Breast model suitable for robot operation training and preparation method thereof

Abstract

The invention relates to an operation training model, and discloses a breast model preparation method suitable for robot operation training, and the method comprises the following steps: respectively obtaining a skin model, a breast model, a tumor model and a blood vessel model by pouring a hydrogel precursor solution; the breast model, the tumor model and the blood vessel model are placed into the skin model, then the hydrogel fat model precursor solution is poured, after a fat model is formed, the hydrogel muscle model precursor solution is poured, cryopreservation is conducted after gelatinization, and the hydrogel breast model is obtained after thawing. By combining the characteristics of multi-layer structural design, acoustic characteristic matching, electrocoagulation adaptive materials, a replaceable tumor module and the like, a synergistic effect of ultrasonic development, layered stripping and robot electrocoagulation cutting can be generated, so that the whole process of a robot breast surgery from preoperative image positioning to intraoperative layered resection can be completed on the same non-biological model; the system has comprehensive technical advantages and training effects.

Description

Technical Field

[0001] This invention relates to a surgical training model, and more particularly to a breast surgery training model. Background Technology

[0002] Breast cancer is one of the most common malignant tumors in women, and surgical resection remains a primary treatment for early-stage and some locally advanced breast cancers. In recent years, with the development of minimally invasive surgery and aesthetic plastic surgery concepts, nipple-sparing mastectomy (NSM), endoscopic-assisted and robot-assisted breast surgery (RAS) have been gradually implemented in multiple centers. Related studies indicate that robot-assisted breast surgery has certain advantages in terms of magnified visualization, instrument flexibility, and reconstructive results; however, it has a long learning curve and requires a systematic, phased training system.

[0003] Current robotic breast surgery training primarily relies on three types of resources: 1. general simulators and basic skill modules provided by robotic manufacturers; 2. animal and cadaver dissection experiments; and 3. a limited number of 3D virtual simulation systems based on case images. For example, training on cadavers and animal models can improve operational proficiency and anatomical understanding to some extent in robotic mastectomy. However, such training is constrained by ethical approvals, specimen availability, cost, and venue limitations, significantly restricting its reproducibility and widespread application.

[0004] Current surgical training models do not have structural and material designs for the complete operation process of breast resection, especially robot-assisted breast surgery. They also usually do not support the operation of energy instruments such as electrocoagulation and cutting. Moreover, their internal structure is mostly a simplified "homogeneous breast + several masses", which is not enough to simulate operation scenarios such as flap separation, glandular mobilization, and pectoralis major muscle exposure.

[0005] Therefore, as robotic breast surgery gradually enters routine clinical practice, providing more surgeons with reusable, structurally simulated, and robot-supporting dedicated training models has become a real need in this field. Summary of the Invention

[0006] This invention addresses the problems existing in breast surgery training models in the prior art by providing a breast model suitable for robotic surgical training and its preparation method.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for preparing a breast model suitable for robotic surgical training includes the following steps: Mold fabrication: Based on CT image data, skin molds, breast molds, tumor molds, and blood vessel molds are obtained through 3D printing. Model preparation: Based on skin molds, breast molds, tumor molds, and blood vessel molds, skin models, breast models, tumor models, and blood vessel models were obtained by pouring hydrogel precursor liquid, respectively. Model assembly involves placing the breast model, tumor model, and blood vessel model into the skin model, then pouring the hydrogel fat model precursor solution. After the fat model is formed, the hydrogel muscle model precursor solution is poured in. After gelation, the model is frozen and thawed to obtain the hydrogel breast model.

[0008] Preferably, the skin model, breast model, tumor model, and vascular model are obtained by casting a hydrogel precursor solution, respectively, based on the skin mold, breast mold, tumor mold, and vascular mold, including: To prepare the hydrogel precursor solution, acrylamide and water were mixed to obtain mixed solution A. N'N-methylenebisacrylamide and ammonium persulfate were added to mixed solution A and ultrasonically stirred until completely dissolved to obtain mixed solution B. Polyvinyl alcohol was added to mixed solution B, stirred evenly, and then vacuum treated. Skin models, breast models, and tumor models were prepared by casting the hydrogel precursor solution into the skin mold, breast mold, and tumor mold, respectively, and freezing them after gelation. After thawing, the skin models, breast models, and tumor models were formed. To prepare a vascular model, first place the vascular core in the vascular mold, then pour in the hydrogel precursor solution. After gelation, remove the vascular core and freeze it. After thawing, the vascular model is formed.

[0009] Preferably, the mass ratio of acrylamide to water in mixed solution A is 1:2; By mass, mixed solution B includes 0.07% ammonium persulfate and N'N-methylenebisacrylamide, wherein the mass ratio of N'N-methylenebisacrylamide to acrylamide is 0.07%. The mass of polyvinyl alcohol added to mixed solution B is equal to the mass of water added to mixed solution A.

[0010] Preferably, the step of placing the breast model, tumor model, and vascular model into the skin model respectively includes: The breast model, tumor model, and blood vessel model were coated with Vaseline and threaded with metal wires. The breast model, tumor model, and blood vessel model were each suspended from the groove of the skin model by metal wires.

[0011] Preferably, the preparation method of the hydrogel fat model precursor solution includes: Acrylamide and water were mixed at a mass ratio of 1:3 to obtain mixed solution C. 0.1% ammonium persulfate and 0.9% sodium chloride were added to mixed solution C. N'N-methylenebisacrylamide was also added to mixed solution C, with a mass ratio of N'N-methylenebisacrylamide to acrylamide of 0.05%. After ultrasonic stirring until completely dissolved, mixed solution D was obtained. 10 wt% polyvinyl alcohol was added to mixed solution D, with the mass of polyvinyl alcohol being 50% of the mass of water in mixed solution C. After ultrasonic stirring until completely dissolved, a hydrogel fat model precursor solution was obtained.

[0012] Preferably, the preparation method of the hydrogel muscle model precursor solution includes: Acrylamide and water were mixed at a mass ratio of 1:2 to obtain mixed solution E. Ammonium persulfate with a mass fraction of 0.07% was added to mixed solution E. N'N-methylenebisacrylamide was also added to mixed solution E, with a mass ratio of N'N-methylenebisacrylamide to acrylamide of 0.1%. After ultrasonic stirring until completely dissolved, mixed solution F was obtained. Polyvinyl alcohol with a mass fraction of 10 wt% was added to mixed solution F, with the mass of polyvinyl alcohol being equal to that of water in mixed solution E. After adding red dye, the mixture was stirred evenly and then vacuum-treated to obtain the precursor solution for the hydrogel muscle model.

[0013] Preferably, the gelation and freezing conditions during model preparation and assembly are both -20°C freezer for 8 hours.

[0014] A breast model suitable for robotic surgery training is prepared using the aforementioned method for preparing a breast model suitable for robotic surgery training.

[0015] This invention, by adopting the above technical solutions, has significant technical effects: This invention combines features such as multi-layered structural design, acoustic characteristic matching, electrocoagulation adaptable materials, and replaceable tumor modules, and can produce a synergistic effect of "ultrasound imaging + layered dissection + robotic electrocoagulation cutting". This allows the entire process of robotic breast surgery, from preoperative image localization to intraoperative layered resection, to be completed on the same non-biological model, which has a relatively comprehensive technical advantage and training effect. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the side structure of the breast model in Embodiment 5 of the present invention.

[0017] Figure 2 This is a schematic diagram of the frontal structure of the breast model in Embodiment 5 of the present invention.

[0018] Figure 3 yes Figure 2 Sectional view of plane AA.

[0019] Figure 4 This is a graph showing the conductivity test results in Embodiment 3 of the present invention.

[0020] Figure 5 yes Figure 4 A schematic diagram of the skin model structure. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0022] Example 1 A method for preparing a breast model suitable for robotic surgical training includes the following steps: Step S1: Mold preparation. Based on CT image data, skin molds, breast molds, tumor molds, and blood vessel molds are obtained through 3D printing.

[0023] The three-dimensional structure of the female breast and its internal mammary glands is obtained by reconstructing CT image data and using computer-aided design (CAD) software (UG, Magics). Based on the shape, size, and location parameters of the breast tumor, the three-dimensional structure of the tumor is designed in the three-dimensional structure of the mammary glands inside the breast. The vascular structure is created using UG, Magics software, resulting in the overall model design.

[0024] Based on the three-dimensional structure, size and other parameters of each part in the modeling, skin molds, breast molds, tumor molds and blood vessel molds are obtained by 3D printing. The skin molds, breast molds, tumor molds and blood vessel molds can be made of 3D printed resin molds and silicone replicas.

[0025] Step S2, Model Preparation: Based on the skin mold, breast mold, tumor mold, and blood vessel mold, skin model 2, breast model 3, tumor model 5, and blood vessel model 4 are obtained by pouring hydrogel precursor solution, respectively. This specifically includes the following steps: Step S21: Prepare the hydrogel precursor solution. Mix acrylamide and water at a mass ratio of 1:2 to obtain mixed solution A. Add N'N-methylenebisacrylamide and ammonium persulfate to mixed solution A and sonicate until completely dissolved to obtain mixed solution B. Add 10 wt% polyvinyl alcohol and color dyes corresponding to or close to the colors of real skin, breast, tumor, and blood vessels to mixed solution B. Sonicate and stir evenly and vacuum to eliminate air bubbles. By mass, mixed solution B includes 0.07% ammonium persulfate and N'N-methylenebisacrylamide, wherein the mass ratio of N'N-methylenebisacrylamide to acrylamide is 0.07%. The mass of polyvinyl alcohol added to mixed solution B is equal to the mass of water added to mixed solution A.

[0026] Step S22: Prepare skin model 2, breast model 3 and tumor model 5. Cast the hydrogel precursor solution into the skin mold, breast mold and tumor mold respectively. After gelation, freeze at -20℃ for 8 hours. After thawing, hydrogel skin model 2, hydrogel breast model 3 and hydrogel tumor model 5 are formed. Step S23: Prepare vascular model 4. First, place the vascular core in the vascular mold, then pour the hydrogel precursor solution. After the gelation reaches a certain degree, remove the vascular core and freeze it. After thawing, vascular model 4 is formed.

[0027] Step S3: Model assembly. Place the breast model 3, tumor model 5, and blood vessel model 4 inside the skin model 2, respectively. Then pour the hydrogel fat model 6 precursor solution. When the gelation reaches a certain degree, pull out the metal wire to obtain the breast and surrounding tissue model, including the fat model 6. Finally, pour the hydrogel muscle model 7 precursor solution. After gelation, freeze the model at -20℃ for 8 hours. After thawing, the entire hydrogel breast model 1 is obtained.

[0028] Specifically, the breast model 3, tumor model 5, and blood vessel model 4 are placed into the skin model 2, including: Step S31: Apply petroleum jelly to the breast model 3, tumor model 5, and blood vessel model 4 and thread a metal wire through them; Step S32: Suspend the breast model 3, tumor model 5 and blood vessel model 4 in the groove 203 of the skin model 2 with metal wires, and position them at their respective locations based on the modeling position.

[0029] To align with the common clinical location of breast cancer, tumors are preferably located in the upper outer quadrant of the breast, between the middle and deep layers of breast tissue.

[0030] Step S3 also includes the preparation of the precursor solution for the hydrogel fat model 6, including: Step S33: Mix acrylamide and water at a mass ratio of 1:3 to obtain mixed solution C; Step S34: Add 0.1% ammonium persulfate and 0.9% sodium chloride to mixed solution C. N'N methylenebisacrylamide is also added to mixed solution C. The mass ratio of N'N methylenebisacrylamide to acrylamide is 0.05%. After ultrasonic stirring until completely dissolved, mixed solution D is obtained. Step S35: Add 10 wt% polyvinyl alcohol to the mixed solution D. The mass of polyvinyl alcohol is 50% of the mass of water in the mixed solution C. After ultrasonic stirring until completely dissolved, the precursor solution of hydrogel fat model 6 is obtained.

[0031] Step S3 also includes the preparation of the precursor solution for the hydrogel muscle model 7, including: Step S36: Mix acrylamide and water at a mass ratio of 1:2 to obtain mixed solution E; Step S37: Add ammonium persulfate with a mass fraction of 0.07% to mixed solution E. Mixed solution E also contains N'N methylenebisacrylamide with a mass ratio of 0.1% to acrylamide. After ultrasonic stirring until completely dissolved, mixed solution F is obtained. Step S38: Add 10 wt% polyvinyl alcohol to the mixed solution F. The mass of polyvinyl alcohol is the same as the mass of water in the mixed solution E. After adding red dye, stir evenly and vacuum process to obtain the precursor solution of hydrogel muscle model 7.

[0032] Example 2 Similar to Example 1, except that the preparation of the hydrogel fat model 6 precursor solution used in this example includes: Acrylamide and water were mixed at a mass ratio of 1:3 to obtain mixed solution C; Ammonium persulfate with a mass fraction of 0.1% was added to mixed solution C. N'N-methylenebisacrylamide was also added to mixed solution C. The mass ratio of N'N-methylenebisacrylamide to acrylamide was 0.05%. After ultrasonic stirring until completely dissolved, mixed solution D was obtained. Add 10 wt% polyvinyl alcohol to mixed solution D. The mass of polyvinyl alcohol is 50% of the mass of water in mixed solution C. After ultrasonic stirring until completely dissolved, the precursor solution of hydrogel fat model 6 is obtained.

[0033] Example 3: Conductivity Test The conductivity of the fat models 6 prepared in Examples 1 and 2 was tested. Specifically, the hydrogel fat models 6 prepared in Examples 1 and 2 were made into circular pieces with a diameter d=1cm and a thickness T=2mm. The resistance of the material was tested using an electrochemical workstation (CHI760E, Shanghai Chenhua Instruments), and the conductivity of the hydrogel was calculated according to the following formula: σ=L / (R×S), where L, R and S are the thickness, resistance and cross-sectional area of ​​the sample, respectively.

[0034] like Figure 4 As shown in the results analysis: the conductivity of the hydrogel fat in Example 2 was measured to be 0.042 S / m, while the conductivity of the hydrogel fat in Example 1 was 0.637 S / m. The conductivity of fat in human breast tissue is approximately 0.6 S / m. Therefore, it can be concluded that the hydrogel fat prepared in the examples is close to that of real tissue. This indicates that the modified hydrogel fat in Example 1 has a conductivity similar to that of the human body, can produce good reactions with electrosurgical instruments, and is well-suited for robotic surgical training.

[0035] Example 4 This embodiment provides a breast model 1 suitable for robotic surgery training, such as... Figures 1-3 As shown, it was prepared using a breast model 1 preparation method suitable for robotic surgery training as described in Example 1.

[0036] The breast model 1 prepared in this embodiment simultaneously includes a skin layer, an adipose tissue layer, a mammary gland module, a tumor module, a vascular module, and a muscle tissue layer. It is assembled from multiple layers with clearly defined anatomical planes between each layer. This allows robotic instruments to complete the entire operational path within the model, such as subcutaneous tunnel establishment, flap separation, and glandular mobilization. It no longer merely provides a static structural display but makes layered dissection and spatial manipulation essential and achievable training steps. Structurally, this overcomes the shortcomings of existing models that cannot simulate key operations in robotic breast surgery.

[0037] Each model is made of a special hydrogel material, which can clearly show the location of the tumor under ultrasound, and its tissue layers can be separated and pulled by robotic instruments, resulting in better training effect.

[0038] It also takes into account thermoelectric response characteristics, enabling the skin, fat, and mammary gland layers to withstand energy instruments commonly used in robots, such as electrocoagulation and electric shears, and to produce resistance and thermal damage patterns similar to real tissue during cutting. Because these layer materials can maintain their basic shape and layer continuity after electrocoagulation, the model can be reused after multiple operations, thus ensuring the feasibility and repeatability of electrocoagulation cutting training in terms of structure. This directly overcomes the shortcomings of traditional ultrasonic phantoms and ordinary simulated prostheses, which cannot be operated by energy instruments or are destroyed after one use.

[0039] In summary, the model in this embodiment combines features such as multi-layer structure design, acoustic characteristic matching, electrocoagulation adaptable materials, and replaceable tumor modules, which can produce a synergistic effect of "ultrasound imaging + layered dissection + robotic electrocoagulation cutting". This allows the entire process of robotic breast surgery, from preoperative image localization to intraoperative layered resection, to be completed on the same non-biological model, which has comprehensive technical advantages and training effects.

[0040] Example 5 This embodiment provides a specific structure of breast model 1 in embodiment 4, as follows: Figures 1-3 As shown, the structure is as follows: Breast model 1 includes skin model 2, which is constructed in a shell shape and has an internal cavity 201. The skin model 2 has a protruding breast portion 202 in the middle, and a groove 203 that communicates with the cavity 201 is formed at the breast portion 202; It also includes a breast model 3 and a blood vessel model 4 set in the groove 203. The breast model 3 contains a tumor model 5. The groove 203 is filled with a fat model 6 that surrounds the breast model 3 and the blood vessel model 4. The cavity 201 is filled with a muscle model 7.

[0041] In this embodiment, the overall breast model 1 is assembled from multiple independent models, which can realize training steps such as layered dissection and spatial manipulation, and has a better training effect.

[0042] The outer surfaces of breast model 3, tumor model 5, and blood vessel model 4 are all coated with petroleum jelly. The petroleum jelly can form an isolation layer, which makes the layering and peeling during the training process more effective.

[0043] The skin model 2 is equipped with an instrument inlet 208, while the muscle model 7 and fat model 6 are equipped with instrument channels 8 for connecting the instrument inlet 208 with the tumor model 5. In this embodiment, the instrument channels 8 can be cut directly before training or cast by adding an inner core during the casting process.

[0044] Skin model 2, breast model 3, tumor model 5, and blood vessel model 4 were all cast using hydrogel. The hydrogel material allows the tumor location to be clearly displayed under ultrasound, and its tissue layers can be separated and pulled by robotic instruments, further enhancing the training effect of robotic surgery.

[0045] The tumor model 5 was placed in the upper outer quadrant of the breast 202 and located between the middle and deep layers of the breast tissue.

[0046] like Figure 5 As shown, the skin model 2 includes an integrally formed upper wall 204, lower wall 205 and front wall 206. The upper wall 204, lower wall 205 and front wall 206 together form a cavity 201 with a rear opening. The upper and lower ends of the front wall 206 are respectively connected to the upper wall 204 and lower wall 205. The left and right ends of the front wall 206 are bent backward to form two side walls 207. The breast part 202 is located in the middle of the front wall 206. The instrument inlet 208 is located on one side of the front wall 206.

[0047] The imported instrument 208 is set on the side of the skin model 2. It simulates the axillary side and constructs a subcutaneous operating cavity that matches the single incision approach. This allows the robotic instrument to obtain spatial constraints and operating paths consistent with clinical practice within the model, thereby effectively simulating the real separation and resection process of robotic breast surgery and significantly improving the matching degree and practicality of training.

[0048] The muscle model 7 includes a filling portion 701 that fills the cavity 201 and a support portion 702 that protrudes from the cavity 201. The support portion 702 is located at the opening of the cavity 201 and the outer end face of the support portion 702 is constructed as a support plane 703.

[0049] The upper and lower sides of the support 702 are in the same plane as the upper end wall 204 and the lower end wall 205, respectively. The left and right side walls 207 of the support 702 are in the same arc surface as the two side walls 207. The support 702 forms a cover plate at the opening of the skin model 2, so that each model is wrapped inside the skin model 2, which more realistically simulates the human body. The hardness of the muscle model 7 is greater than that of the skin model 2. On the one hand, it conforms to the hardness relationship between human muscles and skin. On the other hand, it can provide support for the skin model 2. The support 702 is directly cast from the muscle model 7 during the casting process. Without the need for additional support, the entire model can be stably placed on the training table, which facilitates surgical training, retrieves assembly procedures, and reduces costs.

[0050] It is readily understood that those skilled in the art can combine, split, or reorganize the embodiments provided in this application to obtain other embodiments, none of which exceed the protection scope of this application.

[0051] In summary, the above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the present invention.

Claims

1. A method for preparing a breast model suitable for robotic surgical training, characterized in that, Includes the following steps: Mold fabrication: Based on CT image data, skin molds, breast molds, tumor molds, and blood vessel molds are obtained through 3D printing. Model preparation: Based on skin mold, breast mold, tumor mold and blood vessel mold, skin model (2), breast model (3), tumor model (5) and blood vessel model (4) were obtained by pouring hydrogel precursor liquid respectively. Model assembly: The breast model (3), tumor model (5) and blood vessel model (4) are placed into the skin model (2) respectively. Then, the precursor solution of hydrogel fat model (6) is poured. After the fat model (6) is formed, the precursor solution of hydrogel muscle model (7) is poured. After gelation, it is frozen and then thawed to obtain the hydrogel breast model (1).

2. The method for preparing a breast model suitable for robotic surgical training according to claim 1, characterized in that, The skin model (2), breast model (3), tumor model (5), and vascular model (4) are obtained by pouring hydrogel precursor liquid based on skin mold, breast mold, tumor mold, and vascular mold, respectively, including: To prepare the hydrogel precursor solution, acrylamide and water were mixed to obtain mixed solution A. N'N-methylenebisacrylamide and ammonium persulfate were added to mixed solution A and ultrasonically stirred until completely dissolved to obtain mixed solution B. Polyvinyl alcohol was added to mixed solution B, stirred evenly, and then vacuum treated. Prepare skin model (2), breast model (3) and tumor model (5). Cast the hydrogel precursor solution into the skin mold, breast mold and tumor mold respectively. After gelation, freeze and store. After thawing, form skin model (2), breast model (3) and tumor model (5). To prepare a vascular model (4), first place the vascular core in the vascular mold, then pour the hydrogel precursor solution. After gelation, remove the vascular core and freeze it. After thawing, the vascular model (4) is formed.

3. The method for preparing a breast model suitable for robotic surgical training according to claim 2, characterized in that, The mass ratio of acrylamide to water in mixed solution A is 1:2; By mass, mixed solution B includes 0.07% ammonium persulfate and N'N-methylenebisacrylamide, wherein the mass ratio of N'N-methylenebisacrylamide to acrylamide is 0.07%. The mass of polyvinyl alcohol added to mixed solution B is equal to the mass of water added to mixed solution A.

4. The method for preparing a breast model suitable for robotic surgical training according to claim 1, characterized in that, The step of placing the breast model (3), tumor model (5), and vascular model (4) into the skin model (2) includes: The breast model (3), tumor model (5) and vascular model (4) were coated with petroleum jelly and threaded with metal wire; The breast model (3), tumor model (5) and blood vessel model (4) are suspended by metal wires in the groove (203) of the skin model (2).

5. A method for preparing a breast model suitable for robotic surgical training according to claim 1 or 4, characterized in that, The preparation methods of the precursor solution for the hydrogel fat model (6) include: Acrylamide and water were mixed at a mass ratio of 1:3 to obtain mixed solution C. Ammonium persulfate with a mass fraction of 0.1% and sodium chloride with a mass fraction of 0.9% were added to mixed solution C. N'N methylenebisacrylamide was also added to mixed solution C. The mass ratio of N'N methylenebisacrylamide to acrylamide was 0.05%. After ultrasonic stirring until completely dissolved, mixed solution D was obtained. 10 wt% polyvinyl alcohol was added to mixed solution D. The mass of polyvinyl alcohol was 50% of the mass of water in mixed solution C. After ultrasonic stirring until completely dissolved, the precursor solution of hydrogel fat model (6) was obtained.

6. The method for preparing a breast model suitable for robotic surgical training according to claim 1, characterized in that, The preparation methods of the precursor solution for the hydrogel muscle model (7) include: Acrylamide and water were mixed at a mass ratio of 1:2 to obtain a mixed solution E. Ammonium persulfate with a mass fraction of 0.07% was added to the mixed solution E. N'N methylenebisacrylamide was also added to the mixed solution E. The mass ratio of N'N methylenebisacrylamide to acrylamide was 0.1%. After ultrasonic stirring until completely dissolved, a mixed solution F was obtained. 10wt% polyvinyl alcohol was added to the mixed solution F. The mass of polyvinyl alcohol was equal to the mass of water in the mixed solution E. After adding red dye, the mixture was stirred evenly and vacuumed to obtain the precursor solution of the hydrogel muscle model (7).

7. The method for preparing a breast model suitable for robotic surgical training according to claim 2, characterized in that, The gelation and freezing conditions during model preparation and assembly were both -20°C for 8 hours.

8. A breast model (1) suitable for robotic surgical training, characterized in that: It is prepared using a breast model preparation method suitable for robotic surgical training as described in any one of claims 1-7.

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