METHOD AND DEVICE FOR DETECTING AND THERAPEUTICALLY MONITORING KNEE LIGAMENT INJURIES

Abstract

According to the method of the invention, a translational movement of the tibia of a patient is caused by a first motor (9b) for moving a thrust member (9a) of the patient's calf, and is measured by a first sensor (15a) located on the Tibial Tuberosity, Anterior (TTA). The tibia is caused to rotate by a second motor (12) for rotating a foot support (11b) of the patient, and is measured by a second sensor (14b) located as close as possible to the TTA. The respective operations of the first motor (9b) and of the second motor (12) are correlated by a control member, by being mutually controlled according to pre-set and reproducible force models.

Claims

1. A measuring device for characterizing an anterior cruciate ligament injury to a patient's knee of a patient, comprising a seat provided with a squab having a tiltable backrest, a support platform for supporting the patient's leg, rotationally movable relative to the squab, and provided with a thrust member for pushing the patient's calf equipped with a first member for immobilizing the patient's knee on the platform and with a thrust member for pushing the knee mounted translationally movable on the platform wherein said device further comprises: a foot support, rotationally movable on the platform, capable of causing the tibia to rotate at a desired force threshold, said foot support being provided with a second immobilization member for immobilizing the patient's foot; a first sensor capable of being positioned on the TTA of said patient as well as a second sensor assigned to measuring an angle of rotation of the tibia and mounted on a member for positioning said second sensor relative to the foot support; and a system for analyzing measurements respectively supplied by the first sensor and by the second sensor and relating to their strokes as a result of a respective translational and rotational movement of the tibia, and an interface for displaying the data supplied by the analysis system.

2. The measuring device for characterizing an injury to the anterior cruciate ligament of a patient's knee according to claim 1, wherein the device comprises a first motor controlling the translation of the thrust member and a second motor controlling a rotation of the foot support.

3. The measuring device for characterizing an injury to the anterior cruciate ligament of a patient's knee according to claim 1, wherein the device comprises a computer memory for recording at least one digital force model and a computer controlling said motors by applying control laws depending on the contents of said computer memory.

4. The measuring device for characterizing an injury to the anterior cruciate ligament of a patient's knee according to claim 1, wherein the second member for positioning said second sensor is arranged in said legging.

5. The measuring device for characterizing an injury to the anterior cruciate ligament of a patient's knee according to claim 1, wherein the first member for positioning the first sensor and said second member for positioning said second sensor are mounted on at least one articulated beam which is attached to the platform.

6. The measuring device for characterizing an injury to the anterior cruciate ligament of a patient's knee according to claim 1, wherein it is also provided with an assistance device at least comprising a signal transmitter capable of indicating to a practitioner correct positioning of the first sensor and/or of the second sensor on a specific patient, with regard to reference positions respectively of the first sensor and/or of the second sensor on the patient previously defined and stored in a second directory of individualized sensor positions for various patients via a second memory of the assistance device.

7. The device according to claim 1, wherein the control member includes a second module for controlling at least one configuring of the seat for a specific patient, the second control module being a servo-control module correlated with at least one third motor for positioning in relative inclination between the squab and the backrest, a fourth motor for positioning in relative inclination between the platform and the squab, the second control module comprising a third memory for storing a third directory of individualized seat configuration models for various patients which are pre-set and are reproducible by the control member.

8. The measuring device for characterizing an injury to the anterior cruciate ligament of a patient's knee according to claim 2, wherein the device comprises a computer memory for recording at least one digital force model and a computer controlling said motors by applying control laws depending on the contents of said computer memory.

9. The measuring device for characterizing an injury to the anterior cruciate ligament of a patient's knee according to claim 2, wherein the second member for positioning said second sensor is arranged in said legging.

10. The measuring device for characterizing an injury to the anterior cruciate ligament of a patient's knee according to claim 2, wherein the first member for positioning the first sensor and said second member for positioning said second sensor are mounted on at least one articulated beam which is attached to the platform.

11. The measuring device for characterizing an injury to the anterior cruciate ligament of a patient's knee according to claim 2, wherein it is also provided with an assistance device at least comprising a signal transmitter capable of indicating to a practitioner correct positioning of the first sensor and/or of the second sensor on a specific patient, with regard to reference positions respectively of the first sensor and/or of the second sensor on the patient previously defined and stored in a second directory of individualized sensor positions for various patients via a second memory of the assistance device.

12. The device according to claim 2, wherein the control member includes a second module for controlling at least one configuring of the seat for a specific patient, the second control module being a servo-control module correlated with at least one third motor for positioning in relative inclination between the squab and the backrest, a fourth motor for positioning in relative inclination between the platform and the squab, the second control module comprising a third memory for storing a third directory of individualized seat configuration models for various patients which are pre-set and are reproducible by the control member.

Description

DESCRIPTION OF THE FIGURES

[0098] The invention will be better understood on reading the following detailed description of an example embodiment of the present invention, in relation with the following figure:

[0099] FIG. 1 is a schematic profile presentation of a patient installed on a seat that a device according to an example embodiment of the invention comprises.

DETAILED DESCRIPTION OF THE INVENTION

[0100] The figure and its non-limiting detailed description show the invention according to particular conditions which are not restrictive as to the scope of the invention. The figures and their detailed descriptions of an example embodiment of the invention can be used to better define it, if necessary in relation with the general description that has just been given.

[0101] In FIG. 1, a device is organized to evaluate a potential injury to the ACL of a patient's knee. The device comprises a seat (1) for placing the patient in for their examination by a practitioner. The seat (1) includes a squab (18) and a backrest (19) which are tiltable relative to one another, the position of the squab (18) being adjustable in height. A support platform (17a) for supporting a leg of the patient is mounted on a support (17b) which is articulated in pivoting relative to the squab (18)).

[0102] The seat (1) can thus be located in various specific configurations for seating the patient on the device, by adjusting the relative positions between the squab (18), the backrest (19) and the platform (17a). During an examination of the patient, the practitioner can thus modify the configuration of the seat (1) according to specific implementations of the device in order to carry out an evaluation at various degrees of bending of the patient's knee.

[0103] The platform (17a) is equipped with a base (11a) for supporting the patient's knee. The platform (17a) is also equipped with a foot support (11b) receiving the patient's foot and a thrust member (9a) comprising a shell (9c) on which the patient's calf rests, near his knee.

[0104] The patient's knee is firmly held on the base (11a) via a first immobilizing member (16) arranged in a strap tying the knee onto the base (11a). The foot of the patient is firmly held on the foot support (11b) via a second immobilizing member (13) arranged in a strap tying at least the foot and the base of the patient's leg onto the foot support (11b).

[0105] The thrust member (9a) is mounted so as to be translationally movable on the platform (17a), in order to exert a thrust force against the patient's calf at a desired force threshold. The foot support (11b) is mounted so as to be able to rotate on the platform (17a), in order to cause the tibia to be rotated at a desired force threshold.

[0106] The device is equipped with different motors (4, 5, 7) to adjust the configuration of the seat (1) in various stations of examination of the patient. The motor (4) makes it possible to adjust the tilt between the squab (18) and the backrest (19). The motor (7) makes it possible to adjust the tilt between the squab (18) and the platform (17a) via the support 10 carrying the platform (17a). The motor (5) makes it possible to adjust the height position of the squab (18).

[0107] The device is also equipped with different motors (9b, 12) to place the patient's tibia under stress in translation and/or in rotation. A first motor (9b), such as especially an electric cylinder, is assigned to the translational operation of the thrust member (9a), in order to cause a translational movement of the tibia relative to the femur. A second motor (12), such as especially an electric rotary motor, is assigned to the rotational operation of the foot support (11b), in order to cause the patient's tibia to be rotated.

[0108] The device is also equipped with a first sensor (15a) for measuring the translational movement of the tibia as a result of the activation of the first motor (9b) causing the translational movement of the thrust member (9a).

[0109] The first sensor (15a), such as a proximity sensor with potential difference, is mounted on a beam (15b) attached to the platform (17a) by being applied against the TTA during the examination of the patient. A second sensor (14b) such as a proximity sensor with potential difference configured as an inclinometer and/or accelerometer is mounted in the example shown on a legging (14a) enveloping the patient's calf by being applied against the tibia near the first sensor (15), as close as possible to the TTA.

[0110] A human/machine interface, hereinafter referred to as a HMI, allows the practitioner to establish their diagnosis from logical processing by a system for analyzing measurements supplied at least by the first sensor (15a) and the second sensor (14b) which are carried out at different degrees of bending of the knee by tilting the platform (17a) with respect to the squab (18) according to the predefined configurations of the seat (19).

[0111] At the end of a sequence of examination of the patient, an interface for displaying the logical processing of the measurements performed by the analysis system, provides a display of the obtained result in the form of a diagram. The diagram includes two comparative curves, one a reference curve relating to an absence of injury to the ACL (green curve) and the other a curve relating to a possible injury to the ACL (red curve) identified by the analysis system on the basis of the processing of the measurements carried out.

[0112] To perform the examination of the patient, a control member included in the HMI comprises a second control module which regulates the operation of motor (4), motor (5) and motor (7) to place the seat (19) in configurations previously defined with different degrees of knee bending.

[0113] The configurations of the seat (19) are then applied according to configuration models of the seat (19) which are selectable and/or adaptable by the practitioner, and which are classified according to a third directory previously established and stored in a third memory of the second control module.

[0114] Prior to an examination of the patient, the first sensor (15a) and the second sensor (14b) are calibrated by being located at reference positions (15b, 14a), respectively against the TTA for the first sensor (15a) and in proximity to the TTA for the second sensor (14b) according to the shown example. The HMI comprises an assistance device guiding the practitioner to reproduce the reference positions (15b), (14a) of the first sensor (15a) and of the second sensor (14b) to perform an examination of the patient. The respective reference positions (15b, 14a) of the sensors (15a, 14b) are classified according to a second directory previously established and stored in a second memory of the assistance device.

[0115] Subsequently, during therapeutic monitoring of the patient, the installation positions of the sensors (15b, 14a) by the practitioner are compared with their respective reference positions (15a, 14b), in order to define the relevance of subsequent positioning of the sensors (15a, 14b) on the patient. In the event of a position shift of the sensors (15a and 14b) relative to their previously stored reference positions (15b, 14a), the practitioner is then guided via an emitter of a sound and/or light signal to place the first sensor (15a) and the second sensor (14b) on the patient in accordance with their respective reference positions (15a, 14b).

[0116] To perform an examination of the patient, the practitioner uses the HMI to cause the translational movement of the thrust member (9a) and the rotation of the foot support (11b). For this purpose, the control member comprises a first control module for implementing the first motor (9b) and the second motor (12), which are controlled in correlation by the first control module.

[0117] More particularly for an examination phase of the patient, the forces and/or the amplitudes of stressing of the tibia translationally—via the first motor (9b)—and rotationally—via the second motor (12) are controlled according to force models selectable and/or adaptable by the practitioner, which are classified based on a first directory, pre-set and stored in a first memory. Each of the force models comprises a first force law regulating the operation of the first motor (9b) and a second force law regulating the operation of the second motor (12).

[0118] The first motor (9b) and the second motor (12) are thus controlled in combination, by applying a force model—combining in correlation said first force law and said second force law—which is selected by the practitioner among various force models listed in the first memory, and this for various degrees of bending of the knee.

[0119] The operation of the first motor 9a and of the second motor 12 according to a force model selected by the practitioner makes it possible to regulate—via the control member—conditions for stressing the tibia as desired by the practitioner. On the basis of the application of a force model, a combined servo-control of the first motor (9a) and of the second motor (12) by the first control module makes it possible to subject the patient's tibia to a translational and rotational stress according to forces and amplitudes which are correlated, with the ability to be selectively applied—per the practitioners demands—simultaneously or consecutively.

[0120] The various measurements of the translational and/or rotational movement of the tibia are selectively carried out by the practitioner according to pre-defined force models and adapted to a specific patient; from said force models, the respective operations of the first motor (9b) and of the second motor (12) are correlated. The force models are pre-set on the basis of standardized force models or on the basis of specific force models constructed and/or potentially adapted during an initial examination of a patient, by being reproducible during therapeutic monitoring of the patient and/or adapted according to the progress of the injury to the ACL identified during the initial examination.

[0121] A precise and reliable diagnosis may thus be rapidly made by the practitioner, taking into account a rotational instability of the tibia evaluated accurately on the basis of various measurements of a translation of the tibia and of a rotation of the tibia which are correlated by the combined control of the operations of the first motor (9b) according to said first specific force law and of the second motor (12) according to said second specific force law.

[0122] The reproducibility of the examination during therapeutic monitoring is made reliable and/or can be adapted depending on the progress of the injury to the patient's ACL, from a choice by the practitioner of the force models to be applied and/or adapted. The accuracy of the measurements carried out is also reinforced by applying the first sensor (15a) and/or the second sensor (14b) against the TTA, or at least as close as possible to the TTA.

[0123] The analysis system can provide performance and comparative results between measurements whose measurement conditions can be diversified by being easy to implement by the practitioner on the basis of pre-set and/or adapted force models. The mutual servo-control of the stresses applied to the tibia for its translational movement for various configurations of the seat—under the control of the operation of the first motor (9b) and of the second motor (12) by the control member—contribute to the quality and accuracy obtained—via the analysis system—from the analysis of the measurements carried out.

USE OF THE PATENTED EQUIPMENT

[0124] The aforementioned device is especially intended for preoperative diagnosis.

[0125] It makes it possible to implement a method for measuring a rotational movement of a patient's knee in combination with a measurement of a translational movement of the associated tibia relative to the associated femur of the patient at different degrees of bending of the knee, the method being implemented by a device at least comprising a seat (1) for placing the patient in, including a squab (18) extended by an inclinable back rest (19) relative to the squab (18), and including a platform (17a) for supporting a leg of the patient which is pivotably mounted in position on the squab (18), the platform (17a) being equipped with a first member (16) for immobilizing the patient's knee on the platform (17a), a foot support (11b) which is provided with a second member for immobilizing (13) the patient's foot and which is mounted so as to be rotationally movable on the platform (10), and a thrust member (9a) for pushing the patient's knee which is mounted so as to be translationally movable on the platform (17a), the device being equipped with a first sensor (15a) for measuring a translational movement of the tibia relative to the femur located on the TTA, and a second sensor (14b) for measuring an angle of rotation of said tibia, close to the TTA, wherein the method of collecting and logical processing is performed by a measurement analysis system at least comprising a first measurement provided by the first sensor (15a) and a second measurement provided by the second sensor (14b) for each of said different degrees of bending of the knee, characterized in that: [0126] the measurement of the translational movement of the tibia is carried out by the first measurement sensor (15a) from a translation of the thrust member (9a) on the platform (17a) which is performed by a first motor (9b), [0127] the measurement of the angle of rotation of the tibia is carried out by the second sensor (14b) located as dose as possible to the TTA of the patient's knee, from a rotation of the foot support (11b) which is performed by a second motor (12), and [0128] The respective operations of the first motor (9b) and of the second motor (12) are correlated by a first control module that a control member includes, [0129] the respective activation conditions of the first motor (9b) and of the second motor (12) are mutually controlled in at least one listed force model for stressing the tibia of a specific patient that is pre-set and reproducible and/or adaptable to the patient in question, [0130] said at least one force model combines, for each of the degrees of bending of the patient's knee, on the one hand a first force law relating to the translational movement of the tibia, via the thrust member (9a) moved in translation on the platform (17a) by the first motor (9b), and on the other hand a second force law relating to the rotation of the patient's foot, via the foot support (11b), by the second motor (12) for rotating the foot support (11b).

[0131] Preferably, the second sensor (14b) is located near the thrust member (9a) following the extension of the leg, the first sensor (15a) being located on the TTA and the second sensor (14b) being located adjacent to the first sensor (15a), close to the TTA.

[0132] Advantageously, the second sensor (14b) is mounted on a legging (14a) installed around the patient's calf.

[0133] According to first conditions of examination, the measurement of the translational movement of the tibia by the first sensor (15a) and the measurement of the angle of rotation of the tibia by the second sensor (14b), are carried out simultaneously under the control of the control member in accordance with said at least one force model.

[0134] According to second conditions of examination, the measurement of the translational movement of the tibia by the first sensor (15a) and the measurement of the angle of rotation of the tibia by the second sensor (14b), are carried out consecutively under the control of the control member in accordance with said at least one force model.

[0135] Advantageously, prior to a reading of measurements on the patient, the first sensor (15a) and the second sensor (14b) are calibrated at respective reference positions (15b, 14a) by examining a healthy leg of the patient subjected to said at least one force model.

[0136] Preferably, the control member includes a second servo-control module correlated with at least one third motor (4) for positioning in relative tilt between the squab (18) and the backrest (19), a fourth motor (7) for positioning in relative tilt between the platform (17b) and the squab (18), and a fifth motor (5) for positioning in height the squab (18), the respective strokes of the third motor (4), the fourth motor (7) and the fifth motor (5) being mutually controlled according to at least one pre-set and reproducible configuration model of the seat (3 and 8) for a specific patient.