Medical phantom comprising an echogenic and radiopaque bone-mimicking product

Abstract

The invention relates to a medical phantom (1) suitable for ultrasound and radiography training, comprising a silicone dummy (3) which contains a product (5) that mimics at least one bone. The product (5) is formed from a polymer doped with a radiopaque agent according to either of the compositions below: - 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 curing agent, the radiopaque agent being barium sulfate.

Description

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, thanks to 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 transmitting and receiving ultrasound. The probe generally comprises a piezoelectric ceramic which, when subjected to electrical impulses, generates ultrasound. The probe is placed in contact with the skin and the emitted ultrasound passes through the tissues, more or less deeply depending on their frequency, then is returned in the form of echoes. Computer processing then converts the received echoes into images of the anatomical region being explored. A gel can be applied to amplify the transmission of ultrasound 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 intra-articular injection of medication—or infiltration—using a needle to relieve a painful joint. It is also common for a healthcare professional to use ultrasound during a transcutaneous biopsy to guide the needle.

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

[0006] X-rays are produced by an X-ray tube formed by a vacuum chamber within which a cathode and an anode are arranged. An electric current is applied to the cathode to heat it while a potential difference is generated between the cathode and the anode. A beam of electrons is emitted by the cathode to the anode and is accelerated by the potential difference. The anode releases the energy provided by the electrons partly in the form of X-rays. The X-rays then pass through anatomical structures which differ in their thickness and their attenuation coefficient. Finally, a detector converts the captured photons into X-rays. anatomical region into a grayscale image. A contrast agent may be injected to improve visibility.

[0007] X-rays can be used to visualize muscles, joints, and especially bones, which have a higher attenuation coefficient than soft tissues. This is called radiopacity - or radiodensity -, i.e., the ability to block the passage of X-rays. X-rays are used to diagnose cracks and fractures or to detect foreign bodies.

[0008] Mastering these medical imaging techniques requires training. Currently, there are medical phantoms for ultrasound guidance training to practice handling the probe, and possibly the needle. In addition, medical phantoms for radiography guidance training allow you to learn how to use 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 X-ray training.

[0010] The present invention improves the situation.

[0011] In this respect, the invention relates to a medical phantom comprising a silicone mannequin within which is arranged a product imitating at least one bone.

[0012] The product is formed from a polymer doped with a radiopaque agent according to: - a first composition in which the polymer is polylactic acid, the radiopaque 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 radiopaque agent being barium sulfate.

[0013] In one or more embodiments, the product is formed according to the first composition in which the polylactic acid is doped with copper at a doping level 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 the polylactic acid is doped with the 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 the polylactic acid is doped with the 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 level of between 5 and 18%, and preferably substantially equal to 12%.

[0017] Alternatively, the epoxy resin is Resoltech 1050 resin and the hardener is type 105xS.

[0018] In 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 Pl 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 level 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 the MD type.

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

[0023] The process includes the following operations: - manufacture the product from the first composition or the second composition, - superimposing 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 leaving an imprint of the shape of the product 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 comprising an imprint of the shape of a posterior 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 placed.

[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 made by casting the second composition in liquid form into an impression of a mold.

[0026] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings in which:

[0027] [Fig.l] 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 a product for imitating a spine of a medical phantom according to the invention;

[0030] [Fig.4] illustrates images, in a sectional view, obtained by ultrasound respectively of a medical phantom according to the invention imitating a human hand and of a real human hand;

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

[0032] [Fig.6] illustrates attenuation characteristics of a detector used in radiography;

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

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

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

[0036] [Fig.l] 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 under 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 typically involves handling a probe to be 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 commonly cortisone—into a joint or to perform a transcutaneous biopsy. Ultrasound allows for more precise needle guidance.

[0039] 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 provides a grayscale image of an anatomical region and requires practice to obtain an image of sufficient quality and be able to interpret it. In addition, the injection of a contrast agent, sometimes necessary to visualize soft tissues or organs, may also require training.

[0040] It should be noted that Medical Phantom 1 is not intended solely for ultrasound and X-ray training. Its properties, detailed in the following description, allow it to be used for training in other techniques. medical imaging or even non-medical uses.

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

[0042] Manikin 3 is suitable for mimicking a part of the human body. As such, silicone exhibits properties similar to those of soft tissue in the presence of ultrasound or X-rays. Furthermore, silicone has the advantage of having self-healing properties, which is useful in the event of holes forming through repeated use of a needle.

[0043] Advantageously, the mannequin 3 has an external shape similar to that of the body part that it is intended to imitate in ultrasound and X-ray. Such a shape in fact 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 health professional to train in ultrasound for the detection of plantar fasciitis or tendonitis or in X-rays to evaluate the positioning of the heel during support or to diagnose a metatarsal fracture. The product 5, arranged within the mannequin 3, is not visible in [Fig. 2].

[0045] However, the manikin 3 can also have any shape, in which case the manikin 3 mainly allows to imitate the soft tissues which envelop and maintain the skeleton.

[0046] The product 5 is suitable for imitating a bone and, more generally, a part of the human skeleton. Unlike the mannequin 3 which can have any external shape, the external shape of the product 5 is advantageously similar to that of the bone or the 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 - or vertebral column. The product 5 then comprises several dummy bones so as to imitate, among other things, the cervical spine, the thoracic spine, the lumbar spine, the sacrum and the coccyx. The product 5 shown in [Fig. 3] is intended to be placed in a silicone mannequin 3 advantageously taking the form of a human thorax to form a medical phantom 1. Such a medical phantom 1 allows a health professional to practice ultrasound for location before an epidural infiltration or radiography to look for a static disorder such as scoliosis or kyphosis.

[0048] Bones are rigid structures, primarily made of connective tissue, that together form the skeleton. Bones protect internal organs and facilitate movement. They are involved 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 on ultrasound and radiography.

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

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

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

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

[0054] An example of an epoxy resin is Resoltech 1050 resin, marketed by Resoltech (registered trademark). Resoltech 1050 resin can be mixed with a 105xS hardener to form an epoxy polymer - or polyepoxide. The recommended dosage is 35 parts 105xS hardener to 100 parts Resoltech 1050 resin by mass. These hardeners can also be mixed to adjust the curing speed. It should be noted that 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, 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 dosage is 36 parts SD 7561 hardener to 100 parts SR GreenPoxy 56 resin by mass. Again, mixing can be carried out at room temperature.

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

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

[0058] In the remainder of the description, a distinction is made, for product 5, between a first composition in which the polymer is polylactic acid and a second composition in which the polymer is an epoxy resin or a polyurethane resin.

[0059] Fa [Fig.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 to visualize, according to a sectional view, the metacarpus which is therefore imitated, in the medical phantom 1, by a product 5. Fa comparison of these two images highlights that the product 5 offers a satisfactory visual and therefore allows to practice guidance under ultrasound.

[0060] The inventor then tested different radiopaque agents to be mixed with the polymer to obtain a product 5 capable of obstructing the passage of photons and being characterized by a high attenuation coefficient to provide the desired visibility in radiography.

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

[0062] In particular, polylactic acid may be doped with copper at a doping rate advantageously between 14 and 20%. Preferably, the doping rate is substantially equal to 18%.

[0063] Alternatively, the polylactic acid may be doped with the stainless steel at a doping rate advantageously between 13 and 27%. Preferably, the doping rate is substantially equal to 21%.

[0064] Alternatively, the polylactic acid may be doped with brass at a doping rate advantageously between 14 and 28%. Preferably, the doping rate is substantially equal to 23%.

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

[0066]

[0067] where: - T is the doping rate, - in., r<) is the mass of radiopaque agent, and - m PLA is the mass of polylactic acid.

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

[0069] Now concerning the second composition of product 5, that is to say the one in which the polymer is epoxy resin or 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 may be doped with barium sulfate at a doping rate advantageously between 5 and 18%. Preferably, the doping rate is substantially equal to 12%.

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

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

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

[0075] where: - r is the doping rate, - m., r<) is the mass of radiopaque agent, - m res is the mass of resin, and - m hard is the mass of hardener.

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

[0077] By way of illustration, [Fig. 5] illustrates, on the same image obtained by radiography, 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 arranged in a silicone mannequin 3 whose external shape is that of a human hand. The comparison with the real human hand 7 makes it possible to verify that the medical phantom 1 thus obtained is visually very close to the part of the body - in this case a hand - to be imitated and therefore offers the necessary guarantees for training in guidance under radiography.

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

[0079] The detector converts the received photons into a grayscale image. The grayscale 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 I o and the attenuation coefficient p, of the material according to the following exponential attenuation law:

[0080] I = I o ^

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

[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 curve C exp which corresponds to the experimental characteristic C expof a detector and a C curve app which corresponds to an approximation of the experimental characteristic C exp The thickness on the abscissa is in millimeters (mm) while the attenuation coefficient on the ordinate is unitless.

[0083] Therefore, in an image obtained by radiography, 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 bones and other tissues. The ratio of the attenuation coefficient of bones to the attenuation coefficient of other tissues is approximately 2.5. To assess the quality of a composition, i.e. a polymer doped with a radiopaque agent, the inventor makes a cube of the composition to be tested and takes an X-ray to obtain, on the same image, the manufactured cube and a cube of silicone. The contrast between the two cubes on the image obtained makes it possible to deduce the ratio of the attenuation coefficient of the tested composition to the attenuation coefficient of the silicone, the quality of the composition being all the more satisfactory as the measured contrast corresponds to a ratio of the order of 2.5.

[0084] A method of 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 phase of manufacturing the product 5. The second phase, corresponding to operations 710, 720, 730, 740, 750, 760 and 770, is a phase of manufacturing the mannequin 3 around the product 5.

[0086] In step 700, product 5 is made from a polymer doped with a radiopaque 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 the particularity that the polymer is polylactic acid and the radiopaque 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 (better known by the English acronym FDM).

[0089] This technique involves feeding an extrusion head - or extruder - of a 3D printer with polylactic acid and the 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 in the form of granules into the extrusion head. The extrusion head is heated to melt the first composition and then deposit it, via an extrusion nozzle, on a printing platform. The first composition is thus deposited layer by layer so as to obtain the product 5. An operator can in fact program the 3D printer to obtain the shape of his choice, namely a bone or a part of the skeleton to imitate. To improve the adhesion of the successive layers, the printing platform can be heated.

[0090] Three-dimensional printing allows us to obtain a hollow product that, 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 has the particularity that the polymer is an epoxy resin or a polyurethane resin and is mixed with a hardener, while the radiopaque 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 part of the skeleton to be imitated is placed in a formwork having an opening. The model may be held, to facilitate subsequent removal of the model, by a rod extending outside the formwork. Silicone is then poured into the formwork through the opening until it covers the model. After curing (for example, a vulcanization-type polymerization) of the silicone, the formwork is removed along with the model, for example, using the rod provided for this purpose. A silicone mold is then obtained whose impression, that is to say, the cavity left by the model in the silicone, has the shape of the bone or part of the skeleton to be imitated. Finally, the doped resin is poured in liquid form into the impression to obtain, after curing of the doped resin and removal from the mold, the product 5.

[0094] In the particular case where the resin used is polyurethane resin, it can be sprayed into the impression using a foam gun, in particular to better control the expansion of the polyurethane resin following 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 do this, two negative molds are used: a first negative mold 9 and a second negative mold 11 each having an imprint whose shape is respectively that of the front face and that of the rear 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 arranged within the mannequin 3.

[0097] In the example illustrated in [Fig. 8], the mannequin 3 to be obtained has the shape of a hand. Consequently, the first negative mold 9 has an imprint of the shape of the palmar face - or anterior face of the hand - while the second negative mold 11 has an imprint of the shape of the dorsal face - or posterior face of the hand. The relief of the positive mold 13 has 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 has been previously manufactured.

[0098] As mentioned previously, the mannequin 3 does not necessarily have the external shape of a body part, in which case the anterior face and the posterior face 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] on which the first negative mold 9 and the positive mold 13 are fitted together. The second negative mold 11 is left aside for the moment.

[0101] In 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 curing (for example, a vulcanization-type polymerization) of the silicone. The impression of the first negative mold 9 is then filled with silicone. Furthermore, the outer surface of the silicone, i.e., the surface which is not in direct contact with the first negative mold 9, has an impression formed and left by the positive mold 13.

[0103] During operation 740, the product 5 is placed in the impression 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 external surface of the silicone whose imprint receives the product 5 and, on the other hand, by the imprint 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 there.

[0108] Finally, during operation 770, the first negative mold 9 and the second negative mold 11 are removed after hardening (for example, a vulcanization-type polymerization) of the silicone. The medical phantom 1 is then obtained, comprising the mannequin 3 within which the product 5 is arranged.

[0109] In the above, the medical phantom 1 is presented as an ultrasound and radiography training tool 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 a part of the human skeleton and possibly by the shape of the mannequin 3. However, the 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 vertebrate sub-phylum and thus be intended for a veterinarian.

Claims

Claims

1. Medical phantom (1) comprising a silicone mannequin (3) within which is arranged a product (5) for imitation of at least one bone, said medical phantom (1) being characterized in that the product (5) is formed from a polymer doped with a radiopaque agent according to: - a first composition in which the polymer is polylactic acid, the radiopaque 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 radiopaque 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 the 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 the polylactic acid is doped with the 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 the polylactic acid is doped with the 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 of 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 Pl i.

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 the MD type.

11. Method for manufacturing a medical phantom (1) according to 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 imprint of the shape of a front face of the mannequin (3) to be obtained and a positive mold (13) comprising a relief of the shape of the product (5), - pour (720) silicone between the first negative mold (9) and the positive mold (13), - removing (730) the positive mold (13) after hardening of the silicone, said positive mold (13) leaving an imprint of the shape of the product (5) in the silicone, - placing (740) the product (5) in the first negative mold (9) in the imprint left by the positive mold (13), - superimposing (750) the first negative mold (9) and a second negative mold (11) comprising an imprint of the shape of a posterior 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 hardening of the silicone to obtain the mannequin (3) within which the product (5) is arranged.

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

13. Method according to claim 11, characterized in that the product (5) is manufactured by casting the second composition in liquid form into an impression of a mold.

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