Engineering and Research Portfolio

Sid Annapragada
B.S. Electrical Engineering and Behavioral Neuroscience, Northeastern University
Interested in merging neuroscience, medicine, and engineering to help people struggling with mental and neurological illnesses
Projects
Research

Datta Lab @ Harvard Medical School
Developed instrumentation for recording data from freely moving mice
An Active Commutator device I designed to track mouse head angle and actively rotate a tether connected to head sensors to alleviate cable tension on the body of a freely moving mouse.






Small amplifier circuit with DAC for offset adjustments for a thermistor sensor implanted in the nose of freely moving mice to sense breathing.
Small, implantable LED array for simple patterned optogenetic stimulation in freely-moving mice.
Ultra-lightweight IMU headstage for monitoring head movements in freely moving mice.
My primary project at the Datta lab involved studying a mouse social olfactory behavior called the social transmission of food preference. In this paradigm, a simple odor input from the breath or excrement of another mouse induces a change the exposed mouse’s food preference: an interesting type of learning. We used various techniques to study this including many behavioral recordings with fiber photometry, optogenetics, and behavioral videos as odors and stimuli were being presented. I was responsible for helping build the experimental rigs, running experiments, and writing python code to scale up our analysis pipelines from handling single sessions, to TBs of data.

Action Lab @ Northeastern University
Developed a device to record human movements while interacting with a movement game.
Custom designed device to measure arm angle during an interactive game-like experiment. Involved mechanical, electrical, firmware, software development.


PCB with MCU and USB connection for interfacing with encoder, user interaction button, and the MATLAB app on the host computer.
Conducted experiments studying human movement and complex object manipulation in healthy and stroke populations.
My primary personal project at the Action Lab was called the Bell Task, an experiment where we investigated how humans control a bell, which is a complex object requiring precise force control.
I also helped collect data for and rewrite a python-based computer vision system for an experiment called Magic Table. In this experiment, we record stroke and healthy patients manipulating a 3D printed cup with a ball inside (a complex object again) and analyze their movments. I upgraded the code to be compatible with a 3D depth camera instead of a 2D webcam, for future 3D experiments, and made it easier for the user to use.

Shown is the camera color and depth views, with the orange cup and green ball being tracked as I move the cup around.

Engineering Capstone: Rhythm Rehab Revolution
Engineering Capstone Project: Rhythm Rehab Revolution, a custom controller and game for finger and hand rehabilitation. Controller incorporates haptics, and force-sensing buttons for complex rehabilitation paradigms. I did the hardware design (ME, EE). Firmware and Software were done by teammates.
Fully assembled custom force-measuring handheld controller for a handmade rehabilitation-focused rhythm game.






SLA printed top shell, holding four force-sensitive, spring loaded button modules.
SLA printed bottom shell, holding a haptic motor and various mounting points.
Contains BLE module, battery management, IMU, haptic driver, LED driver, and analog front end for force sensors.
Stroke often results in dexterity loss, so having a way to progressively and personally train this is useful for rehabilitation. Incorporating gross arm movements helps improve whole body coordination training, and varying between rhythmic and discrete movements engages more of the motor system.


We developed an algorithm that used the on-board IMU to detect right and left swipe gestures as part of the training program.

Dynamica
Research project involving developing devices and software to assess finger dexterity in stroke and aging populations. I am responsible for the scientific idea, leadership, mechanical design, and software development. Team of 5 engineers involved, as well as two professors.
A device for precisely measuring finger forces during custom Python-based experimental tasks with stroke patients, to assess dexterity changes. I did the mechanical design and software. Collaborators did the PCB and firmware.






Designed by Walter Stadolnik. This board contains an MCU, an analog front end for the sensors, an IMU, haptic motor, and power management.
SLA printed force-sensitive button design, with snap-hooks and spring-loaded force applicator.
A 3D mockup of a handheld version of the finger force measurement system, with adjustable sensor positions.
~70 million Americans are over 65 — and most will lose hand dexterity as they age. This loss signals cognitive decline and reduced independence. Yet clinicians have no way to accurately quantify dexterity under real-world conditions.
We are developing a series of devices to solve this problem by bringing low-cost, highly accurate force sensors to an accessible form factor for impaired populations with a neurology and rehabilitation informed software analysis and game suite.




Clinicians tend to use tools that are very qualitative, giving only time to completion or other single number metrics or very expensive, with advanced robotic technologies. We are seeking a middle ground.
We validated the market gap with a handful of researchers in the field.
Based on the gap we found, we identified two priorities: making our device accessible and reasonably-priced, and making it quantitative with enough sensing and actuation capabilities to realistically perform rehabilitation and monitoring functions.
Using the design priorities we found, we can visually demonstrate the market gap.

Sonar Transceiver
Developing a long-range sonar transceiver for underwater biomimetic robots. PI: Joseph Ayers
Render of final circuit board design. Contains a receiver amplification module (log amp) with tone-decoding, a transmitter module (Class AB, 2W), PIC MCU + custom C firmware, power management, and a USB interface.

Battery management section not populated. Hand-assembled board used for testing.
Personal and Consulting

Daneel MK 1 Robot
Autonomous robot designed for the Trinity Firefighting Robotics Competition.
I did mechanical, electrical, firmware, and software. IR, ultrasonic, encoders, IMU sensors included.


PCB containing MCU, battery management, various sensor interfaces, and motor control interfaces.

Miscellaneous Board Designs
Various board designs done for clients and myself
Contains low-noise DC power supply design with analog front end and ADC.






Low-power, low-cost design for a cellular-based water leak detector. Contains battery management, analog sensor interface, and cellular module.
Solid State relay board for switching ~20A loads.
An analog op-amp circuit which simulates the hindmarsh-rose neuron equations to generate spiking electrical activity.

Wifi Enabled Kitchen Automation
A series of wifi-enabled IOT devices for a client for kitchen automation. Includes an automatic powder dispenser, load cell sensor, and AC relay controller.
Wifi enabled automated powder dispenser. Contains a load cell and stepper driver with custom C firmware to automatically dispense a user-specified weight of loaded powder.






Custom PCB with Wifi module, load cell amplifier, and stepper motor driver.
Prototype load cell amplifier PCB with wifi module
Prototype Wifi enabled relay control board

Small Builds
Various miscellaneous electromechanical builds
Hardware for lab kit for freshmen engineers to program their own strain testing device. Contains a current sensor and motor driver, and interacts with student MATLAB programs via arduino.




Freshmen engineering project. Science exhibit demonstrating electromagnetism with two electromagnetic race cars. Includes custom software and a PCB for driving the magnets. I was responsible for mechanical and electrical design.
board for pulsing two electromagnets

Agriculture Technology
Various devices made as a consultant to an agriculture technology startup
Contains water speed, pressure, and turbidity sensor, with interface board to monitor soil runoff from fields.




10+ units deployed in the field. An interface board to connect environmental various sensors to an off-the-shelf datalogger.
Sheet metal design for a flume for runoff