Medical ASIC Design

System to ASIC has extensive experience in design and manufacturing of ASICs for medical applications. Our medical ASICs are used for measuring, monitoring and reporting of vital parameters for in-home and clinical patient care, as well as for metabolic parameters used in sports training and lifestyle management.  A few of our medical ASIC projects are summarized below.

IDM ASIC

IDM (Inhaler Delivery Monitor) ASIC is used to build a “Smart Inhaler” that tracks and records every inhaler dose delivery event.  When a dose sequence is executed through the inhaler mouthpiece, the smart inhaler is able to log schedule and delivery technique that can be retrieved by the prescribing physician during an office visit.  Errors in schedule and technique can be addressed before adjusting a prescription.

The IDM ASIC design integrates all of the analog and digital signal processing required for implementation of a smart inhaler with very low power dissipation for long battery life.  This custom ASIC chip conditions and processes analog input from sensors embedded in the inhaler body. Embedded sensors include a pair of thermistors to monitor direction, flow and timing of breath, while a strain gauge tracks dose dispensing.  Conditioned signal is digitized by a very low power analog to digital converter, then analyzed and recorded by an embedded processor.  Accumulated data and programming information is transferred with a bi-directional IR communication interface.

IDM ASIC development – Results:

  • Cost reduction – 31 components, including amplifiers, comparators, DACs, ADCs and microcontroller
  • ROI <  6  month
  • Development cycle 24 weeks

IDM ASIC’s Functional Features:

  • Extended battery life with a very low sleep current < 1µA and low voltage (<1V) operation
  • Low power differential thermistor signal processing for bidirectional breath flow measurement
  • Noise and sunlight immune optical communication interface for remote programming and stored data download
  • Low power, signature dose detection for proper vs. improper utilization identification.

IDM ASIC’s Performance Features:

  • Voltage Range: 8 – 5.0VDC
  • Low sleep current < 1µA
  • Low min life operating current < 12µA
  • <1µA, fully differential, sampled 40dB strain gauge interface front end
  • <3µA, 100Khz IR transceiver
  • 200nA, temperature and supply compensated bandgap voltage reference
  • < 200nA, 32.768Khz closed loop crystal oscillator
  • 8 bit controller
  • EEPROM

 

Pulse Oximetry ASIC

Transmissive pulse oximetry is a method of non-invasively determining oxygen saturation level and can also produce a close measure of heart rate.  Pulse oximeters have a wide range of use scenarios from vitals monitoring in emergency, clinical, and home care, to metabolic monitoring for sports training and lifestyle tracking.  The Pulse Oximeter ASIC provides the drive and processing resources for a small low-power battery operated instrument that measures haemoglobin oxygen saturation and heart rate.  Signal processing within the ASIC is optimized for monitoring heart rate up to 185 bpm, making this useful for sports training.  Multiwavelength processing offers improved accuracy and immunity to measurement error due to non-uniform tissue, low perfusion levels, presence of venus blood, and motion artifacts.

Pulse Oximetry ASIC development – Results:

  • New Product Family
  • Development cycle 24 weeks

Pulse Oximetry ASIC Functional Features:

  • Extended battery life with a very low sleep current < 1µA and low voltage (<1V) operation
  • Low power differential thermistor signal processing for bidirectional breath flow measurement
  • Noise and sunlight immune optical communication interface for remote programming and stored data download
  • Low power, signature dose detection for proper vs. improper utilization identification.
  • Pulse oximeter with very low power operation
  • High heart rate measurement accuracy for up to 185 bpm, good for fitness applications
  • Accurate SpO2 measurement over a wide perfusion (blood flow) range
  • Single cell battery operation
  • Constant current LED drive with pulse shaping
    • Temperature compensation
    • Correction for aging
    • Programmable pulse duration amplitude and interval timing
    • Individual control of  5 LED drive channels for multiwavelength operation
  • High gain synchronous light measurement channel
    • Automatic Gain Control with wide dynamic range
    • Programmable AGC attack and decay timing
    • High noise immunity
    • Adjustable pulse sampling window
  • LCD drive
  • Audio drive circuitry for conveyance of SpO2 and heart rate