Automatic Analyzer Heater Pulse Control for Flicker Compliance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing automatic analyzers face challenges in conforming to IEC60601-1-2: 2014 standards regarding voltage fluctuation and flicker due to frequent ON and OFF cycles of heaters, which cause power consumption fluctuations around 8 Hz to 10 Hz.
Innovation Solution
Implementing a control system that adjusts the pulse widths of ON and OFF signals for the heater to maintain a frequency of 50 Hz or 60 Hz by setting a < b, where a is the pulse width of the ON signal and b is the pulse width of the OFF signal, ensuring the heater is not continuously turned on or off for more than 100 ms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the heater is turned on and off frequently to maintain constant temperature, then the temperature control is effective, but the power consumption fluctuates around 8 Hz to 10 Hz causing flicker that may not conform to IEC60601-1-2: 2014 standards
Solution Approach 1:
The patent applies periodic action by intentionally introducing a high-frequency switching component (superimposed switching) on top of the regular heater control cycle. This creates a composite switching pattern where the heater is controlled at both the original low frequency (for temperature maintenance) and a higher frequency (to shift power consumption spectrum away from the 8-10 Hz flicker range). The high-frequency switching component effectively redistributes the power consumption fluctuations to a frequency range that does not cause visible flicker and complies with medical device standards.
Solution Approach 2:
The patent changes the temporal parameters of heater switching by superimposing a high-frequency switching signal on the existing control cycle. This parameter modification transforms the single-frequency power consumption pattern into a multi-frequency pattern, shifting the dominant frequency components away from the problematic 8-10 Hz range. The parameter change involves adding a time-varying switching component with frequency characteristics that prevent flicker while maintaining temperature control effectiveness.
2Reliability
If the heater switching is optimized to prevent flicker, then compliance with IEC60601-1-2: 2014 standards is achieved, but the control system complexity increases
Solution Approach 1:
The patent merges the temperature control function with a flicker prevention function by combining them into a single integrated control mechanism. Instead of adding a separate complex flicker suppression system, the invention superimposes the high-frequency switching component directly onto the existing temperature control cycle, achieving both temperature maintenance and flicker prevention through one unified control approach. This merging reduces overall system complexity compared to implementing separate independent systems for each function.
Solution Approach 2:
The patent maintains continuous temperature control while simultaneously achieving flicker prevention through uninterrupted heater operation. The superimposed high-frequency switching does not create gaps or interruptions in the heating process, ensuring that the useful action of temperature maintenance continues without pause. This continuity ensures that the heater remains effectively engaged in temperature control while the high-frequency component manages the power consumption spectrum to prevent flicker.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents flicker and ensures compliance with medical electrical device standards by maintaining a stable power consumption pattern, reducing Plt to below the IEC standard limits.
Implementation Method 1
a heater configured to heat the constant-temperature water
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Provided is an automatic analyzer that prevents flicker and conforms to standards for medical electrical devices. The automatic analyzer includes: a constant-temperature bath configured to store constant-temperature water that maintains a mixed liquid of a specimen and a reagent in a reaction container at a predetermined temperature; a heater configured to heat the constant-temperature water; and a control unit configured to control the heater. a and b have fixed lengths and a < b, where a (ms) is a pulse width of an ON signal that is a control signal for turning the heater ON, and b (ms) is a pulse width of an OFF signal that is a control signal for turning the heater OFF.