Cranial immobilization system

1. A head immobilization system for immobilizing a patient's head in a supine position of the patient, the system comprising:

a support rail structure adapted to be coupled to a patient rest and configured to extend at least on both lateral sides of the patient's head;

a mask frame adapted to be coupled to at least one deformable upper mask sheet, wherein the mask frame is releasably connected to the support rail structure via a first interface section and a second interface section, with at least two pins protruding from the first interface section in a first direction, and at least two pin-receptions provided at the second interface section, wherein each one of the pin-receptions receives one of the pins, and the at least two pins are in a fixed position with respect to the first interface;

a catch-mechanism for each pin-reception and each corresponding pin, wherein the catch-mechanism includes saw-toothing formed vertically along a surface of each corresponding pin, which interlocks with saw-toothing of the corresponding pin-reception that is held resiliently with respect to the pin-reception, and the catch-mechanism allows the pin to be pushed further into the pin-reception in the first direction, wherein movement of the pin in the first direction causes a decrease in a distance between the mask frame and the support rail structure, and the catch-mechanism interlocks to prevent the pin from moving with respect to the pin-reception in a second, opposite direction; and

a release mechanism that includes grasping sections that, while pressed together, cause the saw-toothing of the pin-reception to move away from the saw-toothing of the corresponding pin to allow the pin to move with respect to the pin-reception in the second direction.

2. The system according to claim 1 , wherein two pins are configured to protrude on each one of the lateral sides of the patient's head.

3. The system according to claim 1 , wherein at least one of the pins has a guidance protrusion that engages into a notch formed in the corresponding pin-reception.

4. The system according to claim 1 , wherein the support rail structure is configured to extend cranially around and in close proximity to the patient's head.

5. The system according to claim 1 , wherein the first interface section or the second interface section comprises at least one adjustable stop-mechanism that limits the distance by which the pins can be pushed into the pin-receptions in the first direction, the at least one stop-mechanism comprises at least one section having stepped locating surfaces, and wherein the section is displaceable with respect to the pins.

6. The system according to claim 5 , wherein the stop mechanism comprises at least one adjustment wheel connected to the at least one section via a rack and pinion drive.

7. The system according to claim 1 , wherein the mask frame comprises a first sub-frame adapted to be coupled to at least one first deformable upper mask sheet, and a second sub-frame adapted to be coupled to at least one second deformable upper mask sheet, wherein the first sub-frame is adapted to be connected to the second sub-frame in a detachable or a non-detachable manner.

8. The system according to claim 1 , wherein the support rail structure comprises a rear mask rest providing support for a head support.

9. The system according to claim 8 , further comprising the head support, wherein the head support is held in place by the rear mask rest via a snap-in form fit.

10. The system according to claim 8 , wherein the rear mask rest comprises on each one of the lateral sides of the patient's head two or more protrusions extending in a medial direction, wherein the snap-in form fit is provided in a cranial-caudal direction by outermost protrusions in a cranial-caudal direction.

11. The system according to claim 1 , wherein the support rail structure is integrally formed with the patient rest, both of which are made at least partially from a carbon-composite material.

12. The system according to claim 1 , wherein the saw-toothing of the pin-reception is spring loaded with respect to the second interface section.

13. The system according to claim 3 , wherein the pins are configured to be disposed at each one of the lateral sides of the patient's head in a most caudal position, and have a guidance protrusion that engages into a notch formed in the corresponding pin-reception.

14. The system according to claim 5 , wherein the first interface section or the second interface section comprises at least one adjustable stop-mechanism configured to be on each one of the lateral sides of the patient's head.

15. The system according to claim 1 , wherein the dimensions of the pin-receptions in the cranial-caudal direction are sized to allow the pins to enter the pin-receptions even with the mask frame being tilted up to a predetermined angle with respect to the support rail structure and around a medial-lateral direction.

16. The system according to claim 1 , wherein the release mechanism comprises a double-lever having lever ends that include the saw-toothing of the pin-reception.

17. The system according to claim 1 , wherein the grasping sections are ring-shaped.