Repositioner for head, neck, and body

#In the above-mentioned parent patent application, a patient immobilizer and localizer was described which is suitable for image scanning and for positioning on a treatment table, such as a linear accelerator (LINAC). Various embodiments of the invention were described therein including an over-arm structure oriented in the quasi-sagittal plane of the patient which immobilizes the head by, for example, a dental impression with biasing straps to apply pressure on the upper teeth, an occipital form, various external molded forms, etc. Various types of graphic reference structures to index tomographic scanning through the patient with the immobilizer in place were described and various target and therapeutic beam localizing structures were described to align internal targets determined from scanning to the convergence or path of external beams or other probes or instruments to the patient's head, neck, and upper thorax regions.

#In general, the system and method of the present invention is directed to further examples, embodiments, and improvements of the foregoing patent application. Further examples of patient immobilizer structures are given. A reference structure is shown which enables the repeat orientation and positioning of the head relative to the neck, spine, and upper thorax. Further examples of graphic reference structures for image scanning and target and beam localization structures for therapy or other interventions are described.

#In the drawings which constitute a part of the specification, exemplary embodiments exhibiting various objectives and features hereof are set forth, specifically:

#FIG. 1 is a diagram of a head immobilizer and a translation system for repositioning of the torso relative to the head in accordance with the present invention.

#FIG. 2 is a schematic elevation view illustrating an embodiment of the present invention with a mechanical referencing structure and shoulder positioning structure for repeat localizing.

#The following embodiments illustrate and exemplify the present invention and concepts thereof, yet in that regard, they are deemed to afford the best embodiments for the purpose of disclosure and to provide a basis for the claims herein which define the scope of the present invention.

#Referring to FIG. 1, the patient's head H is immobilized by several elements. A dental tray 2 is in the mouth and an impression of the upper dentition and/or the lower dentition can be made. The dental plate is connected by element 3 to an over-arm structure 4 which is fastened by further vertical structures 5 to the base form 6 and sub-plate 7, which is attached to the couch 8. Further structures 9 secure an impression or cushion 10 for the back portion of the patient's head. A biasing strap 11 is secured to the dental tray portion by an attachment device 12 which provides a biasing force of the dental tray to the upper teeth of the patient and supplies a securing force of the patient's head H to the cushion 10. The patient's head H is thus immobilized and can be repositioned in the same orientation. The plate 6 may be tilted about axis A for orientation of the patient's head in the event of sag of the table 8 or in the event of sag of any of the structures such as 5, 4, etc. It may be desirable to orient the torso or upper shoulders T of the patient relative to the patient's head in the same position during CT or MRI image scanning as when the patient is repositioned on a treatment couch such as for a LINAC X-ray treatment machine. In this sense, the position, orientation, and articulation of the torso T can be variable relative to the head H under unconstrained conditions. Thus, to align and position the torso T relative to the head in an identical position as in repositioning on a treatment couch for multiple fractionated treatments over many sessions, a referencing of the torso T relative to the head can be made. The torso may be laid on a flat table whose elevation is known relative to cushion 10 and dental form 2. If cushions or uncertainties are present during scanning, it is desirable to make quantitative reference measurements of the relative positions of the torso, neck, spine, and head. An example of such referencing is shown in part in FIG. 1. A laser source 15 shines laser beam 16 onto a spot 17 on the patient's head from a vertical orientation. Another laser source 18 shines similarly laser light on another spot 19 on the torso. Similar lasers 20 and 22 shine on markings 21 and 23 on the surface of the patient. The laser beams could be sheets, lines, or cross lines as is common. Lasers 15, 18, 20, and 22 could be on a fixed mechanical structure which can be placed and aligned relative to couch 8. Or the lasers may be displaced on a track or sliding system such that 15 may be slid to position 18 for the purpose of aligning to marks 17 and 19, and similarly could be done for sliding laser 20 to position of laser 22 in FIG. 1. In this way, the laser referencing structure could be implemented at the time of CT scanning, and the markings 17, 19, 21, and 23 could be put onto the patient's body. At the time of treatment, a similar laser reference system could be put into place, and the laser beams from the respective lasers made to align to the surface markings on the patient 17, 21, 19, and 23 by articulation and movement, for example, of the torso T relative to the head H. The position of the head H can also be moved by translation structures in elements 4, 5, etc. Or, the torso T may be moved by a translation of, for example, a sub-table 25 which can move in the lateral direction L, the AP direction A, or the vertical direction V, indicated by the arrows, with reference to the patient's coordinates. Thus the torso can be translated and trammed in by, for example, the jack screws 26 and 27 and similar jack screws on the opposite side of the patient not shown. The tilt of the patient's torso could also be manipulated in pitch, roll, and yaw angles, for example, of the platform 25 by adjustment screws. In this way, the skin mark 19 and 23 on the torso, for example, could be brought into relative alignment with respect to the lasers 18 and 19, they being in a relatively known position with respect to lasers 15 and 20 and their respective skin marks 17 and 21. This illustrates a way of orienting the otherwise multiple-degree-of-freedom orientation of torso and neck with respect to an immobilized head.

#FIG. 2, in accordance with the present invention, illustrates an elevation view of the head H with cushion structure 10 and over-arm structure 5 and bar 4 with dental piece 2, similar to FIG. 1. The treatment or scanning couch 8 is shown, and a sub-plate 25 is illustrated with the same possibility of translation and rotations as described for FIG. 1. In addition, a reference structure 29 is shown attached to over-arm element 4. It has depth probes 30 and 31 which can determine the distance to positions 17 and 19 on the patient's head and torso, respectively. The depth rods 30 and 31 may have scales on them, such as 32, to illustrate the depth from the upper surface of reference structure 29. Thus, when the patient's head H is positioned repeatedly by means of the dental impression 2 and cushion 10, the torso T, and therefore the upper shoulders and neck, can be appropriately positioned in a repeat orientation to the head H by the reference structure 29 by bringing into alignment via the depth probes 30 and 31 a predetermined position or marking 19 on the chest relative to a predetermined marking or position 17 on the head. Many such markings as 17 and 19 could be made at various positions of the head H, the neck N, and the torso T so that a considerable amount of geometric data can be taken of the relative orientation and articulation of the body portion from head to torso. If needed, the torso could be translated relative to the head by, for example, anterior-posterior movements A, lateral movements L (not shown), or vertical movements V of the table 25 so as to bring the points 17 and 19 into appropriate relative alignment via the reference structure 29. In this way, a patient's head and neck and upper torso can be brought into a repeat similar alignment for one episode after another on a scanning or treatment couch.