MEASURING DEVICE FOR THIGH STUMP

The invention relates to a measuring device for a femoral stump.

The development of a prosthetic leg adapted to a femoral stump typically includes a phase take measurements on the patient, and a molding step for manufacturing a socket whose shank is adapted to the stump. Taking measurements is conventionally performed the patient standing. The latter series of measurements enables consideration of displacements of flesh soft by gravity.

The measurements made with the patient standing relate to the length of the stump, the distance between the ground and the ischio-pubic branch of the patient, and measuring the perimeter of the stump in cutting planes orthogonal to the femur and spaced apart by a predetermined interval.

Such measurements are difficult to perform and remain inaccurate because they are distributed by a simple tape measure. Gold, such inaccuracies may emanate directly on the shape of the artificial limb socket performed next, to the detriment of the patient comfort and reliability of the prosthesis.

The object of the invention is to perform measurement device for femoral stump which is of simple and inexpensive design, and which improves the accuracy of the measurements made from the patient.

The measuring device according to the invention is characterized in that it comprises:

• a telescopic mast having graduations corresponding to the distance between its first and second ends,
• a ruler having one end attached to the telescopic mast by a hinge proximate the first end of said mast, the slide having graduations whose origin is coincident with the first end of the mast,
• a closed loop belt adjustable perimeter, mounted sliding along the strip and having graduations corresponding to its perimeter.

The telescoping mast of a measuring device according to the invention is intended to be positioned between the ground and the ischio-pubic branch of a patient standing on which measurements are to be made. The telescoping mast serves as a crutch and reading of its graduations corresponding to the distance between its ends provides access to the distance between the ground and the ischio-pubic branch of the patient. The slide is disposed against the femoral stump through the joint and the belt is adjusted at the perimeter of the stump in successive planes perpendicular to the femur. For each measurement, which is carried out in a given plane, the graduations corresponding to the perimeter of the belt giving access to the perimeter of the stump while the divisions of the ruler provide access to very precisely to the distance between said plane and the ischio-pubic branch.

According to a preferred embodiment, the telescopic mast comprises a guide provided with a fixed mark and a slide movable in the guide sliding along a longitudinal direction, the slider being provided with graduations positioned on the slider so that an aligned position of the fixed mark of one of said indicia corresponds to a distance between the first and second ends of the telescopic mast equal to the value of said scale.

Other technical features may be used alone or in combination:

• the articulation of the rule comprises two pivot axes perpendicular to each other,
• the belt is fitted sliding in a first direction in a guide member mounted to sliding in a second direction along the rule, the first and second directions being perpendicular to each other,
• the first end of the telescopic mast comprises a bearing support mounted to rotate freely,
• the belt is formed by a semi-rigid tape,
• a bracket is slidably mounted along the rule.

Other advantages and features shall become apparent from the description which will follow of a particular embodiment of the invention given by way of non-limiting example and represented to the drawings enclosed, in which:

• the fig. 1 represents, in perspective, an example of a measuring device according to the invention,
• the fig. 2 is a front view of the device of the fig. 1,
• The fig. 3 is a side view of the device of figure 1 and 2 after pivoting the strip at an angle ϕ 1 around a first pivot axis,
• the fig. 4 is a front view of the device of the fig. 3,
• the fig. 5 is a front view of the device of figure 1 and 2 after pivoting the strip at an angle ϕ 2 about a second pivot axis.

With reference to the drawings, the exemplary measuring device 10 for a femoral stump has a telescopic mast 11 consisting of a guide 12 and a slide 13 movable in the guide 12 in a longitudinal direction of sliding. The telescoping mast 11 has graduations corresponding to the distance between its first and second ends, marked 11 has, 11 B respectively. For example, such graduations are performed using a fixed mark (not shown) integral with the guide 12 and graduations connected to the ram 13 and made for example by using a rule mllimetered. The graduations of the slide 13 are positioned on the slider 13 so that an aligned position of the fixed mark of one of the division corresponds physically to a distance between the ends 11 a and 11 b of the telescopic mast 11 which is equal to the value of the scale aligned with the fixed mark. The first end of the telescopic mast has 11 11 is constituted by one of the ends of the guide 12 and its end 11 b is constituted by one end of the slide 13. The other ends of the guide 12 and the slide 13 serve to engagement of the slide 13 in the guide 12. a locking device (not shown) ensures a controlled blocking translation of the slider 13 in the guide 12.

The first end of the telescopic mast 11 11a has one support 14 curved in the shape of circular arc whose concavity faces the opposite side to the telescopic mast 11. The bearing 14 is mounted to rotate freely on the guide 12 along an axis of rotation that coincides with the sliding direction of the slider 13 in the guide 12. the bearing 14 has a shape adapted to the anatomy of the human body at the ischio-pubic branch with which it is intended to come into contact as explained farther, and for that purpose has a padding for patient comfort. The first end 11a corresponds geometrically to the recess of the bearing 14. In other words, the height of the telescopic mast 11, indicated by the graduations described above, is counted between its second end 11 b and the recess of the bearing 14. A removable disposable covers, for hygiene reasons, the end 11a.

The measuring device 10 also includes a strip 15 having one end bonded to the guide 12 of the telescopic mast 11 by a hinge proximate the first end 11a. This hinge comprises two pivot axes perpendicular to each other. Thus, the slide 15 is articulated at its end relative to the telescopic mast 11 about a first pivot axis d1 (fig. 2) which is perpendicular to the sliding direction of the slider 13 in the guide 12. in independent movement, the slide 15 is also articulated at its end relative to the telescopic mast 11 about a second pivot axis d2 (fig. 3) which is simultaneously d1 and perpendicular to the sliding direction of the slider 13 in the guide 12. constructed therewith, the slide 15 is mounted, relative to the telescopic mast 11, according to a spherical connection to finger disallowing, at each instant, the rotation on itself of the strip 15. The center of the ball joint is defined by the star point of the pivot axes and d2 d1. Such a joint may, for example, be carried out with the aid of a spider having a first leg is pivotally mounted relative to the guide 12 of the telescopic mast 11, and the otherBranch from the socket 15. However any equivalent embodiment achieve the same result may be contemplated.

The figure 3 to 5 illustrate the measuring device 10 for different configurations of pivoting of the strip 15. On the figure 3 and 4, the slide 15 is represented after pivoting angle ϕ 1 around the first pivot axis d1. The angle ϕ 1 is measured from a first plane p1 (fig. 3) defined as the plane containing the first pivot axis and the d1 sliding direction of the slider 13 in the guide 12. on the fig. 5, the slide 15 is represented after pivoting angle ϕ 2 about the second pivot axis d2. The angle ϕ 2 is measured from a second plane p2 (fig. 5) defined as the plane containing the second pivot axis d2 and the sliding direction of the slider 13 in the guide 12. consequently, the second plane p2 constitutes the plane in which occurs the pivoting of the strip 15 around the first pivot axis d1. Reciprocally, the first plane p1 constitutes the plane in which occurs the pivoting of the strip 15 around the second pivot axis d2. The planes p1 p2 and are orthogonal to each other.

According to the invention, the slide 15 has graduations whose origin is coincident with the first end of the telescopic mast 11a 11. To achieve this, the value of the first scaling of the rule 15 (from the joint of the strip 15 on the telescoping mast 11) corresponds to the distance between said first scale and the first end 11a when the mast 11 and the slide 15 are parallel. Such an embodiment makes it possible to include, in the value of the graduations, the distance separating the first end 11 a of the mast 11 and the articulation of the rule on the mast 15 11. The graduations may be performed using a rule mllimetered whose positioning along the rule 15 is fixed and selected to meet the criteria above under its scales. The slide 15May be semi-rigid to follow the shape of the stump if it is not straight.

The measuring device also includes a belt 16 closed loop perimeter adjustable. The belt 16 is fitted sliding in a first direction in a guide member 17 mounted sliding in a second direction along the rule 15. The first direction is perpendicular to the main direction of the strip 16 while the second direction corresponds to the main direction of the strip 16. The first and second directions are perpendicular to each other. Such a structure ensures that the belt 16 extends in a plane perpendicular to the main direction of the rule that the belt 15 and 16 can move translationally along the rule 15 by sliding the guide element 17. A series of index holes 18 is formed along the rule 16 d is marked at regular intervals (the fig. 3 watch the interval between two holes 18 non-successive equal to 2 times the distance d) along its main direction. Indices of the holes 18 are intended to cooperate with the guide member 17 by any known means. When they cooperate, the distance between the first end of the telescopic mast 11 has the guide member 11 and 17 supporting the belt 16 is fixed and corresponds to a predetermined distance.

The belt 16 has graduations corresponding to its perimeter. Such a band 16 can be made of a semi-rigid tape, metal or plastic for example. In a first embodiment, a first strand of the belt 16 is integral with the guide element 17 and the other strand, the second, is slidable in the guide member 17 in the second direction. In this case, the guide member 17 permits the reading on the second strand of the scale which coincides with the origin of the graduations on the first strand. The read value is equal to the perimeter of the belt 16. In the second embodiment, the first strand is secured to a loop (notRepresented) and the second strand is slidably mounted in the loop. Near its middle, the belt 16 is slidably mounted in the guide member 17. In this variation, the loop allows the reading on the second strand of the scale which coincides with the origin of the graduations on the first strand. Regardless of the embodiment, the reading should take place on the side diametrically opposite the strip 15 for reasons of readability.

Finally, the measuring device 10 comprises an angle bracket 19 which is mounted to slide along the rule 15. Indices of the holes 18 are not intended to cooperate with the bracket 19. The distance between the first end of the telescopic mast 11 has 11 and square 19 is variable and the displacement of the bracket 19 is manually controlled. The bracket 19 is perpendicular simultaneously to the first displacement direction of the belt 16 in the guide member 17 and the second displacement direction of the guide member 17 along the rule 15.

The telescoping mast 11 is placed vertically below the patient who is standing, between the ground and the ischio-pubic branch of the patient on the side of amputation. The mast 11 is oriented such that the second plane p2 coincides with the sagittal plane of the patient. The sagittal plane is defined as the vertical plane oriented in the antero-posterior midline on the patient's body. The first plane p1 longer registered with the medio-lateral plane forehead of the patient.

Adjustment of the length of the mast 11 is often necessary and practical by the latch means arranged to control the movement of the slider 13. The locking device is first unlocked it can translate the slide 13 in the guide 12 toContacting the bearing 14 against the ischio-pubic branch of the patient. Then the locking device is locked to prevent translation of the slider 13. Subsequently, the patient can rest on the support 14 so that the telescopic mast 11 constitutes a crutch. Reading the value of the scale of the slider 13 aligned with the fixed mark the guide 12 provides access to the distance separating the ends 11 has, 11 b of the mast 11, and thus the distance between the ground and the ischio-pubic branch of the patient.

Then the slide 15 is oriented substantially parallel to the femoral stump to be measured on the patient, a hinge providing a spherical connection to finger. The slide 15 bears against the inner face of the stump. The belt 16 is disposed around the residual limb near the groin of the patient, and then fitted to the perimeter of the stump. The bracket 19 is then slid along the rule 15 until it engages with the end of the stump. The reading of the scale of the strip 15 which coincides with the bracket 19 provides access to the distance separating the bracket 19 and the first end of the telescopic mast has 11 11, and hence the length of the stump of the patient, counted from its ischio-pubic branch.

Then, the measurement of the perimeter of the stump in different cutting planes orthogonal to the femur is performed. For each measurement, the belt 16 is adjusted to the stump and the reading of the scale of the belt 16 corresponding to its perimeter provides access to the perimeter of the stump. The reading of the scale of the rule 15 aligned with the guide member 17 provides access to the distance between the belt 16 and the first end of the telescopic mast 11a 11, and thus the distance between the belt 16 and the ischio-pubic branch of the patient. Thanks to indexing 18, the latter range belongs to a set of predetermined values and thus is not random. On the contrary, it is perfectly quantifiable and accurately. And then the guide member 17 is disengaged from the indexing hole 18 with which it cooperates, and then is translated along the rule16 in the direction opposite to the connection with the telescopic mast 11 to cooperate with the indexing hole 18 according to perform the next measurement. The measurements of the perimeter of the stump is effected with a regular incrementation of the distance between the belt 16 and the ischio-pubic branch, according to a pitch equal to the interval between two indexing holes 18. of course that the measurements of the perimeter of the stump can be performed for positions of the belt 16 which are spaced apart by equal intervals to a multiple of the distance between two indexing holes 18. said succession of stages may easily know, ultimately, the value of the perimeter of the stump in a plane perpendicular to the femur in accordance with the distance separating this very precise plane and the ischio-pubic branch of the patient.

The accuracy of the measurements made by the measurement device 10 according to the invention has a substantial effect on the quality of the artificial limb socket made from these measurements, on behalf of the patient comfort and reliability of the prosthesis.