Background
In 2018, 1 in 6 cardiovascular disease deaths were due to stroke. Stroke is a leading cause of long-term disability. Strokes can be caused by excessive bleeding (hemorrhagic stroke) or caused by lack of blood flow to a vital organ (ischemic stroke). 87% of strokes are ischemic, and they stem from the obstruction of blood vessels in the brain. To successfully treat ischemic stroke, the blood clot must be removed. Lack of blood flow to the brain causes necrosis and eventually death. Each minute, 1.9 million neurons die, along with 14 billion synapses and 12 kilometers of myelinated fibers during an average ischemic stroke. Additionally, an ischemic brain ages 3.9 years each hour without treatment.
Within the emergency department, stroke patients undergo a cranial CT to determine the type of stroke. Once diagnosed with ischemic stroke, tissue plasminogen activator (tPA or alteplase) is infused intravenously for 60 minutes. tPA breaks down the blood clot, restoring blood flow to the brain, but it can only be administered within 5 hours of stroke onset. Occasionally, mechanical thrombectomy is performed to physically remove the blood clot. Alteplase is the only effective stroke medication, but its success can vary. tPA reduces mortality by 37-42% if the patient arrives to a hospital within 3 hours of onset. On average, treated patients live one year longer than untreated patients, and have increased scores for independence and activity levels post-stroke. Alteplase is not always effective and has recanalization rates of 46.2%.
Client
UN&UP, a start-up company based in St. Louis, has received an NIH grant to design a solution that will simultaneously decrease the infusion time of tPA and increase recanalization rates for ischemic stroke. This novel treatment includes co-infusion of tPA and magnetic nanoparticles. The nanoparticles will be controlled by an external magnetic field and will “steer” the tPA towards the clot. The approach will reach clots with long stretches of stagnant blood, shorten the time for tPA to be effective, and increase recanalization rates. As UN&UP develops their treatment, they need to thoroughly test their nanoparticle solution. The concentration of nanoparticles must remain consistent as it is administered. To test devices that will administer the solution, UN&UP needs a sampling system that will prepare solution samples that will eventually undergo testing to evaluate their nanoparticle concentration.
Design Requirements
| Client Need | Design Specification |
|---|---|
| Software | A GUI interface should ensure that the system is user-friendly. |
| Sample collection | One sample should collect effluent for 60 seconds before moving to the next sample. |
| Tubes | The samples should be collected in 1.5mL Eppendorf tubes. |
| Number of samples | The system must be functional for 72 samples (12×6). |
| Minimal spilling | The system should have a component to ensure no loss of effluent between tubes. |
| Moving stages | The system must incorporate a two-axis linear stage. |
| Process monitoring | There must be a mechanism for passive monitoring of the entire process to allow for post-sampling review. |
| Feedback quality | The feedback should be in a format that yields helpful data and is easy to use. |
| Non-magnetic components | The stage components must yield a magnetic field with strength 0T. |
| Ease of use | The device must be reliable and must not be difficult to operate. |
| Power compatibility | Power compatibility The device must be compatible with a standard wall outlet (60 Hz). |
| User safety | The system is safe with standard laboratory clothing and techniques. |
| Cost | The cost of all components of the device must not exceed $750. |
| Completion date | The final prototype will be completed by Friday, April 22, 2022. |
Schedule
Please see the Gantt chart for the schedule and responsibilities for each team member.