Doppler Ultrasound Flow Detector

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Doppler Ultrasound Flow Detector
Sponsoring Organization University of
Connecticut Electrical and Computer
Engineering Department

• Team Members
• Timea Mate (EE)
• Alfred Hajati (EE)
• Joel Henry (EE)
• Advisor Quing Zhu

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Overview

• Background
• Statement of Problem
• Proposed Solution
• Design Specification
• Timeline
• Design Budget
• Conclusion Q A

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Background

• The analysis of blood flow patterns is of great
  importance in assessing Cardiovascular disease.

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Background (contd)

• Flow meters are also vital in the detection and
  diagnosis of COPD (Chronic Obstructive Pulmonary
  Disease).
• These diseases affect the respiratory system and
  some examples are
• Asthma
• Bronchitis
• Lung Cancer
• Emphysema

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Background (contd)

• Doppler Ultrasonography
• Diagnostic procedure that changes sound waves
  into an image that can be viewed on a monitor
• May help diagnose
• blood clots
• Detects heart valve issues
• Assessing blood flow in stroke patients
• viewing the heart to monitor carotid artery
  diseases.

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Statement of Problem

• The need to build and implement an Ultrasonic
  Doppler Flow Detector that will measure direction
  and monitor the speed of blood flow.

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Proposed Solution
Skin Surface
Blood Flow
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Proposed Solution
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Design Specifications

• Main Components
• Crystal Oscillator HS-49U
• Transducer Driver (Provided)
• Ultrasonic Transducer Panametrics
• Pre-amplifier AD600
• Diode Mixer LT551
• Band-Pass Filter MAX263
• Digital Filter (Provided)
• Speaker, Pump Labview Interface Graphical
  Output

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Design Specifications

• Crystal Oscillator HC-49U
• Frequency 8 MHz max
• Load Capacitance 20 F
• Extended temperature range

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Design Specifications

• Transducer Driver
• Power Amplifier is needed to provide the high
  voltage pulses required to drive the Transducer.
• For safety reasons, the power amplifier will be
  provided by the sponsor (Electrical engineering
  Department).

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Design Specifications

• Ultrasonic Transducer
• Panametrics Dual Element
• Transducer
• Two Crystal Elements
• Sends a Crossed-Beam Sound Path
• Improves Near Surface Resolution
• Reduces Direct Back-Scattering Noise
• Nominal Element Size 0.25 (6mm)

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Design Specifications

• Transducer (contd)
• Two basic quantities are measured
• Time of sound travel through the object
  Amplitude of received sound
• T c ts /2
• dB 20 log10(A1/A2)
• Sound Filed
• Two Zones
• Near Field
• Far Field

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Design Specifications

• Angle Beam Transducer

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Preamplifier

• A high preamplifier input impedance (100?)is
  needed to avoid the signal from the transducer
  being damped.
• Assuming the peak transducer signal is typically
  a few mVolts and the peak input signal for the
  AD600 is around the same level, than the gain for
  the preamplifier should be 60dB resulting in 1V.

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Design Specification

• Ultra-Low Noise Preamplifier
• High gain means also high noise gain.
• The challenge here is to build a low noise
  preamplifier to maximize performance.
• Review data sheets before buying the Op-amp for
  the lowest voltage and current noise spectral
  densities.
• Minimize the noise figure and maximize the
  signal-to noise-ratio (SNR).

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AD604 LNA

• 2 channels with independent gain control
• Gain 0dB 40dB per channel
• Low input noise 1.4 nV/?Hz
• Low distortion -60dBcTHD at 1V output
• High bandwidth dc to 35MHz (-3dB)
• Low power 125 mW (maximum) per amplifier

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AD604 LNA

• 2 channel 16-lead PDIP (N)
• The SNR for 1V rms output and a 1MHz noise
  bandwidth is typically 76dB
• Each amplifier can drive 100? load impedance with
  low distortion.
• Operating temperature 0C to 70C

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AD600 LNA

• By changing VG, we can control the gain of the
  LNA
• A1HI is the input signal for the LNA
• A1OP is the output from the LNA
• A1OP G A1HI

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AD600 LNA

• The gain of the AD600 can be calculated by
• Gain (dB) 32 VG 20
• We can solve for VG
• VG (V) Gain(dB) 20 / 32
• Example Find the VG for a gain of 30 dB?
• VG 30-20/32 0.3125 V
• To achieve a gain of 60dB or 70dB, which is
  greater than the maximum gain of one AD600
  channel, a second AD600 channel cascaded in
  series with the first one is needed.

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AD600 LNA

• For an 80 dB gain
• GA1 32VG1 20 32 2.5 - 1.841 20
  41.07dB
• GA2 32VG2 20 32 2.5 - 1.908 20
  38.93dB
• Total Gain GA1 GA2 41.07dB 38.93dB
  80dB

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1KHz - 3GHz Mixer

• Manufacturer Linear Technology
• Device LT5512

• Supply Voltage (VCC1, VCC2, IF, IF) 5.5V
• Enable Voltage 0.3V to VCC 0.3V
• LO to LODifferential Voltage 1.5V (6dBm
  equivalent)
• RF to RF Differential Voltage 0.7V (11dBm
  equivalent)
• Operating temp -40C to 85C
• Storage Temperature Range -65C to 125C

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Design Specification

• Dielectric BandPass Filter
• Maxim Pin Programmable BandPass and Universal
  Filter
• MAX263 Q 64 Mode 4 Clock f 40Hz
  2.0 MHz
• Center f 0.4Hz 20kHz

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Design Specification

• LabView Interface
• Our Doppler Shift will be inputted in LabView to
  graph the actual output and to display and
  measure speed.

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Budget

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Budget

• Consumer price
• Market Comparison
• Vascular Doppler Meter 470 655
• Fetal Doppler Meter 390 - 715