Cross references to related applications: This non-provisional specification is filed further to Indian patent application No. 202021013918 dated 30 April 2020.

FIELD OF THE INVENTION

This invention generally relates to the field of preemptive care in diabetes afflicted individuals. More particularly, the present invention relates to a device, and it’s implementing method, whereby plantar foot temperatures of diabetes afflicted individuals can be accurately mapped to identify predisposition and / or early onset of ulcerous foot and / or Charcot’s foot.

Definitions

Before undertaking the description of the invention below, it may be advantageous to set forth definitions of certain words or phrases used throughout this patent document. Also, as some technical terms are not used uniformly in the field of the instant invention, a few definitions are given in the following to clarify the meaning of terms as they are used in this paper. Accordingly, the following terms shall have the under-assigned interpretations-

“TLC” shall refer Thermochromic Liquid Crystals, which are heat-sensitive and have the property of exhibiting different colors, when visualized against a black background, indicative of the temperature of an object placed there-against; “Diabetic Foot” and “ulcerous foot” are used synonymously for each other in this document, and refer a foot that exhibits any pathology that results directly from diabetes mellitus or any long-term complication of diabetes mellitus;

“PCB” refers a printed circuit board;

“Processor” refers micro controllers (Arduino or other) other processor types and their equivalents;

“MQTT” refers Message Queuing Telemetry Transport. BACKGROUND OF THE INVENTION AND DESCRIPTION OF PRIOR ART

Diabetes is a group of metabolic disorders characterized by a high blood sugar level over a prolonged period of time ("About diabetes". World Health Organization). If left untreated, diabetes can lead to many serious long-term complications including diabetic keto-acidosis, hyper osmolar hyperglycemic state, cardiovascular disease, stroke, chronic kidney disease, foot ulcers, damage to the nerves, damage to the eyes, or even death ("Diabetes Fact sheet N°312". WHO). Hence there is a global demand for newer and better means of achieving reliable management of diabetes.

From a clinical perspective, the actual disease of diabetes can be controlled with medication in addition to dietary modifications, but the aforementioned complications of the disease are what cause the real damage to its victims. Hence, there is a pressing need in the art to have some means of avoiding or at least early detection of said complications.

As will be appreciated by the reader, complications associated with diabetic foot are a cause of frequent hospitalization. Proverbial lack of patient awareness, negligence, access to timely medical assistance and consequently the lack of due attention and care result in progression of this complication, which requires curetting of gangrenous mass, abscesses or even amputation of the affected limb. Open sores often form septic breeding grounds for infection, which can lead to further serious health complications, and in severe conditions, death. Hence, there is an acute need for having some means that can reliably determine the predisposition and / or onslaught of foot complications in diabetic patients in early stages.

Ironically, foot disease / complications in diabetic patients is often accompanied by peripheral neuropathy, which results in a false sense of well-being as the patient feels no sensation, pain or trauma. Unable to feel pain, the insensate foot patient is at great risk of foreign body infiltration, shoe irritation and the trauma caused by simple ambulation. Thus, it would be desirable that the means for determining the predisposition and / or onslaught of foot ulceration (or other foot complications) in diabetic patients are independent of these symptoms and external visual inspection.

Ulceration on the sole of the foot is most often preceded by an increase in skin surface temperature at the pre-ulceration and ulceration site and also before a dreaded complication known as Charcot’s foot. Rise in temperature is also associated with onset of Charcot’s foot. Thus, thermography has been identified in state of the art as a potential diagnostic tool in determining the predisposition and / or early onslaught of diabetic / insensate foot in diabetic patients.

While there were many common art references researched by the inventor(s) in ensuring that the present invention is novel, the following patent prior art was identified as related to the present invention, and thus worthwhile to discuss in more detail in context of the present invention - One set of such related prior art references is US5124819 (issued to Davis) US5678566 (issued to Dribbon), US4327742 (issued to Meyers et. al.). and US4327743 (issued to Katz) which disclose methodologies and devices to measure visual pattern of infrared heat emissions from a particular area of the body employing TLC technology.

Another reference is US8360987B2 (issued to Scott Kantro) discloses a console for measuring plantar foot pressure includes a support case and at least two temperature sensitive pads, disposed in the case, configured to allow a user to measure the temperature of the soles of their feet without assistance.

Yet another reference is US9095305B2 (assigned to Podimetrics Inc) which teaches a method of monitoring a patient's foot provides an open platform for receiving at least one foot. The platform has at least one temperature sensor for generating a plurality of temperature data values after receipt of the at least one foot. The method then forms a thermogram of the sole of the at least one foot from the temperature data, and determines whether the thermogram presents at least one of a plurality of prescribed patterns. Next, the method produces output information indicating the emergence of a pre-ulcer or progression of a known pre-ulcer in the at least one foot as a function of whether the thermogram is determined to present the at least one pattern.

However, none of the prior art references listed above have been able to achieve a simple, easy to use, low-cost, device for mapping plantar foot temperatures on a regular basis which is characterized in being amenable to patients with limited mobility, and otherwise designed to be used from a seated or standing position, and having sufficient sensitivity and resolution needed for allowing a patient to focus on high risk areas of the plantar surface of the foot. Thus, needs of art have not been satisfactorily addressed, preserving the need to invent for the applicants named herein.

Prior art, hence to the limited extent presently surveyed, does not list a single effective solution embracing all considerations mentioned hereinabove, thus preserving an acute necessity-to-invent for the present inventor who, as result of his focused research, has come up with novel solutions for resolving all needs of the art once and for all. Work of the presently named inventor, specifically directed against the technical problems recited hereinabove and currently part of the public domain including earlier filed patent applications, is neither expressly nor impliedly admitted as prior art against the present disclosures.

Technical issues that remain to be resolved

From the foregoing narration, at least the following issues are identified in prior art devices and techniques which are hence intended to be resolved by the present invention- a) Lack of precision and accuracy in identification of exact points for determination of plantar foot temperatures in diabetes afflicted individuals b) Lack of precision and accuracy in measurement of plantar foot temperatures in diabetes afflicted individuals c) Non-amenability to allow diabetes afflicted individuals to take their own plantar foot temperatures d) Non-amenability to allow temperature readings to be properly logged and / or transmitted to healthcare professionals (more so if the patient is in a different geography than the healthcare professional). e) No standard reference / calibration for clear determination of predispositions / early diagnosis for opportunity of early intervention and hence better prognosis.

The virtual absence of any reliable means to achieve the aforesaid wants of art form the background, hence incentive, for this invention.

A better understanding of underlying principles of the present invention will be obtained from the following narration which sets forth an illustrative yet-preferred embodiment. BRIEF DESCRIPTION OF DRAWINGS

The present invention is explained herein under with reference to the following drawings, in which- FIGURE 1 is a schematic isometric view of the device of the present invention. FIGURE 2 is a schematic sectional view of the device of the present invention. FIGURE 3 is a block diagram to explain operational logic of the present invention.

FIGURE 4A is a graph showcasing results of comparative study 1 , wherein a peer device is used for temperature measurements.

FIGURE 4B is a graph showcasing results of comparative study 1 , wherein the device of the present invention is used for temperature measurements.

FIGURE 5A is a graph showcasing results of comparative study 1 , wherein the device of the present invention is used for temperature measurements. FIGURE 5B is a graph showcasing results of comparative study 1 , wherein a peer device is used for temperature measurements.

The above drawings are illustrative of particular examples of the present invention but are not intended to limit the scope thereof. The drawings are not to scale (unless so stated) and are intended for use solely in conjunction with their explanations in the following detailed description. In above drawings, wherever possible, the same references and symbols have been used throughout to refer to the same or similar parts, as under-

(01) - hollow enclosure / box (06) - lead cable of (05) (02) - top-side surface of (01 ) (07) - pcb

(03) - base of (01 ) (08) - processor

(04) - heel-rest (09) - power cable

(05) - temperature sensor Though numbering has been introduced to demarcate reference to specific components in relation to such references being made in different sections of this specification, all components are not shown or numbered in each drawing to avoid obscuring the invention proposed.

Attention of the reader is now requested to the brief description to follow which narrates a preferred embodiment of the present invention and such other ways in which principles of the invention may be employed without parting from the essence of the invention claimed herein.

SUMMARY OF THE INVENTION

The present invention is directed toward a simple and cost effective device to identify predisposition and / or early onset of foot complications in diabetes patients. Said device comprises an enclosure having its top-side surface inclined at an angle of 30° which is provisioned with sensitive temperature sensors at strategic locations for automatic temperature measurement at said positions whenever the user places his / her foot / feet onto the foot template / outline provided on said top-side surface.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed at absorbing all advantages of prior art while overcoming, and not imbibing, any of its shortfalls, to thereby establish a simple and cost effective device, and it’s implementing method, whereby plantar foot temperatures of diabetes afflicted individuals can be accurately mapped to identify predisposition and / or early onset of foot complications in diabetes patients.

Preferred embodiment and reduction to practice-

The inventive device proposed herein foremost comprises a base module for allowing a diabetic patient to rest his / her feet for determination of plantar temperature. As seen in the accompanying FIGURE 1 , said base module is essentially a hollow enclosure / box (01) having its top-side surface (02) inclined at an angle of 30° with respect to the base (03) of said hollow box (01). This geometry allows the box to be placed flush on its base (03) atop a flat / ground surface, therein disposing the inclined surface (02) for placement of feet by the diabetic patient for determination of plantar temperature as will be disclosed further in this document. As seen further in the accompanying FIGURE 1 , an outline / map of a pair of feet (03a and 03b) and heel-rests (04a and 04b) are provided on the inclined surface (02) for allowing precise placement of feet by the diabetic patient. Seven sensitive temperature sensors (represented by the common numeral 05) are disposed in each of the outline / map of pair of feet (03a and 03b), therein protruding 2 mm above the outline / map (03a and 03b), for determination of plantar temperature, when feet of the diabetic patient are placed within the outline / map (03a and 03b) atop the inclined surface (02).

According to one aspect of the present invention, the hollow box (01) is made from suitably rigid material chosen among wood and / or 3D-printing composites and their combinations, and is made durable enough to bear the weight of the average human being.

According to another aspect of the present invention, the seven sensitive temperature sensors are designated, and so disposed at co-planar coordinates within the zones (03a and 03b) atop the inclined surface (02), so as to allow each sensor to independently measure temperature at the following sites- a) Great toe b) First metatarsophalangeal joint c) Mid fore foot d) 5 ^th metatarsophalangeal joint e) Lateral arch f) Medial to medial arch g) Heel

According to another aspect of the present invention, the temperature sensors (05 identified as a) to g) as above) are DS18B20 which have an accuracy of 0.05°C and measuring the temperature within -55 °C to +125 °C.

As seen next in the accompanying FIGURE 2, the temperature sensors (05 identified as a) to g) as above) are connected, via independent lead cables (represented by common numeral 06) to a PCB (07) placed within the hollow box (01). A processor (08) is provided on the PCB (07), a ESP8266 SoC (System on Chip) in particular, for execution of logic necessary for logging and interpretation of signals received from the temperature sensors (05 identified as a) to g) as above). A power cable (09) is provided traversing the hollow box (01) for connecting the PCB (07) to an external source of utility power (not shown in the drawing). In alternative embodiments, the device proposed herein may be provisioned to have batteries on-board within the enclosure (01) to thereby source electrical power required for operating the device disclosed herein.

The physical act of using the base module for allowing a diabetic patient to rest his / her feet for determination of plantar temperature is evident from the foregoing narration of this invention. Operational logic beyond this act is showcased in the accompanying FIGURE 3. In one embodiment, the plantar temperature data of a patient is relayed, via the low latency MQTT protocol, first to a mobile phone belonging to the patient or caregiver, and from there, secondly to a remote server belonging to a healthcare facility (for example a hospital, doctor’s clinic and the like) whereby expert personnel can monitor, ideally in real time, and prescribe / take suitable actions should the readings for any patient be beyond the thresholds normally expected. Interpretation of plantar temperatures logged in this manner follows conventional standards and knowhow in the art.

A cloud server is intended, in yet another embodiment, whereby plantar temperature data of a patient can be uploaded in real time for aforementioned analysis and action. It shall be understood that this system can be configured to take / convey plantar temperature data of a patient continuously Or at predetermined time intervals as may be desired.

Once data is available, it is parsed by conventional algorithms for establishment of thermograms and their differential diagnosis to determine incidence of ischemic or inflammatory processes, indicative of predisposition / early onslaught of diabetic foot.

The device for determination of plantar foot temperature as particularly disclosed in this paper has been reduced to practice by the applicants named herein, which list of materials and assembly protocol outlined above lends favorably to mass-production.

It shall further be generally understood by the reader that the modularity in construction of the device for determination of plantar foot temperature as particularly disclosed in this paper mandates part-wise serviceability and severance in parts that need to be replaced (particularly only those experiencing wear and tear) over replacement of the entire assembly / part thereof, thus saving on maintenance and operational costs, besides enhancing service life of said assembly.

Experimental validation The device for determination of plantar foot temperature as particularly disclosed in this paper has been experimentally validated for its intended performance.

In an independent study, a cohort of one hundred patients was selected, all adults, either male or female of age 21 years or above, of which 90 were diabetic patients. The median of these readings have been taken according to the category of patients which are shown in the tables 1 to 4 below.

Table 1 (Diabetic patient with foot problem)

From this table, it can be seen that the patients with diabetic foot problem have a temperature difference of 2.2 °C and greater, the device also helps in localizing where the issue lies to prevent any future complications, which in the given case is in 1st metatarsophalangeal joint and lateral arch.

Table 2 (Median of data of Diabetic patients with a foot problem)

The data in Table 2 doesn’t provide conclusive evidence as it is the median of all diabetic patients with foot issues, however, compared to readings of Table 4 a large variation can be seen in the temperature ranges and higher foot temperatures can be noted. Table 3 (Diabetic patients without a foot problem)

The data in Table 3 consists of the readings from diabetic patients without a foot problem and it acts as a point of reference with respect to the readings for diabetic patients having foot problems.

Table 4 (Patients without Diabetes)

Table 4 consists of the readings from patients without diabetes and it acts as a point of reference with respect to the readings for diabetic patients.

Table 5 gives an overall range of temperature amongst the entire group of patients, as under-

Table 5 (Foot Temperature Range for all patients)

Comparative studies Study 1 Efficacy and performance of the device for determination of plantar foot temperature as particularly disclosed in this paper has been studied in comparison to next-peer device, being a Kody Medical Non - contact Handheld Infrared Camera which has a measurement unit / resolution of 0.1 °C and accuracy of 0.3/0.5°C. In the study protocol herein, temperature was measured using both devices at following six points on feet of a cohort of human subjects -

1) Toe

2) 1 st Metatarsal

3) 3rd Metatarsal

4) 5th Metatarsal

5) Medial Arch

6) Sole

The toe region readings are compared of diabetic patients. The difference between the left and right toe for the peer device and the device of the present invention are as shown in FIGURE 4A and FIGURE 4B respectively. The results show that the device of the present invention, when compared to the peer device, shows a more consistent data measurement with lesser spread of data which speaks of improved precision and confidence of temperature measured to be used by healthcare professionals for interpretative analysis.

Also as seen in the FIGURE 4A and FIGURE 4B, the readings with a difference of 4+ °C would mean, when not necessarily the case, that the patient has heavy diabetes and might have problems with blood circulation or need amputation. This false positive result is not seen in the device of the present invention.

As true with all peer devices, the difference in readings might be due to either or both among measurement of wrong reading by the peer (Infrared) device and / or observer error in reading temperature. Both of these eventualities are avoided in the device of the present invention, as the temperature readings are logged automatically and / or displayed directly on the screen.

As can be further appreciated, wrong reading from the peer (infrared) device may be due to two reasons, one of them being not holding the thermometer at a proper distance or using them in unclean environments. The environment and the distance doesn’t affect the readings in the present invention, hence avoiding the possibility of wrong readings in the inventive device taught herein. The inaccuracy of peer (infrared) devices is well documented phenomena, thus cannot be reliable over sensors which are measuring by complete contact with the precise point / position where temperature needs to be measured. It is intended for the present invention to progress into related embodiments wherein temperature and pressure are attributes being mapped to identify predisposition and / or early onset of foot complications (such as ulcerous foot and others) in diabetic patients. Accordingly, the reduction to practice may embody footwear with in-built sensors which allow the logging of temperature and / or pressure data while the patient is going about his / her normal chores, that is regularly and without causing as fewer disruptions in life as possible and that too, outside hospital settings, even at home.

Study 2

Efficacy and performance of the device for determination of plantar foot temperature as particularly disclosed in this paper has been studied in comparison to another next-peer device, being a handheld infrared skin thermometer. The results are shown in graphs at FIGURE 5A and FIGURE 5B.

As for the protocol underlying the results showcased in graph at FIGURE 5A, the subject chosen is a male patient of age 58 years, with an 8 year history of diabetes but no amputation. First metatarsal temperature was logged using the device of the present invention over an extended period (in days).

As for the protocol underlying the results showcased in graph at FIGURE 5B, the subject chosen is a male patient of 56 years age, with a 7 year history of diabetes and amputation. First metatarsal temperature was logged using the peer device (handheld infrared skin thermometer) over an extended period (in days).

As seen from the accompanying FIGURE 5A and FIGURE 5B, the patients maintain a consistent temperature pattern throughout the period as seen in the graphs and did not experience any foot complication in that duration. The data for proposed device has been taken at the same position of 1st metatarsal, wherein it was seen that The temperature difference did go above 2.2 °C for the peer device but did not stay at that level, the same is observed in FIGURE 5B.

FIGURE 5A, in which study the device hereof was used, clearly shows a difference of more than 2.2 °C for a person suffering with diabetic foot problem and it is in arch and 1 ^st metatarsal region of the foot as recorded by the device. This aids the doctor in treating specific area and prevent further ulceration or pain for the patient. It can be concluded with this that the novel device design proposed herein helps in identifying the location where the problem exactly lies on the foot as compared to the devices that are conventionally used / available in the field of this invention. In FIGURE 5B, the temperature difference between the first metatarsal of right and left feet for 1 ^st metatarsal. Measurements that are above the 4°F “boundary” limit at the top of the graph represent higher temperatures on the right foot, and measurements beyond the lower “boundary” represent higher temperatures on the left foot.

From this study, it can be concluded that the device proposed herein gives similar results to an infrared thermometer while also being able to interpret data at various points simultaneously. The position of the foot is also constant for proposed device giving results in the same region accurately which is difficult to achieve with a handheld device.

Thus, this comparative study with the LCT (liquid crystal thermography) device led to the following conclusions-

1) LCT (device that requires contact with foot) provides thermographic images which can be hard to interpret, whereas the device proposed provides digitally readable data which can be easily interpreted by lay-man;

2) Even if contact-less LCT is used, it requires assistance for scanning the foot and interpreting the results, device proposed does not require any assistance or training;

3) LCT devices also require pre-defined time for reading the temperature otherwise it might lead to contamination of data, this is not the case when sensors are used as it does not lead to data contamination;

4) As the device proposed herein gives digital data corresponding to sites on the foot while having a designated area for foot positioning, it can be used by patients without extensive training.

The inventors named herein are of the belief that use of the device proposed herein shall assuredly help in not only curbing the incidence of diabetic foot but also the good habits inculcated could help in preventing the development of other disease- associated complications. Accordingly, use of the device proposed herein at home monitoring can reduce foot ulcers and further complications in >60% cases, which can be achieved with the proposed device. No advanced image processing techniques are required making the device considerably cost effective and robust for daily use. From the foregoing narration, an able device, and it’s implementing method, whereby plantar foot temperatures of diabetes afflicted individuals can be accurately mapped to identify predisposition and / or early onset of foot complications (including ulcerous foot) is thus provided with improved functionality, durability and long service life than any of its closest peers in state-of-art.

It shall be generally understood by the reader that although the present invention is described herein using specific terms, these are used in a generic and descriptive sense only and are not intended to be limiting.

As will be realized further, the present invention is capable of various other embodiments and that its several components and related details are capable of various alterations, all without departing from the basic concept of the present invention. Accordingly, the foregoing description will be regarded as illustrative in nature and not as restrictive in any form whatsoever. Modifications and variations of the system and apparatus described herein will be obvious to those skilled in the art. Such modifications and variations are intended to come within ambit of the present invention, which is limited only by the appended claims.

Most respectfully submitted on this 30 ^th Day of April 2021

Duly constituted agent for the applicant,

Rohit Nitin Deshpande

Advocate [MAFI/4858/2012] & Patent Agent [IN/PA-1389]

Address for service: Inventillect Consultants, Office no. 307, Business Guild Condominium, Apex Colony, ILS Law College road, Erandwane, Pune, Maharashtra, India - 411004 Email: rd@inventillect.com Phone: +91-9422944630