Improved prosthetic feedback device

Abstract

A prosthetic feedback device (1) is provided, configured to be associated with a prosthesis (10) and comprising a base body (2) having a first end (2a) bound to the prosthesis (10) and a second end (2b) in contact with the user; an acquisition block (3) for detecting first vibrations transmitted by the prosthesis (10) to the base body (2); a vibrator (4) emitting second vibrations via an emission surface in contact with the user; and a unit (5) controlling the vibrator (4) as a function of the first vibrations.

Description

[0001] DESCRI PTION

[0002] IMPROVED PROSTHETIC FEEDBACK DEVICE

[0003] The present invention relates to a prosthetic feedback device of the type specified in the preamble of the first claim.

[0004] In particular, the present invention relates to a device configured to provide the user of a prosthesis with feedback resulting from the interaction of the prosthesis with the external environment. More specifically, the device can be associated with a limb, preferably an upper limb, and more preferably a hand, so as to provide feedback from the interaction, specifically tactile, of the hand with an object or other element of the external environment.

[0005] As is well known, prostheses are used to partially or completely replace a part of the human body lost due to acquired causes, such as a traumatic event or congenital causes, restoring the body image and functionality. They are thus bound to the stump (that is, what remains of a limb after it has lost at least part of it for some reason) and reproduce the amputated part.

[0006] An important example of prostheses are artificial prosthetic hands configured to interact with the external environment and, for example, perform the grasping of an object.

[0007] Currently, many prosthetic hands are underactuated, i.e. , equipped with a number of actuators smaller than the degrees of freedom.

[0008] One example of an underactuated artificial hand provides an actuator per finger, bound to the individual phalanges to control their rotation. The fingers can thus be moved independently of each other. Another example is that of artificial hands wherein a single actuator is provided (or at most two), which, bound to the various phalanges, allows their simultaneous flexion to be controlled. Examples of artificial hands are described in US10912661 B2, WO2023012613A1 , and US10695913B2.

[0009] The described known art has some significant drawbacks.

[0010] In particular, these artificial prostheses (such as actuated or underactuated hands) do not allow the user to receive feedback from the interaction between the prosthesis and the external environment, such as for example those related to grasping, for instance, hardness or softness of the object being held.

[0011] It is obvious that this drawback is particularly relevant in cases of loss due to acquired causes, where due to the persistence of a latent feeling (that is, an image / processing that remains in the brain related to the feeling experienced before the loss) and no longer obtained through the act of grasping the object.

[0012] In this situation, the technical task underlying this invention is to devise a prosthetic feedback device capable of substantially overcoming at least part of the mentioned drawbacks.

[0013] Within the scope of this technical task, an important purpose of the invention is to achieve a prosthetic feedback device, and in particular, a prosthesis capable of providing feedback from the interaction between the prosthesis and the external environment.

[0014] In particular, an important purpose of the invention is to make a prosthetic feedback device capable of communicating or allowing the user to perceive the contact with an external object, reducing issues related to a latent feeling.

[0015] Consequently, an important purpose of the invention is to provide a prosthetic feedback device capable of providing a particularly realistic contact feeling without compromising the usability of the prosthesis and / or its complexity, and hence the cost of the prosthesis. The technical task and the specified aims are achieved by a prosthetic feedback device as claimed in the appended claim 1. Examples of preferred embodiments are described in the dependent claims.

[0016] The features and advantages of the invention are clarified below throughout the detailed description of preferred embodiments of the invention, with reference to Fig 1, which shows, to scale, a prosthesis associated with a prosthetic feedback device according to the invention.

[0017] In this document, measurements, values, shapes, and geometric references (such as perpendicularity and parallelism), when associated with words like "approximately" or other similar terms such as "practically" or "substantially," are to be understood as within measurement errors or inaccuracies due to production and / or manufacturing errors and, above all, to a slight deviation from the value, measurement, shape, or geometric reference to which they are associated. For instance, such terms, if associated with a value, preferably indicate a deviation not exceeding 10% of the value itself.

[0018] Furthermore, when terms such as "first," "second," "upper," "lower," "main," and "secondary" are used, they do not necessarily identify an order, priority of relation, or relative position but may simply be used to more clearly distinguish different components one from the other.

[0019] Unless otherwise indicated, terms such as "perpendicular," "transverse," "parallel," or "normal," or other terms of geometric positioning between geometric elements (for example, axes, directions, and straight lines) are to be understood as referring to their mutual geometric position among their corresponding projections. Said projections are defined on a single plane parallel to the one(s) on which said geometric elements lie. The measurements and data reported in this text are to be considered, unless otherwise indicated, as taken in the ICAO International Standard Atmosphere (ISO 2533:1975).

[0020] Unless otherwise specified, as reflected by the following discussions, terms such as "processing," "computing," "determination," "computation," or similar are considered to refer to the actions and / or processes of a computer or similar electronic computing device that manipulates and / or transforms data represented as physical quantities, such as electronic quantities in the records of a computer system and / or memories, into other data similarly represented as physical quantities within computer systems, records, or other information storage, transmission, or display devices.

[0021] With reference to the Figures, the prosthetic feedback device according to the invention is globally denoted by the number 1.

[0022] The device 1 is configured to provide the user of a prosthesis 10 with feedback resulting from the interaction of the prosthesis 10 with the external environment, and specifically with an object. In particular, it can be identified in at least a portion of a limb (lower or upper) to provide a feedback regarding its interaction with the external environment. Preferably, it is configured to provide a feedback from the interaction of an upper limb with an object and more preferably of a hand identifiable in said prosthesis 10.

[0023] The device 1 is thus configured to be associated with a prosthesis 10.

[0024] In this document, the expression "in use" means that the device 1 is associated with a user, and therefore that a prosthesis 10 is bound to the device 1 , which in turn is bound to the user, appropriately at the stump.

[0025] It defines a longitudinal axis 1a, appropriately barycentric. The device 1 comprises a base body 2 configured to be bound, preferably integrally, to the user (appropriately at the amputated limb) and to the prosthesis 10. It is thus configured to be interposed between the user and the prosthesis 10, at least when in use.

[0026] The base body 2 comprises a first end 2a configured to be integrally bound to the prosthesis 10 and a second end 2b configured to come into contact and, specifically, to be integrally bound to the user, appropriately at the amputated end of a limb.

[0027] The first end 2a defines a first surface configured to contact with the prosthesis 10 and is therefore configured to be integrally bound to said prosthesis.

[0028] The second end 2b is configured to directly contact the user. It defines a second surface configured to contact the user when the device 1 is in use. Preferably, the second end 2b and therefore the second surface may be concave and configured to house, in use, the amputated end of a limb and, in particular, of an arm or forearm. Specifically, the contact surface 2a and specifically the base body 2 may be domeshaped.

[0029] The second end may identify the prosthetic socket, also referred to as a prosthetic socket.

[0030] The device 1 comprises an acquisition block 3 configured to detect and specifically measure first vibrations of the first end 2a transmitted from the prosthesis 10 to the base body 2.

[0031] The acquisition block 3, as described in more detail below, is configured to detect and thus measure the vibrations generated by the interaction of the prosthesis 10 with the external environment and transmitted from the prosthesis 10 to the device 1 via the first end 2a and therefore via the first surface.

[0032] The acquisition block 3 comprises at least one inertial sensor 31 configured to detect and specifically measure one or more first vibrations and is appropriately positioned near the first end 2a and specifically near the first surface.

[0033] Preferably, it comprises multiple inertial sensors 31 angularly spaced apart, appropriately angularly and preferably radially, with respect to the longitudinal axis 1 a. More preferably, it comprises an odd number of inertial sensors 31 , for example five, which are specifically equidistantly spaced apart (angularly and preferably radially) with respect to the longitudinal axis 1 a.

[0034] Said sensors 31 may be distributed along a circumference centered on axis 1 a.

[0035] Each inertial sensor 31 may be located at the first end 2a and thus configured to come directly into contact with the prosthesis 10. It may thus define a detection surface for said first vibrations as part of said first surface.

[0036] Each inertial sensor 31 may be configured to detect and appropriately measure first vibrations along three axes, which are appropriately perpendicular to each other. Each of them detects and defines, for each first vibration, the intensity and magnitude for each of these three axes.

[0037] The sensor 31 may be an accelerometer and thus measures the first accelerations of the first vibrations.

[0038] Each inertial sensor 31 , and thus the acquisition block 3, is bound to the base body 2.

[0039] The device 1 comprises a vibrator 4 configured to generate second vibrations.

[0040] The vibrator 4 defines at least one for second vibrations emission surface.

[0041] The emission surface is configured to be placed in contact with the user directly, appropriately at the amputated end. Therefore, the vibrator 4 is configured to generate second vibrations that vibrate at least the amputated end of the user.

[0042] Alternatively or additionally, the emission surface may be configured to be placed indirectly in contact with the user via the base body 2. In this case, the vibrator 4 is configured to generate second vibrations that vibrate the second end 2b, and therefore, as the second end 2b is configured to be in contact with and integral with the user, at least the amputated end of the user's limb.

[0043] The vibrator 4 comprises at least one actuator 41 configured to generate one or more second vibrations and transmit them to the second end and specifically to the second surface, and consequently to the user, appropriately at the amputated end of a limb.

[0044] Preferably, it comprises multiple actuators 41 angularly spaced apart, appropriately angularly and preferably radially, with respect to the longitudinal axis 1 a. More preferably, it comprises an odd number of actuators 41 , for example five, which are equidistantly spaced apart (angularly and preferably radially) with respect to the longitudinal axis 1a.

[0045] The at least one actuator 41 is located near the second end 2b and specifically near the second surface. In particular, each actuator 41 is located at the second end 2b and preferably configured to directly contact the user, appropriately at the amputated end of a limb. In this case, the second vibrations emission surface is part of said second surface.

[0046] Each actuator 41 may include one or more of linear electromagnetic actuators, and / or ceramic piezoelectric actuators.

[0047] Each actuator 41 , and thus the vibrator 4, is bound to the base body 2.

[0048] The device 1 comprises a database of first positions of at least one inertial sensor 31 , and in particular of the plurality of said inertial sensors 31 . The database of first positions associates each sensor 31 with a first position and specifically with first coordinates, preferably three coordinates, with respect to a first reference system appropriately relative to the device 1 and specifically to the base body 2 (for example, an axis of said reference system may be the longitudinal axis 1 a).

[0049] The device 1 comprises a database of second positions of at least one actuator 41 , and in particular of the plurality of actuators 41. The database of second positions associates each actuator 41 with a second position and specifically with second coordinates, preferably three coordinates, with respect to a second reference system appropriately relative to the device 1 and specifically to the base body 2 (for example, an axis of said reference system may be the longitudinal axis 1 a). Preferably, the first and second reference systems substantially coincide.

[0050] The device 1 comprises a unit 5 configured to control the vibrator 4 to emit second vibrations as a function of the first vibrations detected by the acquisition block 3.

[0051] The unit 5 may be an electronic board or any other processor capable of controlling the operation of the device and optionally the prosthetic system as described below. The unit 5 is in data connection with the block 3 and the vibrator 4.

[0052] The unit 5 is integral with the base body 2.

[0053] The unit 5 may include a data memory.

[0054] The memory may include the database of first positions of the inertial sensors 31. The unit 5 can reconstruct the vibration transmitted from the prosthesis 10 to the device 1 as a function of the data from each inertial sensor 31 (for example, the intensity and magnitude of the vibration detected by each sensor 31 along the three axes) and the aforementioned first positions. Consequently, it defines and then controls the vibrator 4 to produce one or more second vibrations as a function of the first accelerations, appropriately determined by the sensors 41 , and on said database of first positions.

[0055] Alternatively or in addition, the memory may contain the database of second positions of the actuators 41. The unit 5 can reconstruct the vibration to be generated by the vibrator 4, i.e. , to be transmitted to the user, as a function of the aforementioned second positions. Consequently, the unit 5 defines and then controls one or more actuators 41 to generate one or more second vibrations as a function of the first vibrations and on the said database of second positions.

[0056] Preferably, the unit 5 defines and then controls one or more actuators 41 to generate one or more second vibrations as a function of the first accelerations of the database of first positions and of the database of second positions.

[0057] It should be noted that the unit 5 can differently control the actuators 41 , so that the combination of the actions of each actuator 41 defines the desired second vibration. The actuators 41 can therefore be controlled simultaneously, sequentially, and / or only partially, each with its own force / power.

[0058] The device 1 includes a power battery for the entire device.

[0059] The battery is integral with the base body 2.

[0060] The invention also introduces an innovative prosthetic system 100.

[0061] The prosthetic system 100 includes the prosthetic feedback device 1 and a prosthesis 10. For example, the prosthetic system 100 can be at least part of an upper limb, and thus the device 1 may identify at least part of the forearm (or arm), and the prosthesis 10 may identify the hand and, appropriately, the wrist.

[0062] The memory may include a damping coefficient defining the damping of vibrations passing through the prosthesis 10, and the unit 5 may be configured to control the vibrator 4 to generate second vibrations as a function of the first vibrations and the damping coefficient.

[0063] Such damping coefficient thus defines the behaviour of the prosthesis 10 when subjected to an external load (for example, an impact). Consequently, the unit 5 is able to identify, as a function of the first vibrations and the said damping coefficient, the external load acting on the prosthesis 10 and thus define and control the vibrator 4 to generate second vibrations according to the said external load.

[0064] The prosthesis 10 may include a motor for actuating the prosthesis 10. In particular, it may include a base structure 11 configured to be integrally bound to the device 1 , appropriately at the first end 2a and thus at the first surface; interface means 12 configured to contact an external object; and said motor is configured to move the interface means 12 relative to the base structure 11 .

[0065] The motor may be electric.

[0066] The prosthesis 10 may include an additional unit for the motor and thus for the prosthesis 10. This additional unit may be in data connection with the unit 5, which is thus in indirect data connection with the motor by means of the additional unit. Alternatively, the prosthesis 10 may lack the additional unit, and the motor may be in direct data connection with the unit 5 and thus controlled by it.

[0067] Preferably, the prosthesis 10 is a robotic hand, appropriately underactuated, so the base structure 11 is identified as the palm of the hand, and the interface means 12 as one or more fingers of the hand. Examples of underactuated prosthetic hands are described in WO2017077429 and WO2017199127.

[0068] The device 1 includes a noise database associating at least one third vibration with the prosthesis 10, as a function of the motor and thus the movements of the prosthesis 10. The noise database associates each actuation of the motor (for example, each motor speed) with the movements of the prosthesis 10 and thus the third vibrations specific to the prosthesis 10 when actuated by the motor. Consequently, the unit 5 can be configured to control the vibrator 4 to generate second vibrations as a function of the first vibrations and the said noise database. In summary, the unit 5 defines and then controls the vibrator 4 (specifically, one or more actuators 41 ) to generate one or more second vibrations as a function of the first vibrations and, appropriately, on the database of first positions and / or the database of second positions. Additionally, the second vibrations may be determined as a function of the said noise database and / or the damping coefficient. It should also be noted that the device 1 may include, at the second end 2b, control means 6 configured to come into contact with the user in order to receive a control impulse from the motor of the prosthesis 10.

[0069] The control means 6 may be in data connection with the motor via the unit 5 and / or the said additional unit.

[0070] The control means 6 may include at least one EMG sensor (or prosthetic or myoelectric sensor) configured to measure a potential variation in a muscle and generate a signal proportional to that measurement.

[0071] The operation of the device 1 , and specifically of the prosthetic system 100 previously described in structural terms, is as follows.

[0072] Initially, the device 1 , and specifically the base body 2, are anchored to the user, appropriately at the amputated limb. In particular, the second end 2b is placed in contact with the user and integrally bound to it, so as to position the vibrator 4, and specifically one or more actuators 41 , in contact with the user.

[0073] Then the prosthesis 10 is integrally bound to the device 1 and, specifically, to the base body 2 at the first end, so that the acquisition block 3, and specifically one or more inertial sensors 31 , are able to detect the first vibrations transmitted from the prosthesis 10 to the base body 2.

[0074] The prosthesis 10, when, for example, it strikes an object and thus vibrates, transmits that vibration to the device 1 via the connection between the base body 2 and the prosthesis 10, defining first vibrations acquired by the acquisition block 3, which then transmits to the unit 5 a signal proportional to said first vibrations. Specifically, each inertial sensor 41 acquires a first variation as a function of the vibration transmitted from the prosthesis 10 to the device 1 and sends a signal to the unit 5 proportional to said first vibration.

[0075] At this point, the unit 5, as a function of the database of first positions, reconstructs the vibration transmitted by the prosthesis 10 to the device 1 , and as a function of this, controls each actuator 41 to generate a second vibration. Specifically, as a function of the database of second positions, the unit 5 controls the actuators 41 to generate second vibrations in such a way as to transmit to the user a resulting vibration of said second vibrations proportional to the one generated by the impact of the prosthesis with the object.

[0076] It should be noted that the first vibrations are influenced by the prosthesis 10, and thus the unit 5 reconstructs the vibration transmitted by the prosthesis 10 to the device 1 and then defines the second vibrations also as a function of the damping coefficient of the prosthesis 10.

[0077] Furthermore, if the prosthesis is actuated by the motor, the first vibrations are also influenced by the vibrations of the prosthesis 1 generated by the motor. In this case, the unit 5, being in data connection with the motor, identifies in the noise database the third vibration associated with the motor actuation and thus controls the vibrator 4 to generate second vibrations also as a function of said third vibration.

[0078] The device 1 and thus the prosthetic system 100 according to the invention achieve important advantages.

[0079] In fact, thanks to the specific arrangement of the vibrator 4 and the acquisition block 3, the device 1 allows to realistically transmit any impacts or other vibrations to which the prosthesis 10 is subjected, without increasing the complexity and thus degrading the usability of the prosthesis 10 and / or the device 1. This advantage is enhanced by the ability to process the acquired first vibrations and the second vibrations transmitted to the user, respectively, as a function of the position of the inertial sensors 31 and the actuators 41 .

[0080] This enhanced realistic effect can be further accentuated by the ability to establish the second vibrations also as a function of the third vibrations, i.e. , the vibrations created by the prosthesis 10. In fact, the motor of the prosthesis 10 and thus the actuation of the prosthesis give rise to vibrations which, being said vibrations detected by the acquisition block, could lead to the definition of incorrect second vibrations, if not considered in the determination of the same second vibrations.

[0081] Moreover, the realistic effect is enhanced by the fact that the second vibrations are also determined as a function of the damping coefficient of the prosthesis, which would otherwise have altered the first vibrations.

[0082] The invention is susceptible to variations falling within the scope of the inventive concept defined by the claims.

[0083] For example, the base body 3 may include a static support and a first movable element relative to said static body, configured to be integrally bound to the prosthesis 10. Said first movable element thus defines the first end 2a and said first surface.

[0084] In this case, the acquisition block 3, and specifically one or more inertial sensors 31 , are interposed between the first movable element and the static support, so as to detect the first vibrations transmitted by the prosthesis 10 to the base body 2, as a function of the first vibrations and thus the movements of the first movable element relative to the static support. In another example, the base body 3 may include a static support and a second movable element relative to said static body, and configured to come into contact with the user and to be integrally bound to the user. The second movable element thus defines the second end 2b and the second surface. In this case, the vibrator 4, and specifically one or more actuators 41 , are interposed between the second movable element and the static support, so as to set in vibration in accordance with the second vibrations, relative to the static support the second movable element, which, when integrally bound to the user, transmits these second vibrations to the very user. In this context, all details can be replaced by equivalent elements, and the materials, shapes, and dimensions can be any.

Claims

C LAI MS1. A prosthetic feedback device (1 ) configured to be associated with a prosthesis (10) and comprising- a base body (2);- an acquisition block (3);- a vibrator (4) defining a second vibrations emission surface, said emission surface being configured to be placed in contact with said user either directly or indirectly via said body; and characterized in that- said base body (2) comprises o a first end (2a) configured to be integrally bound to said prosthesis (10); and o a second end (2b) configured to be placed in contact with the user and integrally bound to said user;- said acquisition block (3) is configured to detect first vibrations of said first end (2a) transmitted from said prosthesis (10) to said base body (2);- said vibrator (4) defines, at said second end (2b), said second vibrations emission surface; and in that it comprises- a unit (5) of said vibrator (4) configured to control said vibrator (4) to emit said second vibrations as a function of said first vibrations.

2. The device (1 ) according to claim 1 , defining a longitudinal axis (1a); and wherein said acquisition block (3) comprises inertial sensors (31 ) angularly spaced with respect to said longitudinal axis (1 a); each of said inertial sensors (31 ) is configured to detect first accelerations of said first vibrations along three axes; adatabase of first positions of said inertial sensors (31 ); and wherein said unit (5) defines said second vibrations as a function of said first accelerations and said database of first positions.

3. The device (1 ) according to at least one preceding claim, defining a longitudinal axis (1 a); and wherein said vibrator (4) comprises actuators (41 ) angularly spaced with respect to said longitudinal axis (1a); each of said actuators (41 ) is configured to generate at least part of said second vibrations; a database of second positions of said actuators (41 ); and wherein said unit (5) controls each of said actuators (41 ) to generate said second vibrations as a function of said first vibrations and said database of second positions.

4. A prosthetic system (100) comprising said prosthesis (10) and said device (1 ) according to at least one preceding claim.

5. The prosthetic system (100) according to at least the preceding claim, comprising a damping coefficient defining the damping of vibrations passing through said prosthesis (10); and wherein said unit (5) is configured to control said vibrator (4) to generate said second vibrations as a function of said first vibrations and said damping coefficient.

6. The prosthetic system (100) according to at least one of the preceding claims 4-5, wherein said prosthesis (10) comprises a motor for actuating said prosthesis (10) in data connection with said unit (5); wherein said device (1 ) comprises a noise database associating at least a third vibration with said prosthesis (10) as a function of said motor; and wherein said unit (5) is configured to control said vibrator (4) to generate said second vibrations as a function of said first vibrations and said noise database.

7. The prosthetic system (100) according to the preceding claim, whereinsaid device (1 ) comprises, at said second end (2b), control means (6) configured to contact said user to receive a control impulse from the motor of said prosthesis (10).

8. The prosthetic system (100) according to at least one of the preceding claims 4-7, wherein said prosthesis (10) is an underactuated robotic hand.

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