner element is connected, in said distal end to a cylindrical protrusion having a third main longitudinal axis;

said protrusion comprises at least one bulge perpendicular to said third longitudinal axis bulging from said cylindrical protrusion shell;

said at least one bulge having a distal and a proximal end;

said distal end is in contact with said cylindrical protrusion;

b. connecting said first shaft to said proximal end of said outer element (520);

said first rotating shaft has a limit of torque it can receive (Ty);

c. connecting said second shaft to said proximal end of said inner element;

said second shaft is applying torque (Tx) (530);

d. accommodating said protrusion within said cylindrical bore (540); and

,

e. rotating said protrusion within said cylindrical bore by torque (Tx) applied by said second shaft (550);

wherein said SFM is transitioning from said RC to said TC when said protrusion rotates and said proximal end of said bulge changes its location from outside said aperture to within said aperture;

wherein said SFM is temporarily collapsing outwardly when transitioning to said TC;

wherein said clutch is ceasing to engage said rotation of said first and said second rotatable shafts when said SFM collapse outwardly;

wherein said proximal end of said bulge is accommodating within said aperture when said Tx is above a predetermined torque value (PTV) and said proximal end of said bulge is locating outside said aperture when said Tx equals or is lower than said PTV.

27. The method of claim 26, additionally comprising at least one step selected from a group consisting of (a) adjusting said PTV;

(b) dropping immediately said Tx when said mechanical clutch is disengaging;

(c) disengaging by transitioning said bulge from said aperture; and

any combination thereof.

28. The method of claim 26, additionally comprising a step of reengaging said mechanical clutch in a manner selected from a group consisting of:

automatic, manual, and any combination thereof.

29. The method of claim 28, wherein said reengaging is possible only when said Tx is less than said PTV.

30. The method of claim 26, wherein said Tx<

Ty.

31. A method for operating a mechanical clutch for engaging the rotation of at least one capacitor with a at least one tuning rod of a resonance coil of an MRI (TR) (500);

said method comprises steps of;

a. obtaining (510);

i. an outer element having a first main longitudinal axis with distal and proximal ends, further having, in a plain perpendicular to said longitudinal axis on said distal end, a substantially cylindrical bore, said cylindrical bore comprises at least one semi-flexible member (SFM) comprising at least one aperture;

said SFM is configured to reversibly transition from a relaxed configuration (RC) to a tensed configuration (TC);

said member;

ii. an inner element, having a second main longitudinal axis with distal and proximal ends;

said inner element is connected, in said distal end to a cylindrical protrusion having a third main longitudinal axis;

said protrusion comprises at least one bulge perpendicular to said third longitudinal axis bulging from said cylindrical protrusion shell;

said at least one bulge having a distal and a proximal end;

said distal end is in contact with said cylindrical protrusion;

b. connecting said at least one capacitor to said proximal end of said outer element (520);

);

said at least one capacitor has a limit of torque it can receive (Ty);

c. connecting said at least one TR to said proximal end of said inner element (530);

said second shaft is applying torque (Tx);

d. accommodating said protrusion within said cylindrical bore (540); and

,

e. rotating said protrusion within said cylindrical bore by torque (Tx) applied by said second shaft (550);

wherein said SFM is transitioning from said RC to said TC when said protrusion rotates and said proximal end of said bulge changes its location from outside said aperture to within said aperture;

wherein said SFM is temporarily collapsing outwardly when transitioning to said TC;

wherein said clutch is ceasing to engage said rotation of capacitor and said TR when said SFM collapse outwardly;

wherein said proximal end of said bulge is accommodating within said aperture when said Tx is above a predetermined torque value (PTV) and said proximal end of said bulge is locating outside said aperture when said Tx equals or is lower than said PTV.

32. The method of claim 31, additionally comprising at least one step selected from a group consisting of (a) adjusting said PTV;

(b) dropping immediately said Tx when said mechanical clutch is disengaging;

(c) automatically reengaging said mechanical clutch when said input torque returns to less than said predetermined value;

(d) manually reengaging said mechanical clutch;

(e) changing by a Carden joint the angle of said Tx before its transmission to said capacitor;

(f) disengaging by transitioning said bulge from said aperture;

(g) any combination thereof.

33. The method of claim 31, additionally comprising a step of reengaging said mechanical clutch in a manner selected from a group consisting of:

automatic, manual, and any combination thereof.

34. The method of claim 33, wherein said reengaging is possible only when said Tx is less than said PTV.

35. The method of claim 31, wherein said Tx<

Ty.