Design on a new photoplethysmographic-clip

Design on a new photoplethysmographic-clip

Van Geest, G.

Moes, C.M.M. (mentor)
Vonck, D. (mentor)
Van Velzen, M.H.N. (mentor)
Mik, E. (mentor)

Industrial Design Engineering

Design Engineering

Master of Science Integrated Product Design

2012-06-14

This report reflects the graduation process of Gerjan van Geest a master student of Integrated Product Design at the faculty of Industrial Design Engineering at the Technical University Delft. The graduation subject was: “Design of an improved photoplethysmographic-clip” With a photoplethysmographic (PPG) sensor it is possible to measure the heartbeat and oxygen saturation. The department of Experimental Anaesthesiology, laboratory of Experimental Anaesthesiology, at the Erasmus Medical Centre is developing an improved PPG-sensor technology, with the new technology it becomes possible to assess the condition of the blood vessels and thereby heart and vascular diseases can be diagnosed in an early phase of development. Heart and vascular diseases is an umbrella term for multiple diseases like heart attacks, strokes and transient ischemic attacks (TIA’s). The Analysis outcomes Several issues have been found that cause artefacts in the measurements of the PPG- sensor, such as movement of the clip on the finger, the size of the finger, incorrect placement of the clip on the finger and the pressure of the clip on the fingers. Next to that subjects like cleaning the clip and safety issues should also be taken into account. The most intensive users: the patients, the nursing staff and the doctors, are the main stakeholders of the PPG-clip. They all prefer a clip that is comfortable in use. It should fit nicely, be easy to place and give no wrong signals. If these three stakeholders are convinced of the ease of the clip the rest will follow at the condition that the clip stays affordable. Vision To prevent movement artefacts the new clip has to be stable on the fingers of a variety of patients. This means that the clip is not able to move while it is in use and that the clip has to be easy to place on a finger, no matter what size the finger is. Next to that the clip should be comfortable to wear for at least four hours, although the patient is passive. The clip should give extra information about the conditions of the blood vessels, if there are any impurities inside the blood vessels, which could indicate to heart and vascular diseases. The exact kind of signal that the doctor receives, a number, some sort of graph or a sound, should be determined in a later stadium. Ideas By using a morphological chart multiple ideas have been generated, based on the outcomes of the vision created at the end of the analysis. All ideas were defer to a list of criteria to select the best ones. Two ideas were developed further into concepts: ‘Toy’ and ‘Inflated’. Concept choice Both concepts are very interesting to work out completely and both concepts could work in reality. But only one should be chosen to work out completely, so a comparison will be made between both concepts. The comparison was based on the positive and negative points in different kinds of fields and makes that ‘Toy’ will be the most favourite concept. Next to that is it the most intuitive concept of the two. The name of this concept was later on changed into Vamulec. Vamulec Vamulec is a clip consisting of two elements, the body and a roller. The body is a cylinder, which is split up in two antennas that contain the sensors. The patient’s finger will be placed between the two antennas. The roller will be rolled over the two antennas, which will press them down unto the patient’s finger. In this way does the Vamulec variety of finger sizes and keeps the sensors stable during use. A prototype is made to test whether or not the Vamulec works. Out of these tests it became clear that there is a lot of room for improvement. A redesign should be made implementing all the outcomes of the usage tests. Also more research is needed to prove that it is possible to assess the condition of the blood vessels and thereby heart and vascular diseases with a photoplethysmograph.

photoplethysmograph
vamulec
heart and vascular diseases
design

http://resolver.tudelft.nl/uuid:79afd4cb-0813-4bed-9289-3fb41ad6baf0

2013-06-14

Campus only

Student theses

master thesis

(c) 2012 Van Geest, G.