Medical phantom comprising an echogenic and radiopaque bone imitation product

Abstract

The invention relates to a medical phantom (1) adapted for ultrasound and radiography training, comprising a silicone mannequin (3) within which is formed a product (5) imitating at least one bone. The product (5) is formed from a polymer doped with a radiopaque agent according to one of the following compositions: - in a first composition, the polymer is polylactic acid and the radiopaque agent is selected from copper, stainless steel, and brass; - in a second composition, the polymer is an epoxy resin or a polyurethane resin and is mixed with a hardener, the radiopaque agent being barium sulfate. [Fig. 5]

Description

Title of the invention: Medical phantom comprising an echogenic and radiopaque bone imitation product

[0001] The field of the invention relates to a medical phantom comprising an echogenic and radiopaque bone imitation product. Such a medical phantom is particularly suitable for training in medical imaging techniques, in particular ultrasound and radiography.

[0002] Ultrasound is a medical imaging technique which allows, through the analysis of echoes produced by ultrasound on internal tissues, the morphological exploration of anatomical structures.

[0003] Ultrasound requires the use of a probe for emitting and receiving ultrasound waves. The probe generally comprises a piezoelectric ceramic which, when subjected to electrical pulses, generates ultrasound waves. The probe is placed in contact with the skin, and the emitted ultrasound waves pass through the tissues, to a greater or lesser depth depending on their frequency, and are then reflected back as echoes. Computer processing then converts the received echoes into images of the anatomical region being examined. A gel can be applied to amplify the transmission of the ultrasound waves and improve the quality of the images obtained.

[0004] Ultrasound can be used to diagnose abnormalities, conditions, or pathologies affecting organs, as well as to monitor the progress of a pregnancy. Ultrasound is also used in rheumatology for the intra-articular injection of medication—or infiltration—using a needle to relieve joint pain. Furthermore, it is common for healthcare professionals to use ultrasound during a percutaneous biopsy to guide the needle.

[0005] Radiography is a medical imaging technique which consists of exposing an anatomical region to X-rays to generate a greyscale image on which the anatomical structures can be visualized by contrast according to their respective attenuation coefficients.

[0006] X-rays are produced by an X-ray tube consisting of a vacuum chamber containing a cathode and an anode. An electric current is applied to the cathode to heat it, while a potential difference is generated between the cathode and the anode. An electron beam is emitted from the cathode towards the anode and is accelerated by the potential difference. The anode releases some of the energy supplied by the electrons in the form of X-rays. The X-rays then pass through anatomical structures that differ in their thickness and attenuation coefficient. Finally, a detector converts the captured photons at the output of the Anatomical region in a greyscale image. A contrast agent can be injected to improve visibility.

[0007] Radiography allows visualization of muscles, joints, and especially bones, which have a higher attenuation coefficient than soft tissues. This is referred to as radiopacity—or radiodensity—that is, the ability to impede the passage of X-rays. Radiography is used to diagnose fissures and fractures, or to detect a foreign body.

[0008] Mastering these medical imaging techniques requires training. Medical phantoms for ultrasound guidance training are currently available for practicing the use of the probe, and possibly the needle. Furthermore, medical phantoms for radiography guidance training allow users to learn how to operate the X-ray tube and detector, as well as how to interpret the resulting image.

[0009] However, no known medical phantom is suitable for both ultrasound and radiography training.

[0010] The present invention improves the situation.

[0011] In this respect, the invention relates to a medical phantom comprising a silicone mannequin in which is provided an imitation product of at least one bone.

[0012] The product is formed from a polymer doped with a radio-opaque agent according to: - a first composition in which the polymer is polylactic acid, the radio-opaque agent being chosen from copper, stainless steel and brass, or - a second composition in which the polymer is an epoxy resin or a polyurethane resin and is mixed with a hardener, the radio-opaque agent being barium sulfate.

[0013] In one or more embodiments, the product is formed according to the first composition in which polylactic acid is doped with copper at a doping rate of between 14 and 20%, and preferably substantially equal to 18%.

[0014] According to one variant, the product is formed according to the first composition in which polylactic acid is doped with stainless steel at a doping rate of between 13 and 27%, and preferably substantially equal to 21%.

[0015] According to another variant, the product is formed according to the first composition in which polylactic acid is doped with brass at a doping rate of between 14 and 28%, and preferably substantially equal to 23%.

[0016] In one or more embodiments, the product is formed according to the second composition in which the polymer is an epoxy resin and is doped with barium sulfate at a doping rate of between 5 and 18%, and preferably substantially equal to 12%.

[0017] According to one variant, the epoxy resin is Resoltech 1050 resin and the hardener is type 105xS.

[0018] According to another variant, the epoxy resin is SR GreenPoxy 56 resin and the hardener is SD 7561.

[0019] According to another variant, the epoxy resin is CHS-EPOXY 324 resin and the hardener is PI 1.

[0020] In one or more embodiments, the product is formed according to the second composition in which the polymer is a polyurethane resin and is doped with barium sulfate at a doping rate of between 20 and 50%, and preferably substantially equal to 33%.

[0021] For example, the polyurethane resin is a resin from the Formousse range and the hardener is of type MD.

[0022] The invention also relates to a method for manufacturing a medical phantom as described above.

[0023] The process comprises the following operations: - to manufacture the product from the first or second composition, - superimpose a first negative mold comprising an imprint of the shape of a front face of the mannequin to be obtained and a positive mold comprising a relief of the shape of the product, - Pour silicone between the first negative mold and the positive mold, - Remove the positive mold after the silicone has hardened; the positive mold will leave an imprint of the product's shape in the silicone. - place the product in the first negative mold in the imprint left by the positive mold, - superimpose the first negative mold and a second negative mold containing an imprint of the shape of the back face of the mannequin to be obtained, - Pour silicone between the first negative mold and the second negative mold, - remove the first negative mold and the second negative mold after the silicone has hardened to obtain the mannequin in which the product is contained.

[0024] In one or more embodiments, the product is manufactured by three-dimensional extrusion printing from the first composition.

[0025] In one or more embodiments, the product is manufactured by pouring the second composition in liquid form into a cavity of a mold.

[0026] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings on which:

[0027] [Fig.1] schematically illustrates a medical phantom according to the invention;

[0028] [Fig.2] illustrates a medical phantom according to the invention comprising a mannequin of a human foot;

[0029] [Fig.3] illustrates an imitation product of a medical phantom spine according to the invention;

[0030] [Fig.4] illustrates images, in cross-section, obtained by ultrasound respec tivement of a medical phantom according to the invention imitating a human hand and of a real human hand;

[0031] [Fig. 5] illustrates an image, from a top view, obtained by radiography of a medical phantom according to the invention imitating a human hand and a real human hand;

[0032] [Fig. 6] illustrates characteristics of the attenuation of a detector used in ra diography;

[0033] [Fig.7] illustrates a method for manufacturing a medical phantom according to the invention;

[0034] [Fig.8] illustrates molds used during the process of [Fig.7]; and

[0035] [Fig.9] illustrates casting operations of the process of [Fig.7] involving the molds of the [Fig.8].

[0036] Fig. 1 schematically illustrates a medical phantom 1.

[0037] The medical phantom 1 can allow a healthcare professional, for example a radiologist, to practice guidance under ultrasound and X-ray without having to use different training devices. For such use, the medical phantom 1 can be described as a procedural medical simulator.

[0038] Ultrasound training generally involves handling a probe applied to the skin to visualize an anatomical region. Such training may include applying a gel to amplify ultrasound transmission and, in conjunction with the probe, handling a needle to inject an anesthetic—most often cortisone—into a joint or to perform a percutaneous biopsy. Ultrasound allows for more precise needle guidance.

[0039] The technique of radiography requires mastery of various tools, including an X-ray tube and a detector. In particular, prolonged exposure to X-rays, which are ionizing electromagnetic radiation, can pose a risk to the patient's health, so the X-ray tube must be handled with care. The detector produces a grayscale image of an anatomical region and requires practice to obtain an image of sufficient quality and to be able to interpret it. Furthermore, the injection of a contrast agent, sometimes necessary to visualize soft tissues or organs, may also require training.

[0040] It should be noted that the medical phantom 1 is not limited to ultrasound and radiography training. Its properties, detailed later in the description, allow it to be used for training in other techniques. medical imaging or even non-medical uses.

[0041] As illustrated in [Fig.1], the medical phantom 1 comprises a silicone mannequin 3 in which is provided a product 5 imitating at least one bone.

[0042] The mannequin 3 is adapted to imitate a part of the human body. As such, the silicone exhibits properties similar to those of soft tissue in the presence of ultrasound or X-rays. Furthermore, silicone has the advantage of possessing self-healing properties, which is useful in the event of the formation of holes by the repeated use of a needle.

[0043] Advantageously, the mannequin 3 has an external shape similar to that of the body part it is intended to imitate in ultrasound and radiography. Such a shape makes it possible to increase the realism of the medical phantom 1 and to make the training as close as possible to a real examination.

[0044] For example, [Fig. 2] illustrates an embodiment of the medical phantom 1 in which the mannequin 3 takes the form of a human foot. The medical phantom 1 shown here allows a healthcare professional to practice ultrasound for the detection of plantar fasciitis or tendinitis, or radiography to assess heel positioning during weight-bearing or to diagnose a metatarsal fracture. The product 5, contained within the mannequin 3, is not visible in [Fig. 2].

[0045] However, the mannequin 3 can also have any shape, in which case the mannequin 3 mainly serves to imitate the soft tissues that envelop and support the skeleton.

[0046] Product 5 is adapted to imitate a bone and, more generally, a part of the human skeleton. Unlike mannequin 3, which can have any external shape, the external shape of product 5 is advantageously similar to that of the bone or part of the skeleton to be imitated.

[0047] In the example illustrated in [Fig. 3], the product 5 takes the form of a human spine. The product 5 comprises several artificial bones designed to imitate, among others, the cervical spine, thoracic spine, lumbar spine, sacrum, and coccyx. The product 5 shown in [Fig. 3] is intended to be placed in a silicone mannequin 3 advantageously shaped like a human thorax to form a medical phantom 1. Such a medical phantom 1 allows a healthcare professional to practice ultrasound for localization prior to an epidural injection or radiography to detect a static disorder such as scoliosis or kyphosis.

[0048] Bones are rigid structures, essentially made up of connective tissue, which together form the skeleton. Bones protect internal organs and facilitate movement. They play a role in calcium metabolism, mineral storage, and blood cell production.

[0049] The constitution of a bone gives it specific properties in the presence of ultrasound or X-rays which make it visible in ultrasound and radiography.

[0050] First, bones are hyperechoic solid structures. During an ultrasound examination, bones reflect the ultrasound waves to the probe in the form of echoes. This property makes it possible, for example, to detect an irregularity in the hyperechoic cortical line, which suggests a fracture or the avulsion of an enthesis, as well as to diagnose and then aspirate subperiosteal hematomas.

[0051] Furthermore, bones have a higher attenuation coefficient than soft tissues or organs, thus obstructing the passage of photons that constitute X-rays. This property—radiopacity—allows bones to be visible in the grayscale image obtained by radiography. It is therefore possible to observe, at the bone level, a fracture, a bone deformity, an infection, or a tumor, and at the joint level, osteoarthritis, fluid accumulation in a joint (effusion), or a dislocation.

[0052] Consequently, the inventor focused his research on compositions for manufacturing artificial bones, in this case product 5, whose properties are close to those of real bones in both ultrasound and radiography. The results of the inventor's work are detailed below and concern compositions in which product 5 is formed from a polymer doped with a radiopaque agent.

[0053] The inventor has observed that polylactic acid (better known by the English acronym PLA for "polylactic acid"), epoxy resin and polyurethane resin allow the product 5 to reflect ultrasound in a manner similar to that of bones and therefore provide the desired visibility to ultrasound.

[0054] The epoxy resin is, for example, Resoltech 1050 resin, marketed by Resoltech (registered trademark). Resoltech 1050 resin can be mixed with a 105xS type hardener to form an epoxy polymer—or polyepoxide. The recommended ratio is 35 parts 105xS hardener to 100 parts Resoltech 1050 resin by mass. It is also possible to mix these hardeners to adjust the curing rate. It should be noted that the mixing can be carried out at room temperature, i.e., between 18 and 25°C, and that post-curing is not necessary for demolding.

[0055] Alternatively, the SR GreenPoxy 56 resin marketed by Sicomin can be used. SR GreenPoxy 56 resin can be mixed with SD 7561 hardener to form an epoxy polymer. The recommended ratio is 36 parts SD 7561 hardener to 100 parts SR GreenPoxy 56 resin by mass. Again, the mixing can be carried out at room temperature.

[0056] As an alternative, the CHS-EPOXY 324 resin marketed by Spolchemie (Registered trademark) may be used. CHS-EPOXY 324 resin can be mixed with PI 1 hardener to form an epoxy polymer. The recommended ratio is 7 parts PI 1 hardener to 100 parts CHS-EPOXY 324 resin by mass.

[0057] Regarding polyurethane resin, the Formousse range marketed by COP (registered trademark) can be used, for example, Formousse 60 or Formousse 200 resin. Formousse polyurethane resin can be mixed with MD hardener, which is a liquid polymeric isocyanate of the MDI type. The recommended ratio is 100 parts MD hardener to 100 parts Formousse polyurethane resin by mass.

[0058] In the following description, for product 5, a first composition is distinguished in which the polymer is polylactic acid and a second composition in which the polymer is an epoxy resin or a polyurethane resin.

[0059] Figure 4 illustrates two images obtained by ultrasound: the image on the right is that of a medical phantom 1 imitating a human hand, while the image on the left is that of a real human hand 7. More precisely, these images allow visualization, according to a cross-sectional view, of the metacarpus, which is thus imitated, in the medical phantom 1, by a product 5. Comparison of these two images highlights that the product 5 offers a satisfactory visual and therefore allows training in ultrasound guidance.

[0060] The inventor then tested different radio-opaque agents to be mixed with the polymer to obtain a product 5 suitable for blocking the passage of photons and characterized by a high attenuation coefficient to offer the desired visibility for radiography.

[0061] Regarding first of all the first composition of product 5, that is to say the one in which the polymer is polylactic acid, the inventor has established that copper, stainless steel (more commonly called "inox") and brass (also referred to by the English term "brass") make it possible to give the desired radio-opacity to polylactic acid.

[0062] In particular, polylactic acid can be doped with copper at a doping level advantageously between 14 and 20%. Preferably, the doping level is approximately 18%.

[0063] Alternatively, polylactic acid can be doped with stainless steel at a doping level advantageously between 13 and 27%. Preferably, the doping level is approximately 21%.

[0064] Alternatively, polylactic acid can be doped with brass at a doping level advantageously between 14 and 28%. Preferably, the doping level is approximately 23%.

[0065] The doping rate here refers to the ratio of the mass of radio-opaque agent to the mass total of the first composition, therefore the mass of polylactic acid and radiopaque agent:

[0067] where: - r is the doping rate, - m^ is the mass of radio-opaque agent, and - mPLA is the mass of polylactic acid.

[0068] By "substantially equal," it is meant here that, ideally, the polylactic acid is doped with the radiopaque agent—copper, stainless steel, or brass—at the indicated doping level. However, in practice, it is difficult or even impossible to obtain exactly the desired doping level, so the actual doping level may deviate by up to 1% from the target level.

[0069] Regarding now the second composition of product 5, that is to say the one in which the polymer is the epoxy resin or the polyurethane resin, the inventor has established that barium sulfate (also designated by its chemical formula BaSO4) makes it possible to confer the desired radio-opacity to the selected resin.

[0070] In particular, the epoxy resin can be doped with barium sulfate at a doping level advantageously between 5 and 18%. Preferably, the doping level is approximately 12%.

[0071] In more detail, the barium sulfate doping rate is advantageously between 5 and 18% for resoltech 1050 resin and between 6 and 17% for SR GreenPoxy 56 resin.

[0072] With regard to polyurethane resin, and more particularly Formousse 60 or Formousse 200 resin, the barium sulfate doping level is advantageously between 20 and 50%. Preferably, the doping level is approximately 33%.

[0073] The doping ratio here refers to the ratio of the mass of radio-opaque agent, i.e. barium sulfate, to the total mass of the second composition, i.e. the mass of resin, hardener and radio-opaque agent:

[0075] where: - r is the doping rate, - m^ is the mass of radiopaque agent, - mres is the mass of resin, and - mhard is the mass of hardener.

[0076] By "substantially equal," it is meant here that, ideally, the resin is doped with barium sulfate at the indicated doping level. However, in practice, it is difficult or even impossible to obtain exactly the desired doping level, so the doping level may deviate by up to 1% from the target doping level.

[0077] By way of illustration, [Fig. 5] shows, on the same radiographic image, a medical phantom 1 imitating a human hand and a real human hand 7. Here again, the product 5 imitates the bones of the hand and is contained within a silicone mannequin 3 whose external shape is that of a human hand. Comparison with the real human hand 7 confirms that the medical phantom 1 thus obtained is visually very close to the body part—in this case, a hand—to be imitated and therefore offers the necessary guarantees for radiographic guidance training.

[0078] To determine the appropriate doping level, the inventor used a detector commonly employed in radiography. Such a detector is, for example, an inorganic scintillator comprising crystals and a photomultiplier tube (PMT). The crystals are arranged in a lattice configuration and each comprises a scintillation material, generally sodium iodide, which, in response to X-ray absorption, emits photons in the visible range. The photomultiplier tube exploits the photoelectric effect to convert the light received from the crystal lattice into an electrical signal.

[0079] The detector converts the received photons into a grayscale image. The grayscale level of a given point in the image depends on the intensity I of the X-ray beam received by the corresponding crystal of the detector. The intensity I of the X-ray beam after passing through a material depends on the incident intensity Io and the attenuation coefficient q of the material according to the following exponential attenuation law:

[0080] l = Io^

[0081] where: the attenuation coefficient q of the material is a function of the thickness x of the material traversed.

[0082] The operation of a detector can be characterized by the function that associates an attenuation coefficient with a given thickness of a material. Such a function—also called a characteristic—is illustrated in [Fig. 6]. More precisely, [Fig. 6] illustrates a Cexp curve that corresponds to the experimental characteristic Cexp of a detector and a Capp curve that corresponds to an approximation of the experimental characteristic Cexp. The thickness on the x-axis is in millimeters (mm), while the attenuation coefficient on the y-axis is dimensionless.

[0083] Therefore, in a radiographic image, the difference in gray level between two points indicates a difference in attenuation coefficient. In particular, the contrast of such an image results from the difference in attenuation coefficient between bone and other tissues. The ratio of the attenuation coefficient of bone to the attenuation coefficient of other tissues is approximately 2.5. To evaluate the quality of a composition, i.e., a polymer doped with a radiopaque agent, The inventor manufactures a cube of the composition to be tested and takes an X-ray to obtain, on the same image, the manufactured cube and a silicone cube. The contrast between the two cubes on the resulting image allows the ratio of the attenuation coefficient of the tested composition to the attenuation coefficient of the silicone to be deduced; the quality of the composition is all the more satisfactory when the measured contrast ratio corresponds to a ratio of approximately 2.5.

[0084] A method for manufacturing the medical phantom 1 will now be described with reference to [Fig.7].

[0085] The process can be broken down into two phases. The first phase, corresponding to operation 700, is a manufacturing phase of product 5. The second phase, corresponding to operations 710, 720, 730, 740, 750, 760 and 770, is a manufacturing phase of the mannequin 3 around product 5.

[0086] During operation 700, product 5 is manufactured from a polymer doped with a radio-opaque agent according to the first composition or the second composition.

[0087] We first consider the case where the first composition is chosen. As detailed previously, the first composition has this particularity in that the polymer is polylactic acid and the radio-opaque agent is copper, stainless steel or brass.

[0088] Product 5 can then be manufactured by three-dimensional printing – also called 3D printing or additive manufacturing – by extrusion (also referred to by the English term "Material Extrusion"). More precisely, the extrusion is carried out by fused deposition modeling (FDM).

[0089] This technique involves feeding a 3D printer's extrusion head—or extruder—with polylactic acid and a radiopaque agent. Conventionally, the extrusion head can be fed by a spool around which the first composition is wound in the form of a filament. However, it is also possible to introduce the polylactic acid and the radiopaque agent into the extrusion head in the form of granules. The extrusion head is heated to melt the first composition and then deposit it, via an extrusion nozzle, onto a printing platform. The first composition is thus deposited layer by layer to obtain the product 5. An operator can program the 3D printer to obtain the desired shape, such as a bone or a part of the skeleton to be imitated. To improve the adhesion of successive layers, the printing platform can be heated.

[0090] Three-dimensional printing makes it possible to obtain a hollow product which, visually, is very close to the bone or part of the skeleton to be imitated.

[0091] We then consider the case where the second composition is chosen. As detailed Previously, the second composition had this particularity in that the polymer is an epoxy resin or a polyurethane resin and is mixed with a hardener, while the radio-opaque agent is barium sulfate.

[0092] Product 5 can then be manufactured by casting according to a known process.

[0093] Typically, a model of the bone or skeletal part to be imitated is placed in a mold with an opening. The model can be held in place, to facilitate its subsequent removal, by a rod extending outside the mold. Silicone is then poured into the mold through the opening until it covers the model. After the silicone has hardened (for example, through vulcanization), the mold and the model are removed, for example, using the rod provided for this purpose. This yields a silicone mold whose impression, i.e., the cavity left by the model in the silicone, has the shape of the bone or skeletal part to be imitated. Finally, the doped resin is poured in liquid form into the impression to obtain, after the doped resin has hardened and the mold has been removed, the product 5.

[0094] In the particular case where the resin used is polyurethane resin, it can be sprayed into the mold using a foam gun, in particular to better control the expansion of the polyurethane resin which follows spraying.

[0095] Once product 5 is obtained, the manufacturing phase of mannequin 3 is implemented. Mannequin 3 is formed so as to envelop product 5, in the same way that the soft tissues of the human body envelop the skeleton.

[0096] To this end, two negative molds are used: a first negative mold 9 and a second negative mold 11, each having an impression whose shape is respectively that of the front face and that of the back face of the mannequin 3 to be manufactured. Finally, a positive mold 13 is also used and has a relief whose shape is, at least partially, that of the product 5 intended to be contained within the mannequin 3.

[0097] In the example illustrated in [Fig. 8], the mannequin 3 to be obtained is shaped like a hand. Therefore, the first negative mold 9 has an impression of the shape of the palmar surface—or anterior surface of the hand—while the second negative mold 11 has an impression of the shape of the dorsal surface—or posterior surface of the hand. The relief of the positive mold 13 shows the shape of all the bones of the hand—carpus, metacarpus, and phalanges. A product 5 (not shown here) imitating all the bones of the hand was previously manufactured.

[0098] As mentioned previously, the mannequin 3 does not necessarily have the external shape of a body part, in which case the front and back faces of the mannequin 3 to be manufactured are arbitrary.

[0099] During operation 710, the first negative mold 9 and the positive mold 13 are superimposed so as to form a cavity delimited, on the one hand, by the imprint of the first negative mold 9 and, on the other hand, by the relief of the positive mold 13.

[0100] This operation is illustrated by [Fig. 9] in which the first negative mold 9 and the positive mold 13 are fitted together. The second negative mold 11 is set aside for the moment.

[0101] During operation 720, silicone is poured between the first negative mold 9 and the positive mold 13. In other words, the silicone is poured into the cavity formed by the first negative mold 9 and the positive mold 13.

[0102] During operation 730, the positive mold 13 is removed after the silicone has hardened (for example, through vulcanization-type polymerization). The cavity of the first negative mold 9 is then filled with silicone. Furthermore, the outer surface of the silicone, i.e., the surface not in direct contact with the first negative mold 9, bears an imprint formed and left by the positive mold 13.

[0103] During operation 740, the product 5 is placed in the imprint left by the positive mold 13 in the silicone.

[0104] During operation 750, the first negative mold 9 and the second negative mold 11 are superimposed. It is understood that the product 5 is then taken between the first negative mold 9 and the second negative mold 11.

[0105] The superposition of the first negative mold 9 and the second negative mold 11 forms a cavity delimited, on the one hand, by the outer surface of the silicone whose impression receives the product 5 and, on the other hand, by the impression of the second negative mold 11.

[0106] This operation is illustrated by [Fig.9] on which the first negative mold 9 and the second negative mold 11 are fitted together, thus enclosing the product 5. The positive mold 13 has been removed and is left aside.

[0107] During operation 760, silicone is poured between the first negative mold 9 and the second negative mold 11. In other words, the silicone is poured into the cavity formed by the first negative mold 9 and the second negative mold 11 and covers the product 5.

[0108] Finally, during operation 770, the first negative mold 9 and the second negative mold 11 are removed after the silicone has hardened (for example, through vulcanization-type polymerization). This yields the medical phantom 1, comprising the mannequin 3, within which the product 5 is contained.

[0109] In the foregoing, the medical phantom 1 is presented as a training tool for ultrasound and radiography imitating a part of the human body, in particular by the shape of the product 5 which is as similar as possible to that of a human bone or part of the human skeleton and possibly by the shape of the mannequin 3. However, a person skilled in the art understands that the medical phantom 1 can also be adapted to imitate a part of the body of an animal of the subphylum of vertebrates and thus be intended for a veterinarian.

Claims

Demands

1. Medical phantom (1) comprising a silicone mannequin (3) in which is provided a product (5) imitating at least one bone, said medical phantom (1) being characterized in that the product (5) is formed from a polymer doped with a radio-opaque agent according to: - a first composition in which the polymer is polylactic acid, the radio-opaque agent being selected from copper, stainless steel and brass, or - a second composition in which the polymer is an epoxy resin or a polyurethane resin and is mixed with a hardener, the radio-opaque agent being barium sulfate.

2. Medical phantom (1) according to claim 1, characterized in that the product (5) is formed according to the first composition in which polylactic acid is doped with copper at a doping rate of between 14 and 20%, and preferably substantially equal to 18%.

3. Medical phantom (1) according to claim 1, characterized in that the product (5) is formed according to the first composition in which polylactic acid is doped with stainless steel at a doping rate of between 13 and 27%, and preferably substantially equal to 21%.

4. Medical phantom (1) according to claim 1, characterized in that the product (5) is formed according to the first composition in which polylactic acid is doped with brass at a doping rate of between 14 and 28%, and preferably substantially equal to 23%.

5. Medical phantom (1) according to claim 1, characterized in that the product (5) is formed according to the second composition in which the polymer is an epoxy resin and is doped with barium sulfate at a doping rate of between 5 and 18%, and preferably substantially equal to 12%.

6. Medical phantom (1) according to claim 5, characterized in that the epoxy resin is resoltech 1050 resin and the hardener is type 105xS.

7. Medical phantom (1) according to claim 5, characterized in that the epoxy resin is SR GreenPoxy 56 resin and the hardener is SD 7561.

8. Medical phantom (1) according to claim 5, characterized in that the epoxy resin is CHS-EPOXY 324 resin and the hardener is Pli.

9. Medical phantom (1) according to claim 1, characterized in that the product (5) is formed according to the second composition in which the polymer is a polyurethane resin and is doped with barium sulfate at a doping rate of between 20 and 50%, and preferably substantially equal to 33%.

10. Medical phantom (1) according to claim 9, characterized in that the polyurethane resin is a resin from the Formousse range and the hardener is of type MD.

11. A method for manufacturing a medical phantom (1) according to any one of the preceding claims, said method being characterized in that it comprises the following operations: - manufacturing (700) the product (5) from the first composition or the second composition, - superimposing (710) a first negative mold (9) comprising an impression in the shape of an anterior face of the mannequin (3) to be obtained and a positive mold (13) comprising a relief in the shape of the product (5), - pouring (720) silicone between the first negative mold (9) and the positive mold (13), - removing (730) the positive mold (13) after the silicone has hardened, said positive mold (13) leaving an impression in the shape of the product (5) in the silicone, - placing (740) the product (5) in the first negative mold (9) in the impression left by the positive mold (13),- superimpose (750) the first negative mold (9) and a second negative mold (11) comprising an impression in the shape of a rear face of the mannequin (3) to be obtained, - pour (760) silicone between the first negative mold (9) and the second negative mold (11), - remove (770) the first negative mold (9) and the second negative mold (11) after the silicone has hardened to obtain the mannequin (3) in which the product (5) is contained.

12. A method according to claim 11, characterized in that the product (5) is manufactured by three-dimensional extrusion printing from the first composition.

13. A method according to claim 11, characterized in that the product (5) is manufactured by pouring the second composition in liquid form into a cavity of a mold.

Images