Project: Design and production of a biosensor system for non-invasive assessment of peripheral limb hemodynamic characteristics
Advisor: Charles Davis, Hemonix, Inc.
Project Description: Hemonix has developed a technology (PeriVasc) which can satisfy the needs of an effective means of noninvasively examining the hemodynamic characteristics of a region of vasculature in the peripheral limb. The essential physical parameters necessary for this kind of comprehensive noninvasive measurement were Pressure and Volume. Furthermore, these two parameters needed to be measured concurrently and coextensively on the same tissue samples in situ. We thoroughly assessed the various modalities of applying and measuring pressure and measuring volume changes which could be melded into an easy to use and familiar clinical device. We implemented the use of a standard blood pressure cuff as a pressure applicator and measurement device along with an integrated bioimpedance based electrode system to measure the volume changes in the underlying tissue beds. Accurate measurement of the relationships between Pressure and Volume required coextensivity of the two sensor systems and a complete circumference of the measured limb by both sensors. The ability of this technology to segment the peripheral vascular bed into vessel type segments allows for the novel, direct measurement of the Compliance of the vessels in situ. Therefore, the PeriVasc has great importance in both research and clinical applications.
The project that Hemonix proposes will focus on optimization and production of the sensory components of the system. The bioimpedance sensor was originally produced from a material that was specially made for vascular lab use for cutting custom electrodes for bioimpedance monitoring in vascular labs. We could cut and tape these electrodes together to form the channels that we desired in our electrode tests. The ultimate goal of this project is to convert the bioimpedance sensor production capability into a printing press-like machine that would automatically produce the electrodes at a low cost. The base material that we purchased had been produced in this fashion so we had a predicate device that we could point to in order to establish feasibility. Therefore, there is opportunity for students to combine the mechanical, electrical, material, and industrial engineering disciplines in the design and production of this machine.
Team recruitment: The vascular dynamics design team may be strengthened by the addition of a student majoring in Chemical Engineering or Industrial Engineering. The student would contribute to general development of the sensor system, evaluate the feasibility of possible designs for commercial manufacturing, and propose a method for fabrication of the sensor system on a commercial scale. It is expected that the student would use BIOEN 404-405 to satisfy the capstone requirement in his or her home department. Interested students may obtain additional information about technical aspects of the project by contacting Christopher Neils (cmneils@uw.edu). Students may apply to join the design team by submitting a statement of their interest, preparation, and senior course plan to the MSE or ChE department academic advisor, for forwarding to Bioengineering.
Project: Design of a pressure monitoring device for the investigation of glaucoma asymmetry
Advisor: Parisa Taravati, M.D., Assistant Professor, Dept. of Ophthalmology, UW
Project Description: Glaucoma is a common disorder of the optic nerve and can result in irreversible loss of vision if left untreated. In glaucoma, damage to the optic nerve has been associated with increased intraocular pressure (increased pressure within the eye), and all glaucoma treatments are aimed toward lowering intraocular pressure to prevent additional vision loss. Glaucoma can affect the both eyes to the same extent, or it can affect one eye more than the other. However, not much is known about the reason for glaucoma affecting one eye more than the other. There have been studies showing that human intraocular pressure varies not only during the sleep-wake cycle, but also by changes in posture (i.e. sleeping upright, with head of bed elevated or lying flat). The purpose of this project is to design a pressure-monitoring device to ultimately determine if head position during sleep contributes to asymmetry of glaucoma between the eyes. The hypothesis that this device will help test is that sleeping on one side regularly would cause increased external pressure to the eye on that side, which in turn, would cause more damage to the optic nerve in an eye that already has glaucoma or is at risk of developing glaucoma.
Clinical Relevance: After informed consent is obtained, patients with glaucoma, elevated intraocular pressure, or who are suspects for glaucoma, will be asked to fill out a survey asking what position they usually sleep in. The patients’ charts will be retrospectively and prospectively reviewed to determine the type of glaucoma they have and whether or not they have asymmetry of glaucoma between their two eyes. Unfortunately, not much is known about how much agreement there is between a patient’s perceived sleep position and actual sleep position at night. For this reason, there is a need for a device that could measure the amount of time someone spends sleeping on either side, as well as how much pressure is exerted onto the eye when sleeping on that side. This information can then be used to: 1. Determine if patients’ reported vs. actual sleep positions correlate, and 2. Determine if the head position during sleep contributes to the asymmetry of glaucoma.
Team recruitment: The pressure-monitoring device design team may be strengthened by the addition of a student majoring in Electrical Engineering. The student would contribute to general development of the pressure-monitoring system, and specifically to the filtering, recording, and transmission of time and pressure data. Experience with wireless connectivity and microprocessor implementation is preferred, but not required. The EE team member should have an interest and some preparation in medically related subjects, such as biology, biochemistry, or physiology. It is expected that the student would use BIOEN 404-405 to satisfy the capstone requirement in his or her home department. Interested students may obtain additional information about technical aspects of the project by contacting Christopher Neils (cmneils@uw.edu). Students may apply to join the design team by submitting a statement of their interest, preparation, and senior course plan to the EE department academic advisor, for forwarding to Bioengineering.
Project: Design of a hand-held laparoscopic tool for improved dexterity
Advisor: Prakash Gatta, MD FACS, Valley Medical
Project Description: Laparoscopic surgery is a modern surgical technique in which operations in the abdominal cavity are performed through small incisions, as compared to larger incisions needed in traditional surgical procedures. There are a number of advantages to undergoing laparoscopic surgery versus an open procedure, including reduced pain due to smaller incisions, reduced hemorrhaging, and a shorter recovery time. The use of laparoscopic techniques has been augmented by the creation of specialized tools. There are current products on the market which translate the motions of a surgeon’s hand, but there is room for improvement in terms of dexterity and strength of these hand-held tools. Thus, the goal of this project is to engineer a laparoscopic hand-held tool that translates the 7 degrees of motion of a surgeon's hand into a 5-10 mm instrument. Ultimately, with the design of such a hand held tool, "force feedback" or haptics may be more of a possibility than with the robotic tools currently used.
