通信單片機(jī)外文翻譯---一個完全植入式無線壓力監(jiān)測系統(tǒng)的開發(fā)（英文）

1、Development of a fully implantable wireless pressure monitoring systemRobert Tan it represents the first step in developing a ubiquitous sensing platform for telemedicine and remote patient monitoring.Keywords MEMS . Pr

2、essure sensor. Implantable .Patient monitoring . Telemetry. Telemedicine .Bladder. Wireless1 IntroductionThere has been significant interest in the medical commu- nity in telemedicine and remote patient monitoring at hom

3、e and in the hospital (Field and Grigsby 2002). Current patient monitoring instrumentation and practices can be cumbersome and restrictive. For example, in the intensive care unit, blood pressure monitoring can be monito

4、red continuously with an arterial line. This is a catheter that is placed in the artery, and an external transducer detects the pressure. The limitations of this are that the accuracy is highly variable, and the patient

5、is often sedated to prevent him from injuring himself from movement. On the other hand, in standard floor care, while completely non-invasive and burden-free to the patient, standard blood pressure measurements with a cu

6、ff are non-continuous point meas- urements typically taken every 2–12 h. The development of critical vital signs between measurements could be missed. Currently, there is no device which provides clinicians with continuo

7、us monitoring of vital signs without being ex- tremely invasive and/or cumbersome. A device capable of continuous and real time measure- ment and monitoring without significantly reducing the patient’s comfort or restric

8、ting his movement would fill the gaps in performance and comfort between intensive and standard care. A simple and cost effective solution is to utilize implantable microsystems utilizing wireless teleme- try. Wireless t

9、elemetry frees the patient from being tethered to large hospital monitors and can participate in a hospital sensor network, which could increase monitoring efficiencyBiomed Microdevices (2009) 11:259–264DOI 10.1007/s1054

10、4-008-9232-1R. Tan: C. K. Lin: J. Schmidt (*) Department of Bioengineering, University of California, Los Angeles, CA 90095, USA e-mail: schmidt@seas.ucla.eduT. McClure: P. Schulam Department of Urology, University of Ca

11、lifornia, Los Angeles, CA 90095, USAD. Jea: M. Srivastava Department of Electrical Engineering, University of California, Los Angeles, CA 90095, USAF. Dabiri: T. Massey: M. Sarrafzadeh Department of Computer Science, Uni

12、versity of California, Los Angeles, CA 90095, USAC. D. Montemagno College of Engineering, University of Cincinnati, Cincinnati, OH 45221, USAtation (Nusil 2008). The PDMS was mixed in a 10:1 elastomer base to curing agen

13、t ratio and degassed under vacuum. Once in the mold, the PDMS was allowed to cure for ～24 h at room temperature. The final diameter of the molded tip of the catheter lead measured about 12 French (4 mm).2.2 Sensor nodeTh

14、e sensor node consists of three components: amplifying electronics, microcontroller and wireless transmitter, and the battery. The free end of the catheter lead is soldered onto a custom-designed circuit board. On this c

15、ircuit board are a quad micro-power, single supply operational amplifier (Texas Instruments TLV2764), a 2.5 V voltage regulator chip (Analog Devices REF192), and a single pole, double- throw (SPDT) magnetic reed switch t

16、o turn the device on and off (Hamlin) (Lin 2007). The voltage regulator chip sets the supply voltage powering the device and other electronics to 2.5 V to prevent any variations in signal from the pressure die due to var

17、iations in battery voltage. The operational amplifiers were configured to null any offset from the sensor bridge and amplify the bridge voltage by a factor of 300. The physiologically-relevant pressure mea- surement rang

18、e was 1.5 psi gauge pressure, and with thedevice sensitivity, supply voltage, and amplification, the device output was 1.2 V/psi and 1.8 V for the physiological pressure range. The output of the amplifying circuit was co

19、nnected to the microcontroller and wireless transmitter (Mica2Dot (Crossbow MPR510CA), hereafter referred to as the dot mote), which transmits at 433 MHz. We programmed the microcontroller to acquire and transmit data wh

20、ile maxi- mizing battery life in three ways: first, the microcontroller pulses the sensor for only 30 μs each measurement cycle, after which the entire device goes into sleep mode. Second, the measurements are taken only

21、 once per second. Finally, since the greatest power draw comes from transmission, the sampled data is stored locally on the dot mote and is transmitted every 30 measurements (Lin et al. 2007). These techniques reduce the

22、 energy consumption from 3 mJ per measurement to 625 μJ (Lin 2007; Lin et al. 2007). The battery used is a 3.7 V, 850 mAH lithium-polymer battery (Batteries America). The device was observed to have a lifetime of 387,300

23、 measurements or >4 days at this sampling rate before the battery voltage dropped below the supply voltage of the device. Once fully fabricated, the sensor node was wrapped in 25 μm-thick low density polyethylene (LDP

24、E, Plastic Sheeting Supply) and compression-molded in PDMS. Afterwards, the device was dipped into PDMS for a second silicone layer to plug any holes in the first PDMS layer. During and after the packaging process, the b

25、attery cannot be charged or replaced, so neodymium magnets were stacked on top of the mold to activate the magnetic switch and turn off the device while it cured for 24 h.2.3 Wireless communicationThe dot mote communicat

26、es with a complementary receiver station (Crossbow MIB510CA), which is connected to a computer. The dot mote sends data in a hex format that includes a timestamp, a unique ID tag, the remaining battery voltage, and the a

27、mplified pressure data. LabVIEW (National Instruments) was programmed to read and convert the data packets, which are stored in a text file and graphed in real time.2.4 In vitro testsOnce fabrication of each catheter lea

28、d was completed, the lead alone was tested and characterized by placing it in a sealed pressure chamber (Binks). It was electrically connected to wires threaded through the lid of the pressure chamber. The lead was exter

29、nally powered (Agilent E3630A) and the output voltage was read by a high precision multimeter (Keithley 2000). The pressure was held constant at atmospheric pressure for 30 min while theFig. 2 Artist’s rendition of cathe

30、ter lead tip. (a) Shows the lead tip unpackaged. A commercial pressure die is affixed and wirebonded onto a PCB substrate. Four Pt–Ir wires fed through the catheter are soldered onto the PCB. (b) Depicts the lead after p