The present invention generally relates to medical diagnostic devices. More particularly, the present invention relates to a device to detect and monitor diabetic foot ulcers.
Comprehensive diabetic medical care involves regularly scheduled clinic visits with an experienced podiatrist for foot ulcer surveillance. Frequent visits are required as diabetic neuropathy, which leads to impaired proprioceptive and nociceptive signaling along distal nerve tracks, especially in the lower extremities, is a significant feature of diabetes progression. Therefore, an appreciable and growing minority of the national population is susceptible to the development of foot ulcers. Current estimates of the national diabetes population approach 40 million Unites States citizens alone. Nearly a quarter of these individuals will develop a foot ulcer at one point in their life, with foot ulcers representing the primary inciting event that may ultimately lead to limb amputation.
Various methods and devices for early detection of tissue injury in the lower extremities, especially the plantar surface, have been implemented over the past decades. These methods range in sophistication from deep tissue imaging and real-time temperature recording to simple visual inspection. However, the most common treatment remains the combination of regular visual inspection by the patient or their partner in combination with multi-annum visits to a foot specialist trained in the management of diabetic patients. Consistency with this simple regimen has proven to be the most cost-effective approach as it does not require a great degree of technological sophistication whilst achieving adequate efficacy for per foot ulcer prevention.
Though ulcers are frequently seen daily in busy podiatric practices, most patients will present with the plantar surface completely intact and without any obvious lesions even though pre-lesions are present. Further, the patient may present with calluses or tissue changes that occur gradually over time as dictated by friction and pressure. These subtle tissue changes may easily be missed by practitioners.
There are sophisticated pressure sensor systems regularly used by podiatry clinics to diagnose issues with the plantar surface. These devices normally perform diagnostics by monitoring weight redistribution across the plantar surface during ambulation. However, minor changes which can be clinically meaningful in plantar surface structure/composition or other baseline physiological signals can be missed in these systems. It is thus to an improved diabetic foot ulcer diagnostic device that the present invention is primarily directed.
Briefly described, the present system and device is a diabetic foot examining device designed to fit within the paradigm of already established medical practice which could be more readily produced at scale and easily implemented into the current workflow of a footcare specialist, or deployed with a patient in a home-healthcare setting. The present technology is in the form of a frontend image capture system which acts as a structure for easily acquiring images, in addition to containing software to locally method video and image recordings to extract relevant physiological data in the assessment of acute and chronic plantar surface wounds. The build design, namely, an angled transparent diagnostic pane with sufficient surface area and imaging distance to simultaneously capture both left and right plantar surfaces using a simple off the shelf camera at a distance.
In one embodiment, the invention is a diabetic foot examination device, having a body with a base and an upper structure, and the base including a generally horizontal support configured to rest on a generally planar surface. There is a diagnostic pane located on the upper structure of the body, the diagnostic pane held at an angled relation to the base, the diagnostic pane at least partially transparent to visible light and configured to support at least one foot placed thereupon. There is also at least one camera affixed to the body and detecting illumination in the electromagnetic spectrum, with the camera positioned to view a foot placed against the diagnostic pane and generating diagnostic data from the detected illumination.
The device also includes at least one illumination source affixed to the body, that provides, at least, illumination in the electromagnetic spectrum directed at the diagnostic pane. A computer platform, which can be located in the or next to the body, is in communication with the camera and illumination source and is configured to control the illumination source to selectively direct illumination at the diagnostic pane when at least one foot is placed thereagainst, receive diagnostic data from the camera, and detect a presence of diabetic ulcers in the at least one foot based upon the received diagnostic data to create a diabetic ulcer diagnostic data.
The device can be embodied with at least one sensor connected to the computer platform, the at least one sensor detecting at least one foot being placed on the diagnostic pane. The device can also further include a wireless transmission module connected to the computer platform that selectively transmits the diabetic ulcer diagnostic data to other computer devices. Alternatively, the computer platform can be in wired communication with at least one other computer device and selectively transmit diabetic ulcer diagnostic data across the wired communication.
In one embodiment, the body of the device further includes a power source conductively connected to and powering the computer platform, camera and at least one illumination source. Further, the camera can detect visible light, or non-visible light such as UV or infrared. The diagnostic data can include multi-spectral imaging of at least one foot placed against the diagnostic pane.
Additionally, the device can include a second diagnostic device affixed to the body and selectively obtaining secondary diagnostic data from a foot placed on the diagnostic pane. The second diagnostic device can create secondary diagnostic data from one of optical coherence tomography, ultrasound scanning, Doppler scanning, autofluorescence, or laser speckle flowmetry.
In one embodiment, the invention includes a method of diagnosing diabetic ulcers in a foot utilizing the device. The method starts with placing at least one foot against a diagnostic pane of a diabetic foot examination device, illuminating the at least one foot from the illumination source, generating diagnostic data from the camera, receiving the diagnostic data at the computer platform, detecting a presence of diabetic ulcers in the at least one foot based upon the received diagnostic data, and creating, at the computer platform, a diabetic ulcer diagnostic data. The method can further include detecting at least one foot being placed on the diagnostic pane from at least one sensor connected to the computer platform.
Additionally, the method can further include selectively transmitting the diabetic ulcer diagnostic data to other computer devices, either wirelessly or in wired transmission. If embodied with a power source, the method can further include powering the computer platform, camera and at least one illumination source from a power source conductively connected thereto. The power source can be integrated into the device or be located externally thereto.
The method can include selectively obtaining secondary diagnostic data from a second diagnostic device affixed to the body, if present, and the secondary diagnostic data is for a foot placed on the diagnostic pane. The second diagnostic device can detect one or a combination of: visible light, ultraviolet light, and infra-red light.
The device can further include additional equipment to monitor physiological signals which can be captured for diagnostic purposes. These include, but are not limited to, photoplethysmography technique which extracts small signal pulsations to infer vascular flow in a tissue bed, and two-dimensional tissue oxygen saturation (SpO2) using the modified Beer-Lambert law.
The present invention therefore is advantageous in that it can reliably diagnose diabetic foot ulcers based on, at least, precise visual image data, either in a clinic or at-home setting. The present invention also has industrial applicability in that it provides a manufacturable medical device providing useful diagnostic information. Other objects, advantages, and features of the present invention will be apparent to one of skill in the art after review of the present application.
With reference to the figures in which like numerals represent like elements throughout the several views,
The device 10 also includes at least one illumination source 22 affixed to the body 11, such as an LED bar or other lighting source, that provides, at least, illumination in the electromagnetic spectrum directed at the diagnostic pane 16. There is a computer platform 24, which can be located in the or next to the body 11, that is in communication with the camera 18 and illumination source 22 and is configured to control the illumination source 22 to selectively direct illumination at the diagnostic pane 16 when at least one foot 20 is placed thereagainst. The computer platform 24 then receives diagnostic data from the camera 18 and detects a presence of diabetic ulcers in the at least one foot 20 based upon the received diagnostic data to create a diabetic ulcer diagnostic data.
The device 10 can be embodied with at least one sensor connected to the computer platform, the at least one sensor 26 detecting at least one foot being placed on the diagnostic pane 16. The device 10 can also further include a wireless transmission module 52 connected to the computer platform 24 that selectively transmits the diabetic ulcer diagnostic data to other computer devices, such as diagnostic computer device 50. Alternatively, the computer platform 24 can be in wired communication with at least one other computer device, such as diagnostic computer device 50, and selectively transmit diabetic ulcer diagnostic data across the wired communication.
In one embodiment, the body 11 of the device 10 further includes a power source 54 conductively connected to and powering the computer platform 24, camera 28, and at least one illumination source 22. Further, the camera 18 can detect visible light, or non-visible light such as UV or infrared. The diagnostic data can include multi-spectral imaging of at least one foot 20 placed against the diagnostic pane 16, as more specifically shown in
Additionally, the device 10 can include a second diagnostic device 62 affixed to the body 11 and selectively obtaining secondary diagnostic data from a foot 20 placed on the diagnostic pane 16. The second diagnostic device 62 can create secondary diagnostic data from one of optical coherence tomography, ultrasound scanning, Doppler scanning, autofluorescence, or laser speckle flowmetry. The device 10 can therefore detect one or more of frank ulcers, regions of skin irritation/inflammation, dryness, changes in plantar surface integrity (using patient history), heart rate (pulse waveform), blood pressure (using PTT and HR current signal), or local tissue oxygenation (via multi-spectral imaging) (
The aluminum frame for the body 11 can be made with machined aluminum brackets to fix the shown angles. The imaging plane, which can be angled between 30-60 degrees above the horizontal plane (angle B), acts as a footrest which the patient places their feet 26,38 on to be imaged by the camera 18 which is positioned at the posterior position. The distances are such that the camera, using a custom lens, captures the full extent of the image plate. IR sensors 26 flank the edge of the diagnostic pane 16 to detect the presence of a foot 20 to be imaged.
Then, in this embodiment, the method continues with RGB debayering of the illumination data from the camera 18, as shown at step 76, which can occur on the computer platform 24. The plantar surface, such as plantar surfaces 36,38 in
Otherwise, if the received diagnostic data at the computer platform 24 is adequate at decision 82, the received data is segments and the method detects a presence of diabetic ulcers in the at least one foot 20 based upon the received diagnostic data, as shown at step 84. Then diabetic ulcer diagnostic data is created at the computer platform 24 and can be stored and/or output, as shown at step 86. Then the diagnostic method stops, as shown at Stop 88.
If the device 10 is so embodied such as in
If the device 10 is so embodied such as in
As shown in
As shown, the image capture sequence starts with illumination source 22, which is multispectral (White, Red 106, Green 110, Blue 108), signals the patient to keep feet in place. First, the white light turns on to capture a base image, as in
Once the capture sequence is complete, initial modeling begins to segment regions of the foot vs non-foot regions. A preliminary analysis is performed to determine if the next stage of modeling can proceed or whether a new capture sequence should occur. In one embodiment, the decision is signaled to the user via a light sequence (at decision 82). If the decision to proceed with analysis occurs, then the system completes a more sophisticated modeling algorithm where subregions of the foot (heel, midfoot, large toe, pinky toe, etc) are automatically identified using geometric assumptions of foot shape. Next, lesions across the plantar surface are detected using simple segmentation and multispectral weighting, as shown, such as by a vector combination of RGB in pixel space to differentiate neighboring healthy tissue from a lesioned area (ulcer 104). In addition to lesion identification, an estimate of SpO2 can derived using the modified Beer lambert law.
The device 10 can therefore provide a lesion detection system which will identify and track current (or predict future) plantar surface lesions using a lesion classification system. The decision matrix include not only areal extent of the lesion segment, but also the position classification on the foot. For example, a lesion of equivalent area on the heel, a surface which supports a high load, would have a poorer predictive score than on the medial arch of the foot. Each area can be defined in a gradient manner not necessarily restricted to medically or anatomically defined regions, i.e., there may be patient specific morphology which causes a region of a patient's foot has a worse predictive score than another.
Local areas of tissue oxygenation (estimated by RG channel ratio reflectance) can be followed over time to quantify the recovery from the induced ischemia. The graph below shows the oxygenation correlated over time in the region of the Hallux (big toe) for both the occluded and non-occluded feet.
The vascular damage to various tissues that occurs with progression of diabetes is not evenly distributed in space or time. A multitude of factors including friction, exposure, and trauma contribute to accelerated tissue damage. Conversely, certain tissues are less affected by diabetes related vascular injury but are still subject to age related changes and other processes which are, in part, a function of anatomy (e.g., the prolonged vessel length supplying distal extremities). Therefore, comparisons of like to like tissue surfaces heightens the ability to distinguish physiologic vascular features from pathologic changes. Within the appropriate patient population (i.e. those with bilaterally intact plantar surfaces), the present invention offers a fundamental advantage: the simultaneous imaging of left and right plantar surfaces. This feature is exploited in the software processing pipeline to accentuate differences between plantar surfaces 36,38. Following low pass spatial filtering and automated labelling of plantar tissue regions, corresponding locales are compared to amplify differences in moment-to-moment tissue oxygenation and pulsation signals. This process is analogous to analog difference amplifiers which maximize differences in voltage signals as would be known to one of skill in the art.
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below, if any, are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of one or more aspects of the invention and the practical application, and to enable others of ordinary skill in the art to understand one or more aspects of the invention for various embodiments with various modifications as are suited to the particular use contemplated.
This application claims the benefit of U.S. Provisional Patent Application No. 63/458,991, filed Apr. 13, 2024, the entirety of which is hereby incorporated herein by this reference.
Number | Date | Country | |
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63458991 | Apr 2023 | US |