Design and Development of a Micromachined Non-invasive Pressure-flow

m One of th'e most challenging concerns of Urosurgeons is to be able to diagnose a prostate cancer non-i;nvasivel~@xisting techniques for diagnosis of prostate cancer are a invakive in nature and lack concern for patient safety and comfort. These concerns have been the compelling force for urosurgeons to investigate new non-invasive techniques for the detection of prostate cancer in men: Urodynamic literature states that measurement of bladder pressure and urinary flow rate can be'hsed in the evaluation of patients suspected of having prostate cancer. For example, a high bladder pressure due to an obstruction in ' the bladder neck and a low k i n e flow rate may be evaluated as a presence of potential prostate cancer. In'normal conditions, the biadder pressure just before voiding is in the range of 40 to 60 mm of Hg, and the vording flow rate in the order of 15 mlls. A presence of obstruction in the bladder neck can result in the bladder pressure being as high as 80 e . mm of Hg or more and the f ow rate lower than 10 mlls. This thesis presents thp design, 1 fabrication and the preliminary testing results of a silicon micromachined pr&ssure and flow sensor which are integrated together on a single silicon substrate. This thesis also presents the packaging of the device which will make the detection of prostate cancer pos\ sible non-invasively. The pressure sensing principle is based on the change in the resistance of piezo/ resistors due to stress (pressure). The well k wn simple anemometry technique being the ')" flow sensing principle. The fabricated device has a pressure sensitivity of I mV110 mm of Hg and a flow sensitivity of 0.98 mVl(ml1s). The working device exhibits the pressure range of 0 to 78 cm of Hg, and a flow range of 0 to 45 mlls., and the time response of 100 msec., which are ideally suitable for the evaluation of prostate cancer.' dedicated to my parents, brothers and their families. B Acknowledgments . This thesis can not have come about without the help and encouragement from some very special people. I offer my sincere thanks to the following: * My supervisor, Ash, for showing confidence in my ability and working with me and assisting me all throughout towards the progress of this project. * Dr. Jim McEwen and Dr. Larry Goldenberg, from Vancouver General Hospital, for holding numerous technical meetings to explain anything and everything I needed (and not what I didn't need to) to know about the human (and not an'elephant3s) t prostate. * Dr. Ash for, also, carefully reviewing the thesis and for his valuable suggestions to a, make it more interesting thesjs to read. 1 * Dr. Mak Paranjape for accompanying me to the interesting meetings with uroser , geons to improve his technical knowledge regarding the human prostate and also. with the help of Ash, giving me atleast a mil l io~ nicknames most of which are too embar&ssing even to mention here. * Dr. Marek Syrzycki and Dr. Shahram Payandeh for being the committee members and Dr. Paul Ho for chairing my thesis defense session. # -C * Micromachining colleagues Jianming Chen, Manish Mehta, Shaoqing Wo, Dr. M. Paranjape for their constant help inside and outside the cleanroom. * Dr. Eva ~z i zewska . Bill Woods for their help in various stages during the fabrica tion of the device in the cleanroom and also for helping me clean the mercury spill in the clean room (what a disaster it was!!). . 4 . * Bahram Ghodsiais the Guru of Frame Maker for his valuable help with it. * Anjali Atal for proof-reading my thesis and working on my language and gram ar. !?? * Brigitte Rabold --for helping me with all the Graduate Studies Program related work. .*Jt > * Family and friends 1 They all helped me to keep my sanity and constantly reminded ' me that there are pleasures other than a cleanroom that life has to offer.