Design and Implementation of a Novel Real-time Wearable System for Early Detection of Diabetic Foot Ulcer (DFU)
Why many of diabetic patients are losing their feet, and can we prevent that before it happens?
Diabetic Foot Ulcer (DFU) is one of the many life-threatening and lifelong consequences of Diabetes, a silent killer affecting the whole world, as well as the Qatari population. DFU is the devastating direct result of a condition known as “Diabetic Neuropathy” which causes damage to the nervous system. This harm is often unnoticed by the patient as the nerves themselves die out and become numb, without pain. While it is fortunate that this effect is painless, it has the unfortunate consequence of going unnoticed, and thereby untreated. In this case the problem only becomes obvious when the permanent nerve damage causes loss of feeling in a large portion of the foot or leg. At this point, amputation is the only option.
Our team has collaborated tirelessly to tackle this trauma by designing a product that can detect DFU in its earliest stages. We are proud to detail this product extensively throughout this website, for the sole purpose of saving people from suffering. To be effective, our product has been successfully designed to be reliable, inexpensive, and non-invasive. The product attaches to the sole of the foot to detect telltale effects of DFU on a person’s gait.
The technology that enables this product has been assessed against all options and have been determined to be the most feasible and the most effective. Real-time monitoring can be done from each person’s own home by relying on a low-energy Bluetooth wireless transfer method. Assessment of severity will be conducted by established Machine Learning classifiers which will continue to improve with expanded use. Furthermore, the product requires low maintenance and can be operated easily. We hope to massively expands the ability to detect this disastrous damage while simultaneously reducing the strain on the healthcare system.
Background
Diabetes Mellitus is a chronic medical condition resulting from a high amount of sugar in the blood, which often leads to severe health complications like heart-related diseases, kidney failure, blindness and lower limb amputation.
Feet neuropathy is another issue encountered by diabetic patients that leads to the improper blood supply in leg veins, which accordingly leaves the patient suffering from poor foot healing and un-recoverable infections. Due to poor blood circulation, the infection may easily spread unnoticed until it requires complete amputation.
The development of diabetic foot ulcer (DFU) arises with the absence in the lower limb sensations, which eventually leaves the patient applying extra pressure on the foot and skin wounds to start appearing as well, and the planter temperature rises which indicates that the patient is at risk.
Statistically, diabetes is causing approximately eighty-four percent lower limb amputation among the diabetic population. DFU’s recurrences rate is also significantly high and approximately 40% after the first year whereas 60% within three years of occurrence.
Qatar especially is witnessing a dramatic rise in DFU due to the high spread of diabetes which is about 16%, and DFU has been reported to be a major reason for people’s check-in at Hamad General Hospital. Nonetheless, this is a worldwide pandemic and it has been reported that amputation operation is performed every 20 seconds because of diabetes.
Prevention is better than cure for this disease in particular, as the severe effects at the advanced stages of the disease could be inevitable. This can be performed through careful self-monitoring with no medical assistance. There are a variety of different techniques for early detection of DFU available worldwide however, all currently available techniques have limitations. One requires extensive medical assistance and as such can only be performed once a day with clinical guidance, others propose materials that are too expensive or too fragile.
Problem Definition
A stepwise survey done in Qatar by the World Health Organization (WHO) during 2012 indicated that 16.7% of the Qatari population suffers from Diabetes. Moreover, 11-23% of people in Qatar have pre-Diabetes symptoms or under risk of being detected Diabetes positive, and approximately 23% of pregnant women in Qatar are diagnosed with Gestational Diabetes, which occurs only in pregnant women and appears after giving birth.
Perhaps most frightening is that one-third of the Qatari population with diabetes remained unaware of their disease during the time of the survey, thereby underscoring the need for effective detection of this condition and its symptoms.
The consequences of Diabetes do not only comprise a person’s health, but also their money, time, and the food they can eat. Individual and societal mental health are also severely affected. It can even be passed down to our children.
Sadly, the initial diagnosis of Diabetes is often dismissed as trivial and easily controlled. In reality proper monitoring and mitigation efforts prevent this condition from resulting in in increased healthcare costs, decreased quality of life, amputation and death.
To avoid these unwanted consequences, currently a diabetic patient considered at ‘high risk’ of being infected with DFU) needs regular check-ups, hygienic personal care, and continuous expensive medication. As such, early detection and better classification tools for DFU symptoms can enable correct diagnosis, effective treatment and timely intervention.
There are two critical features to enable this. Real-time results make these devices robust reliable for diagnoses. Second, home-monitoring is also crucial to enable widespread adoption. Visual inspection cannot fully satisfy these requirements as patients do not have the expertise to recognize the symptoms of DFU.
On the other hand, our wearable solution monitors foot pressure and gait patterns on a regular basis as an indicative early warning system, and its visual representation on a computer screen is easily understandable making it suitable for home-monitoring.
Justification of the Novelty
After checking many research and commercial products, it was found that,
- Previous works did part of the research
- Some analyzed Gait Cycle by vGRF or IMU, others analyzed EMG or Foot temperature
- A few researchers worked in Machine Learning, Statistical Analysis or even efficient Data Gathering
- But combining Machine Learning to classify data collected by constructed Smart Insole and Data Logger is completely NOVEL.
Aims and Objectives
Our team builds upon work completed by our predecessors to propose our final solution, as summarized below.
Design Constraints and Standards
1. Constraints
The real-time wearable system for early detection of DFU has specific constraints and limitations that must be taken into consideration when designing and implementing the system which are as following:
Functional Constraints
- Transmission Techniques: To guarantee comfortability, safety, and natural gait, the system wiring should be limited. To ensure free movement, the connection between the smart insole and the computer interface should be wireless. As such, Radio Frequency based wireless communication has been selected for this purpose.
- Power Consumption: Power consumption is a critical component in a portable device as it is limited and should not be exhausted too quickly to not compromise functionality. Most of the power consumed will be through wireless communications, with other major sources being turning on, data processing, etc. Our solution involves a 3800 mAh Lithium-Ion (Li-ion) battery which should at live for at least one year with 30 minutes of daily usage.
- Real-Time Data Acquisition: The readings from the wearable insole will have to be presented on a display screen in real-time while conducting the experiment. It is one of the core targets of this project along with portability.
- Data Logging, Remote Patient Monitoring, and Display: An Internet of Things (IoT) logging platform will facilitate access to the acquired data and make it available to both medical professionals for remote monitoring and the patients themselves through a cloud service that will provide interactive graphs and charts, accessible from a mobile app.
- Sampling Rate and Resolution: To get an accurate and quality data while converting analog body signals to digital signals, a minimum sampling frequency and resolution must be used. The range of the sampling frequency might vary from 25 to 200 Hz and the resolution should be at least 10 bits (more is better).
- Compactness: Since the circuit should be inserted into a box to be tied behind the ankle, it must be printed into a Printed Circuit Board (PCB) and the PCB size should be compact and light enough so that it does not cause discomfort for the subject while walking.
Safety Constraints
- Electrical Safety: To mitigate risk to the patient, the current flowing through the circuit should not be more than the patient can withstand, i.e. 5 volts.
- Biocompatibility: The materials used in the foot sole must not be harmful or corrosive to the human body in the short or long run.
- Heat Sink: A proper heat sink is required to ensure that the heat produced by the circuit is dissipated promptly. Too much heat not only affects the efficiency of a device but also poses the harm of damaging the patient and the device.
Environmental Constraints
- Temperature and humidity: Operating temperature and humidity will be considered as parameters as the reading area will be in a closed area under the feet.
Economic Constraints
- Maintaining the Budget: The cost of all the components must be within the budget that is provided by Qatar University and capable enough to meet the objectives of this project.
Time Constraints
- The project must be done within the official duration of the SDP at Qatar University which is divided into two parts: SDP-1 and SDP-2. The project plan is cleverly developed keeping track of this constraint.
Aesthetic Constraints
The device’s complexity should be minimized to maximize reliability and longevity in the widest selection of patients.
The table below shows a list of system constraints:
2. Standards
- ISO/IEEE 11073-20701-2018 [Health Informatics-Point of Care Medical Device Communications]
- ISO 10993 [Biocompatibility of Medical Devices]
Project plan
