Medical Applications User Guide (pdf) - Freescale Semiconductor

More documents

Recommendations

Info

Appendix Analog Measurement Engine Some of the analog modules are commonly used in most of the medical applications. Therefore, it is necessary to add them in the design separately, which increases the PCB size and increases the cost. Freescale medical-oriented solutions embed these modules—reducing PCB size, cost and increasing the design performance. Modules included in the analog measurement engine are: OPAMP, TRIAMP, ADC, DAC, ACMP, VREF and PDB. These modules are explained below. OPAMP Operational amplifiers (OPAMPS) have several purposes. They can be configured as simple as a buffer circuit or as complex as an N order filter, OPAMPS have a huge application field in the medical industry. Freescale medical oriented MCUs integrate operational amplifiers on chip. These OPAMPS can be configured to work as general purpose OPAMPS, buffer circuit or configurable gain inverting and non-inverting amplifiers. TRIAMPS Transimpedance amplifiers (TRIAMP) are special general purpose OPAMPS with reduced input offset voltage and bias current, ideal for applications which requires low amounts of voltage and current. TRIAMPS can be also used as general purpose OPAMPS to reduce BOM and PCB size. ACMP Analog comparators (ACMP) compare two analog inputs and generate a high or low state depending on the input values. Output is high when the positive input is greater than the negative input and low when the negative input is greater than the positive input. Analog comparators can be constantly checking the value of both inputs and generate an interrupt when a change occurs. Figure A-8: Test Strip Basic Block Diagram Using Flexis MM Figure A-8: Test Strip Basic Block Diagram Using Flexis MM Blood Sample Reactive Electrode External Components Embedded Transimpedance Amplifier Figure A-9: Kinetis K50 Family Block Diagram Figure A-9: Kinetis K50 Family Security and Integrity Cyclic Redundancy Check (CRC) Random Number Generator Cryptographic Acceleration Unit (CAU) Core ARM ® Cortex-M4 72/100 MHz Debug Interfaces Interrupt Controller Standard Feature MCU/MPU System Memories Internal and External Watchdogs Memory Protection Unit (MPU) Embedded ADC Xtrinsic Low-Power Touch-Sensing Interface Segment LCD Controller Kinetis K50 Family of MCUs can provide up to 31 16-bit ADC channels 108 Medical Applications User Guide DSP Analog 16-bit ADC PGA Analog Comparator 6-bit DAC 12-bit DAC Voltage Reference OPAMP TRIAMP DMA Low-Leakage Wake-Up Unit Timers FlexTimer Carrier Modulator Transmitter Programmable Delay Block Periodic Interrupt Timer Low-Power Timer Independent Real-Time Clock (IRTC) IEEE ® 1588 Timer Optional Feature Program Flash (128 to 512 KB) FlexMemory (32 to 256 KB) (2 to 4 KB EE) Serial Programming Interface (EZPort) SRAM (32 to 128 KB) External Bus Interface (FlexBus) Clocks Phase-Locked Loop Frequency- Locked Loop Low/High- Frequency Oscillators Internal Reference Clocks Communication Interfaces HMI I 2 C UART (ISO 7816) SPI IEEE 1588 Ethernet MAC I 2 S Secure Digital Host Controller (SDHC) USB OTG (LS/FS) USB Charger Detect (DCD) USB Voltage Regulator GPIO
ADC Analog-to-digital converters (ADC) are one of the most important modules on the medical and overall electronics field. This module allows the conversion of an analog input into a digital value that can be processed by a MCU or MPU. ADCs output an N-bits value as a result of the conversion, and can take significant amount of PCB size placed separately. Embedded ADCs reduce PCB size and processing efforts reducing the access time to the result value. DAC The digital-to-analog converter (DAC) generates an analog voltage depending on the value in its input register and the module resolution. DACs are useful in the generation of reference voltages or as wave form generators. Electrocardiography uses DACs for ECG baseline adjustment. PDB The programmable delay block (PDB) provides controllable delays from either an internal or an external trigger, or a programmable interval tick, to the hardware trigger inputs of ADCs and/or generates the interval triggers to DACs, so that the precise timing between ADC conversions and/or DAC updates can be achieved. The PDB can optionally provide pulse outputs (pulse-outs) that are used as the sample window in the Analog Comparator. VREF VREF module generates a static voltage that can be used as a reference on an OPAMP, DAC, ACMP or other application without need of external regulators. Embedded VREF modules are programmable and can reduce the amount of external components on a PCB eliminating the need of external regulators or voltage dividers for VREF applications. Table A-1: Filters for Medical Applications Appendix Type Circuit Cut frequency Equation Band-pass passive Reject-band passive 0.1 Hz–150 Hz Heart operating range 40 Hz–60 Hz Noise signal from the line Band-pass active 400 Hz–4 KHz Sound wave bounced (range depends of the transducer) Low-pass active 150 Hz Heart operating range (if the passive filter is not enough, use an active filter) High-pass filter active Filter Design A lot of noise is present in biophysical signals. To attenuate this noise, low pass filters and high pass filters are used to amplify the small AC components and reject DC components. The filters allow only the useful signals, which helps to attain a more accurate diagnosis. These filters can be built with passives or actives (op amps) depending on the application, although active filters are more effective at rejecting noise. Passive filters are more cost-effective and are suitable in some cases. Sometimes the MCU does not have a DAC. This can be built by the PWM module and external low pass filter to convert digital data to analog data. Some medical applications Not specific freescale .com/medical 109
Page 1 and 2:
Medical Applications User Guide TM
Page 3 and 4:
freescale.com/medical 3 Introductio
Page 5 and 6:
Introduction 1.1 Freescale Offers T
Page 7 and 8:
Monebo Kenetic ECG Algorithms Free
Page 9 and 10:
Home Portable Medical 2.1 Introduct
Page 11 and 12:
3.2 Home Health Hub (HHH) Reference
Page 13 and 14:
3.3 Power Management Every design n
Page 15 and 16:
MC34704 The MC34704 is a multi-chan
Page 17 and 18:
3.7 How it Works The external capac
Page 19 and 20:
eliably monitor and manage non-crit
Page 21 and 22:
3.19 Standard Medical USB Communica
Page 23 and 24:
Freescale has developed sample code
Page 25 and 26:
4.2 Heartbeat Detection The heartbe
Page 27 and 28:
4.6 Blood Pressure Monitor Referenc
Page 29 and 30:
MCF51MM: Flexis 32-bit ColdFire V1
Page 31 and 32:
Heart Rate Monitor 5.1 Introduction
Page 33 and 34:
Instrumentation amplifier requireme
Page 35 and 36:
6.2 Test Strip A test strip consist
Page 37 and 38:
fully featured products at lower co
Page 39 and 40:
Freescale’s Xtrinsic acceleromete
Page 41 and 42:
7.2 Signal Acquisition This applica
Page 43 and 44:
AN4327 Pulse Oximeter Fundamentals
Page 45 and 46:
8.2 Electrocardiography (ECG) Acqui
Page 47 and 48:
Xtrinsic Touch-Sensing Software Xtr
Page 49 and 50:
• Internal voltage reference •
Page 51 and 52:
9.2 Microphone Amplifier The microp
Page 53 and 54:
9.5 Digital Signal Processor The di
Page 55 and 56:
Diagnostic and Therapy Devices 10.1
Page 57 and 58: 10.4 Filtering ECG The ECG has thre
Page 59 and 60: Features: • ColdFire V1 core deli
Page 61 and 62: The eMAC improvements target three
Page 63 and 64: 11.2 Circuit for Capacitive Dischar
Page 65 and 66: 12.2 System Sensors Figure 12-1: Ve
Page 67 and 68: • i.MX Processors The most versat
Page 69 and 70: MPX230xDT1: High Volume Pressure Se
Page 71 and 72: S08MM: Flexis 8-bit MCUs The 9S08MM
Page 73 and 74: 13.2 Brief Theory As mentioned in C
Page 75 and 76: Vital Signs 14.1 Introduction A vit
Page 77 and 78: 14.6 Motor Control with Freescale D
Page 79 and 80: State-of-the-art technology—inclu
Page 81 and 82: 15.5 Communication Interfaces USB P
Page 83 and 84: 15.7 Multimedia Applications with i
Page 85 and 86: 16.2 Ultrasonic Probe The ultrasoni
Page 87 and 88: segments. Devices start from 128 KB
Page 89 and 90: Powered Patient Bed 17.1 Introducti
Page 91 and 92: accelerometer is required. The Free
Page 93 and 94: Table 17-1. Freescale Technologies
Page 95 and 96: 18.2 Ultrasound Ultrasound is a non
Page 97 and 98: The depth in color used in the fina
Page 99 and 100: significant amount of precision ana
Page 101 and 102: All the devices featured are pin co
Page 103 and 104: Summary Summary Applications Freesc
Page 105 and 106: Appendix Digital Signal Processing
Page 107: Freescale Technologies • ColdFire
Page 111 and 112: freescale .com/medical
show all

Medical Applications User Guide (pdf) - Freescale Semiconductor

Create successful ePaper yourself

Delete template?

Save as template?