The incessant and destructive march of Covid-19 across the world continues unabated. Until a proven vaccine is made available to large number of people there is only one system that stands between life and death for people that can be adversely impacted by Covid-19 – A Ventilator.
Many people are casually asking why isn’t Tesla, Ford, GM, or the local machine shop not building a ventilator by the hundreds of thousands and ship them to hospitals. While ventilators may not be as sophisticated as rockets or autonomous cars, they are not simple blowers/HVAC systems either. The reference design document from Freescale (NXP) gives an outline of medical grade ventilator design.
Before you read this blog post you should really read this reference design document from Freescale/NXP thoroughly.
The following is a picture of a ventilator
The main components are shown below
The full Bill of Material of a ventilator may look like this.
Ventilator Bill of Material (Includes System Board BOM)
| Part Number | Part Name | Quantity | Part Type |
|---|---|---|---|
| Medical Ventilator | Medical Ventilator | Assembly | |
| LCD Character Display Module | LCD Character Display Module | 1.00000 | Part |
| Standoff HexM4 THR Alum | Standoff HexM4 THR Alum | 4.00000 | Part |
| Connection Socket | CONN SOCKET 30 Yes 22-26AWG 30AU CRIMP | 30.00000 | Part |
| 3/2 Electrovalve Plate | 3/2 Electrovalve Plate | 2.00000 | Part |
| Board With Components | Board with Components | 1.00000 | Assembly |
| Color Button | Color Button | 4.00000 | Part |
| AW 24 Wire | AW 24 Wire | 1.00000 | Part |
| Conn Rcpt | CONN RECEPT 16POS 24AWG MTA100 – Display | 1.00000 | Part |
| Air Chamber | Air Chamber | 1.00000 | Part |
| Anesthetic Patient Circuit | Anesthetic Patient Circuit | 1.00000 | Part |
| 2/2 Miniaturized Electrovalve | 2/2 Miniaturized Electrovalve | 2.00000 | Part |
| Anesthetic Bag | Anesthetic Bag | 1.00000 | Part |
| Electrical Valve Connector | Electrical Valve Connector | 4.00000 | Part |
| 4mm Air Hose | 4mm Air Hose | 2.00000 | Part |
| Aluminum Panel | Aluminum Panel | 1.00000 | Part |
| Espirometry Hose | Espirometry Hose | 1.00000 | Part |
| 3/4 CPVC Female Adapter | 3/4 CPVC Female Adapter | 2.00000 | Part |
| Air Compressor | Air Compressor | 1.00000 | Part |
| Suitcase | Suitcase | 1.00000 | Part |
| 2/2 Electrovalve Plate | 2/2 Electrovalve Plate | 2.00000 | Part |
| Conn Housing | CONN HOUSING 30POS .100 SINGLE | 1.00000 | Part |
| Conn Receptable Housing | CONN RCPT HSNG 2POS CST-100 II – I- button | 1.00000 | Part |
| 3/2 Miniaturized Electrovalve | 3/2 Miniaturized Electrovalve | 2.00000 | Part |
| Y Reduction Connector | Y Reduction Connector | 1.00000 | Part |
| 3/4 to 3/8 Reduction | 3/4 to 3/8 Reduction | 2.00000 | Part |
| Pressure Sampling Line | Pressure Sampling Line | 1.00000 | Part |
| Fitting | Fitting | 8.00000 | Part |
| Reduction 1/4 to 4mm | Reduction 1/4 to 4mm | 4.00000 | Part |
| D-Lite Sensor | D-Lite Sensor (Venturi) | 1.00000 | Part |
| 3/8 to 5/32 Reduction | 3/8 to 5/32 Reduction | 2.00000 | Part |
| Computer Power Supply | Computer Power Supply | 1.00000 | Part |
| Board With Components | Board with Components | Assembly | |
| Capacitor Ceramic 0.47UF | CAP CER .47UF 50V X7R 0805 | 1.00000 | Part |
| Transistor NPN | TRANS NPN EPITAX 100V 3A TO-220 | 5.00000 | Part |
| IC Reg Positive | IC REG POSITIVE 2A 5V TO-220 | 1.00000 | Part |
| IC Pressure Sensor 7 PSI | IC PRESSURE SENSOR 8-SOP 7PSI | 1.00000 | Part |
| Buzzer Mag | BUZZER MAG 2.0KHZ 3V 12MM | 1.00000 | Part |
| Resistor 220 Ohm | RES 220 OHM 1/8W 5% 0805 SMD | 2.00000 | Part |
| LED Red | LED 5MM RED 1000MCD ALINGAP GAAS | 1.00000 | Part |
| IC Temp Sensor | IC TEMP SENSOR MULTI-GAIN SC70-5 | 1.00000 | Part |
| LED Green | LED GREEN S-J TYPE 0805 | 1.00000 | Part |
| LCD Connection Header | LCD CONN HEADER VERT 16POS .100 TIN | 1.00000 | Part |
| Ferrite Chip 220 Ohm | FERRITE CHIP 220 OHM 2000MA 0805 | 3.00000 | Part |
| Conn Term Block | CONN TERM 6 BLOCK 2.54MM 2POS | 6.00000 | Part |
| LED Soft Orange | LED SOFT ORANGE S-J TYPE 0805 | 1.00000 | Part |
| 32 Bit Medical MCU | 32 Bit Medical MCU | 1.00000 | Part |
| Resistor 33 Ohm | RES 33 OHM 1/8W 5% 0805 SMD | 2.00000 | Part |
| Jumper 3 Pin | CONN HEADER VERT 3POS .100 TIN | 2.00000 | Part |
| Crystal 16 Mhz | CRYSTAL 16.000000 MHZ 8PF SMD | 1.00000 | Part |
| Capacitor 4.7UF | CAP ELECT 4.7UF 50V VS SMD | 2.00000 | Part |
| Diode Schottky | DIODE SCHOTTKY 30V 2A SMA | 7.00000 | Part |
| Resisitor 0.0 Ohm | RES 0.0 OHM 1/8W 0805 SMD | 6.00000 | Part |
| IC LDO Reg FXD | IC LDO REG FXD- VOLT 3.3V TO-220 | 1.00000 | Part |
| Resistor 180 Ohm | RES 180 OHM 1/8W 5% 0805 SMD | 1.00000 | Part |
| Diode Rect Ufast | DIODE RECT UFAST 150V TO220AC | 1.00000 | Part |
| Resistor 470 Ohm | RES 470 OHM 1/8W 1% 0805 SMD | 5.00000 | Part |
| Resistor 4.7K Ohm | RES 4.7K OHM 1/8W 5% 0805 SMD | 1.00000 | Part |
| Resistor 330 Ohm | RES 330 OHM 1/8W 5% 0805 SMD | 2.00000 | Part |
| LED Amber | LED AMBER S-J TYPE 0805 | 1.00000 | Part |
| IC Pressure Sensor 14 PSI | IC PRESSURE SENSOR 8-SOP 14PSI | 1.00000 | Part |
| Optocoupler | OPTOCOUPLER TRANS-OUT 6-DIP | 1.00000 | Part |
| Capacitor 47 | CAP 47UF 35V ELECT WT SMD | 3.00000 | Part |
| Capacitor Ceramic 10000PF | CAP CER 10000PF 50V 10% X7R 0805 | 2.00000 | Part |
| Thumbwheel Pot 10K Ohm | POT 10K OHM THUMBWHEEL CERM ST | 1.00000 | Part |
| Ferrite Bead 270 Ohm | FERRITE BEAD 270 OHM 0603 | 2.00000 | Part |
| Ibutton Tactile Probe | IBUTTON TACTILE PROBE CONN HEADER VERT 2POS .100 TIN | 5.00000 | Part |
| Switch Tact | SWITCH TACT SILVR 200GF GULLWING | 1.00000 | Part |
| Resistor 1.0M Ohm | RES 1.0M OHM 1/8W 5% 0805 SMD | 1.00000 | Part |
| Sealed PCB | RELAY AUTO 15A 12VDC SEALED PCB | 1.00000 | Part |
| Conn Recept Mini USB | CONN RECEPT MINI USB2.0 5POS | 1.00000 | Part |
| Diode TVS | DIODE TVS 13V 1500W UNI 5% SMC | 1.00000 | Part |
| Connection Header Vert .100 | CONN HEADER VERT .100 6POS 15AU | 1.00000 | Part |
| Capacitor 10UF | CAP ELECT 10UF 25V VS SMD | 1.00000 | Part |
| Resistor 330K Ohm | RES 330K OHM 1/8W 5% 0805 SMD | 3.00000 | Part |
| Pressure Sensor Dual Port | PRESSURE SENSOR DUAL PORT 8-SOP | 2.00000 | Part |
| Resistor 10K Ohm | RES 10K OHM 1/8W 5% 0805 SMD | 1.00000 | Part |
| Resistor 169K Ohm | RES 169K OHM 1/8W 1% 0805 SMD | 2.00000 | Part |
System Board Manufacturer Parts List
(Keep in mind that the reference design is from 2011 so many of the parts may not be available)
| Part Number | Manufacturer | Mftr’s Part No | Ro HS | Max Temp |
|---|---|---|---|---|
| LED Soft Orange | Panasonic – SSG | LNJ806K5SRX | ||
| 32 Bit Medical MCU | Freescale Semiconductor | MCF51MM256CLL | ||
| Capacitor Ceramic 10000PF | Murata Electronics | GRM216R71H103 KA01D | ||
| Resistor 4.7K Ohm | Panasonic ECG | ERJ-6GEYJ472V | ||
| IC Pressure Sensor 14 PSI | Freescale Semiconductor | MPXV5100GP | ||
| Resistor 33 Ohm | Stackpole Electronics | RMCF0805JT33R0 | ||
| LCD Connection Header | Tyco Electronics | 1-640456-6 | ||
| Resistor 180 Ohm | Panasonic ECG | ERJ-6GEYJ181V | ||
| Diode Schottky | Diodes Inc | B230A-13-F | ||
| Buzzer Mag | CUI Inc | CSQG703BP | ||
| Sealed PCB | Panasonic Electric Works | JSM1A-12V-5 | ||
| IC Reg Positive | ST Microelectronics | L78S05CV | ||
| Resistor 330K Ohm | Panasonic ECG | ERJ-6GEYJ334V | ||
| LED Red | Vishay | TLHK5800 | ||
| Resistor 330 Ohm | Panasonic ECG | ERJ-6GEYJ331V | ||
| Capacitor 4.7UF | Panasonic ECG | EEE-1HA4R7AR | ||
| Capacitor 47 | Nichicon | UWT1V470MCL1G S | ||
| Switch Tact | C&K Components | KSR221GLFS | ||
| Connection Header Vert .100 | Tyco Electronics | 87227-3 | ||
| IC Pressure Sensor 7 PSI | Freescale Semiconductor | MP3V5050GP | ||
| Resistor 220 Ohm | Panasonic ECG | ERJ-6GEYJ221V | ||
| LED Amber | Panasonic – SSG | LNJ406K5YUX | ||
| Crystal 16 Mhz | NDK | NX3225SA-16.000 000MHZ | ||
| IC LDO Reg FXD | Texas Instruments | TLV2217-33KCSE3 | ||
| Ferrite Chip 220 Ohm | Murata | BLM21PG221SN1 D | ||
| Resisitor 0.0 Ohm | Panasonic ECG | ERJ-6GEY0R00V | ||
| Diode TVS | Littelfuse | SMCJ13A | ||
| Capacitor Ceramic 0.47UF | Murata Electronics | GRM21BR71H474 KA88L | ||
| Resistor 1.0M Ohm | Panasonic ECG | ERJ-6GEYJ105V | ||
| Pressure Sensor Dual Port | Freescale Semiconductor | MPXV7025DP | ||
| Ibutton Tactile Probe | Tyco Electronics | 640456-2 | ||
| Jumper 3 Pin | Tyco Electronics | 3-644456-3 | ||
| Resistor 10K Ohm | Panasonic ECG | ERJ-6GEYJ103V | ||
| LED Green | Panasonic – SSG | LNJ306G5UUX | ||
| Transistor NPN | Fairchild Semiconductor | IP31C | ||
| Capacitor 10UF | Panasonic ECG | EEE-1EA100SR | ||
| Optocoupler | Fairchild Semiconductor | 4N27M | ||
| Conn Term Block | Phoenix Contact | 1725656 | ||
| Ferrite Bead 270 Ohm | Taiyo Yuden | BKP1608HS271-T | ||
| Thumbwheel Pot 10K Ohm | Bourns Inc | 3352W-1-103LF | ||
| Resistor 470 Ohm | Panasonic ECG | ERJ-6ENF4700V | ||
| Diode Rect Ufast | NXP | BYW29E-150,127 | ||
| Conn Recept Mini USB | Hirose Electric | UX60A-MB-5ST | ||
| IC Temp Sensor | National Semiconductor | LM94021BIMG/ NOPB |
Ventilator Manufacturer Parts List
| Part Number | Manufacturer | Mftr’s Part No | Ro HS | Max Temp |
|---|---|---|---|---|
| LCD Character Display Module | Optrex America | C-51847NFJ-SLW- ADN | ||
| Standoff HexM4 THR Alum | Keystone Electronics | S24453 | ||
| Connection Socket | Tyco Electronics | 5-103171-5 | ||
| 3/2 Electrovalve Plate | Festo | MHP1-AS-3-M3 | ||
| Board With Components | ||||
| Color Button | ||||
| AW 24 Wire | ||||
| Conn Rcpt | Tyco Electronics | 4-643814-6 | ||
| Air Chamber | IDEAS | |||
| Anesthetic Patient Circuit | Hudson | |||
| 2/2 Miniaturized Electrovalve | Festo | MHP1-M4H-2/2G- M3-TC | ||
| Anesthetic Bag | Sunmed | |||
| Electrical Valve Connector | Festo | KMH-0,5 | ||
| 4mm Air Hose | Festo | |||
| Aluminum Panel | ||||
| Espirometry Hose | GE Health | |||
| 3/4 CPVC Female Adapter | ||||
| Air Compressor | Goodyear | I300 | ||
| Suitcase | Pelican | |||
| 2/2 Electrovalve Plate | Festo | MHP1-AS-2-M3 | ||
| Conn Housing | Tyco Electronics | 5-87499-8 | ||
| Conn Receptable Housing | Tyco Electronics | 1375820-2 | ||
| 3/2 Miniaturized Electrovalve | Festo | MHP1-M4H-3/2G- M3-TC | ||
| Y Reduction Connector | Festo | QSY-8-4 | ||
| 3/4 to 3/8 Reduction | ||||
| Pressure Sampling Line | ||||
| Fitting | Festo | QSM-M3-4 | ||
| Reduction 1/4 to 4mm | Festo | QS-1/4-4 | ||
| D-Lite Sensor | GE Health | |||
| 3/8 to 5/32 Reduction | ||||
| Computer Power Supply | Acteck |