DEVICE AND METHOD FOR TREATMENT OF A PATIENT BY HIGH-INTENSITY FOCUSED ULTRASOUND (HIFU)

Abstract

The invention relates to a device (1) and a method to avoid artefacts in second circulation mode imaging during ultrasound treatments of the human body (P). Specifically and amongst other effects, the invention provides a way to adequately control, in particular turn on and off, the fluid circulation (12) in a cavity (7) such as to avoid artefacts while still enabling practical imaging.

Claims

1.-22. (canceled)

23. A device for treatment of a patient by HIFU, the device comprising a treatment head including a HIFU emitting unit, for generating HIFU pulses, an imaging device a pump for circulating a fluid in a cavity between the treatment head and a contact surface of the device adapted to be brought into contact with the patient's (P) skin a control unit for controlling operation of the imaging device and the pump wherein the control unit is adapted for operating the fluid circulation at least in a second circulation mode different from a regular circulation mode.

24. The device of claim 23, wherein the control unit is adapted for switching to the second circulation mode, which comprises stopping the fluid circulation, when Doppler imaging mode and/or elastography mode is activated.

25. The device of claim 23, wherein the control unit is adapted for switching to the regular circulation mode, which comprises switching the fluid circulation on again or increasing the flow when the Doppler imaging mode and/or elastography mode is deactivated.

26. The device of claim 23, wherein the treatment head includes a balloon through which said fluid can be circulated and wherein the control unit is adapted to control the fluid circulation in such a way that a preset pressure is achieved within the balloon during the regular circulation mode.

27. The device of claim 26, wherein the control unit is adapted to reactivate the regular circulation mode after a delay has elapsed after sending the command to switch to the regular imaging mode.

28. The device of claim 26, wherein the control unit is adapted to reactivate the regular circulation mode after the imaging device has switched to and is operating in the regular imaging mode.

29. The device of claim 27, where the control unit is adapted to temporarily change to a pressure control mode based on at least one of the following resume conditions: a movement of the treatment head along any axis the measured pressure value is above or below a certain threshold relative to the current pressure setpoint the geometry of the skin has deformed as assessed by an automatic detection algorithm a dedicated control is activated.

30. The device of claim 29, wherein the control unit is adapted to change back from the temporary pressure control mode to the second circulation mode based on at least one of the following conditions: no movement has been detected along any axis since a certain predefined period of time the pressure is within a predetermined range around the pressure setpoint the pressure is sufficiently stable in case where the pressure regulation is performed using two pumps, the speed of the inlet and outlet pumps, as determined by the feedback loop, are close enough from each other during a certain time Lapse of a certain time a dedicated input is activated.

31. The device according to claim 23, wherein the control unit is adapted for reducing the speed of the fluid in the second circulation mode.

32. The device according to claim 31, wherein the control unit (20) is adapted for reducing the speed of the fluid (9) to a predetermined speed.

33. A method for treatment of a patient by HIFU, the method comprising the following steps: treating a target of the patient with HIFU pulses, circulating a fluid in a cavity between a treatment head and a contact surface of the device adapted to be brought into contact with the patient's skin in a regular circulation mode monitoring the target with an imaging device operating temporarily in a Doppler imaging mode and/or elastography mode, changing the circulation of the fluid to a second circulation mode at least temporarily during monitoring in the Doppler imaging mode.

34. The method according to claim 33, comprising the further step of switching to the second circulation mode, comprising at least one of stopping or reducing the fluid circulation, when Doppler imaging mode is activated, such that Doppler imaging mode is not activated unless second circulation mode is also activated.

35. The method according to claim 33, comprising the further step of switching back to the regular circulation mode, which comprises switching the circulation on again or increasing the flow when the Doppler imaging is deactivated, such that Doppler imaging mode and/or elastography mode is not activated unless second circulation mode is activated.

36. The method according to claim 33, wherein a treatment device comprises a balloon through which the fluid can be circulated and wherein the method further comprises the step of controlling the fluid circulation in such a way that a preset pressure is achieved within the balloon during regular circulation mode.

37. The method according to claim 35, further comprising the step of reactivating the regular circulation mode after a delay has elapsed after sending the command to switch to the regular imaging mode.

38. The method according to claim 33, further comprising the step of reactivating the regular circulation mode after the imaging device has switched to and is operating in the regular imaging mode.

39. The method according to claim 37, further comprising the step of temporarily change to a pressure control mode based on at least one of the following conditions: A movement of the treatment head along any axis the measured pressure value is above or below a certain threshold relative to the current pressure setpoint the geometry of the skin has deformed as assessed by an automatic detection algorithm a dedicated control is activated.

40. The method according to claim 39, further comprising the step of changing back from the temporary pressure control mode to the second circulation mode based on at least one of the following conditions: no movement has been detected along any axis since a certain predefined period of time the pressure is within a predetermined range around the pressure setpoint the pressure is sufficiently stable in case where the pressure regulation is performed using two pumps, the speed of the inlet and outlet pumps, as determined by the feedback loop, are close enough from each other during a certain time Lapse of a certain time a dedicated input is activated.

41. The method according to claim 33, further comprising the step of reducing the speed of the fluid in the second circulation mode.

42. The method according to claim 41, wherein the speed of the fluid is reduced to a predetermined speed.

Description

[0053] In the following, the invention is described in detail with reference to the following figures, which show:

[0054] FIG. 1 a schematic representation of a device according to the invention

[0055] FIG. 2a-2e a schematical representation of the working principle of a preferred embodiment of the invention.

[0056] FIG. 3 a flow chart showing relevant steps of the method according to the invention

[0057] FIG. 4 a schematic representation of the general idea of the invention

[0058] FIG. 1 show a device 1 for treating a target T within a body part of a patient P with HIFU pulses. The device 1 comprises a treatment head 3. The treatment head 3 is provided with treatment transducer 5 and an imaging transducer 6. The treatment head is further equipped with a cavity 7 for a fluid 9, in the present embodiment in the form of a balloon 7. The balloon 7 is composed of a membrane 8 that can be filled with a fluid 9. The fluid 9 can be circulated 12 through the balloon with a pumping system 10 that is connected to the balloon 7 via an operative connection such as a pipe 11. The device further comprises a control unit 20 that is operatively connected 21 to the treatment head 3 and controls the imaging transducer 6 and the treatment transducer 5, as well as the pumping system 10.

[0059] FIG. 2a shows schematically the treatment head 3 that is in contact with the skin of a patient P. The pumps 10 are activated by the control unit 20, resulting in circulation 12 of a fluid 9 within the balloon 7 mounted on the treatment head 2. In the depicted embodiment configuration in FIG. 2a, the device is run in B-mode imaging. FIG. 2b depicts an intermediary state before switching to a Doppler imaging mode and/or elastography mode, wherein the pump 10 is turned off, resulting in a stop of fluid circulation in the balloon 7. This corresponds to the second circulation mode of the pumping system, while the imaging is still conducted in B-mode. FIG. 2c depicts the treatment head after switching to Doppler imaging mode and/or elastography mode. FIG. 2d shows the intermediary state when switching back to B-mode imaging, wherein the pumping system 10 keeps the pumps turned off resulting in no circulation but switching the imaging back to B-mode. FIG. 2e shows schematically the treatment head after the pumping system 10 has turned to pump back on after B-mode imaging was resumed.

[0060] FIG. 3 shows a method according to the invention by means of a flow chart. Conventional HIFU treatment is being carried out in a treatment step 31 wherein the imaging device is operated in regular imaging mode. A trigger step 41 can be used to give the command to switch modes. As long as the trigger is not activated 51, the device images in regular imaging mode and the pumping system is in the regular circulation mode. If the operator gives the command to switch to Doppler imaging mode and/or elastography mode 52, in a first step 32, the pumping system is switched to second circulation mode. Typically, in second circulation mode, the pumping system turns off of the pumps. However, second circulation mode may also comprise slowing the pumps down instead of turning them off. Once the pumping system is in second circulation mode, the imaging device is switched to Doppler imaging mode and/or elastography mode in another step of the method 33. Once steps 32 and 33 have been carried out, the device is ready to conduct Doppler imaging without artefacts 34. Another trigger 42 can be used by the user to switch back to B-mode. As long as the trigger is not activated 53, the device remains in second circulation mode. Once the trigger is activated 54, the imaging device is first switched back to regular imaging mode in one step 35. Only once step 35 has been performed, the pumping system is switched back to regular circulation mode in another step 36 which resumes circulation of the fluid. Back in B-mode, the treatment step 31 can be resumed and, optionally, the method carried out again.

[0061] FIG. 4 shows schematically the general concept of the invention by depicting the on and off states of the pumping system modes (Doppler and Regular) and the imaging system modes (Doppler and B-mode). Initially, and as described herein, the device (1) is operating in B-mode imaging while the pumping system (10) is in regular mode. At a time t.sub.1, the user may decide to switch to Doppler imaging. The control unit (20) first switches the pumping system (10) to second circulation mode, and only once second circulation mode is established, at a time t.sub.2, switches to Doppler imaging mode, leading to a delay time Δt.sub.1. Similarly, if the user gives the command to switch back to B-mode imaging at a time t.sub.3, the control unit (20) first switches the imaging device (6) back to regular imaging mode, and after the imaging device (6) is generating a live image in B-mode, at a time t.sub.4, switches the pumping system back to regular circulation mode. This leads to another delay time Δt.sub.2 and ensures that the pumping system mode is never switched while in Doppler imaging mode but only in regular imaging mode, such that movement in the image due to pressure changes can be seen in B-mode.