Voltage-frequency conversion circuit and blood pressure measurement device equipped with same
AssigneeOmron Healthcare Co., Ltd.
InventorEisuke Yamazaki
Life of this patent
Estimating the term…
Abstract
A resistor element is arranged between an input terminal and a node. A switch element is arranged between the node and a ground voltage, and is conducted according to a voltage level of the node. A resistor element is arranged between the nodes. A resistor element is arranged between the node and one side of the input node of an NOR circuit. A capacitor is connected between the nodes. The input node of the NOR circuit is connected to the node through the resistor element and a ground voltage. The input node of an NOR circuit is connected to an output node of the NOR circuit and the ground voltage. The input node of the NOR circuit is connected to the node and the ground voltage.
Claims5
A voltage-frequency conversion circuit comprising:
- an RC oscillation circuit comprising a capacitance component and a resistance component,
- wherein the RC oscillation circuit comprises:
- an input terminal to which an input voltage is input;
- a first resistor element connected between the input terminal and a first internal node;
- a first capacitor comprising one electrode connected to the first internal node and another electrode connected to a second internal node;
- a second resistor element comprising one conductive terminal connected to the first internal node in parallel with the first capacitor;
- a first logic circuit connected to another conductive terminal of the second resistor element and connected between the first internal node and the second internal node through the second resistor element;
- a second logic circuit, connected to the second internal node, that outputs an oscillation signal in accordance with an output signal of the first logic circuit;
- and
- a first switch element that electrically connects the first internal node connected to the one electrode to a fixed voltage to charge and discharge the first capacitor according to a voltage level of the second internal node.
A blood pressure measurement device comprising:
- a cuff to be wrapped around a predetermined measurement site of a person to be measured;
- and
- pressure detection means for detecting the pressure of the cuff,
- wherein the pressure detection means comprises:
- a piezo resistance type sensor that generates a voltage in accordance with the pressure of the cuff;
- and
- an RC oscillation circuit comprising a capacitance component and a resistance component,
- wherein the RC oscillation circuit comprises:
- an input terminal to which an input voltage is input;
- a first resistor element connected between the input terminal and a first internal node;
- a first capacitor comprising one electrode connected to the first internal node and another electrode connected to a second internal node;
- a second resistor element comprising one conductive terminal connected to the first internal node in parallel with the first capacitor;
- a first logic circuit connected to another conductive terminal of the second resistor element and connected between the first internal node and the second internal node through the second resistor element;
- a second logic circuit, connected to the second internal node, that outputs an oscillation signal in accordance with an output signal of the first logic circuit;
- and
- a first switch element that electrically connects the first internal node connected to the one electrode to a fixed voltage to charge and discharge the first capacitor according to a voltage level of the second internal node.
Dependencies are inferred from the claim text.