DEVICE FOR ASSURED MANUAL INJECTION FOR INJECTING A COMPOSITION STORED IN A CONTAINER

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a manual assisted injection device for injecting a composition contained in a container. STATE OF THE ART

[0002] Pre-filled injection devices are containers commonly used for injecting pharmaceutical or cosmetic compositions, and include syringes, cartridges, and auto-injectors. These containers typically include a sealing piston capable of translational movement within the container, the container being filled with a pharmaceutical or cosmetic composition to provide healthcare operators with ready-to-use injection devices for treating patients.

[0003] A container has a cylindrical shape, and comprises an open proximal end through which the plunger can be inserted in order to seal an internal volume of the container containing the composition to be injected, a distal end usually provided with a needle through which the composition is injected, and a lateral surface which extends between the proximal end and the distal end of the container. In practice, the plunger is able to move following a mechanical force exerted on it by a piston rod movable in translation in the container, from the proximal end of the container towards its distal end, in order to inject the composition. Such standard pre-filled containers in the medical industry are, for example, pre-filled syringes (in English, acronym PFS) with or without a needle attached to its distal end, as well as cartridges.The cartridges also have a septum which will be pierced by a needle at their distal end for injection.

[0004] Compared to empty injection devices that are filled just before injection with compositions previously stored in vials, the use of pre-filled injection devices has several advantages. In particular, by limiting the preparation steps before injection, pre-filled injection devices are simpler to use, improve asepsis, and help reduce dosing errors. Pre-filled injection devices encourage and simplify the administration or self-administration of the composition, which reduces the cost of care and facilitates treatment. Finally, pre-filled injection devices reduce the loss of pharmaceutical or cosmetic composition that can occur when the composition is transferred from a storage vial into a non-pre-filled injection device. This results in reduced purchasing and supply chain costs.

[0005] In some cases, injecting the composition contained in the container with a manual injection device, such as a syringe, may be difficult to perform, due to the force that must be exerted on the plunger rod to expel the composition from the container. This occurs, for example, when a small diameter needle, a determined volume to be injected in a given time and certain rheological characteristics of the composition such as a high viscosity are combined, and / or when the injection is performed manually by a user who is unable to press the plunger rod hard enough with his fingers.

[0006] Thus, for the manual injection of gels, cements, suspensions and other highly viscous products, the operator must exert a great deal of force on the plunger of the injection syringe to ensure the material passes into a needle. This results in: an injection speed which decreases when the needle diameter is reduced, for example when injecting wrinkle filler gels or joint viscosupplementation, significant muscular fatigue, or even a limitation in the number of procedures which can be carried out successively by the same operator, a reduction in precision or trembling in the performance of additional procedures which the operator must perform while carrying out the injection, which can influence the placement, depth, or movement of the needle in the injection tissues.

[0007] For manual injection devices, manufacturers have added gripping surfaces or parts to the injection devices, such as large flanges against which the index and middle fingers or thumb can rest when the device is held in a three-fingered manner, with the thumb pressing against the proximal end of the plunger rod to push the plunger rod distally to inject the composition. Also added are passive attachments into which the syringe is slid.

[0008] Gripping surfaces and parts only address ease of gripping, i.e., ergonomics, or the mechanical ability to exert great force by increasing the gripping surface. However, issues related to the maximum force that the hand can exert, muscle fatigue, or muscle tremors resulting from muscle contraction of the hand are not addressed.

[0009] Force multiplication devices have also been developed.

[0010] However, in these force-multiplying devices, the force that the user must apply to perform the injection is reduced, but the variation in injection muscle contraction with the resumption of travel (releasing the injection means, generally a trigger, which returns to its origin, then resuming support) requires delicate coordination during an injection with progressive movement of the needle, for example the injection of a wrinkle-filling gel or bone cement, and induces a parasitic movement of the hand which can lead to a possible injury to the patient by the needle.

[0011] Documents US 6,159,161 A, WO 2011 / 113806 A1 and WO 2017 / 201185 A1 describe injection devices. STATEMENT OF THE INVENTION

[0012] The invention therefore aims to remedy the drawbacks of the prior art.

[0013] To this end, the present invention relates to a manual-assisted injection device for injecting a composition contained in a container, in which the container is provided at its distal end with a needle and contains a piston, the injection device comprising: a body comprising at least one gripping area by which the body can be held by a user, a container holding element configured to receive and hold the container fixedly relative to the body, an electromechanical system comprising: a piston rod capable of moving in translation in the container relative to the body of the device in order to move the piston, a system for actuating the piston rod, a processor capable of communicating with the actuating system, the device being mainly characterized in that it comprises at least one force sensor positioned on the body at a gripping area, the force sensor being configured to receive as input a mechanical force exerted on said sensor by the user during the injection of the composition, and to transmit to the processor an output signal which is a function of said mechanical force, and the processor is configured to send an instruction to the actuation system as a function of the output signal of the sensor to actuate the piston rod according to a predetermined control law, in order to adjust the mechanical force to be exerted by the user on the piston rod to inject the composition.

[0014] According to other aspects, the injection device has the following different characteristics taken alone or according to their technically possible combinations: the actuation system comprises a force multiplication system configured to provide the piston rod with a mechanical force F2 which is a multiple of the force F1 exerted by the user on the sensor, and in which the control law is a force multiplication law; the control law defines a movement of the piston rod in a proximal direction by a predetermined distance D1 when the injection is interrupted and the mechanical force F1 exerted by the user on the sensor is less than a determined threshold value F1ad for a determined duration Δt1;the piston rod has a starting position, and the control law defines a movement of the piston rod in a proximal direction by a predetermined distance D2 when the injection is finished and the mechanical force F1 exerted by the user on the sensor is less than a threshold value F1ad determined for a determined duration Δt2 or when the piston rod is at the end of its distal stroke; the needle being positioned in a subcutaneous area of ​​the human body, the control law defines a movement of the piston rod in a proximal direction by a predetermined distance D3 in order to carry out a calibrated aspiration of a determined volume of a human fluid, in order to detect the possible presence of blood in the needle; the injection device further comprises a selective activation means allowing the user to selectively activate or deactivate the control of the piston rod by the processor via the control law;the selective activation means comprises an adjustment means allowing the user to choose a trigger threshold F1s, so that the control of the piston rod by the processor via the control law is triggered only when the force exerted by the user on the sensor is greater than or equal to the trigger threshold F1s; the body of the injection device comprises at least two gripping zones on a distal surface of the body of the device, at least one of the gripping zones being provided with a sensor and being able to receive the pressure of the index finger, the middle finger, the ring finger, or the little finger of the user, and the piston rod comprises a proximal end comprising a gripping zone, said gripping zone being provided with a sensor and being able to receive the pressure of the thumb of the user, to allow the syringe-type device to be held;the gripping area of ​​the piston rod is positioned on a trigger secured to the piston rod and which extends obliquely or perpendicularly to the piston rod from a distal position relative to the proximal end of said piston rod; the injection device comprises at least three gripping areas arranged on the body of the device around a longitudinal axis of the device, at least one of the gripping areas being provided with a sensor, said gripping areas being able to receive respectively the support of the index finger, the middle finger, or the thumb of the user to allow the pen-type device to be held;the container holding element comprises a pivoting hood provided with an orifice capable of receiving at least the proximal end of the container, the pivoting hood being capable of pivoting between an injection position in which the orifice is aligned with the stroke of the piston rod, and a free position in which the orifice is offset relative to the stroke of the piston rod and accessible by the user to allow insertion of the container into said orifice; the container holding element further comprises a plurality of interchangeable rings provided with orifices of different diameters adapted to receive corresponding containers of different diameters;the pivoting hood is made of several parts, including at least a first part integral with the body of the device, and at least a second movable part capable of pivoting between the injection position and the free position, the two parts of the pivoting hood thus forming a clamp with variable spacing making it possible to accommodate and grip the container in order to keep it in a fixed position; the second movable part is capable of being detached from the body of the device; the second movable part is color-coded to be identifiable by the user or is provided with an electronic recognition and reading device to indicate to the processor the geometric or rheological characteristics of the container and its contents so that the recognition device can automatically calculate the dose of composition delivered for a unitary movement of the piston rod;the electromechanical system comprises a memory in which control laws and / or threshold values ​​are recorded; the injection device further comprises a user interface allowing the user to record and select the operating parameters of the device, and to have feedback from the device on said operating parameters when using the device.; DESCRIPTION OF FIGURES

[0015] Other advantages and characteristics of the invention will appear on reading the following description given by way of illustrative and non-limiting example, with reference to the following appended figures: there figure 1 represents a perspective view from the front of a device for assisted manual injection according to an embodiment of the invention, as well as a container containing a composition to be injected intended to be fixedly mounted on the injection device, the figure 2 represents a perspective view of the injection device of the figure 1 , the container being fixedly mounted on the injection device; the figure 3 represents a side sectional view of the injection device of the figure 2 ; there Figure 4A represents a side sectional view, centered on an adapter ring allowing a small diameter container to be fixedly mounted on the injection device; the Figure 4B represents a side sectional view similar to the Figure 4A , wherein the adapter ring is removed to allow a large diameter container to be mounted on the injection device; the Figure 5 represents a side view of the injection device according to one embodiment, which illustrates the grip of the device according to a tridactyl (three fingers) “syringe” type grip; figure 6represents a side view of the injection device according to one embodiment, which illustrates the grip of the device in a pentadactyl (five finger) “syringe” type grip; figure 7 represents a side view of the injection device according to one embodiment, which illustrates the grip of the device in a three-finger, “pen” type grip; Figure 8A is a side sectional view of the injection device, which illustrates a step of placing the container on the injection device; the Figure 8B is a side sectional view of the injection device, which illustrates a step of docking the piston by the piston rod; the Figure 8C is a side sectional view of the injection device, which illustrates the position of the injection device at mid-stroke of the piston rod; Figure 8Dis a side sectional view of the injection device, which illustrates the situation of the injection device at the end of injection, the piston rod being at the end of its stroke; the Figure 8E is a side sectional view of the injection device, which illustrates a step of withdrawing the piston rod at the end of injection in order to remove the container from the injection device; Figure 9A is a graph which illustrates a first example of a control law, showing respectively the evolution of the force F2 applied by the actuation system on the piston rod and the speed V of the piston rod, as a function of the force F1 applied by the user on a sensor of the injection device; Figure 9B is a graph which illustrates a first embodiment of a second example of control law; the Figure 9C is a graph which illustrates a second embodiment of a second example of a control law; the Figure 9Dis a graph that illustrates a third example of a control law; the Figure 9E is a graph that illustrates a fourth and a fifth example of control law; the figure 10 is a graph which illustrates the evolution of the axial position of the piston rod along the injection axis of the device as a function of time, during an injection of the composition. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0016] The invention relates to a manual assisted injection device, which makes it possible to inject a composition contained in a container. Container

[0017] The container 40, which may also be referred to as a “primary container,” comprises a body 41 delimited by a lateral surface 42 which extends along a longitudinal axis A between a proximal end 43 and a distal end 44 of the body, and defines a chamber capable of containing a composition to be injected. The container preferably comprises a tip 45 on which a needle 46 is fixed. It is preferably a pre-filled type container, i.e. filled, capped with a plunger 50, and packaged before its subsequent use for injection. Alternatively, the container may be initially empty, then filled and capped just before injection. This latter alternative is particularly advantageous when the composition to be injected is obtained by mixing different components, for example during the manufacture of a bone cement to be injected.After filling the container with the composition to be injected, the piston 50 is inserted from the proximal end 43 of the container and separates the composition from the external environment. The container is then fixedly mounted on the injection device of the invention.

[0018] The piston is in contact with the composition to be injected, and is configured to be moved by the injection device, in a translational movement along the longitudinal axis A of the container in the distal direction, in order to inject the composition. This aspect will be explained in more detail later in this text. Injection device - general structure

[0019] THE Figures 1 and 2 illustrate an embodiment of the injection device 1 according to the invention.

[0020] In reference to the Figures 1 and 2, the injection device 1 comprises a body 2 and a piston rod 3 provided with a head 3a at its distal end which extends along an axis B which coincides with the axis A of the container 40 when the latter is mounted on the body of the device. The piston rod 3 preferably comprises a thread functioning as a worm screw.

[0021] The device 1 also includes a container holding system configured to receive and hold the container fixedly relative to the body of the device. The container 1 is removably mounted on the holding system. Thus, the user can change the container for the different injections that he needs to perform.

[0022] On the device shown in the figure 1, the holding system comprises a cover 4 at the distal portion 14 of the body of the device, said cover delimiting an orifice 7 and being provided with a fixing ring 5 integral with the cover or separable from said cover. The fixing ring 5 forms a protrusion 6 which extends distally from the distal surface 14 of the body, and which extends the orifice 7.

[0023] The proximal end 43 of the container is inserted into the orifice 7, the diameter and geometry of which are adapted for this purpose and for retaining the container on the device during its use. For example, as illustrated in figure 3, the orifice may have a first portion 8 whose diameter is slightly greater than the diameter of the body of the container, and a second portion 9 which has a shoulder whose diameter is greater than that of the first portion of the orifice and which is capable of receiving the collar 43 of the container, such a collar being typically present when the container is a syringe as in the figure 1 . Thus, when the syringe is inserted into the orifice and passes through the orifice, the body of the syringe is positioned in the first portion 8 of the orifice and the collar is positioned in the shoulder 9. The syringe is then blocked in translation along the axis B.

[0024] The fixing ring 5 is adjusted according to the dimensions of the containers 40 to be mounted therein. For example, on the Figure 4A , the fixing ring 5 includes an orifice 7 suitable for inserting a small diameter syringe. On the Figure 4B, the fixing ring is absent, the hole being adapted to insert a large diameter syringe.

[0025] According to a preferred embodiment, the cover 4 is pivotable. One of the ends of the cover is pivotally mounted on the body of the device along an axis C parallel to the axis B, so that the cover extends perpendicular to the axis B.

[0026] The cover 4 is movable in rotation around the axis C, between an injection position in which the orifice of the ring is aligned with the axis B, and a free position in which the orifice of the ring is offset relative to the axis B.

[0027] In the free position, the orifice 7 is accessible to the user who can then position the container in the orifice by sliding the ring along it. The user then folds the cover towards the body of the device, until it reaches the injection position.

[0028] According to a variant of the previous embodiment, the pivoting cover 4 is made in several parts, including at least a first part 10 integral with the body of the device, and at least a second part 11 movable in rotation relative to the first part along the axis of rotation C. The two parts of the holding system thus form a clamp, the spacing of which is variable, making it possible to accommodate and grip the container in order to keep it fixed during injection.

[0029] According to this same variant, the second part 11 of the holding system is interchangeable in order to adapt to containers of different dimensions by simply exchanging this second part by the user with another whose orifice has dimensions adapted to the container. This second interchangeable part can also be color coded to be easily identifiable by the user or provided with an electronic recognition and reading device to indicate to the device the geometric or rheological characteristics of the container and its contents so that the recognition device can automatically calculate the dose of composition delivered for a unitary displacement of the piston rod as well as other characteristics to quickly select the control law.

[0030] The body 2 of the injection device is configured to be held by the user.

[0031] To this end, the body 2 of the device comprises one or more gripping zones 12a, 12b, 12c at which the user can position his fingers in order to hold the device securely in his hand while preventing it from slipping out of his hands.

[0032] Each gripping area 12a is preferably in the form of a surface against which one or more fingers of the operator rest. The gripping areas may alternatively comprise a recess 13 into which the user can insert his finger in order to make the grip more secure. In the latter case, the user's finger rests against the internal surface of the recess.

[0033] In reference to the figures 1, 2 , And 3, the body of the device comprises two gripping zones 12a, 12b located on the distal surface 14 of the body, and a gripping zone 12c which constitutes the proximal bearing surface of the piston rod 3. The arrangement of these three bearing surfaces according to the embodiment of the figure 1 defines a grip of the device called “syringe type”, in that it mimics the usual three-finger grip of a syringe: the thumb, index finger, and middle finger.

[0034] According to the syringe-type grip, the user positions his index finger on the first gripping zone 12a on the distal surface 14 of the body, and positions his middle finger and possibly his ring finger on the second gripping zone 12b. The user positions his thumb on the third gripping zone 12c constituting the support zone of the piston rod 3. The index finger and the middle finger are thus arranged on either side of the axis B.

[0035] The syringe-type grip offers the advantage of being familiar to the user in terms of ergonomics and sensations, whether the user is a medical professional or a patient. In addition, it provides a good perception of the movement of the plunger rod via the thumb, and therefore of the dose injected during the injection. It allows the user to easily adjust the injection speed by varying the force exerted by his thumb on the support area of ​​the plunger rod and concomitantly on the other fingers in opposite support.

[0036] THE figures 5 And 6 illustrate two embodiments of the injection device 1 according to the invention, allowing a syringe-type grip.

[0037] On the Figure 5 , the grip is tridactyl in that it involves three of the user's fingers, and syringe-like, similar to the device of the figures 1, 2 , And 3The index finger is positioned on the first gripping zone 12a of the body 2, the middle finger is positioned on the second gripping zone 12b of the body, and the thumb is positioned on the third gripping zone 12c constituting the support zone of the piston rod 3.

[0038] On the figure 6, the grip is a variation of the syringe type, and pentadactyl in that it involves five fingers of the user. The index finger, the middle finger, the ring finger, and the little finger are all positioned on respective gripping zones 12a, 12b, 12d, 12e, located on the distal surface 14 of the body. These four fingers are thus arranged on either side of the axis B. The thumb is always placed in opposition to the other four fingers, but it is positioned resting on a trigger 15 secured to the piston rod 3, which extends obliquely or perpendicularly from said piston rod. The force applied by the user to the gripping zone 12c of the trigger is therefore applied to the piston rod 3. According to this embodiment, the relative gripping zone 12c associated with the thumb is offset relative to the piston rod 3.This offset makes it possible to reduce the distance between the thumb and the other four fingers compared to a positioning of the third gripping zone at the end of the piston rod, while maintaining the force applied by the user via his thumb, and concomitantly via the other fingers in opposite support, to the piston rod. This results in a reduction of muscular fatigue of the hand linked to maintaining the hand on the body of the device.

[0039] Another possible grip of the injection device 1 according to the invention is the so-called “pen-type” grip, in that it mimics the usual grip of a writing pen. This grip is illustrated in the figure 7 .

[0040] According to the most common pen-type grip, the user positions his index finger, middle finger, and thumb on three respective gripping zones 12a, 12b, 12c located around the body of the device, preferably on a distal portion of said body. The first 12a and the second gripping zone 12b, configured to receive the index finger and middle finger, are located substantially in the same axial position along the longitudinal axis of the body. The third gripping zone 12c, configured to receive the thumb, is located proximally relative to the first 12a and the second gripping zone 12b. The index finger, middle finger, and thumb are thus arranged around the axis B.

[0041] On the figure 7 , the pen-like grip shown is tridactyl. The ring and middle fingers are not used.

[0042] The pen-type grip offers the advantage of allowing a firm and secure grip on the injection device, since the index finger, middle finger and thumb all exert a force substantially perpendicular to the longitudinal axis A and oriented towards the body of the device. In addition, with this type of grip, the hand is closer to the end of the needle, which improves precision during injection, although it does not allow the movement of the plunger rod to be directly returned to the user.

[0043] The handling of the device according to the invention is however not limited to the syringe and pen type handlings described above or their combinations, so that the device can be produced and handled differently from these two particular handlings. Sensors

[0044] The device according to the invention comprises at least one force sensor 16a, 16b, 16c which makes it possible to know the force, also called "effort", exerted by the user to carry out the injection. The force sensor can be static or dynamic.

[0045] A static force sensor measures the actual force exerted by the user. It may require calibration to calibrate the signal corresponding to a force considered to be zero by the sensor, the value of the force actually exerted by the user on the sensor may be zero or non-zero.

[0046] A dynamic force sensor measures changes in force. If a force applied to the sensor is kept constant for a set period of time, the sensor considers that no more force is being applied. Therefore, it is necessary to carefully choose the time period based on the intended use. An advantage of this type of sensor is that it self-calibrates at rest.

[0047] The force sensor 16a, 16b, 16c is configured to receive as input a force exerted by the user on said sensor. This sensor makes it possible, via an electromechanical control system, to control an actuator according to a control law chosen as a function of objectives specific to the injection of the composition.

[0048] The force sensor 16a, 16b, 16c is positioned in a gripping area of ​​the body of the injection device. In this way, the force sensor is directly accessible to the user, since he uses his fingers both for gripping the device and for stressing the sensor, and does not need to use other fingers or his other hand to stress the sensor. The sensor(s) are positioned in the different gripping areas depending on the type of gripping of the device, in order to optimize the ergonomics of the device.

[0049] In reference to the figures 1, 2 , And 3 , the injection device 1 comprises up to three sensors 16a, 16b, 16c positioned so as to allow operation of the device according to the syringe-type grip. Thus, a first sensor 16a is located in the first gripping area 12a on the distal surface 14 of the body, a second sensor 16b is located in the second gripping area 12b on the distal surface of the body, and a third sensor 16c is located on the proximal bearing area 12c of the piston rod 3.

[0050] Alternatively, the device may comprise only one or two of the three aforementioned sensors.

[0051] According to a preferred embodiment, the device 1 comprises at least the third sensor 16c located on the proximal support zone 12c of the piston rod 3. This embodiment offers the advantage that the force exerted by the user on the sensor is independent of the distribution of the force exerted on the other fingers at the distal end of the device. The force exerted by the user on the sensor is directed in the same direction as the movement of the piston rod during the injection, i.e. a translation along the B axis in the distal direction. This allows the user to have tactile feedback on the force exerted on the sensor as a function of the resulting movement of the piston rod 3 throughout the injection, as well as on the dose injected via the movement of the piston rod, which thus improves the precision of the injection.

[0052] Obviously, the device 1 may comprise only the first 16a and / or the second sensor 16b on the distal surface 14 of the body. In this case, the force exerted on the sensor is parallel to the movement of the piston rod 3, but oriented in the opposite direction, i.e. in a proximal direction. This embodiment also provides feedback to the operator, but is however less intuitive.

[0053] Depending on the method of implementation of the figure 6 , illustrating the syringe-type pentadactyl grip, the injection device 1 comprises up to five sensors 16a, 16b, 16c, 16d, 16e. Thus, a sensor 16a is located in one of the four gripping areas 12a, 12b 12d, 12e on the distal surface of the body, and a sensor 16c is located in the fifth gripping area 12c of the trigger 15.

[0054] Still according to the figure 6, the device may comprise one sensor 16a per gripping zone 12a, for a total of five sensors, or fewer sensors than gripping zones, for example only one, two, or three sensors on the distal face 14 of the body of the device and / or one sensor on the trigger 15.

[0055] In reference to the figure 7 , the device may comprise up to three sensors 16a, 16b, 16c positioned so as to enable operation of the device according to the pen-type grip. Thus, a first sensor 16a, a second sensor 16b, and a third sensor 16c are located respectively in the first gripping area 12a, the second gripping area 12b, and the third gripping area 12c, on a distal portion of the body of the device.

[0056] When the device 1 is designed to operate according to the pen-type grip, the presence of the three sensors 16a, 16b, 16c allows the device to receive as input three forces of close intensities directed radially towards the body of the device. This facilitates the use of the device by improving the balance of the body in the user's hand during the injection, which thus greatly improves the accuracy of the injection.

[0057] The injection device 1 further comprises an electromechanical system, the latter comprising the piston rod 3, an actuation system 17 of the piston rod, and a processor 18. These different elements are particularly visible on the figure 3 .

[0058] The injection device includes an ON / OFF switch 19 allowing it to be started or stopped.

[0059] The injection device may comprise an on-board electrical energy source 20 for the operation of the electromechanical system, such as a battery or electric cells, and thus operates autonomously. Alternatively, the injection device may be provided with an electrical cable allowing it to be connected to an external electrical energy source, which makes it possible to make the device lighter and reduce its size.

[0060] The electromechanical system comprises an electric motor 21 and a mechanical reducer 22 for reducing the rotational speed of the motor. Such a reducer is known per se and conventionally comprises gears 23, the latter being arranged near the distal surface 14 of the body of the device of the figure 3 .

[0061] The processor 18 is configured to receive as input a measurement signal from the sensor(s) 16a, i.e. a signal representing a force value exerted by the user on each sensor, and to provide as output an instruction for the actuation system 17, which is a function of the signal from the sensor.

[0062] From the instruction of the processor 18, the actuation system converts the value of the force measured by the sensor 16a (“input force” or “input force”) into a force (or a speed) applied by the piston rod 3 (“output force” or “output force”) when using the device, in particular in order to inject the composition which is in the container 40.

[0063] The more sensors 16a, 16b, 16c there are, the greater the amount of input information, and the more precisely the output force is determined from the input force, by means of the control law.

[0064] The output force may in particular be a torque. Indeed, depending on the embodiment of the device illustrated in the figures 1, 2 , And 3 , the piston rod 3 comprises a thread engaged on a thread or a ball nut carried on the axis of a gear, thus functioning as a worm screw. Thus, the torque transmitted to the gear makes it possible to drive in translation said piston rod which is locked in rotation. The rotational movement of the gear being converted into a corresponding displacement in translation of the piston rod along the axis B by the thread or the ball nut of the drive gear.

[0065] The instruction sent by the processor 18 to the actuation system 17 is a function of a control law programmed and recorded in the processor. The control of the piston rod 3 via the control law can be done in force or in speed. When the control is done in speed, the processor 18 receives as input the force signal from the sensor 16a and provides an output signal to the actuation system 17 to control said actuation system according to a certain speed according to the input signal.

[0066] The processor 18 is advantageously provided with a memory in which control laws and other operating parameters of the device can be recorded.

[0067] For example, in order to neutralize the efforts which are necessary for gripping the device without carrying out an injection, the input force can be corrected by a determined threshold, as well as in linearity, to take into account the rheological properties of the injected composition and the needle used, or the sensitivity sought by the user in particular in the working area relevant to the use.

[0068] The control law may include different operating processes to realize different corresponding functions.

[0069] The injection device 1 preferably comprises a programming connector 24 for connecting the injection device to an electronic device from which the user can configure the injection device. Such an electronic device may be, for example, a computer, an electronic tablet, or a mobile phone. Via the programming connector 24, the user can in particular import control laws into the memory of the device, configure control laws according to the desired use, and operate various adjustments to the components of the injection device.

[0070] The injection device 1 is advantageously provided with a selection means 25, such as an actuable button, making it possible to select a control law from among those which are recorded in the memory, so that it is implemented when the device is used.

[0071] The injection device 1 is advantageously provided with an adjustment means, such as an actuable button, making it possible to adjust the threshold F1s for triggering the assistance by control law, i.e. the value of the input force from which the triggering of the selected control law takes place. Thus, as long as the input force is lower than the trigger threshold F1s, the assistance by control law is not triggered. The value of the input force corresponds to the value of the output force. When the input force becomes greater than or equal to the trigger threshold F1s, the assistance by control law is triggered and assists the user in using the device. In order to simplify the use of the device, a single means 25 can make it possible both to adjust the threshold F1s for triggering the assistance and to select a control law, as is the case for the device illustrated in the figures 1, 2 , And 3 .

[0072] The injection device 1 may be provided with a user interface, comprising a screen 26 as illustrated in the figure 7. This interface allows the user to record and select the operating parameters of the device, for example the control laws, the type of container used, or the volume and type of composition to be injected, and to have feedback from the device, in particular visual via the screen, on said operating parameters when using the device. The user can also choose and / or be informed of the control laws recorded in the memory, the currently selected control law, the assistance trigger threshold, the battery charge indicator, the volume of composition injected since the device was last switched on, or since the last composition injection, or since the last selected control law.Other parameters, including variable information in a time interval of the order of the duration of an injection (a few seconds to a few minutes) can also be provided to the user via the interface, such as the input force, the output force, and the speed of the piston rod, i.e. the injection speed. Operating method

[0073] The operation of the injection device 1 will now be described with reference to the figure 2 and to the Figures 8A-E , to illustrate the injection of a composition contained in a PFS type container 40.

[0074] In reference to the figure 2 , the syringe 40 is mounted on the injection device 1. The pivoting hood 4 is open, that is to say that the second part 11 of the hood is moved away from the first part 10. The syringe 40 is moved perpendicular to the axis B, so as to insert the collar 43 into the shoulder 9 of the fixing ring 5.

[0075] The second part 11 of the cover is then joined with the first part 10, in order to enclose the proximal part of the syringe 40 and to hold said syringe fixedly and in alignment with the stroke of the piston rod. The injection device is then as shown in the Figure 8A .

[0076] The gripping area 12c of the piston rod 3 is in contact with a proximal stop element 27 which delimits the proximal end of travel of the piston rod. In other words, the piston rod 3 cannot be in a position more proximal than that of the Figure 8A This position, called the “starting position”, is detected by the processor 18.

[0077] In reference to the Figure 8B, the electromechanical system preferably initiates an automated step of docking the piston 50 by the piston rod 3. The piston rod therefore moves automatically, without user intervention on the piston rod, in the distal direction until it comes to bear against the piston 50.

[0078] At the end of the docking step, the distal end or head 3a of the piston rod 3 is inserted into the piston 50, the latter being advantageously provided with a recess 51 whose shape corresponds to that of the distal end 3a of the piston rod in order to ensure better contact between the piston rod and the piston, which improves the precision of the injection. In addition, the gripping zone 12c of the piston rod is at a determined distance from the proximal stop element 27. This distance is detected by the processor. The piston rod is then in a position called the “starting position”, and ready to be actuated.

[0079] The user can then proceed to inject the composition, by exerting a force on one or more sensors 16a, 16b, 16c of the device. Figure 8C illustrates the situation at the distal mid-stroke of the piston rod.

[0080] The piston rod 3 moves distally into the container 40, carrying with it the piston 50, as the composition is injected. Figure 8D illustrates the situation at the end of the distal stroke of the piston rod. All the composition has been injected, and the piston 50 is in abutment against the distal end of the container.

[0081] In reference to the Figure 8E, the electromechanical system preferably initiates an automated step of undocking the piston rod 3. The piston rod therefore moves automatically, without user intervention on the piston rod, in the proximal direction until the gripping zone 12c of the piston rod comes into contact with the proximal stop element 27.

[0082] The plunger rod is located outside the container, which can then be removed from the device's holding system. The user can then load a new container and perform another injection or stop the device. Example of control laws

[0083] Examples of operating processes corresponding to control laws will now be described according to several embodiments. The embodiments can be combined with each other, so that the device can be configured to operate according to one or more of the described operating processes. Simple law

[0084] According to a first example illustrated on the Figure 9A , the control law is a simple injection law according to which the output force F2 is substantially proportional to the input force F1.

[0085] Since the injection device according to the invention is also speed-controllable, the speed provided by the output actuation system is measured on the ordinate, in parallel with the output force F2. The observations made with regard to the output force F2 and the output speed F2 are the same.

[0086] The output force F2 remains zero until the input force F1 exerted by the user on the sensor(s) reaches the trigger threshold F1s from which the control law assistance is triggered. The output force F2 then increases with the input force F1.

[0087] On the Figure 9A , the increase of F2 with F1 is represented by a straight line and corresponds to a linear function. This representation is simplified. In practice, the device behavior depends in particular on the type of syringe, the filling rate of the syringe, and the viscosity of the composition, so that the increase of F2 with F1 is rather translated by a curve.

[0088] The output force F2 increases up to a ceiling F2max when the input force reaches F1ℓ. This value F2max is recorded in the memory of the injection device, particularly during its manufacture, and makes it possible to avoid any risk of explosion of the syringe or untimely ejection of the needle due to an output force F2 that is too high. Multiplication of effort

[0089] According to a second example, the control law comprises a force multiplication process. According to this process, the output force F2 (respectively the output speed) of the actuation system is increased mainly according to a multiple of the value of the input force F1.

[0090] For this purpose, the actuation system 17 comprises a force multiplication system configured to provide an output force F2 for the actuation of the piston rod 3 which is a multiple of the value of the force F1 received as input by the processor 18.

[0091] There Figure 9B illustrates a first embodiment of a force multiplication control law. The output force F2 remains zero until the input force F1 exerted by the user on the sensor(s) 16a, 16b, 16c reaches the trigger threshold F1s from which the control law assistance is triggered. The output force F2 then increases very sharply, asymptotically, then stabilizes at F2max when the input force F1 reaches a ceiling F1ℓ. Injection is therefore greatly facilitated for low values ​​of F1 < F1ℓ. The injection device is very sensitive from only F1s and not very sensitive after the ceiling F1ℓ.

[0092] There Figure 9Cillustrates a second embodiment of a force multiplication control law. The output force F2 remains zero until the input force F1 exerted by the user on the sensor(s) 16a, 16b, 16c reaches the trigger threshold F1s from which the control law assistance is triggered. The output force F2 then increases gently then sharply, until stabilizing at F2max when the input force F1 reaches the ceiling F1ℓ. The triggering of the assistance is therefore more gradual than for the first embodiment by offering a wide range of sensitivity in the middle of the operating range. Anti-drip device

[0093] In state-of-the-art injection devices, the internal pressure in the container and the deformation in the piston rod actuation system during the injection of viscous products result in a residual injection of the composition after the operator has stopped pressing the syringe piston rod, by a mechanism for releasing the accumulated internal pressure. This excess injected composition, which is not desired, is problematic in the case where a very precise dose of composition is required or the user wishes to move the needle quickly while it is important not to deposit any parasitic material when withdrawing the needle, as is the case with certain rapidly polymerizing bone cements used in vertebroplasty and which must not be deposited outside the treated vertebra.

[0094] In order to overcome this drawback, according to a third example, the control law comprises a process which makes it possible to operate a reverse return of the piston rod 3, that is to say a movement of the piston rod in the proximal direction relative to the body 2 of the device by a determined distance, when the user wishes to stop the injection, either definitively for example when all the composition has been injected and the piston rod 3 is at the end of its travel, or punctually for example when the operator carries out a series of injections by marking a stop time between two consecutive injections.

[0095] This process thus makes it possible to remove any excess composition, and thus to inject a precise dose of composition into chosen locations, without smudging.

[0096] When the injection is interrupted, momentarily or permanently, the force F1 exerted by the user on the sensor 16a, 16b, 16c decreases below a determined withdrawal threshold F1ad, equal to or lower than the activation threshold F1s, without becoming zero. The value of the force F1 of the signal received by the processor 18 from the sensor decreases while the injection device is in operation. In this case, the processor 18 is configured to send an instruction to the actuation system 17 which moves the piston rod 3 in reverse as soon as the input force F1 becomes lower than or equal to the threshold F1ad. The withdrawal threshold F1ad is adjustable depending on the type of injection carried out by the user. When the injection requires very high precision, the threshold F1ad can be high and close to the threshold F1s for triggering the assistance. In this case, a slight release by the user makes it possible to stop the injection and activate the reverse return.On the other hand, when lower accuracy is required, the F1ad threshold can be lower or even zero. In this case, stopping the injection and activating the backflow are only effective when the user completely releases the pressure exerted on the sensor.

[0097] In order to avoid any untimely rollback, a time value is advantageously stored in the processor memory so that the rollback is only carried out when the time interval Δt elapsed from the end of the injection is equal to this time value. The processor is advantageously equipped with a clock programmed to measure the time interval Δt.

[0098] There Figure 9Dillustrates a third example of a control law for an anti-drip process. (a) The output force F2 remains zero until the input force F1 exerted by the user on the sensor(s) 16a, 16b, 16c reaches the trigger threshold F1s from which the control law assistance is triggered; (b) the output force F2 increases as the injection progresses; (c) the output force F2 decreases with the decrease in the input force F1 after injection until it is zero (backward movement along the curve); (d) the output force F2 decreases further and falls below the initial zero value when F1 reaches the value F1ad, which translates into a return of the piston rod in the proximal direction by a predetermined adjustable distance, and the aspiration of the drop.

[0099] The input force F1 is not completely zero, since the user is still holding the device in his hand and therefore exerts a force, even if slight, on the sensor. As long as the input force is between F1ad and F1s, the assistance remains deactivated. Blood detection

[0100] When injecting a composition into irrigated tissue, it is possible for the needle to pierce a blood vessel. State-of-the-art injection devices do not offer any possibility of detecting the penetration of a blood vessel by the needle.

[0101] To overcome this drawback, according to a fourth example, the control law includes a process that allows for calibrated suction to detect the suction of blood by the end of the needle which flows back to the proximal end of the needle. If the user observes that there is no blood sucked, he can continue the injection. Otherwise, he moves the needle into the tissues. The user can trigger the blood detection procedure by a dedicated push button or by using the time information from one of the force sensors, for example through a quick double press.

[0102] There Figure 9Eillustrates a fourth and a fifth example of a control law. These examples reflect the fact that the activation threshold F1s is adjustable (value F1s' or F1s"), in particular depending on the syringe and the use of the injection device. Although this is not shown, the ceiling F1ℓ, the ceiling F2max, as well as the threshold F1 are also adjustable.

[0103] There figure 10 is a graph which illustrates the evolution of the axial position Z of the piston rod along the injection axis of the device as a function of time t, during a series of injections of the same composition. (a) The device is put into operation. The piston rod 3 searches for its starting position and therefore moves in the distal direction until it comes into contact with the proximal stop element 27. On the graph, this results in a decrease in Z as a function of t. The electromechanical system then initiates an automated step of approaching the piston 50 by the piston rod 3. The piston rod therefore automatically moves in the distal direction until it comes into contact with the piston. On the graph, this results in an increase in Z. (b) The device then performs a process of detecting a blood vessel upon user triggering. The calibrated suction and the rearward movement of the piston rod 3 results in a slight decrease in Z. The curve is then flat for a determined duration, which corresponds to a waiting phase during which no force is exerted on the sensor 16a, 16b, 16c.(c) The injection is then carried out. The piston 50 moves in the distal direction following a force exerted by the user on the sensor, and a corresponding dose of composition is injected. Z then increases as a function of t. (d) The device then carries out an anti-drip process. The backflow of the piston rod 3 results in a very small decrease in Z. The series of injections is then continued, each injection (c'), (c"), etc. being preferentially followed by an anti-drip process (d'), (d"), etc. and a waiting phase. (e) At the end of the piston rod's stroke, the device automatically initiates a step of backflow of the piston rod 3 to detach the piston rod from the piston 50. The piston rod therefore moves automatically, without user intervention on the piston rod, in the proximal direction until the gripping zone of the piston rod comes into contact with the proximal stop element 27.

Claims

1. An assisted manual injection device (1) for injecting a composition contained in a container (40), wherein the container (40) is provided with a needle (46) at its distal end, and contains a piston (50), the injection device comprising: - a body (2) comprising at least one gripping zone (12a) by which the body can be held in a user's hand, - a holding element (4) of the container, configured to receive and hold the container (40) in a stationary manner relative to the body, - an electromechanical system comprising: • a piston rod (3) capable of being moved in translation in the container (40) relative to the body (2) of the device in order to move the piston (50), • an actuation system (17) of the piston rod (3), • a processor (18) capable of communicating with the actuation system (17), the device (1) being characterized in that it comprises at least one force sensor (16a) positioned on the body at a gripping zone, the force sensor being configured to receive, as input, a mechanical effort F1 exerted on said sensor (16a) by the user during the injection of the composition, and to transmit to the processor (18) an output signal F2 that depends on the mechanical force, and the processor (18) is configured to send an instruction to the actuation system (17) depending on the output signal from the sensor (16a) in order to actuate the piston rod (3) depending on a predetermined control law, in order to adjust the mechanical effort that needs to be applied by the user to the piston rod (3) in order to inject the composition.

2. The device (1) according to claim 1, wherein the actuation system (17) comprises an effort multiplication system configured to furnish to the piston rod (3) a mechanical effort F2 which is a multiple of the effort F1 exerted by the user on the sensor (16a), and wherein the control law is an effort multiplication law.

3. The device (1) according to claim 1 or claim 2, wherein the control law defines a movement of the piston rod (3) in a proximal direction along a predetermined distance D1 when the injection is interrupted and the mechanical effort F1 exerted by the user on the sensor (16a) is less than a threshold value F1ad determined during a specific duration Δt1.

4. The device (1) according to one of the preceding claims, wherein the piston rod (3) has a starting position, and the control law defines a movement of the piston rod in a proximal direction along a predetermined distance D2 when the injection is terminated and the mechanical effort F1 exerted by the user on the sensor (16a) is less than a threshold value F1ad determined during a specific duration Δt2 or when the piston rod is at the distal end of travel.

5. The device (1) according to one of the preceding claims, wherein the needle (46) being positioned in a subcutaneous zone of the human body, the control law defines a movement of the piston rod (3) in a proximal direction according to a predetermined distance D3 in order to perform a calibrated aspiration of a specific volume of a human fluid, in order to detect the possible presence of blood in the needle.

6. The device (1) according to one of the preceding claims, comprising a selective activation means (25) allowing the user to selectively activate or deactivate the control of the piston rod (3) by the processor (18) via the control law.

7. The device (1) according to claim 6, wherein the selective activation means (25) comprises an adjustment means allowing the user to choose a trigger threshold F1s, in such a way that the control of the piston rod (3) by the processor (18) via the control law is triggered only when the effort F1 exerted by the user on the sensor (16a) is greater than or equal to the trigger threshold F1s.

8. The device (1) according to one of the preceding claims, wherein the body (2) of the injection device comprises at least two gripping zones (12a, 12b) on a distal surface (14) of the body of the device, where at least one of the gripping zones (12a) is provided with a sensor (16a) and is able to receive pressure from the index finger, the middle finger, the ring finger or the little finger of the user, and the piston rod (3a) comprises a proximal end comprising a gripping zone (12c), said gripping zone (12c) being provided with a sensor (16c) and being able to receive the pressure from the user's thumb to allow the device to be held like a syringe.

9. The device (1) according to claim 8, wherein the gripping zone (12c) of the piston rod (3) is positioned on a trigger (15) integral with the piston rod and which extends obliquely or perpendicular to the piston rod from a distal position relative to the proximal end of said piston rod (3).

10. The device (1) according to one of claims 1 to 7, comprising at least three gripping zones (12a, 12b, 12c) arranged on the body (2) of the device around a longitudinal axis (B) of the device, at least one of said gripping zones (12a) being provided with a sensor (16a), said gripping zones (12a, 12b, 12c) being able to receive respectively the pressure from the user's index finger, middle finger, or thumb in order to allow the device to be held like a pen.

11. The device (1) according to one of the preceding claims, wherein the holding element of the container (40) comprises a pivotable cover (4) provided with an orifice (7) capable of receiving at least the proximal end (43) of the container, the pivotable cover (4) being capable of pivoting between an injection position in which the orifice (7) is aligned with the travel path of the piston rod (3), and a free position in which the orifice (7) is offset relative to the travel path of the piston rod (3) and is accessible by the user to allow the insertion of the container (50) into said orifice.

12. The device (1) according to one of the preceding claims, wherein the holding element of the container (40) further comprises a plurality of interchangeable rings (5) provided with orifices (7) of different diameters adapted to receive corresponding containers (40) of different diameters.

13. The device (1) according to claim 12, wherein the pivotable cover (4) is produced in several parts, of which at least a first part (10) is integral with the body (2) of the device, and at least a second movable part (11) capable of pivoting between the injection position and the free position, the two parts (10, 11) of the pivotable cover (4) thus forming a clamp of variable spacing making it possible to receive and clamp the container (40) in order to maintain it in a stationary position.

14. The device (1) according to claim 13, wherein the second movable part (11) is capable of being detached from the body (2) of the device.

15. The device (1) according to claim 14, wherein the second movable part (11) is color-coded to be identifiable by the user or is provided with a recognition and electronic reading device in order to specify to the processor (18) the geometric or rheological characteristics of the container (40) and its contents so that the recognition device can automatically calculate the dose of composition delivered for a unitary movement of the piston rod (3).

16. The device (1) according to one of the preceding claims, wherein the electromechanical system comprises a memory in which control laws and / or threshold values are recorded.

17. The device (1) according to one of the preceding claims, further comprising a user interface (26) allowing the user to record and select the operating parameters of the device, and to have information feedback from the device about said operating parameters during the use of the device.