METHOD AND DEVICE FOR LOCALIZING A VEIN WITHIN A LIMB

Abstract

A method of localizing and preferably visualizing a vein within a limb, preferably within a leg, of a patient, with an imaging device. The method includes the following steps of: fully or partially collapsing at least a segment of the vein to be localized at a collapsing site during a collapsing step; inducing blood flow within the vein at the collapsing site, while the segment of the vein is fully or partially collapsed, during a pumping step; and visualizing the collapsing site with the imaging device in an imaging step, at least during the pumping step.

Claims

1-24. (canceled)

25. A method of localizing a vein within a limb of a patient, with an imaging device, the method comprising the steps of: a. at least partially collapsing at least a segment of the vein to be localized at a collapsing site during a collapsing step; b. inducing blood flow within the vein at the collapsing site, during a pumping step, while the segment of the vein is partially collapsed; and c. visualizing the collapsing site with the imaging device, during an imaging step, at least during the pumping step.

26. The method according to claim 25, wherein the imaging step is performed during the collapsing step and the pumping step.

27. The method according to claim 25, wherein compressing and releasing the vein, during the pumping step, is performed manually.

28. The method according to claim 25, wherein compressing and releasing the vein, during the pumping step, is performed with a compression device.

29. The method according to claim 25, wherein compressing and releasing the vein is repeated while the segment of the vein is fully or partially collapsed.

30. The method according to claim 25, wherein the imaging is at least one of a color Doppler imaging, a pulsed wave Doppler imaging and a B-mode ultrasound imaging.

31. The method according to claim 25, wherein a field of vision or a focus of the imaging device is displaced, during the imaging step, for localizing the collapsed segment of the vein.

32. A method of localizing a vein within a limb of a patient, with a B-mode ultrasound imaging device with a main ultrasound propagation axis, the method comprising the following steps: a. fully or partially collapsing at least a segment of the vein to be targeted at a collapsing site during a collapsing step; b. imaging the collapsing site with the imaging device during an imaging step; c. changing at least one of a position and an orientation of the imaging device until a portion of the collapsed vein, corresponding to a wall of the collapsed vein segment, becomes a hyperechoic spot while the segment of the vein is partially collapsed, in a detecting step.

33. The method according to claim 32, wherein collapsing of the vein is performed by at least one of elevating at least the limb of the patient above a horizontal position, and compressing the vein segment and tumescence.

34. The method according to claim 32, wherein the imaging of the collapsing site is also performed during the collapsing step.

35. The method according to claim 32, wherein changing at least one of the position and the orientation of the imaging device is performed manually.

36. The method according to claim 32, wherein changing at least one of the position and the orientation of the imaging device is performed by a displacement device connected to the imaging device.

37. The method according to claim 32, wherein at least one of the position and the orientation of the imaging device is changed during the detecting step by moving the imaging device in at least one direction selected from: rotating around the main ultrasound propagation axis, rotating around an axis orthogonal to the main ultrasound propagation axis, displacement along a direction orthogonal to a main ultrasound propagation axis, and displacement along a direction parallel to the main ultrasound propagation axis.

38. The method according to claim 32, further comprising a step of: d. targeting a focus of an HIFU device within the localized collapsing site during a targeting step; and e. emitting at least one pulse of HIFU waves onto the targeted collapsing site with the HIFU device during a treatment step.

39. The method according to claim 38, wherein the imaging device is rotated during the detecting step around an axis comprising the focus of the HIFU device.

40. The method according to claim 38, wherein at least one of a diameter and a shape of the vein, at the collapsing site, is determined during a measurement step performed prior to the collapsing step.

41. The method for tumescence of a vein within a limb of a patient, wherein a liquid is injected into a neighboring segment of the vein at a collapsing site such that the vein is not completely surrounded by the liquid, whereupon the segment of the vein closes.

42. The method according to claim 41, wherein the liquid comprises an anaesthetic active substance.

43. The method according to claim 41, wherein a degassed liquid with a concentration of dissolved oxygen below 4 mg/L is used.

44. A degassed liquid, for use in tumescence of a vein of a patient, having a concentration of dissolved oxygen below 4 mg/L.

45. A device for localizing and visualizing a vein within a limb of a patient comprising: an imaging device and compressing device for compressing and releasing the vein at a compression site located near the collapsing site, and further comprising a control unit for controlling the imaging device and the compressing device, whereby the control unit is adapted to synchronize the imaging device to perform imaging of the compression site while the compression device compresses and releases the vein near the collapsing site.

46. A device for targeting and visualizing a vein within a limb of a patient, comprising: an imaging device, and a displacement device connected to the imaging device for displacing the imaging device, wherein the displacement device is adapted to displace the imaging device, and the device further comprising a control unit adapted to synchronize the imaging device to perform imaging of a collapsing site of a vein segment while the imaging device is displaced by the displacement device.

47. The device according to claim 46, further comprising an HIFU device.

48. A method of occluding a vein within a limb with an HIFU device, the method comprising the steps of: a. at least partially collapsing at least a segment of the vein to be localized at a collapsing site during a collapsing step; b. localizing the collapsing site with an imaging device during an imaging step; c. targeting a focus of the HIFU device within the localized collapsing site during a targeting step; and d. emitting at least one pulse of HIFU waves onto the targeted collapsing site with the HIFU device during a treatment step.

49. The method according to claim 25, further comprising a step of: d. targeting the focus of an HIFU device within the localized collapsing site during a targeting step; e. emitting at least one pulse of HIFU waves onto the targeted collapsing site with the HIFU device during a treatment step.

50. The method according to claim 25, wherein at least one of a diameter and a shape of the vein, at the collapsing site, is determined in a measurement step performed prior to the collapsing step.

51. The device according to claim 45, further comprising an HIFU device.

52. The method according to claim 25, wherein collapsing of the vein is performed by at least one of elevating at least the limb of the patient above a horizontal position, and compressing the vein segment and tumescence.

53. The method according to claim 52, wherein the imaging of the collapsing site is also performed during the collapsing step.

Description

[0109] The invention will now be described in more detail by way of non-limiting, exemplary embodiments in connection with the drawings which show:

[0110] FIG. 1 a flow chart according to a first alternative of the method according to the present invention;

[0111] FIG. 2 a flow chart according to a second alternative of the method according to the present invention; and

[0112] FIG. 3 a schematic arrangement of a device according to the present invention.

[0113] FIG. 1 shows a first alternative of the method according to the present invention. In a first collapsing step 101, at least a segment of the targeted vein is collapsed. As cited above, the vein may be collapsed by inclining the limb of the patient or by tumescence.

[0114] In order to reliably localize the collapsed segment of the vein with an imaging device, blood flow is forced into the collapsed vein segment in a pumping step 102. If the pumping step 102 is performed by compressing/releasing the vein, the compression is preferably performed upstream of the collapsed segment, either manually by an operator or with a compression device. A temporary blood flow is therefore forced through the collapsed segment of the vein, making the collapsed segment visible by means of the imaging device during an imaging step 103.

[0115] In the case where colour Doppler is used as imaging method, the blood flow becomes clearly visible. If B-mode ultrasound imaging is used, the blood flow causes opening and closing of the collapsed vein segment. The vein lumen therefore appears as a hypoechoic spot (corresponding to the vein lumen opening and closing). As an alternative, pulsed wave Doppler can also be used as an imaging step. The measurement location of the pulsed wave Doppler device is placed in the region where the collapsed segment is expected and the pumping step 102 is performed. If a signal is detected by means of the pulsed wave Doppler during the imaging step 103, then the pulsed wave Doppler device has been correctly focused onto the collapsed segment of the vein. Otherwise, the measurement location is shifted and the pumping step 102 is repeated until the location of the collapsed vein segment has been correctly determined in the imaging step 103.

[0116] After the correct location of the collapsed vein segment has been determined, a treatment step 104 may be performed. An HIFU device is focused onto the collapsed vein segment and a pulse or a series of pulses of HIFU waves is emitted in order to treat the collapsed vein segment and occlude it.

[0117] As may be seen from FIG. 2, where an alternative of the method according to the present invention is shown, the collapsing step 101 is first performed.

[0118] Instead of the pumping step 102, a detection step 202 is then performed. During the detection step 202, imaging of the region of interest around the collapsed vein segment is performed by means of B-mode ultrasound imaging.

[0119] The B-mode ultrasound imaging device has a main ultrasound propagation axis. During the detection step 202, the imaging device is moved until a hyperechoic spot corresponding to the vein wall of the collapsed vein segment is detected and the location of the collapsed vein segment has been correctly determined.

[0120] Also in this case, the treatment step 104, as described with regard to FIG. 1, may be performed after the detection step 202.

[0121] The HIFU device and the B-mode imaging device are preferably a combined device where the focus of the HIFU device lies in the imaging plane of the imaging device.

[0122] In this case, the displacement of the B-mode imaging device also implicitly causes a displacement of the HIFU device. If the vein does not run parallel to the skin, the HIFU device would not be in the optimal position for emitting the HIFU waves (where the HIFU waves beam is orthogonal to the skin surface to enhance HIFU waves transmission through the skin). In this case, after the detection step 202 has been performed and the correct location of the region to be treated has been determined, the combined B-mode imaging device and HIFU device is displaced to an optimal position for the emission of HIFU waves, while the focus of the HIFU device is positioned onto the region to be treated. Thus, there are two different positions/angles, one which is optimal for visualization (e.g. with the main ultrasound propagation axis orthogonal to the wall of the collapsed vein segment and one which is optimal for delivering HIFU energy (e.g. with the main propagation axis of the HIFU waves orthogonal to the skin).

[0123] Where the combined B-mode imaging device and HIFU device is displaced by means of a device, e.g. a robotic arm, the device may comprise a control unit designed to move the combined B-mode imaging device and HIFU device correctly. The correct location of the region to be treated may in this case be defined by a user or detected automatically by an image processing algorithm of an image processing unit connected to the control unit.

[0124] FIG. 3 shows a device 1 according to the present invention. The device 1 comprises a treatment head comprising an HIFU device 2 and an imaging device 3. The treatment head is mounted on a robot arm 4. Adjacent to the treatment head there is located a compression device 5. The device 1 further comprises a control unit 6 connected (schematically represented by the dotted lines) to the HIFU device 2, the imaging device 3, the robot arm 4, the compression device 5 and a user interface 7.

[0125] The user interface 7 comprises a display 8 and a plurality of switches 9 for manually controlling the device 1.

[0126] A patient P is lying on an inclined table 10, the vein to be targeted has therefore been collapsed.

[0127] The control unit 6 is adapted to control the HIFU device 2, the imaging device 3, the movement of the robot arm 4 and the compression device 5 in order to perform the methods as cited above. In addition, the user can control the operation of the device 1 by means of the user interface 7. The display 8 displays, among other information, the images generated by the imaging device 3. The switches 9 are used for triggering different functions of the device 1, in particular to switch to different operating modes, to trigger emission of HIFU waves by the HIFU device 2 (if this is not performed automatically by the device 1), move the treatment head by means of the robot arm 4 etc.

[0128] As an example, where the device 1 is adapted to perform the method described with reference to FIG. 1, the control unit 1 controls the synchronization of the imaging device 2 and the compression device 5 while the pumping step 102 and the imaging step 103 are performed. The correct localization of the collapsed vein segment is therefore possible. After the collapsed vein segment has been localized, the control unit 1 controls the correct focussing of the HIFU device 2 onto the collapsed vein segments and the triggering of the emission of the HIFU waves.

[0129] In the case the method described with reference to FIG. 2 is performed, the control unit 1 synchronizes the movement of the treatment head and therefore of the imaging device 3 in order to orient the imaging device 3 until the hyperechoic spot corresponding to the collapsed vein segment wall has been correctly localized. In addition, the control unit 1 then controls correct positioning of the focused HIFU device 2 for optimal emission of the HIFU waves. Preferably, the control unit 1 also controls the movement of the treatment head by means of the robot arm 4 when scanning of the vein as described above is performed.