Posts by Bill Cheung

Medical displays are not simply “brighter and more expensive monitors”. They are system-level engineering products, covering optics, electronics, grayscale fidelity, long-term stability, and regulatory compliance.

This blog provides a technical, engineering-oriented breakdown, clearly distinguishing:

• Mandatory requirements
• Advanced requirements for high-end or diagnostic-grade displays

1. Classification of Medical Displays

Grade	Typical Use Cases	Stringency
Observation / Clinical Review	OR auxiliary displays, patient monitoring, endoscopy, PACU, bedside viewing	★★★☆☆
Clinical (General Clinical Use)	Routine clinical image review, department workstations	★★★★☆
Diagnostic	Radiology, mammography, pathology, image-based diagnosis	★★★★★

Important:
Most products marketed as “medical displays” only meet observation-grade requirements.
True diagnostic-grade displays are far more demanding, with a significant cost gap.

 

2. Optical & Display Core Requirements (Most Critical)

2.1 Resolution & Size Matching (Mandatory)

Principle:

• Image pixel resolution should match the native panel resolution
• Strong interpolation or upscaling that affects diagnostic fidelity is unacceptable

 

2.2 Luminance (Brightness) (Mandatory / Stricter for Diagnostic)

Grade	Typical Peak Luminance
Observation	≥ 300 cd/m²
Clinical	≥ 400 cd/m²
Diagnostic	≥ 1000 cd/m² (Mammography ≥ 2000 cd/m²)

Requirements:

• Long-term luminance decay ≤ 10–15%
• Stable operation under continuous use

Common Techniques:

• LED constant-current backlight driving
• Integrated luminance sensor (for closed-loop control)

 

2.3 Contrast Ratio & Black Level (Mandatory)

Typical Targets:

• Observation / Clinical: ≥ 1000:1
• Diagnostic: ≥ 1500–2000:1

Black level must be minimized, especially for lung and soft-tissue visualization.

 

2.4 Grayscale Performance & DICOM GSDF (Mandatory for Diagnostic)

This is one of the fundamental differentiators of medical displays.

• Diagnostic displays must comply with DICOM Part 14 (GSDF)
• Displays without DICOM GSDF compliance cannot legally be marketed as diagnostic displays

Technical Requirements:

• True 10-bit grayscale (1024 levels)
• Diagnostic-grade commonly uses 12-bit LUT + 10-bit panel
• Long-term grayscale consistency without drift
• Support for automatic or semi-automatic DICOM calibration

 

2.5 Color Performance (Application-Dependent)

Application	Color Requirement
Ultrasound / Monitoring	sRGB, 8-bit sufficient
Endoscopy / Surgery	High color gamut & color accuracy
Pathology	High color accuracy, ΔE ≤ 2

High-end configurations:

• Adobe RGB ≥ 90%
• True 10-bit color depth
• Long-term color stability

 

3. Stability & Reliability (Critical for Medical Use)

3.1 Long-Term Stability & Aging (Mandatory / Diagnostic Critical)

• 24/7 continuous operation
• Aging tests ≥ 10,000–50,000 hours
• Controlled drift in luminance, grayscale, and color

 

3.2 Luminance Uniformity (Mandatory / Diagnostic Critical)

Grade	Uniformity Target
Clinical	≥ 80–85%
Diagnostic	≥ 90–95%

Typical Techniques:

• Panel-level zone compensation
• Factory uniformity correction LUTs

 

3.3 Viewing Angle Consistency (Mandatory)

• IPS or equivalent wide-view technology
• No grayscale distortion with viewing angle changes (critical for diagnosis)

 

4. Hardware & Mechanical Design (Often Underestimated)

4.1 Electrical Interface (Mandatory)

Common Interfaces:

• DisplayPort (preferred)
• DVI (legacy systems)
• HDMI (not preferred for medical-critical use)

Requirements:

• Stable high-resolution output
• EMI robustness for medical environments

 

4.2 Surface, Housing & Medical Environment Compatibility (Mandatory)

• Easy to clean
• Resistant to disinfectants

Optional Enhancements:

• Liquid ingress protection (IPx1 / IPx2)
• White or medical-gray surfaces to reduce reflections

 

4.3 Power System Reliability (Mandatory)

• Medical-grade power design
• Strong EMI / ESD immunity
• Strict leakage current control

 

5. Software & Quality Control (Invisible Core)

QA / QC System (Mandatory for Diagnostic)

• Individual factory calibration report per unit
• Per-unit LUT calibration
• Full serial-number traceability

 

6. Regulatory & Compliance (Critical)

Category	Standard
Electrical Safety	IEC 60601-1
EMC	IEC 60601-1-2
Medical Software	IEC 62304
China	NMPA (formerly CFDA)
USA	FDA (Class I / II)
EU	CE / MDR

DICOM Compliance Declaration (Diagnostic Mandatory):

• Explicit statement of DICOM Part 14 support
• Test and validation documentation

 

7. Engineering Summary

Observation-Grade Medical Displays (Most Common)

• IEC 60601 compliant
• Stable luminance & reliability
• DICOM GSDF not mandatory

True Diagnostic Medical Displays

• Full DICOM GSDF pipeline
• Stable grayscale & uniformity
• 12-bit LUT + luminance sensor
• Calibration & QA systems
• Cost typically 3–10× consumer displays

 

8. Observation-Grade Medical Display Module Requirements

(LCD Module Level)

Observation-grade ≈ clinical review, monitoring, surgical viewing
Not used for final diagnosis
Requirements are relaxed compared to diagnostic grade, but still governed by IEC 62563-1

 

8.1 Optical Performance (Panel-Level)

Resolution & Pixel Density

• Common: FHD (1920×1080), 1920×1200, 2560×1440
• Recommended pixel pitch ≤ 0.27 mm

Grayscale

• Minimum 8-bit
• Preferred: 8-bit + FRC (~10-bit equivalent)

 

8.2 Luminance / Contrast / Uniformity

• Typical peak luminance: 350–400 cd/m²
• Calibrated working luminance: ≥ 250–300 cd/m²
• Contrast ratio: ≥ 1000:1
• Black level: ≤ 0.3 cd/m² (at working luminance)
• Uniformity: ≥ 80–90% (min/center)

 

8.3 Panel Technology & Viewing Angle

• IPS / ADS preferred
• Viewing angle ≥ 178° / 178°
• TN panels are not acceptable

 

8.4 Grayscale Linearity & Gamma

• Stable Gamma 2.2 default
• Smooth grayscale transitions, no banding
• Reserve headroom for future DICOM calibration

 

8.5 Color Performance (Color-Critical Observation)

• ≥ 100% sRGB
• Optional: ≥ 95% DCI-P3
• ΔE_avg < 2–3 after calibration
• White point: D65 (≈ 6500K)

 

8.6 Stability & Aging

• Backlight constant-current control
• Temperature compensation
• Target lifetime: 30k–50k hours
• Reserved positions for luminance / temperature sensors

 

8.7 Electrical & Interface

• eDP 1.2+ or dual-channel LVDS
• 8/10-bit support
• ≥ 60 Hz refresh (video/endoscopy: 75–120 Hz recommended)
• PWM + DC dimming with flicker control
• Wide dimming range (1–10% to 100%)

 

8.8 Mechanical & Environmental Design

• Support optical bonding
• AG / AR / AF surface treatment
• Alcohol & disinfectant resistance
• Thermal design suitable for 7×24 operation

 

9. Typical Applications (Observation-Grade)

9.1 Life-Support & Therapy Devices (Bedside / OR)

These are classic observation-grade displays: continuous viewing, safety-critical, but not image-diagnostic.

Respiratory & Critical Care

• Ventilators
  • ICU ventilators
  • Transport ventilators
  • Anesthesia ventilators
  • Neonatal ventilators
• Resuscitators
  • Manual & automated resuscitation systems
• CPAP / BiPAP devices (clinical versions)
• Oxygen concentrators (hospital-grade)

Display role:
Waveforms, numeric parameters, alarms, trends

 

9.2 Infusion & Drug Delivery Systems

All are observation-grade, even though they are safety-critical.

Pumps

• Infusion Pumps
  • Volumetric infusion pumps
  • Smart infusion pumps
• Syringe Pumps
• PCA Pumps (Patient-Controlled Analgesia)
• Insulin infusion systems (hospital use)
• Enteral feeding pumps

Display role:
Dosage, flow rate, volume, time remaining, alarms

 

9.3 Patient Monitoring Devices

Vital-Signs Monitoring

• ECG Monitors
• Multi-parameter Monitors
  • ECG
  • SpO₂
  • NIBP / IBP
  • Respiration
  • Temperature
• Bedside monitors
• Central monitoring stations (viewing-only screens)

Neuro / Physiological Monitoring

• EEG monitors (routine monitoring)
• EMG monitors
• Sleep monitoring systems

Borderline:
EEG used for research or clinical monitoring → Observation
EEG used for formal neurological diagnosis → Diagnostic-adjacent

 

9.4 Imaging Devices (Viewing, Not Diagnosis)

These are very common sources of confusion.

Ultrasound

• Ultrasound systems (real-time viewing)
• Portable ultrasound
• POCUS (Point-of-Care Ultrasound)

Diagnostic decisions are often made with ultrasound,
but the display itself is usually observation-grade, not DICOM-calibrated.

9.5 Endoscopy & Surgical Visualization

Endoscopic Systems

• Gastroscopes
• Colonoscopes
• Bronchoscopes
• Laparoscopes
• Arthroscopes
• Ureteroscopes

Surgical Displays

• OR surgical monitors
• Surgeon-side displays
• Assistant displays

Display role:
Real-time color video, motion clarity, low latency

Key point:
These are never diagnostic-grade displays, even though surgeons make decisions while viewing them.

 

9.6 Emergency & Acute Care Equipment

• Defibrillators
  • AEDs
  • Manual defibrillators
• Patient transport monitors
• Ambulance monitors
• Portable emergency monitors

 

9.7 Laboratory & Clinical Instruments

Analytical Devices

• Blood glucose meters
• Alcometers (breath alcohol testers)
• Blood gas analyzers
• Coagulation analyzers
• Immunoassay analyzers

Lab Equipment

• Centrifuges
• Incubators
• Blood cell counters
• Urine analyzers

Display role:
Results display, status, workflow, alarms

 

9.8 Renal & Long-Term Therapy Devices

• Dialysis machines
  • Hemodialysis
  • Peritoneal dialysis
• CRRT systems

 

9.9 Medical IT & Workflow Displays

• Digital medical records terminals
• Nurse station displays
• Clinical workflow panels
• Medication administration record (MAR) terminals
• Bedside information displays
• Patient-facing displays (education/status)

 

9.10 Rehabilitation & Assistive Devices

• Physiotherapy equipment
• Rehabilitation robots
• Gait analysis systems
• Patient feedback terminals

 

9.11 Portable & Home-Care Medical Devices (Clinical Grade, Not Consumer)

• Hospital-grade portable monitors
• Home dialysis systems (clinical versions)
• Remote patient monitoring hubs
• Telemedicine carts (display side)

 

Summary Table (Quick Reference)

Category	Observation-Grade?	Notes
Ventilators	Yes	Safety-critical, non-diagnostic
Infusion / Syringe / PCA pumps	Yes	Numeric + alarm displays
ECG / Multi-parameter monitors	Yes	Diagnostic logic elsewhere
EEG (routine monitoring)	Yes	Diagnostic only if formal neuro
Ultrasound displays	Yes	Typically not DICOM
Endoscopy / Surgical displays	Yes	Video accuracy > grayscale
Defibrillators	Yes	Numeric + waveform
Dialysis machines	Yes	Continuous monitoring
Blood glucose meters	Yes	Result display
Lab analyzers	Yes	Data review only
EMR / Nurse station displays	Yes	Workflow viewing

 

10. Common Display sizes for Observation-Grade Medical Applications

Application → Optimal Panel Size (Small → Large)

Medical Application	Typical Viewing Distance	Info Density	Recommended Panel Size(s)	Why This Size Is Optimal
Blood Glucose Meter	Handheld (30–40 cm)	Low	3.5″	Numeric + simple graphs; handheld ergonomics dominate
Alcometer (Breath Alcohol Tester)	Handheld	Very Low	3.5″	Digits, icons, pass/fail status only
Portable Pulse Oximeter	Handheld	Low	3.5″ → 4.3″	SpO₂, pulse waveform; 4.3″ improves readability
Syringe Pump	Bedside (0.5–1 m)	Low–Medium	4.3″ → 5″	Flow rate + alarms; must be readable at angle
PCA Pump	Bedside	Medium	4.3″ → 5″	Adds patient status + lockout info
Infusion Pump	Bedside	Medium	5″	Multiple parameters + trend visibility
Portable ECG Monitor	Bedside / Transport	Medium	5″ → 7″	Waveform clarity becomes important
Patient Monitor (Basic)	Bedside	Medium	7″	Multi-wave + numeric panels
Ventilator	Bedside	Medium–High	7″ → 10.1″	Loops, waveforms, settings simultaneously
Resuscitator / Emergency Ventilation Unit	Mobile / Emergency	Medium	7″	Quick recognition, gloves, harsh lighting
Defibrillator (Manual / AED)	Emergency	Medium	7″	ECG waveform + prompts + alarms
Multi-Parameter Monitor	ICU / OR	High	10.1″ → 12.1″	ECG, SpO₂, BP, CO₂, trends
EEG Monitor (Bedside)	Clinical workstation	High	10.1″ → 12.1″	Dense waveforms; longer observation
Centrifuge Control Panel	Equipment front panel	Medium	5″ → 7″	Parameters + program selection
Ultrasound (Portable)	Near-field viewing	High	10.1″	Image interpretation needs area
Ultrasound (Cart-based)	Workstation	Very High	12.1″ → 15.6″	Imaging clarity over portability
Endoscopy Processor (Gastroscope)	OR cart	High	10.1″ → 15.6″	Color accuracy + detail
Dialysis Machine	Bedside	Medium–High	10.1″	Treatment duration + trends
Digital Medical Records Terminal	Nurse station	Medium	10.1″ → 15.6″	Readability + touch usability

 

Key Engineering Patterns

10.1 Small Control Devices → 3.5″ / 4.3″

Common traits

• Handheld or single-hand operation
• Numeric-dominant UI
• BOM-sensitive
• Battery powered

Typical platform

• 3.5″ or 4.3″ TFT
• 480×272 or 800×480
• RGB or LVDS
• 400–600 nits

 

10.2 Bedside Therapy Devices → 5″ / 7″

Common traits

• Must be readable from 0.5–1 m
• Waveforms + numeric overlays
• Gloved operation
• Continuous 24/7 use

Typical platform

• 5″ or 7″ TFT
• 800×480 / 1024×600 / 1280×800
• IPS, wide angle
• High contrast + stable backlight

 

10.3 Monitoring & Imaging Consoles → 10.1″+

Common traits

• Multi-parameter visualization
• Trend charts + waveforms
• Longer viewing sessions
• Less BOM pressure, more reliability pressure

Typical platform

• 10.1″ / 12.1″ TFT
• 1280×800 / 1920×1080
• Optical bonding
• Tight uniformity & color stability

Platform-Unification View (What You Can Reuse)

Platform Size	Can Serve Applications
3.5″	Glucose, alcohol, small handheld monitors
4.3″	Syringe pumps, PCA pumps, portable oximeters
5″	Infusion pumps, transport ECG
7″	Ventilators, defibrillators, bedside monitors
10.1″	ICU monitors, dialysis, ultrasound, endoscopy

• A 5-SKU panel strategy can realistically cover 90% of observation-grade devices

 

11. System-level, engineering-oriented mapping

11.1 Full list of Observation-Grade Medical Applications (practical scope)

Observation-grade = not for final diagnosis, but for monitoring, control, visualization, workflow, and guidance.

Life-support & Therapy Devices

• Ventilators / Respirators
• Anesthesia machines
• Dialysis machines
• Oxygen concentrators
• Resuscitators
• Defibrillators

Infusion & Drug Delivery

• Infusion pumps
• Syringe pumps
• PCA pumps (patient-controlled analgesia)
• Enteral feeding pumps

Monitoring & Vital Signs

• ECG monitors
• EEG monitors
• Multi-parameter monitors (ECG + SpO₂ + NIBP + Temp)
• Fetal monitors
• Bedside monitors
• Transport monitors

Imaging (non-diagnostic display role)

• Ultrasound front panels
• Ultrasound secondary displays
• Endoscopy systems (gastroscope, colonoscope)
• Surgical camera systems
• C-arm auxiliary displays

Laboratory & Point-of-Care

• Blood glucose meters
• Blood gas analyzers
• Alcometers
• Centrifuges
• Hematology analyzers
• Immunoassay analyzers

Emergency & Transport

• Ambulance monitors
• Portable ultrasound
• Portable ventilators
• Emergency carts

Clinical IT & Workflow

• EMR terminals
• Nurse station displays
• Bedside information terminals
• Medical tablets / HMIs

 

11.2 Mapping Table: Application → Optimal Panel Size (Small → Large)

Rule of thumb

• Data-centric → small
• Waveform-centric → medium
• Image-centric → large

Application	Optimal Size	Acceptable Range	Rationale
Blood glucose meter	3.5″	3.2–4.3″	Numeric-dominant, battery device
Alcometer	3.5″	3.2–4.3″	Simple UI, handheld
Syringe pump	3.5″	3.5–4.3″	Rate + volume + alerts
PCA pump	3.5″	3.5–4.3″	Button-driven UI
Infusion pump	4.3″	4.3–5″	Better trend & alarms
Ventilator (compact)	5″	4.3–7″	Waveforms + loops
Ventilator (ICU)	7″	7–10.1″	Multiple waveforms
ECG monitor (basic)	5″	5–7″	ECG + vitals
Multi-parameter monitor	7″	7–10.1″	ECG + SpO₂ + NIBP
Transport monitor	5″	4.3–7″	Power-limited
EEG monitor (bedside)	7″	7–10.1″	Multi-channel waves
Endoscopy control unit	10.1″	7–12.1″	Image + menu
Ultrasound (secondary)	10.1″	10.1–12.1″	Image-centric
Dialysis machine	10.1″	7–12.1″	Process visualization
Defibrillator	5″	4.3–7″	ECG + prompts
EMR bedside terminal	10.1″	10.1–15.6″	Text + UI

 

11.3 Mapping: Application → SoC / Interface / Power Profile

This is where platform reuse becomes clear.

Small Panel Platform (3.5″–4.3″)

Typical Applications

• Syringe pump
• PCA pump
• Glucose meter
• Alcometer

SoC

• STM32F4 / F7 / H7
• NXP i.MX RT
• GD32 / Renesas RA
• No GPU required

Interface

• RGB 16/18/24-bit
• MCU-driven TFT
• SPI + RGB hybrid

Power Profile

• Backlight: 1–2 W
• Total display module: < 3 W
• Battery-friendly

Display Characteristics

• 400–600 nits
• 800:1–1000:1
• 8-bit or 8-bit+FRC
• PWM + DC dimming mandatory

 

Medium Panel Platform (5″–7″)

Typical Applications

• Ventilators
• ECG monitors
• Infusion pumps
• Defibrillators
• Transport monitors

SoC

• NXP i.MX6ULL / i.MX7
• Allwinner T113 / V3
• Rockchip RK3308
• Sitara AM335x

Interface

• RGB (low end)
• LVDS (most common)
• Single-lane eDP (emerging)

Power Profile

• Backlight: 3–6 W
• Module total: 4–8 W

Display Characteristics

• ≥500 nits
• IPS mandatory
• 60–75 Hz
• Optical bonding highly recommended

 

Large Panel Platform (10.1″–12.1″)

Typical Applications

• Dialysis
• Ultrasound UI
• Endoscopy processors
• Multi-parameter ICU monitors

SoC

• NXP i.MX8M / i.MX8MP
• Rockchip RK3566 / RK3568
• TI AM62 / AM64
• Qualcomm QCS (high-end)

Interface

• eDP (preferred)
• Dual-channel LVDS (legacy)
• MIPI-DSI (tablet-like designs)

Power Profile

• Backlight: 6–12 W
• Module total: 8–15 W

Display Characteristics

• 500–800 nits
• Better uniformity
• Optional touch (PCAP)
• Strong EMI design required

 

11.4  Extracted Common Denominators → One Platform Module Strategy

 What all observation-grade devices share

Dimension	Common Requirement
Display type	IPS / ADS only
Brightness	≥400 nits
Operation	24/7 capable
EMI	IEC 60601-1-2 ready
Backlight	DC + PWM dimming
Temperature	−10 to +60 °C panel-safe
Lifetime	≥30k–50k hours
Cleaning	Alcohol-resistant front

 

Recommended Platform Family

Platform	Size	Interface	Target Devices
Platform-S	3.5″/4.3″	RGB	Pumps, meters
Platform-M	5″/7″	LVDS	Ventilator, ECG
Platform-L	10.1″	eDP	Dialysis, ultrasound

Each platform:

• Same backlight driver architecture
• Same optical bonding strategy
• Same reliability qualification flow
• Different glass & resolution only

11.5 MCU, low end MPU, MPU and Soc Explained

MCU (Microcontroller Unit)

• Single-chip control brain
• CPU + Flash + SRAM + peripherals on one die
• Typically no external DRAM
• Runs bare-metal or RTOS (FreeRTOS, Zephyr)

Key characteristics

Aspect	MCU
OS	Bare-metal / RTOS
External DRAM	❌ No
MMU	❌ No
Clock	~50–300 MHz
Power	Very low
Cost	Very low
Boot time	Instant

Display capability

• Small displays only
• RGB, SPI, 8080 interface
• Simple UI (numbers, icons, basic waveforms)

Examples

STMicroelectronics

• STM32F4 / F7 / H7
  (H7 can do small LCD + simple graphics)

NXP

• LPC55xx
• i.MX RT1060 / RT1170 (MCU but very fast)

Microchip

• SAM E70

Medical use cases

✔ Syringe pumps
✔ PCA pumps
✔ Simple infusion pumps
✔ Blood glucose meters
✔ Small ECG transport monitors

Rule of thumb:

If UI is simple, deterministic, and safety-critical → MCU wins

Low-End MPU (Entry-Level Application Processor)

This category sits between MCU and full MPU

• Application processor without GPU
• External DDR memory
• Often no MMU or very limited graphics acceleration
• Can run Embedded Linux or RTOS

Key characteristics

Aspect	Low-end MPU
OS	RTOS / Embedded Linux
External DRAM	Yes
MMU	Limited
GPU	No
Clock	~400–800 MHz
Power	Low–medium
Cost	Low

Display capability

• 4.3″–7″ LCD
• RGB / LVDS / MIPI-DSI
• Moderate UI complexity

Examples

NXP

• i.MX6ULL
• i.MX7ULP

Microchip

• SAMA5D27

Allwinner

• F1C200s / V3s (very common in Chinese pumps)

Medical use cases

✔ Infusion pumps (color UI)
✔ Compact ECG monitors
✔ Dialysis machine UI
✔ Portable patient monitors

Rule of thumb:

If you need Linux UI + moderate graphics, but no video → low-end MPU

 

MPU (Application Processor)

• Full application processor
• External DDR
• MMU + often basic GPU
• Runs Linux

Key characteristics

Aspect	MPU
OS	Embedded Linux
External DRAM	Yes
MMU	Yes
GPU	Basic
Clock	~1–1.5 GHz
Power	Medium
Cost	Medium

Display capability

• 7″–10.1″
• LVDS / MIPI-DSI / eDP
• Waveforms + video + rich UI

Examples

NXP

• i.MX6 Solo / DualLite
• i.MX8M Mini

Rockchip

• RK3288
• RK3566

Allwinner

• A64 / A133

Medical use cases

✔ Ventilators
✔ Multi-parameter monitors
✔ Bedside ECG monitors
✔ Endoscopy processor UI

Rule of thumb:

If you need waveforms + animations + Linux UI, choose MPU

 

SoC (System-on-Chip)

Technically everything above is a SoC,
but in industry people say “SoC” to mean high-integration + GPU/video

• MPU plus GPU + video codec + AI accelerators
• Multiple display pipelines
• Multimedia-grade

Key characteristics

Aspect	SoC
OS	Linux / Android
External DRAM	Yes
GPU	Strong
Video	Encode/decode
Clock	1–2+ GHz
Power	Medium–high
Cost	Higher

Display capability

• 10.1″+
• Multiple displays
• High-FPS waveforms, video, camera input

Examples

NXP

• i.MX8M Plus (GPU + ISP)

Rockchip

• RK3588

Qualcomm

• QCS610 / QCS6490

Medical use cases

✔ Ultrasound
✔ Advanced endoscopy
✔ Imaging carts
✔ AI-assisted monitors

Rule of thumb:

If you need video, camera, AI, multi-display → SoC

 

Quick Comparison Table

Category	MCU	Low-end MPU	MPU	SoC
External DDR	No	Yes	Yes	Yes
Linux	No	Basic	Yes	Yes
GPU	No	No	Basic	Yes
Typical display	≤4.3″	4.3–7″	7–10.1″	10.1″+
UI complexity	Low	Medium	High	Very high
Power	Very low	Low	Medium	Medium–High
Cost	$	$$	$$$	$$$$

Medical Display-Centric Recommendation

Observation-grade medical display platform sweet spot

Device	Best choice
Syringe / PCA pump	MCU
Infusion pump	MCU → low-end MPU
ECG transport	Low-end MPU
ECG bedside	MPU
Ventilator	MPU
Multi-parameter monitor	MPU
Ultrasound / endoscopy	SoC

One-line takeaway

MCU = control
Low-end MPU = simple Linux UI
MPU = waveform-heavy medical UI
SoC = video / imaging / AI

 

Should you have any questions, please consult our engineering.

Normally, for our display screens, when a customer mentions waterproofing, we need to clarify which part of the display needs to be waterproof.

The product needs to be waterproof. This requirement is generally for products with touchscreens. The waterproofing of the back of the display relies on the customer’s housing. We mainly focus on the sealing between the cover plate and the customer’s housing, as well as the sealing at the junction between the touchscreen and the display.

• The touchscreen cover plate needs to be waterproof when assembled into the customer’s product. This requirement is quite common, and customers often have specific data requirements for sealing, such as an IP rating – grading the resistance of an enclosure against the intrusion of dust or liquids. In this case, we only need to choose the appropriate 3M double-sided tape to achieve the desired result. If no touch panel in the design, the polarizer will not resist long term water corrosion. Apply an acrylic protective layer on top of the display screen and securely adhere it with glue.

• The area between the display screen and the touchscreen needs to be waterproof. Although some of our touchscreens are bonded to the display with OCA, the sensor part is still exposed. Therefore, it is necessary to use RTV sealant to seal the perimeter around the bonding area between the touchscreen and the TFT.

• Waterproof Touchscreen Functionality. In some cases, customers may use the touchscreen while water droplets are present. The touchscreen needs to function properly in the presence of water droplets (normal touch function with water/no false touches from falling water droplets). For this situation, it is necessary to select an appropriate touch IC and special sensor design to ensure better reliability.

• Waterproof PCB. Sometimes customers require the PCB to be waterproof. In this case, it is necessary to add a layer of Conformal Coating on the PCB. This involves applying a transparent polymer film over the PCB, which maintains the shape of the printed circuit board and protects the electronic components on the PCB from environmental damage, thereby improving and extending their lifespan. For more severe weatherproofing requirements, the entire circuit board is fully encapsulated in glue, effectively immersing the board in the adhesive. It is essential that this glue is neutral, without any acidic or alkaline properties, to prevent corrosion of the components.

• Housing Assembly. After assembling the casing, apply sealant to the seams of the casing to ensure that the entire hardware part is airtight. However, even with these measures, it cannot be guaranteed that no water vapor will penetrate, as water molecules are very pervasive. The goal is to minimize the ingress as much as possible. Incorporate breathable vents like Gore vents that allow air to pass through but block water and moisture. Sometimes, utilizing laser welding for creating precise and strong seals in the device’s casing.

• Other Waterproofing Ideas
  • Potting: Apply potting compounds around connectors and cables to seal any potential entry points.
  • Sealed Connectors: Use waterproof connectors and cables to prevent moisture ingress at connection points.
  • Incorporation of Desiccants: Place desiccants inside the device to absorb any residual moisture.

 

IP Rating — IP XX

The two digits following IP indicate the level of protection that the device’s enclosure provides against the ingress of solid objects and water. The first digit represents the level of protection against dust and foreign objects, while the second digit indicates the level of moisture and water resistance. The higher the number, the greater the level of protection.

For example, an IP rating of IP54:

• IP: Designates the protection marking.
• 5: The first digit indicates the level of protection against contact and foreign objects.
• 4: The second digit indicates the level of protection against water.

The first digit (5) signifies a level of protection against dust and limited ingress of particles. The second digit (4) signifies a level of protection against water splashes from any direction.

Dust Protection Level

The first digit in the IP rating system represents the level of protection against solid objects, including dust. Here are the possible levels:

• 0: No protection against contact and ingress of objects.
• 1: Protection against solid objects over 50 mm (e.g., accidental touch by hands).
• 2: Protection against solid objects over 12.5 mm (e.g., fingers).
• 3: Protection against solid objects over 2.5 mm (e.g., tools, thick wires).
• 4: Protection against solid objects over 1 mm (e.g., most wires, screws).
• 5: Limited protection against dust ingress (no harmful deposits).
• 6: Complete protection against dust ingress.

Water Protection Level

The second digit in the IP rating system indicates the level of protection against the ingress of water. Here are the possible levels:

• 0: No protection.
• 1: Protection against vertically dripping water.
• 2: Protection against dripping water when tilted up to 15 degrees.
• 3: Protection against spraying water at an angle up to 60 degrees.
• 4: Protection against splashing water from any direction.
• 5: Protection against water jets from any direction.
• 6: Protection against powerful water jets.
• 7: Protection against immersion in water up to 1 meter depth.
• 8: Protection against continuous immersion in water beyond 1 meter.

IP Rating Explanation for Immersion

• 7: The device can be immersed in water under specified pressure for a specified time, ensuring that the amount of water ingress does not reach harmful levels.
• 8: The device can be continuously immersed in water under conditions agreed upon by the manufacturer and the user, typically more stringent than those of IP67.

 

ISO 16750 and Other International Standards:

1. Scope

The waterproof tests include the second characteristic digits from 1 to 8, corresponding to protection levels IPX1 to IPX8.

2. Waterproof Test Content for Various Levels

(1) IPX1

• Method Name: Vertical Drip Test
• Test Equipment: Drip test device and its test method
• Sample Placement: Place the sample in its normal working position on a rotating sample table at 1 rotation per minute (r/min). The distance from the top of the sample to the drip outlet should not exceed 200mm.
• Test Conditions:
  • Drip rate: 1.0 +0.5 mm/min
  • Test duration: 10 minutes

(2) IPX2

• Method Name: Tilted Drip Test
• Test Equipment: Drip test device and its test method
• Sample Placement: Tilt the sample 15 degrees from its normal working position, in four fixed positions, one for each tilted direction.
• Test Conditions:
  • Drip rate: 3.0 +0.5 mm/min
  • Test duration: 2.5 minutes per tilt direction (total 10 minutes)

(3) IPX3

• Method Name: Spraying Water Test
• Test Equipment: Oscillating spray test device or spray nozzle
• Sample Placement: Place the sample in its normal working position.
• Test Conditions:
  • Spray water at an angle up to 60 degrees from vertical.
  • Water flow rate: 10 liters per minute.
  • Test duration: 5 minutes.

(4) IPX4

• Method Name: Splashing Water Test
• Test Equipment: Oscillating spray test device or spray nozzle
• Sample Placement: Place the sample in its normal working position.
• Test Conditions:
  • Splash water from all directions.
  • Water flow rate: 10 liters per minute.
  • Test duration: 5 minutes.

(5) IPX5

• Method Name: Water Jet Test
• Test Equipment: Nozzle with a 6.3mm diameter
• Sample Placement: Place the sample in its normal working position.
• Test Conditions:
  • Water jet flow rate: 12.5 liters per minute.
  • Distance: 2.5 to 3 meters.
  • Test duration: 3 minutes per square meter for at least 3 minutes.

(6) IPX6

• Method Name: Powerful Water Jet Test
• Test Equipment: Nozzle with a 12.5mm diameter
• Sample Placement: Place the sample in its normal working position.
• Test Conditions:
  • Water jet flow rate: 100 liters per minute.
  • Distance: 2.5 to 3 meters.
  • Test duration: 3 minutes per square meter for at least 3 minutes.

(7) IPX7

• Method Name: Immersion Test
• Test Equipment: Water tank
• Sample Placement: Submerge the sample in water.
• Test Conditions:
  • Depth: 1 meter.
  • Test duration: 30 minutes.

(8) IPX8

• Method Name: Continuous Immersion Test
• Test Equipment: Water tank
• Sample Placement: Submerge the sample in water under conditions agreed upon by the manufacturer and user.
• Test Conditions:
  • Depth: Generally deeper than IPX7, specific conditions defined by agreement.
  • Test duration: Typically longer than IPX7, as agreed upon.

These tests ensure that the devices meet specific standards for waterproofing based on their intended use and environmental conditions.

 

If you have any questions about Display and Touch Waterproofing Requirements, please contact Orient Display support engineers

A resistive touch screen is made of a glass substrate as the bottom layer and a film substrate (normally, clear poly-carbonate or PET) as the top layer, each coated with a transparent conductive layer (ITO: Indium Tin Oxide), separated by spacer dots to make a small air gap. The two conducting layers of material (ITO) face each other. When a user touches the part of the screen with finger or a stylus, the conductive ITO thin layers contacted. It changes the resistance. The RTP controller detects the change and calculate the touch position. The point of contact is detected by this change in voltage.

Pros of Resistive Touchscreen

One of the main reasons why resistive touch panels still exist is its simple manufacturing process and low production cost. The MOQ (Minimum Order Quantity) and NRE (Non-Recurring Expense) are low. The driving is simple and low cost. The power consumption is low too. Resistive touch panel also immune to EMI well. Although it can’t use cover lens at the surface, the overlay can make it flexible for designs.

Resistive touchscreens offer an unparalleled level of durability. Manufacturing companies, restaurants and retailers often prefer them over other types of touchscreens for this very reason. With their durable construction, resistive touchscreens can withstand moisture and stress without succumbing to damage.

You can control a resistive touchscreen using a stylus or while wearing gloves. Most capacitive touchscreens only register commands performed with a bare finger (or a special capacitive stylus). If you use a stylus or a gloved finger to tap the interface, the capacitive touchscreen won’t respond to your command. Resistive touchscreens register and respond to all forms of input, though. You can control them with a bare finger, a gloved finger, a stylus or pretty much any other object.

Cons of Resistive Touchscreen

The biggest advantages for resistive touch panel are its touch experience and clarity. It can only be used for single touch, no gestures or multi-touch. False touches can be generated if using two or more fingers to touch it.

Resistive touch panel’s transparency is relatively low. In order to prevent Newton rings or fingerprint mark, sometimes AG(anti-glare) film has to be used to make it look more smoky. Optical bonding can’t be used for RTP. The surface of resistive touch panel is soft and easily get scratched.

There are still a few potential cons associated with resistive touchscreens. When compared to capacitive touchscreens, resistive touchscreens aren’t as sensitive. They are still responsive, but you’ll have to tap or press the interface with greater force for a resistive touchscreen to recognize your input.

Resistive touchscreens usually offer lower display resolutions than capacitive touchscreens. Granted, not all applications require a high-resolution display. If a touchscreen is used as a point-of-sale (POS) system in a retail environment, for example, resolution shouldn’t be a concern.

If you have any questions about Orient Display capacitive touch panels. Please feel free to contact: Sales Inquiries, Customer Service or Technical Support.