HRP20150755A2 - Measuring height difference of lower extremities - Google Patents

Abstract

The measurement of the height difference of the lower extremities is carried out in order to analyze the proper posture and load distribution on both legs, ie how long one leg is longer or shorter than the other leg, all for the purpose of making personalized footwear. Lower extremity height measurement is performed using the spinal column (B) with simultaneous foot diagnostics using software and an advanced 3D scanner (A). - stage two: analysis of 3D scans of the legs - stage three and fourth: positioning and geometry of the implants for final modeling and fabrication of the sole; position for 3D foot scan; - sixth phase: analysis of all previous stages, and finally the production of personalized footwear tailored to the 3D foot model. to the state of the soles of the foot, or to the key points to which it is performed the biggest and smallest pressure. Properly distributed weight on the left leg (L) and right leg (R) has an important impact on the knees, hips and shoulders, especially when making individual shoes.

Description

The field of technology

The invention relates to the procedure for measuring the height difference of the lower extremities. According to the International Classification of Patents, the subject of the invention belongs to area A - daily necessities - health, A61B - diagnostics; identification, i.e. area G – physics, G01 – measurement; testing.

Technical problem

3D reconstruction of the foot, i.e. 3D scanning is carried out, among other things, with the aim of making individual/personalized footwear as faithfully as possible.

Either the foot is scanned directly or a footprint (an older method of taking measurements) in specially made foam is scanned. In the general adult population, there is an increasing number of people with various painful conditions or pathologies of the feet such as plantar fascitis, metatarsalgia, then deformations such as planovalgus, cavus and cavovalgus of the foot, hallux valgus. In the population of children, a tendency to increase foot deformities such as planus, planovalgus feet and hallux valgus has been observed.

In order to make foot diagnostics as high quality as possible, Dr. Luigi 3D diagnostics uses several types of diagnostic devices in its work.

3D SCANNER is a complete CAD/CAM system, portable and quick to set up, it scans feet in just 20 seconds. Replacement for conventional plaster, foam, etc., using a 3D scanner does not have an unpleasant feeling for the patient as with plastering.

The system is designed for a wide range of uses, including medical diagnostics, prevention, biomechanical and ergonomic display of foot statics, both in healthy people, athletes, and people with disabilities, diabetics.

With 3D scanning, the measurement takes less than 1 minute. Taking the measurement is painless, clean and offers the patient comfort.

dr. Luigi footwear made on the basis of 3D biomechanical analysis of static foot loads and the top choice of PU materials, which are used in the production of these soles, ensure that the soles are made individually, i.e. according to the individual needs of the user.

By combining PU materials in the production of soles, the following is achieved:

Physiological position of the feet,

Stabilization of the feet,

Foot relief,

Optimal relationship between the foot and the surface on which it moves.

In addition, there is a large increase in people with diabetes, in whom significant neuro-circulatory changes in the feet have been observed, which are responsible for foot deformations and ulcerations. All the mentioned facts speak in favor of the need to use individual shoes in the prevention and therapy of deformations and various foot pathologies. In this sense, the accuracy of the scanning and the obtained 3D model is of the utmost importance for the creation of a quality individual product.

State of the art

Description of the problem with the conventional 3D scanning method and solution:

The traditional way of making shoes/insoles did not include the use of a computer, but a plaster cast was made from the foot print in foam, according to which the insole/shoe was made almost by hand.

The development of precise CAD/CAM systems has opened up possibilities and their application in orthopedic technology for the production of individual shoes/insoles. The production of shoes/insoles using CAD/CAM technology is based on a precise 3D model of the foot.

Today's typical foot scanning solutions use specialized laser 3D scanners, which specialize in both foot scanning and smaller model/object scanning. Then, advanced laser 3D scanners are relatively fast and thus require the subject of the scan (patient) to remain still for only a few tens of seconds, which is especially important for children and injured patients.

In addition, conventional laser scanners provide a 3D shape from only one view, while scanning from multiple views would facilitate the processing of the reconstructed 3D shape in order to create the foot insole/shoe as faithfully as possible. Unfortunately, scanning from multiple views requires the so-called registration of areas. Common commercial 3D surface registration systems use additional devices such as robotic arms, rotating surfaces (turn tables).

Apart from the fact that such devices significantly increase the price of the 3D system, they do not provide a 100% guarantee that an object will be truly reconstructed in all points.

The essence of invention

Guided by all the mentioned facts, the footwear factory Dr. Luigi, in cooperation with a Lithuanian company, has developed its own 3D diagnostics based on advanced 3D scanners, which, using special software and a spinal column device, enables, in addition to 3D scanning, an analysis of the patient in which way and to what extent he distributes his weight on both legs, and enables proper- correct body posture.

Short description of the pictures

Figure 1.a shows the spinal column device B and the 3D scanner A with balance scales - from the front

Figure 1.b shows the spinal column and scanner with balance scales - back

Figure 1.c shows the spinal column and the scanner with balance scales - side-on

Figure 2 shows a properly distributed load on the 3D scanner monitor

Figure 3 shows a comparison of incorrect and correct body posture, on the 3D scanner monitor

Figure 4 shows the correct holding position

Figure 5 shows the shortening of the left limb

Figure 6 shows the placement of plexi panels under the shorter limb

Figure 7 shows the actual 3D shape-model of the leg

Figure 8 shows the difference between the left leg and the right leg through the circumferences of the toes, the instep and the heel

Figure 9 shows a comparison of the width of the tread of the left and right feet

Figure 10.a shows the position and geometry of the left and right leg implants, view from the inside

Figure 10.b shows the position and geometry of the left and right leg implants, view from the outside

Figure 10.c. shows the position and geometry of the left and right leg implants, bottom view

Figure 11 shows an example of a shortened limb

Figure 12 shows an example of two-component soles with different heights/thicknesses

Figure 13 shows a scan of the shoe mold and a 3D overlay of the leg scan and the mold scan

Description of performance and functioning of the invention

This method of measurement is extremely important because properly distributed weight on both legs has an impact on the knees, hips, shoulders... more precisely, the entire biomechanics of the body.

Following the correct position of the body and the load distribution, it is extremely important that when making individual shoes, we see the patient's current posture and load distribution, in order to get a proper insight into the state of the plantar part of the foot, i.e. the key points - the surface of the sole on which the greatest pressure is applied and the slightest pressure.

Accordingly, Dr. Luigi 3D diagnostics found a solution in the form of a spinal column B, with a support 2 on wheels 4 and vertical slats 3, Fig. 1.a, 1.b and 1.c, with which we place the patient P in the correct position for the 3D scan and on that method, we "balance" that is, we distribute the patient's weight evenly on both legs. By applying this method of proper load distribution and the specialized 3D scanner A, Fig. 1.a, 1.b and 1.c, we are sure of the quality of the results of the foot scan as well as the further treatment of the patient in terms of preventive measures. Applying this foot analysis method, proper posture and proper load distribution, view D and view C on the 3D scanner monitor A, Fig.3. and Fig. 2, it is possible to compare the height difference of the legs, i.e. measure how much longer/shorter one leg is compared to the other.

If there is a shortening of one of the lower extremities, then the anterior superior iliac spine will be lower on the side of the shortened leg, and the joint between the spines will run diagonally, Fig. 4. and 5.

By placing plexi-plates F, of a certain thickness (0.1, 0.3, 0.5, 1 or more cm) under the shorter leg, in the example from this invention the right leg R is shorter, Fig. 6, the shortening is corrected, and the joint between the spin gets a horizontal flow .

The thickness of the used plexi panels F is also a measure of limb shortening.

This method of measurement - a combination of the spinal column B, proper distribution of the load and the placing of plexi-plates F under the shorter extremity - also gives us data on the localization of the shortening. If, in this repaired horizontal position of the pelvis, the joint between the greater prochanters also runs horizontally, i.e. it is parallel to the upper one, then the cause of the shortening lies below the greater trochanter. If the greater trochanter on the side of the shortening, despite the horizontal position of the pelvis, stands higher than on the healthy side, and therefore the junction of the trochanter runs diagonally down towards the healthy side, then the cause of the shortening should be sought in the area of the hip joint (coxa vara, congenital dislocation of the hip), Fig.4 . and 5. Finally, it is necessary to determine whether a shortening is real (anatomical) or apparent (functional). One leg can be functionally shortened - for example due to flexion contracture of the knee or hip - and the patient limps, but it is anatomically as long as the other leg.

Technical description of the measurement

Dr. Luigi 3D diagnostics has implemented its solution for measuring the shortening of the lower extremities through several stages that are essential for the best possible result of the final product and the health of the patient P:

the first phase is based on a 3D scan of the foot, during which patient P, in a painless and short-term way, we scan the appearance of the leg(s), and based on triangulation and polygonization, we get the actual 3D shape-model of the leg 8, view E on the 3D scanner monitor, Fig. .7.;

the second phase is carried out on the basis of the obtained 3D scan of the leg 8, i.e. we control the key ranges of the 3D model of the foot in characteristic positions. On any area of the surface of the 3D foot model, it is possible to control the circumference of the toes 5, the circumference of the instep 6 and the circumference of the heel 7, shown in cross-section in Fig. 8, in all directions of the coordinate system, i.e. rotation of the intersecting surfaces with the foot model.

Also in this phase, a comparison of the deviations of the two extremities L and R (two foot models) is performed in relation to each other, and the difference in deviations, if any, is sought.

The software automatically, based on the 3D scan, calculates the difference in leg length (left/right - L/R) and circumference, and based on the output results provides an estimate of the number of shoes that is completely accurate as well as the differences for all characteristic points, Fig. 8. and data in Table 1.

[image]

Table 1.

It is also possible to determine and compare the width of the tread part of the foot and the size of the surface used to step on a solid surface, Fig. 9.

In the third and fourth phase of measuring and analyzing the results, we arrive at the positioning and geometry of a specific implant G, Fig. 10.a, 10.b and 10.c, which is also one of the more influential factors related to the modeling and making of sole H in the end. The result of this measurement phase is ultimately the actual human footprint + implant (if needed), but this implant is ultimately not separate, but integrated into the entire structure of the polyurethane sole H.

the fifth phase of diagnostics is the basis of this entire project, which is the analysis of the height difference of the extremities (legs), Fig. 6. In this phase during the scan, an additional device, the spinal column B, is used to help us position the patient P in the correct position for the scan. During the scan, the patient must be placed in "balance", that is, the weight distribution must be such that balance scales 1, on the 3D scanner A, read the same load on the left L and right R leg, Fig. 2. If there is a shortening of one of the lower extremities, Fig. 11., then by placing plexiglass plates F of certain thickness under the shorter limb (R), we bring the patient P into the correct position for scanning and place him in "balance", i.e. we correct the shortening, and the thickness of the used the plexi sheet is also a measure of limb shortening.

When laying plexi panels F, we must also take their weight into account in order to ultimately get a correctly distributed load on both legs.

The final, sixth phase is also the analysis of all the previous phases and finally the creation of custom-made footwear, i.e. the creation of a personalized H shoe sole, Fig. 12., based on a 3D model of the foot 8. The goal was to create an H sole, i.e. the entire shoe, which will be visually the same for both the shortened extremity and the "normal" one, i.e. the outer contours of the design will not differ, while the inner part of the footwear will be adapted to each foot.

On Fig. 13. a scan of the shoe mold and a 3D overlay of the scan of the leg 8 and the scan of the mold 9 are shown.

LIST OF LETTER AND NUMERICAL MARKS IN THE DESCRIPTION AND PICTURES:

A – 3D scanner of the lower extremities and feet

1 – 3D scanner balance scales

B - spinal column - a device for placing the patient in the scanning position

2 – support of vertical slats

3 – vertical slats to control the proper posture of the patient's spinal column

4 – wheels of the spinal column

C – load display on the 3D scanner monitor

D – display of a comparison of incorrect and correct body posture on the 3D scanner monitor

E – display of the leg model on the 3D scanner monitor

5 – the circumference of the toes on the left L and right R foot

6 – circumference of the inseam on the L and R feet

7 – heel circumference on L and R foot

F – plexiglass panels

G – implant

8 – leg-foot scan/3D leg-foot model

9 – scan of the mold/3D model of the mold

H – sole

P – the patient

K – skeleton of the patient

L – left leg

R – right leg

Application of the invention

Dr.Luigi 3D diagnostics has a faithful representation of the concept of a computer CAD/CAM system intended for 3D modeling of footwear, based on the application of innovative technology and sophisticated software packages. Our concept involves the use of one or several types of 3D scanners, intended for scanning feet or shoe molds.

Scanning of shoe molds enables the implementation of a computer 3D model of the mold in software packages intended for computer design, 3D modeling, transformation of upper parts into 2D tailoring parts and grading of parts.

The accompanying computer program package of the 3D scanner for scanning the feet also enables the determination of characteristic anthropometric measurements on the foot, necessary for the modeling and production of special purpose footwear, according to the determined measurements and shape of the foot. The introduction of the presented CAD/CAM system into real conditions has the effect of shortening the time required for the development of a new product, while simultaneously saving materials and achieving high quality of the final product.

Claims (6)

1. Measurement of the height difference of the lower extremities, whereby, in order to create individual footwear as faithfully as possible, a 3D scanner is used to scan the feet, indicating that it includes the following stages: - first stage: 3D scan of the feet; - second stage: analysis of 3D leg scans; - the third and fourth stages: positioning and geometry of a specific implant for final modeling and sole making; - fifth stage: analysis of the height difference of the lower extremities using the spinal column device (B) which places the patient (P) in the correct position for the 3D scan of the feet; - sixth phase: analysis of all previous phases, and finally creation of personalized footwear based on a 3D model of the foot. 2. Measurement of the height difference of the lower extremities, according to claim 1, indicated that the first phase is based on a 3D scan of the foot, during which the patient (P) is scanned in a painless and short-term way, and based on triangulation and Polygonization gives the actual 3D shape-model of the leg (8). 3. Measurement of the height difference of the lower extremities, according to requirements 1 and 2, indicated that the second phase is carried out on the basis of the obtained 3D scan of the leg (8), i.e. the key ranges of the 3D model of the foot are controlled in characteristic positions so that on any in which area of the surface of the 3D foot model (8) is it possible to control the circumference of the toes (5), the circumference of the instep (6) and the circumference of the heel (7) in all directions of the coordinate system, i.e. the rotation of the intersecting surfaces with the foot model (8); that in the second phase, a comparison of the deviations of the two extremities - two foot models in relation to each other is made, and if there is a difference in the deviations, the software automatically, based on the 3D scan, calculates the difference in the length and girth of the legs (L) and (R) , and based on the output results gives an estimate of the number of shoes and the difference for all characteristic points of the foot; that in the second phase, the width of the stepping part of the foot and the size of the surface used for stepping on a solid surface are determined and compared. 4. Measurement of the height difference of the lower extremities, according to requirements 1, 2 and 3, indicated by the fact that in the third and fourth stages of measurement and analysis of the results, the positioning and geometry of a specific implant (G) is reached, which is also one of the most influential factors related to the final modeling and making of soles (H); that the result of the third and fourth phase of measurement is a real human impression with an implant, the implant (G) is not separate, but is integrated into the entire structure of the polyurethane sole (H). 5. Measurement of the height difference of the lower extremities, according to claim 1, 2, 3 and 4, indicated by the fact that the fifth phase refers to the analysis of the height difference of the legs (L) and (R) using an additional spinal device pillar (B) which helps to place the patient (P) in the correct position for scanning, so that during scanning the patient is balanced so that the weight is distributed so that the balance scales (1) on the scanner (A) read an equal load on the left (L) and right (R) leg; that if there is a shortening of one of the lower limbs, a plexi-plate (F) of certain thickness is placed under the shorter limb, which corrects the shortening of the leg, and the patient is brought into balance and in the correct position for scanning, that the thickness of the used plexi-plates (F) is also a measure shortening of the limbs, that the weight of the plexi panels is also taken into account when placing the plexi panels in order to ultimately obtain a correctly distributed load on both legs. 6. Measurement of the height difference of the lower extremities, according to requirements 1., 2., 3., 4., and 5., indicating that the sixth phase is the analysis of all previous phases and finally the production of custom-made footwear, that the production of a personalized sole ( H) footwear is based on a 3D foot model (8); that the manufactured sole (H) or the entire shoe, both for the shortened extremity and the normal-length one, is visually the same, that the outer contours of the footwear design do not differ, and the inner part of the footwear is adapted to each foot.