Project :: ECE 445 - Senior Design Laboratory

Project

#	Title	Team Members	TA	Documents	Sponsor
66	A New Approach to an External Ventricular Drain (Capstone Project)	David Kapelyan Isiah Lashley Ralph Nathan	Jason Jung	proposal1.pdf
	Team Members: - Ralph Nathan (ralphn2) - David Kapelyan (davidik2) - Isiah Lashley (ilashl2) # Problem External Ventricular Drains (EVDs) are used to drain cerebrospinal fluid (CSF), but if done incorrectly, they can cause severe damage, including death. To ensure the correct amount of CSF is drained, the pressure transducers on the EVD must be properly zeroed. However, patients often move during sleep or daily activities such as showering, which can lead to incorrect pressure readings and improper CSF drainage. According to Dr. Suguna Pappu, there have been numerous cases where approximately 40 ccs of CSF were drained instead of the intended 10 due to zeroing errors. This, again, can result in significant harm or even death. In summary, a new approach to EVDs is necessary, one that provides stable pressure readings even when the patient is in motion. This capstone project aims to create advancements in EVDs. # Solution We plan to utilize an STM32 microcontroller to process input from a pressure transducer connected to the catheter through which cerebrospinal fluid (CSF) is drained from the brain. Our design will incorporate a pipe tee in series with a two-way solenoid valve. The catheter extending from the skull will be connected to the tee, which will also be fitted with a pressure gauge. This pressure gauge will be linked to the microcontroller, which will control whether the solenoid valve is open or closed. Measuring pressure digitally, rather than using a manometer, will eliminate the issue of set-point shifts caused by patient movement. Additionally, there will be no need to manually set a “zero” point, as this can be calibrated in software. We will use an instrumentation amplifier with a shunt resistor to buffer signals from the pressure transducer, ensuring accurate readings by the microcontroller. Digital signal processing (DSP) will then be performed via the microcontroller, including noise filtering, adaptive thresholding for real-time pressure management, and data logging of pressure readings. The system will regulate the flow of CSF to a drain collection bag via a push-connected solenoid valve. The microcontroller will communicate with a display or bedside monitor via Bluetooth, presenting pressure data—including real-time pressure graphs, an alarm system for abnormal pressure readings, and data logs for physician review—through a graphical user interface (GUI). Additionally, we will implement fail-safes to prevent over-drainage or blockage and include a manual override in case of system failure. # Solution Components ## STM32 Microcontroller An STM32 microcontroller with an on-package RF transceiver that supports Bluetooth will be utilized. The ADC of the controller supports a resolution of 12 bits which will be useful for accurately measuring the output signal of our pressure gauge. The STM32 Microcontroller comes with an internal reference voltage that is typically derived from the supply voltage. ## Power System Circuit A high-voltage rail powered by an AC-DC wall adapter will be used to power the board. A linear regulator will be utilized to decrease the voltage such that it can be used to power the microcontroller. ## Push Connect Solenoid Valve For Drainage A switch will be placed between the high-voltage rail and the solenoid input. The switch will be controlled by an output signal from the microcontroller. ## Pressure Transducer The pressure transducer will be connected to the pipe tee. The pressure transducer will need to be a precision pressure transducer as the standard Intracranial Pressure is approximately 16mg(0.309 PSI) which is a relatively low pressure. The transducer will have a current output which will be connected to a shunt resistor across which the voltage will be measured using an instrumentation amplifier. # Criterion For Success A successful project will result in a device that accurately reads and processes pressure data from a transducer with minimal noise and high precision. The system must effectively regulate cerebrospinal fluid (CSF) drainage by dynamically controlling a solenoid valve to maintain an average outflow of 10cc/hour, preventing over-drainage or blockage. Additionally, the microcontroller must wirelessly transmit real-time pressure readings via Bluetooth to a bedside monitor, where a graphical user interface (GUI) will display real-time pressure graphs, generate alarm notifications for abnormal pressure levels, and log data for physician review. To ensure safety and reliability, the system must incorporate fail-safes to prevent malfunctions and provide a manual override for emergency control. By meeting these criteria, the project will achieve its goal of delivering an automated, accurate, and user-friendly solution for CSF drainage management. # Parts: STM32 PCB Push Connect Solenoid Valve Pipe Tee Pressure Transducer Instrumentation Amplifier Links: ¼” push connect solenoid valve ⅛” npt solenoid valve https://www.omega.com/en-us/pressure-measurement/pressure-transducers/px119/p/PX119-015GI https://www.coleparmer.com/i/cole-parmer-0-25-accuracy-transmitter-0-to-2-psi-4-to-20-ma-output/6807503 https://www.mouser.com/ProductDetail/Analog-Devices/ADR435BRZ?qs=WIvQP4zGanhj7%2FQWeFYslw%3D%3D&utm_id=22030944703&gad_source=1&gclid=CjwKCAiAtYy9BhBcEiwANWQQLyuDFchHNWjCoLscoWoVpM2fdflY2CcCi-fQ9bxPrEm5EPQFvoIeNxoCPqgQAvD_BwE

Title

Team Members

Documents

Sponsor

A New Approach to an External Ventricular Drain (Capstone Project)

David Kapelyan
Isiah Lashley
Ralph Nathan

Jason Jung

proposal1.pdf

Team Members:
- Ralph Nathan (ralphn2)
- David Kapelyan (davidik2)
- Isiah Lashley (ilashl2)

# Problem
External Ventricular Drains (EVDs) are used to drain cerebrospinal fluid (CSF), but if done incorrectly, they can cause severe damage, including death. To ensure the correct amount of CSF is drained, the pressure transducers on the EVD must be properly zeroed. However, patients often move during sleep or daily activities such as showering, which can lead to incorrect pressure readings and improper CSF drainage. According to Dr. Suguna Pappu, there have been numerous cases where approximately 40 ccs of CSF were drained instead of the intended 10 due to zeroing errors. This, again, can result in significant harm or even death.
In summary, a new approach to EVDs is necessary, one that provides stable pressure readings even when the patient is in motion. This capstone project aims to create advancements in EVDs.
# Solution
We plan to utilize an STM32 microcontroller to process input from a pressure transducer connected to the catheter through which cerebrospinal fluid (CSF) is drained from the brain. Our design will incorporate a pipe tee in series with a two-way solenoid valve. The catheter extending from the skull will be connected to the tee, which will also be fitted with a pressure gauge. This pressure gauge will be linked to the microcontroller, which will control whether the solenoid valve is open or closed. Measuring pressure digitally, rather than using a manometer, will eliminate the issue of set-point shifts caused by patient movement. Additionally, there will be no need to manually set a “zero” point, as this can be calibrated in software.
We will use an instrumentation amplifier with a shunt resistor to buffer signals from the pressure transducer, ensuring accurate readings by the microcontroller. Digital signal processing (DSP) will then be performed via the microcontroller, including noise filtering, adaptive thresholding for real-time pressure management, and data logging of pressure readings. The system will regulate the flow of CSF to a drain collection bag via a push-connected solenoid valve. The microcontroller will communicate with a display or bedside monitor via Bluetooth, presenting pressure data—including real-time pressure graphs, an alarm system for abnormal pressure readings, and data logs for physician review—through a graphical user interface (GUI). Additionally, we will implement fail-safes to prevent over-drainage or blockage and include a manual override in case of system failure.

# Solution Components

## STM32 Microcontroller
An STM32 microcontroller with an on-package RF transceiver that supports Bluetooth will be utilized. The ADC of the controller supports a resolution of 12 bits which will be useful for accurately measuring the output signal of our pressure gauge. The STM32 Microcontroller comes with an internal reference voltage that is typically derived from the supply voltage.

## Power System Circuit
A high-voltage rail powered by an AC-DC wall adapter will be used to power the board. A linear regulator will be utilized to decrease the voltage such that it can be used to power the microcontroller.

## Push Connect Solenoid Valve For Drainage
A switch will be placed between the high-voltage rail and the solenoid input. The switch will be controlled by an output signal from the microcontroller.

## Pressure Transducer
The pressure transducer will be connected to the pipe tee. The pressure transducer will need to be a precision pressure transducer as the standard Intracranial Pressure is approximately 16mg(0.309 PSI) which is a relatively low pressure. The transducer will have a current output which will be connected to a shunt resistor across which the voltage will be measured using an instrumentation amplifier.

# Criterion For Success

A successful project will result in a device that accurately reads and processes pressure data from a transducer with minimal noise and high precision. The system must effectively regulate cerebrospinal fluid (CSF) drainage by dynamically controlling a solenoid valve to maintain an average outflow of 10cc/hour, preventing over-drainage or blockage. Additionally, the microcontroller must wirelessly transmit real-time pressure readings via Bluetooth to a bedside monitor, where a graphical user interface (GUI) will display real-time pressure graphs, generate alarm notifications for abnormal pressure levels, and log data for physician review. To ensure safety and reliability, the system must incorporate fail-safes to prevent malfunctions and provide a manual override for emergency control. By meeting these criteria, the project will achieve its goal of delivering an automated, accurate, and user-friendly solution for CSF drainage management.

# Parts:
STM32
PCB
Push Connect Solenoid Valve
Pipe Tee
Pressure Transducer
Instrumentation Amplifier

Links:

¼” push connect solenoid valve
⅛” npt solenoid valve

https://www.omega.com/en-us/pressure-measurement/pressure-transducers/px119/p/PX119-015GI

https://www.coleparmer.com/i/cole-parmer-0-25-accuracy-transmitter-0-to-2-psi-4-to-20-ma-output/6807503

https://www.mouser.com/ProductDetail/Analog-Devices/ADR435BRZ?qs=WIvQP4zGanhj7%2FQWeFYslw%3D%3D&utm_id=22030944703&gad_source=1&gclid=CjwKCAiAtYy9BhBcEiwANWQQLyuDFchHNWjCoLscoWoVpM2fdflY2CcCi-fQ9bxPrEm5EPQFvoIeNxoCPqgQAvD_BwE

Featured Project

# Musical Hand

Team Members:

- Ramesey Foote (rgfoote2)

- Michelle Zhang (mz32)

- Thomas MacDonald (tcm5)

# Problem

Musical instruments come in all shapes and sizes; however, transporting instruments often involves bulky and heavy cases. Not only can transporting instruments be a hassle, but the initial purchase and maintenance of an instrument can be very expensive. We would like to solve this problem by creating an instrument that is lightweight, compact, and low maintenance.

# Solution

Our project involves a wearable system on the chest and both hands. The left hand will be used to dictate the pitches of three “strings” using relative angles between the palm and fingers. For example, from a flat horizontal hand a small dip in one finger is associated with a low frequency. A greater dip corresponds to a higher frequency pitch. The right hand will modulate the generated sound by adding effects such as vibrato through lateral motion. Finally, the brains of the project will be the central unit, a wearable, chest-mounted subsystem responsible for the audio synthesis and output.

Our solution would provide an instrument that is lightweight and easy to transport. We will be utilizing accelerometers instead of flex sensors to limit wear and tear, which would solve the issue of expensive maintenance typical of more physical synthesis methods.

# Solution Components

The overall solution has three subsystems; a right hand, left hand, and a central unit.

## Subsystem 1 - Left Hand

The left hand subsystem will use four digital accelerometers total: three on the fingers and one on the back of the hand. These sensors will be used to determine the angle between the back of the hand and each of the three fingers (ring, middle, and index) being used for synthesis. Each angle will correspond to an analog signal for pitch with a low frequency corresponding to a completely straight finger and a high frequency corresponding to a completely bent finger. To filter out AC noise, bypass capacitors and possibly resistors will be used when sending the accelerometer signals to the central unit.

## Subsystem 2 - Right Hand

The right subsystem will use one accelerometer to determine the broad movement of the hand. This information will be used to determine how much of a vibrato there is in the output sound. This system will need the accelerometer, bypass capacitors (.1uF), and possibly some resistors if they are needed for the communication scheme used (SPI or I2C).

## Subsystem 3 - Central Unit

The central subsystem utilizes data from the gloves to determine and generate the correct audio. To do this, two microcontrollers from the STM32F3 series will be used. The left and right hand subunits will be connected to the central unit through cabling. One of the microcontrollers will receive information from the sensors on both gloves and use it to calculate the correct frequencies. The other microcontroller uses these frequencies to generate the actual audio. The use of two separate microcontrollers allows for the logic to take longer, accounting for slower human response time, while meeting needs for quicker audio updates. At the output, there will be a second order multiple feedback filter. This will get rid of any switching noise while also allowing us to set a gain. This will be done using an LM358 Op amp along with the necessary resistors and capacitors to generate the filter and gain. This output will then go to an audio jack that will go to a speaker. In addition, bypass capacitors, pull up resistors, pull down resistors, and the necessary programming circuits will be implemented on this board.

# Criterion For Success

The minimum viable product will consist of two wearable gloves and a central unit that will be connected together via cords. The user will be able to adjust three separate notes that will be played simultaneously using the left hand, and will be able to apply a sound effect using the right hand. The output audio should be able to be heard audibly from a speaker.

Project Videos

Musical Hand Demo