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- Member of: Barrett, The Honors College Thesis/Creative Project Collection
- Resource Type: Text
Description
Breast microcalcifications are a potential indicator of cancerous tumors. Current visualization methods are either uncomfortable or impractical. Impedance measurement studies have been performed, but not in a clinical setting due to a low sensitivity and specificity. We are hoping to overcome this challenge with the development of a highly accurate impedance probe on a biopsy needle. With this technique, microcalcifications and the surrounding tissue could be differentiated in an efficient and comfortable manner than current techniques for biopsy procedures. We have developed and tested a functioning prototype for a biopsy needle using bioimpedance sensors to detect microcalcifications in the human body. In the final prototype a waveform generator sends a sin wave at a relatively low frequency(<1KHz) into the pre-amplifier, which both stabilizes and amplifies the signal. A modified howland bridge is then used to achieve a steady AC current through the electrodes. The voltage difference across the electrodes is then used to calculate the impedance being experienced between the electrodes. In our testing, the microcalcifications we are looking for have a noticeably higher impedance than the surrounding breast tissue, this spike in impedance is used to signal the presence of the calcifications, which are then sampled for examination by radiology.
ContributorsWen, Robert Bobby (Co-author) / Grula, Adam (Co-author) / Vergara, Marvin (Co-author) / Ramkumar, Shreya (Co-author) / Kozicki, Michael (Thesis director) / Ranjani, Kumaran (Committee member) / School of Molecular Sciences (Contributor) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This is a report of a study that investigated the thinking of a high-achieving precalculus student when responding to tasks that required him to define linear formulas to relate covarying quantities. Two interviews were conducted for analysis. A team of us in the mathematics education department at Arizona State University initially identified mental actions that we conjectured were needed for constructing meaningful linear formulas. This guided the development of tasks for the sequence of clinical interviews with one high-performing precalculus student. Analysis of the interview data revealed that in instances when the subject engaged in meaning making that led to him imagining and identifying the relevant quantities and how they change together, he was able to give accurate definitions of variables and was usually able to define a formula to relate the two quantities of interest. However, we found that the student sometimes had difficulty imagining how the two quantities of interest were changing together. At other times he exhibited a weak understanding of the operation of subtraction and the idea of constant rate of change. He did not appear to conceptualize subtraction as a quantitative comparison. His inability to conceptualize a constant rate of change as a proportional relationship between the changes in two quantities also presented an obstacle in his developing a meaningful formula that relied on this understanding. The results further stress the need to develop a student's ability to engage in mental operations that involve covarying quantities and a more robust understanding of constant rate of change since these abilities and understanding are critical for student success in future courses in mathematics.
ContributorsKlinger, Tana Paige (Author) / Carlson, Marilyn (Thesis director) / Thompson, Pat (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor)
Created2014-05
Description
Theft as well as burglary rates have remained high all across the world. These thefts involve stealing expensive objects like cars, or breaking into homes and stealing televisions, or going to malls and shoplifting. Aside from these kinds of crimes, theft involving personal items like backpacks, laptops, or mobile devices is just as important. Travelers and students can be subjected to these kinds of thefts easily and unnoticeably. According to a report from Kensington IT, an estimated one laptop is stolen every 53 seconds, 70 million smartphones are lost each year, and 52% of devices are stolen from the office/workplaces with 24% from conferences. One way to protect these items is to use a security device to ensure greater safety. The iMovedAlarm is an affordable sensor alarm that notifies people when their belongings are being stolen while also deterring thieves from stealing those belongings. The iMovedAlarm is a module that consists of a sound alarm, an LED light, and sensor technologies that activate when an object leaves the vicinity of the owner. When a thief attempts to steal the object, the iMovedAlarm will know to sound a buzzer alarm, flash an array of LED lights, and send alerts to a user's smartphone or wearable devices. This can help deter a thief from continuing the crime as those around him or her will have a better notice of what is happening. In addition, if the thief continues on with stealing the item, the iMovedAlarm can be tracked with the user's smartphone so that the location of the items can be found. The iMovedAlarm utilizes Arduino technology to make the device even more user-friendly.
ContributorsVergara, Marvin (Co-author) / Wynia, Rachel (Co-author) / Lin, Elva S.Y. (Thesis director) / Lin, Elbert (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05