WO2019004812A1 - System for early detection of diabetic foot syndrome - Google Patents

Abstract

The invention relates to a system for early detection of diabetic foot syndrome, made up of: a raised platform with a seat on which the patient is placed; a base structure, which comprises an upper supporting plate and a lower supporting plate, wherein said upper supporting plate comprises a pair of windows, made of a transparent material, on which the patient places their feet; a terahertz (THz) image capturing system located on said lower supporting plate under the windows; and a PC, which communicates with said image capturing system in order to control same, and which comprises an algorithm for generating an image of the hydration of the foot; said THz image capturing system is made up of a pair of lenses placed at an angle; a photoconductive terahertz emitting means for emitting a THz signal towards the feet of the patient; a photoconductive terahertz detection means which receives the THz signal reflected by the feet of the patient, wherein said reflected THz signal corresponds to a THz pulse measurement in the reflection time domain; a positioning system, which moves the lenses and the emitting and detecting means along the windows to capture the THz pulses along the entire sole of both feet; wherein said PC processes each measurement of said THz pulses via said algorithm and generates an image of the hydration of the foot and reports specific hydration values, by using a Fresnel coefficient.

Description

The present invention directed to the technical field of early diagnosis devices. More particularly, the present invention relates to an early detection system of! diabetic foot syndrome by Terahertz image.

In the state of the art, it is well known that in 2.5% of cases of diabetic patients, the foot suffers a deterioration that ends in an amputation, which decreases the quality of life of the patients and produces an extraordinary cost to them. as to public health systems, since currently, in the state of the art there is no objective method for the early detection of this condition.

 In accordance with the above, the so-called "diabetic foot" or "diabetic foot syndrome" is a common consequence of Mel! Itus Diabetes (DM), where the foot of the diabetic person presents, in many cases, a combination of microvascular and neurological deterioration that results in poor irrigation and loss of sensation in the feet. The combination of these two conditions results in dehydration of the skin, which in turn becomes more fragile, coupled with a compromised ability to feel small injuries. This results in an increased risk for patients to develop severe ulcers, which in many cases requires partial or total amputation of the limb, which is the most common cause of non-traumatic amputations.

 The strict definition of diabetic foot that we can find is

"a foot affected by ulceration, which is associated with neuropathy and / or peripheral arterial disease of the lower limb in a patient with This definition unfortunately does not give much room for an early diagnosis, and is the consequence of the lack of an objective and quantitative detection method that allows to carry out preventive actions.Therefore, the lack of an objective method has caused that to evaluation of preventive treatments is difficult.

 In this sense, podiatric evaluation is known that is the most used for diabetic patients before ulcers occur, it is a subjective test known as the monofilament that assesses neurological deterioration. This test consists of pricking the patient's foot with a flexible tip and asking the patient to report when they feel pressure, when the patient fails to report a number of punctures, the test is considered positive.

 An indirect test known as the arm-ankle index is also known, which uses Doppler ultrasound to compare the blood flow in the arm and ankle, which is an indicator of vascular deterioration. Imaging studies are also used, but they are usually only adequate in relatively advanced stages.

 As already mentioned, dehydration of the skin due to peripheral vascular disease is a central element in the process of deterioration of the diabetic foot, and therefore, the terahertz image according to the invention is an excellent tool for diagnosis.

Therefore, there is no system and method of early detection of diabetic foot syndrome by Terahertz image in the state of the art, which refers to a non-invasive technique, highly sensitive, and completely harmless to organisms, where the system performs an image of the hydration of the skin point to point, being able to detect problems locally before lesions are generated, which can guide both the doctor and the patient in the care of the feet, in addition opens the possibility of evaluating preventive treatments objectively. In this sense, because most foot ulcers experienced by diabetic patients occur in the sole of the foot, either in the big toe, or in the metatarsal area (the region where the toes meet the rest of! foot) and in the heel area, a complete image of the sole of the foot is required, which is possible thanks to the configuration of! system of the present invention. OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide a system and method of early detection of diabetic foot syndrome which §n where the adaptation of! Terahertz's image system allows you to make images of the plant! foot of living human beings.

 Another object of the invention is to provide a system and method for early detection of! diabetic foot syndrome that provides quantitative and objective information on the deterioration of the foot to prevent injury and the subsequent partial or total amputation of the limb,

A further object of the present invention is to provide a system and method of early detection of diabetic foot syndrome that performs a complete image of the sole from point-to-point skin hydration, to detect problems locally before that injuries are generated. ^'

 Another additional object of the present invention is to provide a method of early detection of the syndrome of! Diabetic foot objective, quantitative, non-invasive. fc Kfc ¥ fc Ufc¾L> jF iUiP¾ Ut LA S ¾ ¥ Kri§L »Uj¾

These and other objects are achieved through an early detection system! diabetic foot syndrome, which is conformed by: a raised platform with a seat where it will be placed! patient; a base structure aligned with said raised platform, which comprises a top support plate; and a lower support plate; wherein said upper support plate comprises in turn a pair of windows made of a material transparent to Terahertz radiation (THz), wherein the patient places the feet; an image capturing system of THz placed on said lower support plate under the windows; and a PC having a graphical control interface, which is in communication with said image acquisition system to have control thereof and which comprises an algorithm to generate a foot hydration image; said THz image acquisition system is formed by a pair of lenses placed in an angled manner; a Teraheriz photoconductive emitting medium aligned with the first lens to emit a THz signal towards the patient's feet through the windows; a Terahertz photoconductive sensing means aligned with the second lens which receives the THz signal reflected by the patient's feet, wherein said reflected THz signal corresponds to a THz pulse measurement in the reflection time domain; a positioning system, which transports the lenses and emitter and detector means along the windows to capture the THz pulses along the entire floor of both feet; wherein said PC performs the processing of each measurement of said THz pulses through said algorithm and generates a hydration image of the foot and reporting specific hydration values.

 In a second aspect, the present invention relates to a non-invasive method of early diagnosis of diabetic foot syndrome, which comprises the steps of:

 i) sit the patient in the chair;

 ii) place the patient's feet in the windows of the upper support plate;

 iii) perform the measurement of terahertz pulses in the time domain of the reflection along the entire floor of the patient's foot, by means of the steps of:

 a) emitting a signal of THz to a first point of the sole of the patient's foot through the windows, by means of said photoconductive emitter of Terahertz;

 b) receiving the THz signal reflected by said first point of the sole of the patient's foot;

c) repeat steps a) and b) along the entire sole of the foot, to obtain the measurement of all terahertz pulses of the entire plant! foot;

 iv) perform the processing of each measurement of said THz pulses through said algorithm; Y

 v) generate an image of hydration of the foot and report specific values of hydration of the foot.

 The additional features and advantages of the invention should be more clearly understood by the detailed description of the preferred embodiment thereof, given by means of a non-limiting example with reference to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of the early detection system of diabetic foot syndrome of the present invention.

 Figure 2 is a perspective view of the raised platform with seat of! Diabetic foot syndrome early detection system of the present invention.

 Figure 3 is a perspective view of the base structure and the Terahertz image capture system (THz) of the diabetic foot syndrome early detection system of the present invention.

 Figure 4 is a perspective view showing in detail the Terahertz image capture system (THz) of the diabetic foot syndrome early detection system of the present invention.

 Figure 5 is a schematic view showing measurement of terahertz pulses.

 Figure 6 is a perspective view of a second embodiment of the early detection system of diabetic foot syndrome of the present invention.

Figure 7 shows a comparative example of a hydration image of a healthy foot and a diabetic foot. DETAILED DESCRIPTION OF THE INVENTION

With reference to Figures 1-5 the preferred modality of the early detection system of the syndrome of! diabetic foot of the present invention, generally numbered 1000. Said detection system 1000 is generally formed by a substantially rectangular raised platform 1100; a chair or seat 1200 where the patient will be seated to be diagnosed; a substantially rectangular base structure 1300 aligned with said raised platform; an image acquisition system of Terahertz (THz) 1400; and a PC.

 With reference to Figure 2, it is shown that the raised platform 1100 is formed by a support plate 1110 attached to a frame with four legs 1120, wherein said elevated platform 1100 is configured to support said chair or seat 1200 where it will be made the measurement of the humidity of the feet of the patient. Similarly, as shown in Figure 3, said base structure 1300, is formed by an upper support plate 1310, and a lower support plate 1320 joined together by means of a frame with legs 1330. Said plate upper support 1310 further comprises a pair of rectangular openings or windows 1340, the cuates each comprising a panel made of a material transparent to Terahertz radiation, such as polyethylene, polystyrene, tops, TPX, Bendíay or the like. Said windows 1340 are configured so that the patient supports the soles of the feet, to perform the measurement of Terahertz pulses.

 Although in the preferred embodiment, the support plates 1110 and upper support plates 1310 are smooth, in alternative embodiments, said plates have a non-skid and / or thermal coating, to prevent the user from stepping on it from said plates and this could interfere in the measurement of Terahertz pulses.

As shown in Figures 1 and 3, in said lower support plate 1320 is the Terahertz image capture system (THz) 1400, which is located under the windows 1340 to move to along these to perform the measurement of all terahertz pulses of the entire plant of each foot. As shown in Figure 4, said Terahertz image acquisition system (THz) 1400 is formed by a base plate 1410, attached to said lower support plate 1320, a positioning system formed by a first longitudinal translation means 1420 , and a second transverse translation means 1430. Each of said translation means 1420 ^' , 1430 comprises a housing 1421, 1431 having inside it a positioning block 1422, 1432, which moves from one end to the other of said housing 1421, 1431 by means of an auger 1423, 1433, driven by a motor 1424, 1434. Said Terahertz image capture system (THz) 1400 further comprises an image acquisition means 1440 which is formed by a support plate 1441 having a substantially T-shaped shape, wherein in its upper part, said support plate 1441 comprises a pair of lenses 1442, 1443 of high density polyethylene or other material! transparent, the pairs are slightly angulated in a way found between them, at an angle that is in a range of between 0 ^or 90 ° in such a way that their focal point coincides with the exact position where they cross the two optical axes, forming an "emission-reception" geometry at an angle in the preferred embodiment of 12 ° to 15 °, (see Figure 5); a Terahertz photoconductive emitting means 1444 aligned with the first lens 1442 to emit a THz signal towards the patient's feet through the windows 1340, a Terahertz photoconductive sensing means 1445 aligned with the second lens 1443 which receives the signal from THz reflected by the patient's feet as shown in Figure 5.

As can also be seen in Figure 4, the image acquisition means 1440 is linked to the positioning block 1432 of the second transverse translation means 1430, and said second transverse translation means 1430 is in turn connected to the positioning block 1422 of the first longitudinal translation means 1420, such that said first longitudinal translation means 1420 translationally moves to said second transverse translation means 1430, which in turn translationally moves said image acquisition means 1440, for Positioning said image capturing means 1440 across the length and width of each window to perform the measurement of the Terahertz pulses in the entire floor of each of the patient's feet.

 In accordance with the present invention, the Terahertz systems 1444 and 1445 used are fired by an ultrafast laser which in the preferred embodiment produces pulses of 90 fs with a repetition rate of 100 MHz, with an average power of 120 mW and a length of central wave of 1550 nm. The pulses are divided into two parts, the first is coupled to a fiber and sent to a photoconductive emitter of InGaAs 1444 in order to produce terahertz pulses. The second part of the pulse is sent to a delay line controlled by the computer and later it is collected to a fiber and finally it is sent to a photoconductive detector of InGaAs 1445,

 Although in the preferred embodiment, the ultrafast laser produces pulses of 90 fs, it will be apparent to one skilled in the art that another type of ultrafast lasers can be used with different pulse and frequencies without departing from the scope of the present invention. Likewise, it will also be evident to a person skilled in the art that other types of photoconductive emitters and detectors can be used that perform the same function, without departing from the scope of the present invention.

 Said photoconductive detector means of Terahertz 1445 is connected to a signal acquirer and this in turn to said PC either wired or wirelessly (see Figure 6 as reference), to send the measurements of the. Terahertz pulses of the entire floor of each of the feet of the user, wherein said measurements are made by emitting THz signals towards the sole of the patient's foot, by means of said photoconductive emitter of Terahertz, and subsequently receiving the signals of THz reflected by said plants from the patient's feet.

Said PC comprises a graphical control interface by means of which the user interacts and controls the system, said PC is in communication with said system of capturing images through said photoconductive detector means of Terahertz 1445 to have control thereof and by means of a Algorithm generates a hydration image of the foot. Said algorithm realizes said hydration image of the foot from the radiation reflected in terahertz by means of the following operations:

 a) detect bs points with absence of foot (ie where the second face is polyethylene-air) and reported as "zeros" for the generation of the hydration image. Using these points an empirical calibration factor is calculated.

 b) separating the signal in the time domain in the reflection corresponding to the first window face (air-polyethylene) and the second one (foot-window).

 c) Perform the Founer transform of the two halves of the signal of the points corresponding to the foot separately. d) calculate the Fresnei coefficient of the foot using the first Founer transform as a reference and the second as the sample and taking into account the empirical calibration factor. e) use an optimization method such as or least squares adjustment to find the water content from the Fresnei coefficient mentioned in the above numeral, adjusting the volumetric fraction of water and dry tissue in an effective medium model (co o) LLL or Maxweil-Garnet) combined with the theoretical expressions that relate the dielectric function, the refractive index and the Fresnei coefficient (see Fov / íes.Introduction to Modenr Optics).

 f) Place the hydration values obtained from the adjustment in a matrix according to the position in which each measurement was obtained, from this the hydration image is generated and the other values that have diagnostic relevance can be calculated.

g) Calculate the numerical values such as average ^" hydration, hydration in the big toe and in the heel. An example of the hydration image generated by the PC algorithm is shown in Figure 7, where the teraheríz image a) refers to a healthy foot and the terahertz image (b) refers to a diabetic foot.

 Although in the preferred embodiment, the algorithm used performs the image of hydration of the foot by means of a Fresnel coefficient, it will be evident to a person skilled in the art that another type of algorithm can be used which in turn uses an effective medium model without departing of the scope of the present invention

 The operation of the system is described below:

 First, the PC and the capture system 1400 are turned on, the patient is then seated in the chair 1200 and instructed to place the feet in the windows of the upper support plate and not to move them;

 Subsequently, the measurement of terahertz pulses is carried out in the time domain of the reflection along the entire floor of each foot of the patient, through the operations of:

 * emit a THz signal to a first point of the floor • of the patient's foot through said windows 1310, by means of said photoconductive emitter of Terahertz ® receiving the THz signal reflected by said first point of the sole of the patient's foot ;

 • repeat steps a) and b) along the entire sole of the foot, to obtain the measurement of all the terahertz pulses of the entire sole of the foot;

 Once these measurements are obtained, they are sent to the

PC, to perform the processing of each measurement of said THz pulses through said algorithm, to finally generate a hydration image of the foot and report specific values of foot hydration, as shown in Figure 7.

With reference to Figure 6, a second mode of the early defection system of! diabetic foot syndrome of the present invention numbered 2000, wherein the elevated platform and the The base structure is integrated into a single supporting plate 2100 supported by a single frame 2200 with six legs, wherein the rear part of said frame has a section without upper support plate 2100, in which the seat 2300 where it is placed the patient is directly attached to said frame 2200. Also, on the front of said frame 2200 is the lower support plate 2400 attached to the front and center legs of said frame 2200, where the 2500 collection system is placed .

 The front part of the upper support plate 2100 comprises the windows 2110 where the patient's feet are placed.

 Said early detection system 2000 further comprises a safety rail 2600, which helps the patient to move safely on the upper support plate 2100 to sit on the seat, and a removable step 2800, which facilitates the The patient is placed on the upper support plate 2100. Also, the upper support plate 2100 comprises a coating of anion-slip material to prevent the patient from slipping.

 According to what has been described above, it will be evident to a person skilled in the art that the modalities of the early detection system of the diabetic foot syndrome and its respective components described above are presented for illustrative purposes only, since a person skilled in the art can perform numerous variations thereof, provided they are designed in accordance with the principles of the present invention. As a consequence of the foregoing, the present invention includes all the modalities that a person skilled in the art can propose based on the concepts contained in the present description, in accordance with the following claims.

Claims

1.- Early detection system of! Diabetic foot syndrome, characterized in that it comprises: a raised platform with a seat where the patient will be placed; a base structure aligned with said raised platform, which comprises an upper support plate, and a lower support plate; wherein said top support plate comprises a pair of windows made of a material transparent to Terahertz radiation (THz) in which the patient places the feet; an image capturing system of THz placed on said lower support plate under the windows; and a PC that has a graphical control interface, which is in communication with said image acquisition system to have control thereof and that incorporates an algorithm to generate a foot hydration image; said THz image capture system is UniUH i lclUU pU3 Um as Ufe? ¡¡¿Ut? B UUU UUU Ufe? U!!? <<Á US US US US US US US US US US ¡¡¡¡¡¡¡¡¡¡¡¡¡alineado alineado alineado alineado alineado alineado alineado alineado alineado alineado alineado alineado alineado alineado alineado Te TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH TH; a Terahertz photoconductive detector means aligned with the second lens and which receives the THz signal reflected by the patient's feet, wherein said reflected THz signal corresponds to a THz pulse measurement in the reflection time domain; a positioning system. which transports the lenses and emitting and detecting means along the windows to capture these THz pulses along the entire floor of both feet; wherein said PC performs the processing of each measurement of said THz pulses through said algorithm and generates a hydration image of the foot, reporting specific hydration values. 2, ~ The early detection system according to claim 1, further characterized said windows each comprise a panel made of a material transparent to THz radiation, selected from the group consisting of polyethylene, polystyrene, tops, TPX, Bendlay or the Similary.  3. The early detection system according to claim 1, further characterized in that said supporting plates and upper support comprise a non-slip and / or thermal coating, · 4. The early detection system according to claim 1, further characterized in that the angle between the lenses is in a range of between 0 ^or 90 ° in such a way that its focal point coincides with the exact position where the two intersect optical axes, thus forming an "emission-reception" geometry at an angle between 0 ° to 90.  5. The early detection system according to claim 1, further characterized in that the emitting medium and the detector means correspond to Terahertz systems based on an ultra-fast laser.  8. The early detection system according to claim 1, further characterized in that said Terahertz photoconductive detector means is connected to said PC in a wired or wireless manner. I. System for the early detection of diabetic foot syndrome, characterized in that it comprises: a top support plate, placed on a frame with a plurality of legs; wherein the rear part of said frame comprises a section without said upper support plate, in which a seat in which the patient is placed is attached; and in the front part of said frame there is a lower support plate attached to the front and central legs of said frame; the front part of said upper support plate comprises a pair of windows made of a transparent material in which the patient places the feet; a Terahertz image capture system (THz) placed on said lower support plate under the windows; and a PC having a graphical control interface, which is in communication with said image capture system to have control thereof and which incorporates an algorithm to generate a foot ñidratation image; said THz image acquisition system is formed by a pair of lenses placed in an angled manner; a medium Terahertz photoconductive emitter aligned with the first lens to emit a THz signal towards the patient's feet through the windows; a Terahertz photoconductive detector means aligned with the second lens which receives the THz signal reflected by the patient's feet, wherein said reflected THz signal 5 corresponds to a THz pulse measurement in the reflection time domain; a positioning system, which transports the lenses and emitter and detector means along the windows to capture the THz pulses along the entire floor of both feet; wherein said PC performs the processing of each measurement of said THz pulses through said algorithm and generates a hydration image of the foot and reports specific hydration values; wherein said frame further comprises a safety handrail, which helps the patient to move safely on the upper support plate to sit on the seat,  8. - The early detection system according to claim 7, further characterized said windows each comprising a panel made of a transparent material, selected from the group consisting of polyethylene, polystyrene, tops, TPX, Bendlay or the like.  9. - The early detection system according to claim 7, further characterized in that said upper support plate 20 comprises an anti-skid and / or thermal coating. 10. The early detection system according to claim 7, further characterized in that the angle between the lenses is in a range of between 0 ^or 90 ° in such a way that its focal point coincides with the exact position where the two cross optical axes, thus forming a geometry ^• 25 "emission-reception" at an angle between 0 ^or 90.  1. The early detection system according to claim 7, further characterized in that the emitting medium and the detector means correspond to Terahertz systems based on an ultra-fast laser. 30 12.- The early warning system according to claim 7, further characterized ^■ in that said means photoconductive terahertz detector is connected to said PC or wired manner wirelessly  13. - E! An early detection system according to claim 7, further characterized in that said frame further comprises a step, which facilitates the patient to climb on the upper support plate.  14. - A non-invasive method of early diagnosis of diabetic foot syndrome, which uses the detection system according to claims 1 to 13, characterized in that it comprises the steps of:  i) sit the patient in the chair;  ii) place the patient's feet in the windows of the upper support plate;  iíi) perform the measurement of Terahertz pulses (THz) in the time domain by measuring the reflection of THz radiations along the entire sole of the patient's foot, through the steps of:  a) emitting a THz signal towards a first point of the sole of the patient's foot through the windows, by means of said photoconductive emitter of Terahertz;  b) receiving the THz signal reflected by said first point of the sole of the patient's foot;  c) repeating steps a) and b) along the whole sole of the foot, to obtain the measurement of all terahertz pulses of the entire sole of the foot;  iv) perform the processing of each measurement of said THz pulses through said algorithm; Y * v) generate an image of hydration of the foot and report specific values of foot hydration.