Infant warmer open bed
First Claim
1. An infant warmer bed comprising:
- a base;
an infant support surface mounted on said base;
a heating circuit connectable to a source of electrical energy to energize a heating element connected therein;
a heating element supported on said base and connected in said heating circuit, said element being so positioned and operable to generate heat onto said surface when electrically energized;
means connected in said heating circuit for varying the electrical energy supplied to said element in response to a control signal;
a control circuit having an output connected to said energy varying means for delivering said control signal thereto, said control circuit having an input for receiving a temperature signal; and
a temperature sensing probe positionable at said support surface and attachable to the skin of an infant supported on said surface, said probe having an output connected to the input of said control circuit and operable to generate a temperature signal responsive to the temperature sensed at said probe; and
said control circuit includingmeans for generating an intermediate signal in response to the difference between the temperature signal and a predetermined temperature setting; and
means for generating an offset signal and for algebraically adding said offset signal and said intermediate signal so as to produce said control signal responsive to the algebraic sum of said offset signal and the difference between said temperature signal and said temperature setting; and
said offset signal generating means including means responsive to the sign of the difference between said temperature setting and said temperature signal for periodically and cumulatively incrementing said offset signal a predetermined amount, up or down in accordance with said sign of said difference.
1 Assignment
0 Petitions
Accused Products
Abstract
An infant warmer is provided with a heating element for directing radiant heat onto an infant support surface and a temperature sensing probe attachable to the skin of an infant. A heater control which, in an automatic mode, supplies a control signal to a heater power control which includes a component responsive to the difference between the actual temperature and a set temperature and a component which is added or subtracted in incremental amounts depending on whether the actual temperature is above or below the set point. The control also operates to reduce the power to the heater when the total energy supplied to the heater exceeds a maximum amount over a predetermined time interval. In manual mode, the power level is reduced when a preset temperature is reached or if the temperature is not reached after a predetermined time has elapsed. In addition, the heater power is interrupted whenever the control signal or the current to the heater exist independent of the other. The features operate to provide highly responsive temperature regulation and enhanced safety.
74 Citations
12 Claims
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1. An infant warmer bed comprising:
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a base; an infant support surface mounted on said base; a heating circuit connectable to a source of electrical energy to energize a heating element connected therein; a heating element supported on said base and connected in said heating circuit, said element being so positioned and operable to generate heat onto said surface when electrically energized; means connected in said heating circuit for varying the electrical energy supplied to said element in response to a control signal; a control circuit having an output connected to said energy varying means for delivering said control signal thereto, said control circuit having an input for receiving a temperature signal; and a temperature sensing probe positionable at said support surface and attachable to the skin of an infant supported on said surface, said probe having an output connected to the input of said control circuit and operable to generate a temperature signal responsive to the temperature sensed at said probe; and said control circuit including means for generating an intermediate signal in response to the difference between the temperature signal and a predetermined temperature setting; and means for generating an offset signal and for algebraically adding said offset signal and said intermediate signal so as to produce said control signal responsive to the algebraic sum of said offset signal and the difference between said temperature signal and said temperature setting; and said offset signal generating means including means responsive to the sign of the difference between said temperature setting and said temperature signal for periodically and cumulatively incrementing said offset signal a predetermined amount, up or down in accordance with said sign of said difference. - View Dependent Claims (2, 3, 4)
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5. An infant warmer bed comprising:
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a base; an infant support surface mounted on said base; a heating circuit connectable to a source of electrical energy to energize a heating element connected therein; a heating element supported on said base and connected in said heating circuit, said element being so positioned and operable to generate heat onto said surface when electrically energized; means connected in said heating circuit for varying the electrical energy supplied to said element in response to a control signal; a control circuit having an output connected to said energy varying means for delivering said control signal thereto, said control circuit having an input for receiving a temperature signal; and a temperature sensing probe positionable at said support surface and attachable to the skin of an infant supported on said surface, said probe having an output connected to the input of said control circuit and operable to generate a temperature signal responsive to the temperature sensed at said probe; said control circuit including; means for generating an intermediate signal in response to the difference between said temperature signal and a predetermined temperature setting; and means for generating an offset signal and for combining said offset signal with said intermediate signal to produce said control signal responsive to said offset signal and to the difference between said temperature signal and said temperature setting; and said offset signal generating means including means responsive to the relation of said temperature setting to said temperature signal for intermittently and incrementally modifying said offset signal; and wherein said control circuit further comprises; means for generating an energy level signal responsive to the amount of electrical energy supplied to said element during an interval of time, and for altering said control signal so as to reduce the electrical energy to said element in response to said energy level signal when the amount of energy supplied to said element during said interval exceeds a predetermined energy level.
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6. An infant warmer bed comprising:
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a base; an infant support surface mounted on said base; a heating circuit connectable to a source of electrical energy to energize a heating element connected therein; heating element mounted on said base connected in said heating circuit, said element being so positioned and operable to generate heat onto said surface when electrically energized; means connected in said heating circuit for varying the electrical energy to said element in response to a control signal; a control circuit having an output connected to said energy varying means for supplying said control signal thereto, said control circuit having an input for receiving a temperature signal; and a temperature sensing probe positionable at said support surface and attachable to the skin of an infant supported on said surface, said probe having an output connected to the input of said control circuit and operable to generate a temperature signal responsive to the temperature sensed at said probe; and said control circuit including means for generating said control signal in response to said temperature signal so as to maintain the temperature at said probe at a predetermined temperature setting; and
for generating an energymeans for generating an energy level signal responsive to the amount of electrical energy supplied to said element during an interval of time, and for altering said control signal so as to reduce the electrical energy to said element in response to said energy level signal when the amount of energy supplied to said element during such interval exceeds a predetermined energy level. - View Dependent Claims (7, 8, 9)
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10. An infant warmer bed comprising:
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a base; an infant support surface mounted on said base; a power circuit connectable to a source of electrical energy; a heating element mounted on said base connected in said power circuit to be energized thereby, said element being so positioned and operable to generate heat onto said surface when electrically energized; means connected in said power circuit for varying the electrical energy to said element in response to a control signal; a control circuit having an output connected to said energy varying means for supplying said control signal thereto, said control circuit having an input for receiving a temperature signal; a temperature sensing probe positionable at said support surface and attachable to the skin of an infant supported on said surface, said probe having an output connected to the input of said control circuit and operable to generate a temperature signal responsive to the temperature sensed at said probe; and said control circuit including; means for generating an intermediate signal in response to the difference between said temperature signal and a predetermined threshold signal, and manual startup means for generating said control signal at a predetermined level, in response to a manually initiated command signal, said manual startup means being operative only while said temperature signal remains less than said threshold signal and for up to a predetermined maximum amount of time after the heating element is energized, and automatic temperature control means operative after said temperature signal equals said threshold signal and after said predetermined maximum amount of time after the heating element is energized, and inoperative when said manual startup means is operative, for generating said control signal in accordance with said intermediate signal. - View Dependent Claims (11, 12)
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Specification