ONKOCET Ltd. has exhibited the devices from its portfolio on the MEDTEC UK exhibition in Birmingham, April 2011 through our partner Medical & Partners.
Main Mechanical System is the most important component of Whole-body Stereotactic Radiation Treatment System (SGS-I). It is composed of radiation collimator system, 3D treatment bed, decorative casing, and machine base. The total weight is about 12500Kg.
Main Mechanical System is controlled by the electric control system. During the rotating of radiation treatment, it can open or close beams according to the requirement. And thus the patients’ important organs or tissue can be protected effectively. 3D treatment bed aically moves the patients’ target to the radiation focus by means of three-direction translation (X, Y, Z). Collimators not only can be changed aically (or manually) into another standard collimators as desired, but also can change some collimator into plugs. And thus in clinical use, the important and sensitive organs can be protected more safely and the operation is more flexible. Main Mechanical System adopts open structural design. The graceful appearance reduces the patient’s fears and enhances their sense of security and comfort. In addition, because the radiation source is stored in specific source storage and is equipped with auto/manual safety operation device, the equipment maintenance can be made safely and conveniently either when SGS-I is in service or is under particular circumstances. Therefore, the security of patients, medical staff and equipment maintenance/operating staff can be ensured reliably.
Main Mechanical System is composed of Radiation Collimator System (radiation device and source storage), 3D Treatment Bed, collimator storage, decorative casing and base.
2.1 Radiation Collimator System
Radiation Collimator System is composed of source carrier, collimator, source storage and source box. The collimator channel is composed of preliminary collimators and secondary collimators. Pre-collimators are placed in the Cobalt source package in the source box, and the secondary collimators are placed on the collimator carrier. Different size collimators have various aperture sizes. The collimator carrier is equipped with one group of shield sticks and two groups of collimators. According to the treatment planning, the other two groups of collimators can be selected (changed manually). When the source carrier and the collimator carrier are assembled, they form a concentric fan-shape ball shell and implement their motion by means of servo motors. In the process of treatment, source carrier and collimator carrier rotate synchronistically. The displacement between the source carrier and collimator carrier realizes the switching of the collimators. Different size of focus dose field can be obtained with different collimator size selected. The source box that has 18 Cobalt sources package is loaded into the source carrier while treatment. After treatment, the source box will be withdrawn into the source storage. The load/withdraw of source box is implemented by a pushing bar and a lock mechanism controlled by the electric control system. When the control system fails, the users could withdraw the source manually.
2.1.1 Sealed Cobalt-60 Sources
Sealed Cobalt-60 Sources are Gamma ray Generator. The source jacket is a three-layer stainless steel container. There are several f1×1mm Cobalt-60 grains in the container. In order to enhance the shielding, the tungalloy pre-collimator, tungsten cover and lid are installed between intermediate container and the casing. Each layer of stainless steel container is welded by stainless steel end socket. On one side of Cobalt-60 Radiation, there is a blocking slot for mechanical grabbing and filling. The source jacket has been through series of damaging testing, such as falling down, punctuating, etc. Each source has been completely cleaned after assembled and sealed to prevent from being polluted by the radioactive dust.
Whole-Body Stereotactic Treatment System (SGS-I) has 18 radiation sources altogether. The distribution of Cobalt in the source carrier is within the range of Latitude -25°?25°. The security level of Cobalt-60 sealed radiation is no lower than GB 15849-1995.
2.2 3D Treatment Bed
3D Treatment Bed is composed of Y-direction elevating module, X left Unit, X right Unit, Z sliding parts, protect ring module, and counter weight module (see Figure 2.11-Figure 2.16). Y-direction elevating module is connected to the radiation base at the right side of mainframe via the ball guideway and the nuts pair of ball screw. Y-direction servomotor drives the ballscrew to run via the gear worm. The ball nuts are fixed at the right side of the radiation base, which can fulfill the Y-direction 300mm(+140mm,-160mm ) movement of 3D Treatment Bed. X left unit and X right unit are connected with the Y-direction elevating module respectively through the left-side/right-side ball guideway (primary guideway) and crossed roller guideway (secondary guideway) of the Y-direction elevating module. X left unit is driven by the shift lever from the X-direction driving module that is installed in the left support arm of the Y-direction elevating module. To fulfill the X-direction 400mm(±200mm) movement of 3D Treatment Bed, X right unit and X left unit move synchronistically via the Z-direction sliding part. Z-direction sliding part is connected to the X right unit and X left unit through four groups of crossed roller guideway, and it moves to X direction together with X left unit and X right unit. The Z-direction actuating motor which is installed under X left Unit drive the Z-direction sliding part to do Z-direction movement through the planetary gear reduction unit and the gear and gear rack transmission, which can achieve the Z-direction 900mm(±450mm) of 3D Treatment Bed. There are several micro switches around the Protect ring module. If any point of the Protect ring external outline is touched, the actuating motor will be terminated. And thus the safety of the patients and the equipment is ensured. Counter weight module are connected to the Y-direction elevating module via two chains and the chain wheel that is installed alongside of the radiation base, which balance the weight of 3D Treatment Bed.
2.3 Decorative Casing
The decorative casing of SGS-I is assembled by several curved surface shell parts of glass reinforced plastic. The Decorative Casing is composed of two independent components: Main decorative casing and 3D Treatment Bed decorative casing. The Main decorative casing is equipped with removable parts behind/above the source storage and above the place of replacing collimators. It is also equipped with a removable cover on the zero switch of collimator, the source carrier, the driving gear and the source carrier localization lock, which make the maintenance and adjustment of the equipment more easily. The space in the removable cover which is behind the source storage can be used as the toolbox. The decorative casing moves together with the 3D Treatment Bed. When some internal parts need maintenance and adjustment, the decorative casing will be conveniently disassembled from the 3D Treatment Bed.