Posture Correction Device
Patent Pending
Colaborator: Daniel Yu
Project Overview:
The aim of this project is to create a posture correction device designed to address the shortcomings of traditional posture braces and straps. Resembling a discreet adhesive bandage in form factor, the device integrates innovative sensor technology and real-time feedback mechanisms to promote improved posture habits.
At the core of the device are specialized sensors capable of precisely measuring the curvature of the user's back or neck. Utilizing this data in conjunction with real-time monitoring of posture duration, the device employs sophisticated algorithms to assess and analyze the user's postural habits.
In response to detected deviations from optimal posture, the device provides immediate feedback to the user. This feedback may include vibrations from the device or it can transmit posture data to external devices such as smartphones, enabling notifications and data analysis. These feedback options foster heightened awareness and promote musculoskeletal health over time.
The underlying principle of the invention revolves around neuromuscular retraining, systematically guiding users towards the establishment of sustainable postural habits. By leveraging tactile feedback or personalized notifications, the device serves as a constant companion in the journey towards improved posture and overall well-being.
Skills: Circuit design, product development, electrical lab equipment, C++, app development, JavaScript, React, mechanical engineering, biomechanics, data analysis, patent development, market analysis.
Personal Role: Inventor and Team lead
Background:
Existing technologies in the field of posture correction tools predominantly consist of back braces & straps. These conventional devices, while aimed at addressing poor posture, are characterized by their cumbersome form factor and emphasis on body rigidity, resulting in discomfort during wear. Furthermore, they offer no enduring solutions to posture-related issues and may inadvertently exacerbate underlying problems.
Traditional braces and straps primarily function by imposing external forces to enforce spinal alignment. However, this mechanical approach fails to address the root cause of poor posture and neglects the fundamental role of musculoskeletal engagement in maintaining spinal integrity. By artificially propping the body into correct alignment, these devices relieve the stabilizing muscles of their natural function, leading to muscular atrophy and a reliance on external support for posture maintenance.
In response to these limitations, the present invention introduces a novel approach to posture correction that prioritizes neuromuscular retraining and proprioceptive feedback. By leveraging wearable sensor technology and real-time feedback mechanisms, the proposed device aims to engage the user in an interactive process of posture awareness and corrective action. Through subtle cues and proprioceptive feedback, the device prompts the user to make conscious adjustments to their posture, thereby facilitating the gradual development of lasting postural habits.
Description of work done:
Defining Objectives: The primary objective of the project is to develop a wearable device capable of measuring and monitoring the posture of the wearer's back or neck in real-time and providing feedback to promote better posture. Additional objectives include ensuring the device is comfortable, unobtrusive, and easy to use.
Idea Generation: The project commenced with intensive brainstorming sessions aimed at devising solutions to tackle the issue of poor posture. A range of concepts and methodologies, including the utilization of accelerometers and other technologies, were explored to uncover innovative approaches capable of effectively monitoring and enhancing posture habits. After thorough evaluation, the concept of assessing posture based on the curvature of the back or neck emerged as the most promising solution. This approach was chosen due to its reliability and feasibility, leveraging strain gauges to accurately measure curvature. The decision was reinforced by the compact size of strain gauges, ensuring a discreet and unobtrusive monitoring solution suitable for individuals of varying body types.
Circuit design: The circuitry is based around the implementation of a strain gauge. Because a strain gauge is a variable resistance component with very minute changes in resistance, a wheatstone bridge is used in conjunction with an op-amp to amplify the measured strain. Fig 1 shows the first freehanded test circuit which was then slightly adjusted to achieve the desired gain. Schematic shown in Fig 2. The signal is then read by a microcontroller which proves to be another challenge. Because the final design needs to be small enough to seamlessly fit under medical tape which is no bigger than a typical band-aid, it is imperative that a very small, specific to use microcontroller (ASIC) be designed. This design is still to be completed.
Early Prototyping: These early prototypes helped to further refine the circuitry and conduct tests to understand the nuances in the biomechanics of peoples backs and necks. The prototypes are geared towards running tests rather than replicating the final form as a ASIC microcontroller still needs to be designed. For this reason the prototypes require external wires which connect to an arduino.
App development: Currently developing an app which connects to the device with a focus on user customization and data analysis. This includes the ability to modify the sensitivity levels of the feedback trigger.
Fig 1: Test circuit
A) Strain Gauge
B) Wheatstone bridge
C) Op-Amp circuitry
Fig 2: Circuit Schematic
Fig 5: Prototype output
Explanation:
Prototype V1 is designed only for testing purposes. It does not whatsoever replicate the final design form as that requires further understanding. The three main components of the prototype include the circuit board, housing (black middle section), and the sponge (blue part). As seen on the circuit board, there are headers to which an external power supply and microcontroller should be connected. The black 3D printed housing protects all of the circuitry and separates it from the sponge. The strain gauge is placed on the sponge so that it is able to conform to the wearers back. The analog output which is sent to the microcontroller (arduino) is then continuously plotted for analysis.
Testing:
With prototype V1 the main goal was to validate the idea of using a strain gauge and the curvature of one’s back or neck as a means for assessing one’s posture. With the output of the system being an analog signal representing the strain, the goal was simply to obtain a wide range of output values corresponding to the full spectrum of postural positions, from when the wearer of the device is standing with their back extended all the way back to when the wearer is extended in the opposite direction or slouching. This output range is vital as it will be processed and thresholds will be set accordingly for when to trigger a feedback. For all of the various body types the prototype was tested on, a reasonable range of values was obtained proving the effectivity of the methodology (Figure 5 shows the output from when the back was fully extended to slouching).
Another focus of this prototype was to determine a reasonable curvature threshold for when one is considered to be slouching. The tests found that this threshold varies slightly from person to person but a constant yet encompassing value can still be set for the final implementation. Regardless, the final implementation will be made so that users will be able to adjust this threshold either through advanced settings or by adjusting the sensitivity all through the mobile app.
Fig 7: PCB
Fig 8: PCB
Explanation:
Prototype V2 is designed with mostly the same circuit as V1 but is more resemblant of the final design in form factor. It includes a vibrational motor, strain gauge, and circuitry that is all encased within the medical tape as shown in Fig 6. That being said, because the custom microcontroller is not yet designed, external wires are still present and a external power supply and arduino are still required. Underneath the medical tape is a thin flexible plastic on which the strain gauge and circuitry is placed. The plastic serves as a flexible PCB. Because manufacturing costs of flexible PCBs are high, a homemade version is implemented for this prototype. For the final design, the entire plastic part is going to be a flexible PCB. This is important to note as the strain gauge will sit on the PCB itself and needs to be able to conform to the curvature of the back or neck.
Testing:
With prototype V2 the main goal was to further validate the circuitry and begin moving towards a more finalized design. This sleek implementation is also designed so that full day long tests were able to be performed. The wires were extended so that an arduino and power supply could be placed in the tests subjects pocket while the prototype was attached to their back. The test subjects were then given a button which is also connected to the arduino which they would press in the event of a false positive vibration. They were also told to describe what activity they were doing when that false positive response was triggered.
By conducting these field tests another crucial parameter was found. This is, the amount of time that needs to elapse after a person’s back curvature exceeds the threshold value, for them to be considered slouching or having bad posture. In cases such as when a person bends over to pick something up (curving their back) there is a possibility for false positive readings. For this reason, the device must be designed so that it takes time into account. A reasonable threshold time value has been decided but similar to the curvature threshold, the final implementation should be made so that users will be able to adjust this time threshold either through advanced settings or by adjusting the sensitivity through the mobile app.
Version 1
Version 2
Fig 3: Top view
Fig 6: Prototype Version 2
Fig 4: Bottom view