69 results about "Radioactive particles" patented technology

The utility model discloses a multifunctional biliary tract internal and external drainage tube combination device applied to a patient suffering from hilum cholangiocarcinoma. A drainage catheter is transited from a shaping area and an elastic cabin area to an internal drainage area to form a cylindrical cone; side holes are formed in the inner drainage area and the shaping area; a marker point is arranged between the inner drainage area and the missile cabin area, the missile cabin area is distributed between the inner drainage area and the shaping area, a one-way valve is arranged at the contact position between the shaping area and the missile cabin area, a hole channel is formed in the outer wall, extending into the marker point from the missile cabin area along the one-way valve, of the missile cabin area, and the hole channel forms a missile cabin in the missile cabin area. The magazine is used for placing radioactive particles; the hard support is used in cooperation with the drainage catheter, the hard support penetrates into the outer drainage area and then is pulled to the end of the inner drainage area, and the curled part of the shaping area of the hard support is straightened. The utility model can realize internal and external drainage and achieve the purpose of local tumor treatment, and is simple and convenient to operate and easy for medical staff to use.

The invention discloses a multi-channel radioactive source implantation system with a needle withdrawing driving function, which comprises a push rod output channel, a push rod, a push rod driving mechanism, a first connecting part, a first motion platform and a needle withdrawing driving mechanism, and is characterized in that the push rod pushes a radioactive source arranged in front of the push rod to be output along the push rod output channel; the first connecting part and one end of the push rod output channel are arranged on the two sides of the first moving platform respectively, the needle pulling driving mechanism and one end of the push rod output channel are arranged side by side, and the first moving platform drives one end of the push rod output channel and the needle pulling driving mechanism to move relative to the first connecting part. The push rod output channel is butted with different hole sites through the relative movement of the push rod output channel and the first connecting part, so that multi-channel implantation of radioactive particles is realized; the puncture needle is automatically pulled out through the needle pulling driving mechanism, the implantation precision and the implantation effect are improved, full-automatic operation is achieved, the radiation risk is avoided, the operation time is short, the structure is simple and reasonable, and driving is convenient and fast.

The present application relates to a kind of nuclear power plant surge line nozzle heat shield sleeve structure and system, comprising: support ring, fluid distribution cover, heat shield sleeve, nuclear power plant surge line nozzle and cladding layer.The nuclear power plant surge line nozzle heat shield sleeve structure and system described above when actually used, through the one end of support ring and the cladding layer of surge line nozzle connection, the other end and fluid distribution cover connection, the one end of heat shield sleeve is inserted into support ring and is connected with support ring, to form gap between the other end of heat shield sleeve and the safety end of surge line nozzle, radioactive particles generated in the annular space between heat shield sleeve and surge line nozzle during reactor operation can be discharged from the gap, thereby avoiding the difficulty and cost of in-service inspection caused by the fact that the safety end of heat shield sleeve surge line nozzle forms a sealed space, so that the risk of high radiation faced by inspection and maintenance personnel is reduced.

This invention discloses a radioactive particle strip implantation system and method, relating to the field of medical device technology. It includes: an implantation gun and a particle strip module; the implantation gun includes: a gun body; a drive assembly disposed within the gun body, including a driver and a thrust control unit; a push rod, drively connected to the power output end of the driver; a particle strip placement slot disposed at the front end of the gun body for placing the particle strip module, and coaxially arranged with the push assembly; the gun body has a docking part at the front end of the particle strip module compartment for connecting an implantation needle; the push rod can pass through the particle strip module to push the particle strip into the implantation needle; the particle strip module includes: a module body; multiple radioactive particles and multiple hemostatic drug units are pre-sealed in an alternating arrangement within the module body; the radioactive particles and hemostatic drug units are coaxially arranged and can be pushed into the implantation needle by the push rod. This invention uses a pre-assembled plate stacking structure to make the spacing of the radioactive particles adjustable, simplifying on-site operation.

The invention discloses a handheld radioactive particle implantation device which comprises an implantation device body, a push needle assembly, a puncture needle assembly, a particle cartridge holder and a connecting assembly, the puncture needle assembly and the particle cartridge holder are detachably installed on the connecting assembly, and the connecting assembly and the push needle assembly are installed on the implantation device body; the push needle assembly comprises a push needle and a push needle mounting seat, and the push needle of the push needle assembly is coaxial with the puncture needle and moves back and forth in the axis direction of the puncture needle; a driving assembly is arranged between the needle pushing assembly and the implanting device main body and drives the needle pushing assembly to linearly move back and forth; a grab handle and an operation button are arranged below the implanting device main body, and the operation button is in control connection with the driving assembly. The method has the beneficial effects that the requirement for the operation proficiency of medical staff is lowered, and finger fatigue and psychological burden of the medical staff are relieved; the risk of clamping stagnation when the push needle is pushed and pulled is reduced, the pain of a patient is reduced to a certain extent, and the operation efficiency is improved.

The invention discloses an absorbable particle cannula loaded with double radiosensitizers, and aims to effectively improve the internal radiation radiotherapy effect and facilitate implantation of radioactive particles, and the whole material can be degraded and absorbed in vivo and does not need to be taken out through a secondary operation. The absorbable particle sleeve mainly comprises an absorbable particle sleeve body for packaging radioactive particles, a spacer which is arranged in the sleeve body and is used for spacing the radioactive particles, and a polydopamine coating which is loaded with a double radiosensitizer of metal nanoparticles and aromatic ring structure drugs. In the polydopamine coating, the metal nanoparticles are nanoparticles formed by reducing metal ions on the surface of the coating in situ through catechol groups of polydopamine; and the medicine is loaded on the surface of the coating through non-covalent acting force (pi-pi stacking action, hydrophobic interaction and / or electrostatic attraction).

The invention relates to an implantation device for gold labels or radioactive particles, belongs to the technical field of medical instruments, and solves one of the problems that the number of the gold labels or radioactive particles loaded at one time is insufficient and the implantation counting accuracy of the gold labels or radioactive particles is poor in an existing implantation device. The device comprises a puncture outfit, a loader and an implantation needle, and the puncture outfit is used for puncturing into the body of a patient and puncturing to a tumor area; the loader can load a plurality of gold labels or radioactive particles and can be clamped on the puncture outfit; and the implantation needle is used for implanting the gold label or the radioactive particles loaded in the loader into a tumor area. A plurality of gold labels or radioactive particles can be loaded at a time through the loader, one-time filling and multi-batch continuous implantation are achieved, the device does not need to be frequently disassembled to supplement the gold labels or radioactive particles, the interruption frequency of clinical operation is greatly reduced, the operation efficiency and operation continuity are improved, and the large-dose implantation requirement is met.

The invention discloses an automatic filling device for radioactive particles, and the device comprises a particle sorting mechanism which is used for sorting the radioactive particles; the cartridge holder mounting mechanism is used for mounting a cartridge holder so as to fill the radioactive particles sequenced by the particle sequencing mechanism; the particle conveying mechanism is used for receiving the radioactive particles sorted by the particle sorting mechanism and conveying the radioactive particles to a filling position of the cartridge holder mounting mechanism; the particle pushing mechanism is used for pushing the radioactive particles conveyed by the particle conveying mechanism into the cartridge holder; the cartridge holder control mechanism is used for enabling the cartridge holder to make a particle filling position so as to receive the radioactive particles pushed by the particle pushing mechanism; the particle blocking mechanism is mounted on the cartridge holder mounting mechanism and is used for opening or closing a discharge hole of the particle sorting mechanism; the particle sorting mechanism, the particle conveying mechanism, the particle pushing mechanism and the cartridge holder control mechanism are in signal connection with the control unit. According to the automatic filling device provided by the invention, the particle filling efficiency and safety can be improved.

The invention discloses a radioactive particle interventional operation device which comprises a positioning needle, a flexible needle, a propelling needle, a fixing assembly, a propelling assembly, a rotating assembly, a feeding assembly and a pushing assembly. The propelling assembly is located on the lower end face of a propelling base, and the pushing assembly is located on the upper end face of the propelling base; the rotating assembly is located on the upper end face of the propelling base and located on the left side of the pushing assembly, the feeding assembly is located on the upper end face of the propelling base and located on the right side of the pushing assembly, and the propelling assembly, the pushing assembly, the rotating assembly and the feeding assembly are all arranged in the front-back direction. The propelling assembly and the fixing assembly can be staggered in the vertical direction, parts such as a cable connected to the fixing assembly cannot interfere with the propelling assembly, installation of the device and the mechanical arm of the surgical robot is better facilitated, meanwhile, limitation of the propelling assembly to the action range of the mechanical arm in the action process of the mechanical arm is reduced, and the mechanical arm is more convenient to use. And the mechanical arm can have a larger movement range.

The application belongs to the technical field of biological medicine, and particularly relates to an ultrathin radioactive patch for skin cancer treatment and a preparation method thereof. The preparation method comprises the following steps: adding a photoinitiator solution into a methyl methacrylate gelatin solution, and performing water bath heating dissolution under light shielding conditions; after the dissolution is completed, mixing the radioactive particles used for external irradiation treatment, stirring to a semi-solid state, smearing to a patch bottom film by using a smearing part, covering the patch anti-adhesion paper on the surface, irradiating and curing by using a light source, and obtaining the ultrathin radioactive patch. The patch prepared by the application can be customized according to the size and shape of a lesion site, a corresponding bottom film is cut out and attached to the lesion site, and smearing is directly performed. Compared with a common radioactive hydrogel, the preparation method is simpler, the preparation time is shorter, and the efficiency is higher.

This invention belongs to the field of nuclear facility radiation monitoring technology and aims to solve the problem of low accuracy in identifying and measuring multiple radioactive particles in mixed radiation fields. It provides a quantitative measurement method for multiple radioactive particles in mixed fields. By building a high-speed waveform data acquisition system, it achieves high-speed, high-precision acquisition of radioactive particle waveform data and reconstruction of the entire waveform under different testing conditions. It also utilizes a convolutional neural network model to complete adaptive feature extraction and accurate classification of radioactive particles from the full waveform data. Simultaneously, it establishes a waveform database covering four types of radioactive particles (α, β, γ, and n) under multiple testing conditions. By combining the database with waveform feature matching, it ultimately achieves rapid, high-precision identification and accurate quantitative measurement of the four types of radioactive particles in complex environments, significantly improving the technical level and practical application effect of nuclear facility radiation monitoring.

The silicone stent with the radioactive particles for the pneumology department comprises a main stent body and a first baffle, connecting shafts are rotationally arranged in the main stent body, a through hole is formed in the surface of the main stent body, the tail ends of the connecting shafts are located in the through hole, and the connecting shafts are symmetrically distributed relative to the center of the through hole; and the sliding blocks are fixedly mounted on the left side and the right side of the clamping block. According to the silicone support with the radioactive particles for the pneumology department, when the main support is used, the first baffle and the second baffle are in a vertical state, normal use of the main support is facilitated, when the connecting support needs to be in butt joint, a shifting block is pulled to drive the tail end of a positioning rod to move out of a deep groove, and at the moment, a connecting shaft rotates under the action of a torsion spring; and finally, the first baffle and the second baffle are in a horizontal state, at the moment, the connecting support can be in butt joint, the positioning blocks enter the positioning grooves, then the clamping blocks enter the clamping grooves, and the overall use range of the device is widened.

The invention discloses a clinical prediction model construction method and system for treating oligometastatic non-small cell lung cancer through radioactive particle implantation, and relates to the technical field of medical model construction, and the method comprises the steps: obtaining patient data, taking survival time as a main endpoint event, employing a Cox regression model to carry out single-factor analysis on factors affecting patient prognosis, and obtaining a single-factor analysis result; determining the relationship between each clinical feature and survival time, and incorporating the important factors influencing the prognosis into multi-factor Cox regression analysis to determine independent risk factors influencing the survival prognosis of the patient; generating a first clinical prediction model according to each independent risk factor nano-construction; cD3 + AC, CD4 + AC, CD8 + AC, combined treatment, complete treatment and the number of metastatic lesions are taken as variables together to be included in construction of a clinical prediction model, and a second clinical prediction model is manufactured and generated. Independent risk factors influencing the prognosis of a radioactive particle implantation treatment few-metastatic NSCLC patient are confirmed, the clinical prediction model is established, the treatment prognosis can be accurately predicted, and the treatment cost is reduced. And screening of dominant benefit people is facilitated.

The invention belongs to the technical field of radiochemistry, and particularly relates to a nanofiber filter membrane as well as a preparation method and application thereof. The electrostatic spinning technology is adopted, and the nanofiber filter membrane which is uniform in structure, fine in fiber and free of defects is prepared. By regulating and controlling spinning conditions, optimal fiber diameter distribution is obtained, no spindle exists, and the mechanical property of the filter membrane is improved while the trapping efficiency of the filter membrane on ultrafine particles is improved. The obtained nanofiber filter membrane can keep mechanical stability and low resistance while capturing superfine radioactive particles, the average diameter and the pore diameter of nanofibers are extremely small, the nanofiber filter membrane has a larger comparison area and a porous structure, a large number of contact sites can be provided, and especially the nanofiber filter membrane has excellent capturing efficiency on superfine particles smaller than 100 nm.

A radiotherapy delivery device includes a body having a first end and a second end and a catheter having a lumen extending between a proximal end and a distal end. The proximal end of the catheter is coupled to the second end of the body and the distal end of the catheter includes a cutting tip that penetrates a target site. A sealed pouch containing radioactive particles is positioned within the lumen of the catheter, and a puncture shaft is positioned coaxially within the body. The puncture shaft advances in a longitudinal direction into and through the sealed pouch to release the radioactive particles. A syringe is fluidly coupled to the lumen of the catheter, and the radioactive particles released by the sealed pouch are deposited into the target site when fluid is supplied from the syringe and into the lumen of the catheter.

Disclosed in the present invention are a puncture needle and an automatic particle implantation system using the same. The automatic particle implantation system comprises a controller, an angle adjustment apparatus, and a puncture needle assembly. The angle adjustment apparatus is electrically connected to the controller, the puncture needle assembly is mounted on the angle adjustment apparatus, and the puncture needle assembly comprises a puncture needle. The controller is used for controlling the angle adjustment apparatus to adjust a puncture angle of the puncture needle assembly, and the controller is further used for controlling a particle gun to pass through a septum of the puncture needle to enter the puncture needle to implant radioactive particles, and when the particle gun exits, the septum automatically blocks a wide-diameter section of a needle seat, so as to allow the particle gun to implant radioactive particles again. By means of the precise angle adjustment and the special structural design of the puncture needle, the present invention achieves precise positioning of the puncture needle assembly, thereby significantly improving the efficiency and safety of surgery.

The utility model relates to a kind of gastrointestinal tumor endoscopic radioactive particle implantation device, its structure includes operating part, first striker, second striker, catheter, particle bin, particle loading part and puncture needle;The catheter one end is connected with operating part, and the other end is detachably connected with particle loading part, and the puncture needle is located the end of the particle loading part;First channel and second channel are equipped in the catheter, first striker and second striker pass through operating part respectively, and the first striker is inserted into the first channel, and the second striker is inserted into the second channel, particle bin mounting channel for installing particle bin is equipped in the end of the first channel, and the particle loading part is used to transport the particle exported from particle bin to the position corresponding with puncture needle.The utility model solves the problem of repeatedly loading particles in the prior art, simplifies the operation process, and reduces the operation time.

The application discloses a prostate cancer lesion-based intelligent diagnosis auxiliary method and system and a storage medium, relates to the tumor treatment data processing technical field, and comprises the following steps: acquiring current patient case data and image data of a lesion site; searching for and acquiring reference image data sets, statistically analyzing the probability of the lesion tissue appearing at different positions in space based on the reference image data sets, and generating a probability distribution graph of the lesion tissue; calculating and generating a radiation dose distribution graph of the three-dimensional space of the current lesion area according to particle implantation site coordinates; and determining implantation coordinates of superimposed particles according to the probability distribution graph and the radiation dose distribution graph, and marking the implantation coordinates in the image data of the current patient. Through the above scheme, the implantation coordinates of the superimposed particles are determined, the implantation positions of the radioactive particles are more suitable for the distribution of the lesion tissue, the cancer cells of the lesion tissue are killed, the spread of the cancer cells is slowed down or even blocked, and the treatment effect is improved.

This utility model relates to the field of medical devices, specifically to a ureteral stent capable of carrying particles, comprising: a tube body and a particle chamber structure; the front and rear ends of the tube body are curved into a pigtail shape; the tube body is a single through-hole serving as a drainage cavity; several drainage holes are provided on the curved portions of the front and rear ends of the tube body; a marker ring is provided on the tube body at the junction of the curved portion and the tube body; several radiopaque rings are provided on the tube body between two marker rings; the particle chamber structure is integrally formed with the tube body, and the particle chamber structure includes several particle chambers distributed laterally along the tube body. Each particle chamber is a cylindrical cavity, with one end of the cylindrical cavity serving as a particle placement channel. The entrance to the particle placement channel is sloped, and the bottom of the slope is a baffle to prevent the radioactive particles from slipping out. The cylindrical cavity is filled with radioactive particles. This utility model combines a ureteral stent with radioactive particles, and uses a single particle chamber with several particle chambers arranged laterally, making it simple to operate and convenient to use.

The invention discloses a radioactive particle protection implanting device for tumor treatment. The radioactive particle protection implanting device comprises an implanting gun body, a puncture needle, a loading assembly and a push rod matched with the puncture needle. The loading assembly is detachably installed on the surface of the implantation gun body, a bullet loading box and a rotatable rotating wheel are arranged in the loading assembly, a loading groove is formed in the periphery of the rotating wheel, and through holes are formed in the surface of the shielding protection plate and used for achieving one-by-one alignment and shielding protection of radioactive particles. A trigger, a fixed assisting block, a movable assisting block, an elastic piece and an engaging lug are arranged in the implantation gun body, the push rod is driven to linearly advance through the connecting rod and the sliding lug, one-way limiting is achieved under the clamping action of the engaging lug, and reverse sliding of the push rod is prevented. The guide cylinder is used for guiding the push rod to enter the puncture needle and accurately implanting particles into tumor tissue. The device is provided with a rotary missile cabin type protection structure, an anti-non-return gun type propelling structure and a detachable modular loading assembly, radiation leakage can be effectively avoided, it is guaranteed that particle implantation is accurate and reliable, replacement is rapid, and the device has high clinical application value.

This utility model relates to the technical field of nuclear power plant safety protection facilities, and in particular to a pressure relief device for nuclear power plants with a filtration structure. The device includes a pressure relief pipe with electrically controlled valves installed at both ends, and multiple filters are installed inside the pipe. By installing two filters inside the pressure relief pipe and filling them with different types of filter materials, this device can rapidly release pressure inside the containment vessel while efficiently removing harmful components such as metallic sodium vapor, hydrogen, and radioactive particles from the emitted gas. This effectively reduces harm to the environment and equipment. Compared to traditional pressure relief systems that rely solely on gas recovery bladders to collect gas, this device directly purifies the gas on-site, significantly improving the overall operational safety and environmental protection level of the nuclear power plant.

1. Name of the designed product: filling machine. 2. Use of the designed product: for automatic filling of particle cartridges with radioactive particles. 3. Design points of the designed product: in shape. 4. Picture or photo best showing the design points: perspective view 1.

Disclosed are a particle stent for a portal vein, a particle stent for a lumen, and a kit thereof. The particle stent comprises a fixing part; a first parallel part comprising a plurality of first edges parallel to the length direction of the particle stent; a second parallel part comprising a plurality of second edges parallel to the length direction of the particle stent; a support part extending in a circumferential direction of the particle stent to provide a radial support force for the first edges and the second edges; and a particle filling part. Each group of nitinol wires is mutually wound from a first end to a support starting point to form a first edge. Moreover, the first edge divides into two nitinol wires from the support starting point, and each of the nitinol wires is bent at a support end point and mutually wound with an adjacent group of nitinol wires from the support end point to a second end to form a second edge. The particle stent can not only achieve the accurate arrangement of radioactive particles but also prevent tumor thrombi from being displaced.

This invention relates to the field of medical devices, specifically to a radioactive particle implantation needle for interventional radiology of tumors. The needle includes an implantation needle body with a delivery channel along its length. A material storage slot communicating with the delivery channel is located in the middle of the implantation needle body. The material storage slot contains a supply compartment with a particle placement cavity. A sealing mechanism for sealing the particle placement cavity is located at the bottom of the supply compartment. The supply compartment also contains a compression mechanism for compressing radioactive particles towards the bottom of the particle placement cavity. This invention employs a detachable integrated structure for the implantation needle body and supply compartment, allowing for pre-loading of particles before surgery. This eliminates the need for manual loading of particles into the delivery channel during surgery using external tools, reducing intraoperative steps. The fixing bolts and threaded holes enable quick assembly and disassembly, further shortening preoperative preparation and surgical time, and improving operational convenience.

The utility model relates to the technical field of medical instruments, and provides a particle implantation gun control device which comprises a grip and a front frame, the grip is arranged at one end of the front frame, a butt joint installation assembly is arranged between the grip and the front frame, a gun body is connected outside the front frame in a sliding and sleeving mode, and an implantation assembly is arranged outside the gun body and the front frame. The rotating screw rod is rotationally connected into the grip, and the rotating screw rod is connected with the gun body in a threaded fit manner. By means of the technical scheme, the problems that in the prior art, when an existing particle implantation device completes operation of implanting a plurality of radioactive particles at a time, implantation operation is complex, time and labor are wasted, and flexibility is poor are solved.

The utility model belongs to the technical field of medical instruments, and particularly relates to a radioactive particle implanting device which particularly comprises a needle tube, a sharp-head needle core, a blunt-head needle core, a flat-head needle core and a particle implanting device, the sharp-head needle core is used for puncturing skin, the blunt-head needle core is used for puncturing fragile tissue, the flat-head needle core is used for pushing in particles, and the particle implanting device is used for implanting particles. The needle head of the flat-head needle core is flush with the front end of the needle tube, the tail end of the flat-head needle core is connected with the inlet of the needle core in a clamped mode, it is guaranteed that radioactive particles are accurately fed into tumor cells of tissue to be treated, and meanwhile the length of the needle point of the blunt-head needle core is set to be equal to the height of the implanted particle sealing tube, so that the needle head of the blunt-head needle core is the accurate implantation position of the radioactive particles. And accurate positioning of an implantation part can be further realized, and the device can be widely applied to treatment of tumor cells.

The invention discloses a preparation method and application of a template for particle implantation, relates to the technical field of radioactive auxiliary equipment, and is characterized in that the template for radioactive particle implantation is provided, and meanwhile, the invention further discloses the preparation method of the template. In addition, the template can also be used for measuring whether dose rate distribution after particle implantation conforms to a preset value or not in actual use, so that whether a particle implantation operation is successful or not is judged. The basic structure of the template comprises a flexible grid plate and a gel layer, the flexible grid plate is made of a rubber material containing bismuth, tungsten and tantalum powder, and the gel layer is made of a fluorescent composite material containing ZnS powder.

The utility model relates to the technical field of medical instruments, in particular to an annular hemostatic clip capable of carrying radioactive particles, which is made of titanium-nickel-based shape memory alloy materials and comprises a plurality of outer arc sections and inner arc sections, the outer arc sections and the inner arc sections are arranged in a staggered manner and are connected through fillets, and the integral connecting structure is in central symmetry. An inner tooth is arranged in the middle of each inner arc section, the free end of each inner tooth points to the center of the annular hemostatic clip, placing grooves are formed in the outer arc sections, the inner arc sections, the round corners and the inner teeth, and radioactive particles are embedded in the placing grooves; according to the shape memory characteristic and the superelasticity of the titanium-nickel memory alloy, the annular hemostatic clip can be turned over to be cylindrical, and when the annular hemostatic clip is released at a focus, the annular hemostatic clip contracts inwards and continuously applies pressure to tissues, so that a wound is closed, and further carried radioactive particles start to play a role to continuously carry out close-range irradiation treatment on tumors; and a new solution is provided for the field of tumor treatment.

The invention discloses an intelligent diagnosis auxiliary method and system based on a prostatic cancer focus and a storage medium, and relates to the technical field of tumor treatment data processing, and the method comprises the steps: obtaining the case data of a current patient and the image data of a focus part; searching and acquiring a reference image data set, counting the occurrence probability of the focus tissue at different positions in the space based on the reference image data set, and generating a probability distribution diagram of the focus tissue; calculating and generating a radiation dose distribution diagram of a three-dimensional space of the current focus area according to the particle implantation site coordinates; and according to the probability distribution diagram and the radiation dose distribution diagram, determining implantation coordinates of the superposed particles, and labeling the implantation coordinates in the image data of the current patient. According to the scheme, the implantation coordinates of the superposed particles are determined, so that the implantation positions of the radioactive particles are more matched with the distribution of focus tissues, cancer cells of the focus tissues can be killed, diffusion of the cancer cells is slowed down or even blocked, and the treatment effect is improved.