DESC:FIELD OF THE INVENTION
The present invention relates to the field of gait analysis system and gait analysis method. Particularly, the present invention relates to the field of gait analysis system and gait analysis method for performance improvement of athletes and neuro rehabilitation.

BACKGROUND
Neuropathy and diseases of the musculoskeletal system influence a patient's gait by affecting the coordination, harmonization and interaction of the muscles, skeleton, nerves and joints. Therefore, gait analysis systems and methods have been developed to solve the clinical problems in the fields of orthopedics, rehabilitation and neurology.

Generally, a gait analysis system is useful for providing a doctor/therapist with a patient’s detailed gait assessment data to help elucidate problems of the nervous, muscular and skeletal systems of the patient. With the assessment data, the doctor/therapist can design the most suitable treatment for the patient, such as surgery, rehabilitation or wearing auxiliary instruments. Further, gait analysis may also be useful after the treatment to ascertain success of the treatment and help the doctor/therapist design a further plan for improvement.

Traditional gait analysis systems employ different technologies such as image processing (IP), floor sensors (FS), and wearable sensors (WS). Image processing systems require an expensive setup with elaborate infrastructure facility which does not allow for real-time analysis outside the facility. To obtain a detailed gait assessment data of a patient, it is important that walking parameters such as speed, stride, step length, swing and stance, and force-related parameters such as muscle force and joint momentum be monitored. These parameters must be measured and monitored continuously over prolonged duration which can only be done by means of wearable sensors monitoring the patient during his/her daily activities. Single camera image processing can be used for individual recognition and segment position which provides up to 78% recognition rate. However, a limitation of this technology are the complex algorithms required for analysis.

Floor sensors such as ground reaction force (GRF) plates have been used in the past for step detection, GRF, and gait phase detection. However, a drawback of the GRF plates is that they have an accuracy of only about 10%, and to obtain accurate data the patient must contact the center of the plate. Alternatively, pressure sensor mats and platforms can be used for plantar pressure distribution, gait phase detection, step detection and gait recognition. The pressure sensor mats and platforms have a higher recognition rate of up to 80%, however, these sensors have to be located indoors and require a large space for installation.

The major drawbacks of the afore-noted technologies are the high cost of analysis of gait patterns often requiring elaborate laboratory setups and expensive equipment. Wearable insoles with integrated low-cost sensors for computing important gait features of the patient have been developed to overcome the afore-noted drawbacks of the traditional technologies. However, most of the wearable insoles available presently are made of a combination of piezoresistive pressure sensors at specific foot locations. These sensors are often susceptible to wear and tear as the capacitance reduces with time. Also, the analytics on the data is often biased as a result of lesser sensing points.

OBJECTS OF THE INVENTION
Accordingly, it is an object of the present invention to provide a portable gait analysis and gait training system which provides continuous pressure monitoring at all crucial points along the foot.

One object of the present invention is to provide a portable gait analysis and gait training system and method thereof which provides real-time gait monitoring, analysis and visualization for detection, correction and treatment of physiological defect in the gait.

Other objects and advantages of the present invention will be more apparent from the following description.

DEFINITIONS:
Plantar Pressure Distribution: The distribution of force/pressure over the sole of the foot.
Force Resistive Sensors: Sensor that detects physical pressure, squeezing and weight by change in its resistance when a force or pressure is applied.
Inertial measurement unit (IMU): An electronic device that measures and reports the foot’s specific force, kinematic motion, angular rate, and/or orientation using accelerometers and gyroscopes.
Foot pressure data: Pressure map visually indicating the center of balance of user while walking/moving.
Foot movement data: The data including overpronation and overstriding data of user while walking/moving.
Foot-strike distribution data: The data including weight/force distribution and body balance during strike.

SUMMARY OF THE INVENTION
A portable gait analysis and gait training system is disclosed. The system comprises a smart insole to be worn by a user inside the shoes, and a printed circuit board module electrically connected to the smart insole and positioned on outer side of the user’s shoe. The smart insole comprises a plurality of force resistive sensors positioned at the heel, medial, metatarsal and hallux regions of the foot for determining plantar pressure distribution data. The printed circuit board module comprises one or more inertial measurement unit (IMU) sensors for determining kinematic motion data of the foot, and wireless connectivity modules for communicating the plantar pressure distribution data and the kinematic motion data to a user device for gait analysis and gait training.

The smart insole is a flexible pressure-sensitive polymeric film. Preferably, the plurality of force resistive sensors are fabricated on a flexible printed circuit formed as the shoe insole.

The smart insole may comprise eight force resistive sensors, wherein one force resistive sensor is positioned in the hallux region, three force resistive sensors are positioned in the metatarsal region covering all the metatarsals, one force resistive sensor is positioned on the outer border of the medial region, and three force resistive sensors are positioned in the heel region.

Preferably, a flexible flat cable made of flexible polymeric material is provided for electrically connecting the smart insole to the printed circuit board module.

Preferably, the IMU sensors are embedded in the printed circuit board module. The IMU sensors consist of two 3-axis accelerometers and 3-axis gyroscopes, and can be configured to determine kinematic motion data selected from gait phase, impact analysis, flexion angles, foot orientation and asymmetry.

The printed circuit board module comprises a microcontroller, antenna for wireless transmission and power supply. The printed circuit board module is placed inside a protective cover. Preferably, the wireless connectivity modules can be selected from Bluetooth®, Bluetooth® LE and Wi-Fi.

A gait analysis and gait training method is disclosed. The method comprises:
wearing the smart insole of the portable gait analysis and gait training system to obtain a user plantar pressure distribution data and kinematic motion data;
converting the plantar pressure distribution data and the kinematic motion data to gait assessment data using an algorithm;
providing the gait assessment data containing one or more parameters selected from step length, stride, cadence, balance, angle of pronation, load distribution, strike distribution and supination, at a portable electronic device through the wireless connectivity modules; and
enabling the user or their doctor/practitioner to detect a physiological defect, and thereby correct the user’s gait.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The present invention will be described with the help of accompanying drawings, in which,
FIGURE 1 illustrates a preferred embodiment of the portable gait analysis and gait training system of the present invention;
FIGURE 2 illustrates the system of FIG. 1 placed inside a user’s shoe;
FIGURE 3 illustrates a pressure map showing a user’s load/body weight distribution while walking/moving; and
FIGURE 4 shows foot movements and foot-strike distribution data of a user while walking/moving.

DETAILED DESCRIPTION
The description of the specific embodiments herein will reveal the general nature of the embodiments of the present invention that a person skilled in the art can, by applying current knowledge, readily modify and/or adapt for various applications without departing from the general concept, and, therefore, such adaptations and modifications are to be comprehended within the meaning of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

The present invention relates to a portable gait analysis and gait training system comprising a smart insole to be worn inside the shoes by a user. The smart insole is a flexible pressure-sensitive polymeric film which accurately determines one or more parameters selected from foot pressure data, foot movement data and foot-strike distribution data. The smart insole is further configured to transmit the said data to an IOT (Internet-of-Things) system using Bluetooth modules.

The system of the present invention focusses on the plantar pressure distribution for gait analysis and gait training. The plantar pressure distribution is not even across the foot. Studies have shown that the region under the heel, medial and central metatarsals and hallux (great toe) exhibited the highest plantar pressure. It has been reported that during a normal stance, each foot carries about half of the body weight at the heel, forefoot and big toe, whereas, the lowest plantar pressure is measured under the midfoot. Further, an increase in the speed of the foot movement leads to increase in peak plantar pressure in the heel, medial and central metatarsals and hallux. Thus, these anatomical regions of the foot are of great importance for plantar pressure distribution and gait analysis as they provide valuable information on the characteristics of the pressure and forces acting on the foot. The plantar pressure distribution data can further provide insight into possible risk factors for chronic foot pain, foot ulcers and injuries.

The system of the present invention detects the ground reaction force in 3 major areas of the foot: hindfoot, midfoot and forefoot. The portable gait analysis and gait training system of the present invention can be used by:
1. Geriatric population (people >50 years): The pressure variations recorded by the sensors can help in early detection of several conditions including posture variation, joint and muscle problems etc. This will not only help to design a proper rehabilitation plan but will also function as a preventive healthcare aid.
2. Neuro patients: The pressure variations will help in gait training of hemiplegic and paraplegic patients as the pressure data would accurately point out towards faulty regions, thereby helping the therapist introduce corrective exercise plans.
3. Sportspersons: Athletes having flat feet can wear the smart insoles correctly aligned with their feet and designed according to their body physics which will help them in counterbalancing forces to improve performance. The data can also be used for retrospective precision rehabilitation in cases of injuries by benchmarking the data when in good form. On-field analysis for improving performance is another area of intervention through the insole.
4. Pregnant Women: Gait is largely affected due to pregnancy and returning back to normal is often very cumbersome. With proper insoles and benchmarking, stance can be improved and help the mother return to normal rapidly. This would lead to an overall increase in quality of life.

The portable gait analysis and gait training system allows continuous pressure monitoring across the feet. The system comprises sensors made of piezoresistive material which are capable of sensing and monitoring plantar pressure distribution throughout the feet. The smart insoles of present invention measure multiple point plantar pressure using sensors integrated inside the smart insoles. A 6-axis IMU (Inertial Measurement Unit) sensor is integrated on a printed circuit board module to track any motion of the user if he/she is doing any physical activity.

The system of the present invention is configured to detect the changes in resistance of a piezoresistive material by measuring capacitance to voltage electronically. Thus, when a user wears the smart insoles of the present invention and performs activities, the system can track the foot plantar pressure as they walk or run. The foot posture can also be detected by the accelerometer, compass and gyroscope modules. The different parameters for coaching can be captured such as step length, pitch angle and step clearance, based on the foot pressure data. This data can be used to find which muscles need training and compensation. This will also lead to highly quantified and personalized rehabilitation programs for patients who need foot rehabilitation. All the data gathered can be analyzed by artificial intelligence (AI) or machine learning (ML) to point towards corrective measures in gait and posture training.

FIGURE 1 of the accompanying drawings illustrates a preferred embodiment of the portable gait analysis and gait training system.

According to a preferred embodiment, the system (referenced by numeral 10) comprises: a smart insole consisting of a plurality of force resistive sensors (11), a flexible flat cable (12), a printed circuit board module (15), inertial measurement unit (IMU) sensors (16) and a protective cover (14).

The force resistive sensors (11) on the smart insole allow detection of physical pressure and weight by change in resistance when pressure/force is applied. A plurality of force resistive sensors (11) are printed on a flexible substrate and positioned on the smart insole particularly at the region under the heel, medial (midfoot), metatarsal (forefoot) and hallux (great toe) where plantar pressure distribution is the highest. The force resistive sensors (FSR’s) (11) are fabricated on flexible printed circuit formed as the shoe insole. Each smart insole consisted of the printed FSR’s on flexible substrate fabricated as an insole to be placed beneath the user’s foot inside the shoes. The sensors (11) used in the smart insole are configured to sense parameters that characterize the user’s gait.

According to a preferred embodiment, a total of eight force resistive sensors (11) are positioned on the smart insole, where, one sensor is positioned in the hallux region, three sensors are positioned in the metatarsal region covering all the metatarsals, one sensor is positioned on the outer border of the medial region, and three sensors are positioned in the heel region. The force resistive sensors (11) have a diameter of 5 mm each.

The force resistive sensors (11) are positioned such as to monitor the plantar pressure distribution of the user’s foot. The monitoring of the plantar pressure distribution can also be beneficial in improving health and treating physiological conditions, including foot deformities such as pes cavus and pes planus. Abnormalities in the distribution of plantar pressure or gait have been associated with adverse long-term effects on the health, such as, increased slip and fall risk, diabetes, anxiety, depression or neurodegenerative diseases. Thus, the system of the present invention can also be used as a diagnostic indicator for these physiological or psychological abnormalities.

The flexible flat cable (12) is made of a flexible polymeric material. The flexible flat cable (12) electrically connects the force resistive sensors (11) of the smart insole to the printed circuit board module (15). The printed circuit board module (15) is placed inside a protective cover (14).

The printed circuit board module (15) is designed to connect all the electrical components in a controlled manner. The printed circuit board module (15) comprises the following components:
1. Inertial measurement unit (IMU) sensors (16) (MPU-6050™) embedded in the printed circuit board (15) for the analysis of the kinematic motion of the foot. Two 3-axis accelerometers and 3-axis gyroscopes were placed at the outer side of the shoe, oriented such that the individual sensing axes were aligned along three perpendicular axes. The IMU sensors (16) measure a wide range of biomechanical parameters of gait including gait phase, impact analysis, flexion angles, foot orientation, and asymmetry measures. The IMU sensors (16) typically rely on algorithms to extract the afore-noted useful gait features from the inertial signals. These algorithms can be generally described as software-based methodologies which translate the raw (sample data) into meaningful and quantifiable gait assessment data. The system of the present invention employs a proprietary algorithm for the gait assessment using the smart insole and IMU.

2. Wireless connectivity modules including Bluetooth®, Bluetooth® LE and/or Wi-Fi (ESP32-WROVER-IE) are integrated at the printed circuit board module (15). The integration of Bluetooth®, Bluetooth® LE and/or Wi-Fi ensures that the system of the present invention can be used with a wide range of applications. The Wi-Fi allows the system to be directly connected to the internet through the Wi-Fi router, while the Bluetooth® allows the user to conveniently connect to the smartphone or tablet. Bluetooth® LE is a wireless, low-power personal area network that operates in the 2.4 GHz ISM band, and connects devices over a relatively short range. Bluetooth Low Energy (LE) beacons can be used to broadcast their identifier to nearby portable electronic devices such as smartphones, tablets and other compatible devices for performing actions when in close proximity to the beacon. The sleep current of the ESP32 chip is less than 5 µA, making it suitable for the battery powered and wearable system of the present invention. The module supports a data rate of up to 150 Mbps, and 20 dBm output power at the antenna to ensure the widest physical range. Secure (encrypted) over the air (OTA) upgrade is supported by the system to allow the users to upgrade the system at minimum cost and effort.
3. 1500 mAh Li Battery for power supply to the system (10); and
4. Memory card for storage of data.

The system of the present invention is configured to accommodate the force resistive sensors (FSR’s) (11) beneath the user’s foot, and the electrical components (including the printed circuit board module (15) and the IMU sensors (16)), an antenna for wireless transmission, and a power supply, at the outer side of the user’s shoe. The electrical components including IMU sensors (16), ESP32 microcontroller, antenna, power supply, and conditioning electronics are implemented on the printed circuit board module (15) which is attached to the flexible printed circuit of FSR’s by the flexible flat cable (12), and preferably positioned on the outer side of the user’s shoe, more preferably the outer side of the ankle (at the side of lateral malleolus), to minimize the effect on foot motion. FIGURE 2 of the accompanying drawings shows the preferred embodiment of the smart insole of FIG. 1 being placed inside a user’s shoe (the assembly being referenced by the numeral 20).

The system of the present invention can be connected to the portable electronic device such as smartphone or tablet through a mobile application/ GUI (graphical user interface) using Bluetooth®, Bluetooth® LE and/or Wi-Fi. For the enabled devices to transmit data, a channel of communication is established by the smartphone/tablet by identifying the system of the present invention, and making a connection thereto. Once connected, the data from the smart insole of the system of the present invention can be transmitted to the user device or the device of the doctor/therapist/ practitioner.

The present invention further provides a gait analysis and gait training method which allows real-time gait monitoring, analysis and visualization by means of data upload in the system through the IOT and mobile app. The real-time assessment data is transmitted to a custom mobile app/GUI (graphical user interface) via the bluetooth/wifi along with an option of storing the data for future processing. The mobile app/GUI receives the assessment data and displays vital information like step length, stride, cadence, balance, angle of pronation, load distribution, strike distribution and supination etc. The assessment data enables users/doctors/therapist /practitioners to understand the physiological defects, and thereby enabling correction of gait issues.

The gait analysis and gait training method according to the present invention will now be described with the help of the following example, which shall not, in any manner, be construed to limit the ambit and scope of the invention.

EXAMPLE:
A user wears the smart insole of the system of the present invention while walking or moving to obtain their plantar pressure distribution data and the kinematic motion data. The plantar pressure distribution data and the kinematic motion data is converted into gait assessment data by the system using a proprietary algorithm. The gait assessment data can be transmitted to a smartphone or tablet via Bluetooth/WiFi. The gait assessment data is displayed on a mobile app/GUI in the form of various biomechanical parameters. Table 1 below gives the body weight distribution data at different regions of the foot.

Table 1: User body weight distribution data at different regions of the foot

The gait assessment data displays a pressure map indicating visually the center of balance of the user while walking for a better understanding of the user’s loading. FIGURE 3 displays the pressure map showing the user’s load/body weight distribution while walking/moving.

The gait assessment data further provides foot movement data such as overpronation and overstride data, strike distribution, and body balance data to provide a complete understanding of the pattern of walking of the user. FIGURE 4 displays the foot movements and foot-strike distribution data of the user while walking/moving. The system may further provide a shoe recommendation based on the user’s walking pattern and gait issues as indicated in Table 2.

Table 2: Shoe recommendation for user based on the walking pattern

The system of the present invention provides a complete gait analysis of the user with adequate technical information for any doctor/therapist/ practitioner to detect the physiological defect, and thereby correct/treat the user’s gait.

TECHNICAL ADVANCEMENTS:
The technical advantages of the portable gait analysis and gait training system and method of the present invention are, but not limited to,
1. Reporting - The system records all patient activities and progress. The patient can also report pain or observed abnormalities, e.g., a bruise or a lump.
2. Works as a wearable device – The system monitors and records the movements of the patient. It allows the doctor/therapist to check if the exercises are being done correctly. Capturing the speed and angle of movement is also an effective way to monitor the progress of the patient. The device can also monitor heart rate which can also be an indicator of patient health.
3. Remote video monitoring - A live video feed showing the patient performing their post-trauma exercises and can be used by the physiotherapist to convey instructions.
4. Connects to a cloud network - For the system to work anytime and anywhere, it is connected to a cloud environment. The cloud server can retain all patient files which can then be accessed by the physicians and therapists.
5. Alarm system - The system is able to detect sudden or jerky movements and impact caused by a fall. The system can send an alert to the physician or assigned remote therapist who can verify possible injuries and send emergency personnel.

Embodiment of the present invention is applicable over a wide number of uses and other embodiments may be developed beyond the embodiment discussed heretofore. Only the most preferred embodiments and their uses have been described herein for purpose of example, illustrating the advantages over the prior art obtained through the present invention; the invention is not limited to these specific embodiments or their specified uses. Thus, the forms of the invention described herein are to be taken as illustrative only and other embodiments may be selected without departing from the scope of the present invention. It should also be understood that additional changes and modifications, within the scope of the invention, will be apparent to one skilled in the art and that various modifications to the composition described herein may fall within the scope of the invention.
,CLAIMS:We Claim:

1. A portable gait analysis and gait training system (10) comprising:
a smart insole to be worn by a user inside the shoes; and a printed circuit board module electrically connected to said smart insole and positioned on outer side of the user’s shoe;
characterized by that:
said smart insole comprises a plurality of force resistive sensors (11) positioned at the heel, medial, metatarsal and hallux regions of the foot for determining plantar pressure distribution data; and
said printed circuit board module (15) comprises one or more inertial measurement unit (IMU) sensors (16) for determining kinematic motion data of the foot, and wireless connectivity modules for communicating the plantar pressure distribution data and the kinematic motion data to a user device for gait analysis and gait training.

2. The portable gait analysis and gait training system as claimed in claim 1, wherein said smart insole is a flexible pressure-sensitive polymeric film.

3. The portable gait analysis and gait training system as claimed in claim 1, wherein said plurality of force resistive sensors (11) are fabricated on a flexible printed circuit formed as the shoe insole.

4. The portable gait analysis and gait training system as claimed in claim 1, wherein said smart insole comprises eight force resistive sensors (11).

5. The portable gait analysis and gait training system as claimed in claim 4, wherein one force resistive sensor is positioned in the hallux region, three force resistive sensors are positioned in the metatarsal region covering all the metatarsals, one force resistive sensor is positioned on the outer border of the medial region, and three force resistive sensors are positioned in the heel region.

6. The portable gait analysis and gait training system as claimed in claim 1, wherein a flexible flat cable (12) made of flexible polymeric material electrically connects said smart insole to said printed circuit board module (15).

7. The portable gait analysis and gait training system as claimed in claim 1, wherein said IMU sensors (16) are embedded in said printed circuit board module (15) and consist of two 3-axis accelerometers and 3-axis gyroscopes.

8. The portable gait analysis and gait training system as claimed in claim 1, wherein said IMU sensors (16) are configured to determine kinematic motion data selected from gait phase, impact analysis, flexion angles, foot orientation and asymmetry.

9. The portable gait analysis and gait training system as claimed in claim 1, wherein said wireless connectivity modules are selected from Bluetooth®, Bluetooth® LE and Wi-Fi.

10. The portable gait analysis and gait training system as claimed in claim 1, wherein said printed circuit board module (15) comprises a microcontroller, antenna for wireless transmission and power supply.

11. The portable gait analysis and gait training system as claimed in claim 1, wherein said printed circuit board module (15) is placed inside a protective cover (14).

12. A gait analysis and gait training method using the system of claim 1, which comprises the steps of:
wearing said smart insole of said portable gait analysis and gait training system to obtain a user plantar pressure distribution data and kinematic motion data;
converting the plantar pressure distribution data and the kinematic motion data to gait assessment data using an algorithm;
providing the gait assessment data containing one or more parameters selected from step length, stride, cadence, balance, angle of pronation, load distribution, strike distribution and supination, at a portable electronic device through said wireless connectivity modules; and
enabling the user or their doctor/practitioner to detect a physiological defect, and thereby correct the user’s gait.