CN100404004C - Implantation of Piezoelectric Ceramic Intermittent Power Supply Devices in Joints - Google Patents

Abstract

A piezoelectric ceramic intermittent power supply device implanted in a joint, in particular relates to the design of a piezoelectric ceramic power supply circuit and a low-power consumption voltage regulation circuit, and belongs to the technical field of a piezoelectric ceramic power supply device implanted in a medical joint. The power supply device includes a piezoelectric ceramic device, a rectifier circuit device, an energy storage circuit device, and a voltage regulator. It uses the technology of converting the energy generated by piezoelectric ceramics under pressure into electrical energy. The current generated by piezoelectric ceramics under pressure is rectified. After the circuit, the energy is stored in the energy storage circuit, the energy storage capacitor provides voltage to the voltage regulation circuit, and the voltage regulation circuit outputs a stable voltage for the subsequent circuit to work. Since the piezoelectric ceramic device placed in the implanted joint is under pressure for a discontinuous time, the power supply mode of the device is also intermittent. It provides an effective power supply method for realizing the two-way digital wireless pressure monitoring system for implanted joints in living organisms.

Description

Implantation of Piezoelectric Ceramic Intermittent Power Supply Devices in Joints

technical field

The invention relates to a piezoelectric ceramic intermittent power supply device implanted in a joint, in particular to the design of a piezoelectric ceramic power supply circuit and a low power consumption voltage regulation circuit, and belongs to the technical field of a piezoelectric ceramic power supply device implanted in a medical joint.

Background technique

Physical disability is one of the important diseases that affect the quality of life of the disabled. Artificial joints and prosthetics are an important means of re-establishing motor function for people with joint damage. After the artificial joint is implanted in the human body, it is in a long-term working state. Integrated circuit technology is used to establish a physical channel for signal transmission between the human implanted joint and the outside world, and early monitoring of the working conditions, pressure, and dislocation of the implanted joint. Testing, helping doctors to detect problems early for diagnosis, is an effective means of reducing patient suffering.

To collect the pressure data of the implanted joint, it is necessary to use the integrated circuit in the implanted joint to save the pressure data when the implanted joint is under pressure. In order to realize the collection of data, provide the working power supply for the integrated circuit at first. Due to the narrow space in the implanted joint, it is unrealistic to place the battery, and the life of the battery is limited, and the working life of the implanted joint is generally about 20 years, so other power supply methods must be used.

Implanted joints will generate pressure during daily activities, and piezoelectric ceramics can generate current under pressure. Using this characteristic, piezoelectric ceramic components are placed in implanted joints, and the current generated by them under pressure is first After rectification and energy storage by the energy storage element, a stable voltage is output through the voltage regulation circuit to supply power for the integrated circuit.

At present, the applicant has not seen domestic research on implanting power supply devices in joints.

Contents of the invention

The current invention is to use a piezoelectric ceramic device in the implanted joint, and use the energy generated under pressure to power the integrated circuit, so as to realize the collection of pressure data to help doctors diagnose the patient's implanted joint in time.

The piezoelectric ceramic intermittent power supply device implanted in the joint is characterized in that the power supply device includes the following four parts:

(1) The piezoceramic device, placed in the implanted joint, includes 3 piezoceramic elements, which on the one hand generate current under pressure conditions, and on the other hand they also serve as pressure sensors to transmit pressure data; piezoceramic elements The three output terminals of the circuit are connected with the three input terminals of the rectification circuit device below;

(2) A rectification circuit device for rectifying the current generated by the piezoelectric ceramic element under pressure. The rectification circuit device includes three diode bridge rectification circuits, which respectively rectify each input current and convert alternating current into direct current; the output terminal of the rectification circuit device is connected to the input terminal of the energy storage circuit device;

(3) The energy storage circuit device is used to store electric energy, including a large-capacity electrolytic capacitor, which supplies power to subsequent circuits through the charging process and discharging process of the electrolytic capacitor; its output is connected to the input terminal of the voltage regulator;

(4) A voltage regulator, which is used to adjust the input voltage and output a stable voltage to supply power to the load.

The present invention proposes a piezoelectric ceramic intermittent power supply device implanted in joints for medical use. It is a technology that converts energy generated by piezoelectric ceramics under pressure into electrical energy. The device includes a piezoelectric ceramic device, a rectifier circuit, a storage Energy component capacitance and voltage regulation circuit. The current generated when the piezoelectric ceramic is under pressure passes through the rectifier circuit and stores energy in the energy storage circuit. The energy storage capacitor provides voltage to the voltage regulation circuit, and the voltage regulation circuit outputs a stable voltage for subsequent circuit work. Since the piezoceramic device placed in the implanted joint is under pressure for a discontinuous time, the power supply mode of the device is also intermittent.

The present invention utilizes the piezoelectric ceramics placed in the implanted joints to generate electric energy under pressure conditions, through rectification, energy storage and voltage regulator to supply power to the integrated circuit, thus providing the realization of the two-way digital wireless pressure monitoring system for the implanted joints of living organisms efficient power supply.

Description of drawings

Fig. 1 is a schematic diagram of the logical structure of the present invention.

Fig. 2 is a schematic diagram of the piezoelectric ceramic element of the present invention.

Fig. 3 is a schematic diagram of the operation of the energy storage capacitor in the present invention.

Detailed ways

Fig. 1 is a schematic diagram of the logical structure of the present invention. 1 is a piezoelectric ceramic device, 2 is a rectifier circuit device, 3 is an energy storage circuit device, and 4 is a voltage regulator. Three piezoelectric ceramic elements generate current under pressure, the output end of the piezoelectric ceramic device (1) is connected to the input end of the rectification circuit device (2), and the output end of the rectification circuit device (2) is connected to the energy storage circuit device ( 3) is connected to the input end; the output end of the energy storage circuit device (3) is connected to the input end of the voltage regulator device (4).

Fig. 2 is a schematic diagram of the piezoelectric ceramic element of the present invention, wherein 5 is a pressure dispersing metal plate, 6 is a bearing, and 7 is a piezoelectric ceramic element. Four can be used in the pressure monitoring system, and the more the number, the greater the energy generated. This figure includes 3 piezoceramic elements. The pressure dispersing metal plate (5) is at the top, the piezoelectric ceramic element (7) is in the middle, and the bearing (6) is at the bottom. The pressure from above is distributed to each piezoelectric ceramic element through the pressure dispersing metal plate (5), and the piezoelectric ceramic element generates current under pressure and can be output through wires. Bearings (6) support the entire joint. Lead can be drawn out by bearing (6).

Fig. 3 is a schematic diagram of the operation of the energy storage capacitor in the present invention. 8 is the equivalent capacitance C _p of the piezoelectric ceramic device, 9 is the energy storage capacitance C _s in the energy storage circuit, and 10 is the circuit load. The equivalent capacitance (8) of the piezoelectric ceramic device is connected in parallel with the energy storage capacitor (9) in the energy storage circuit and then connected with the load (10).

The selection of the size of the energy storage capacitor C _s is given below. When C _s =C _p , C _s can get the maximum energy, where C _p is the equivalent capacitance of the piezoelectric ceramic device. The charge obtained by the storage capacitor is:

ΔQ＝C _s ·(V ₁ -V ₂ ) (1)

Where ΔQ is the magnitude of the charge released by C _s during the change of the voltage across it from V ₁ to V ₂ (V ₁ >V ₂ ), and the charge can also be described by the following formula

ΔQ＝I·Δt (2)

Among them, Δt is the time that the voltage changes from _V1 to _V2 , and I is the magnitude of the current generated during this period. According to formula (1) and formula (2), it can be obtained:

$\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

According to the formula (3), the time during which the current can be supplied to the subsequent circuit when the voltage at both ends of C _s changes can be obtained. Due to the charging and discharging process of the energy storage capacitor C _s itself, the power supply process of piezoelectric ceramics is intermittent.

The piezoelectric ceramic device (1) includes three piezoelectric ceramic elements (7), a pressure dispersing metal plate (5) and a bearing (6), and the piezoelectric ceramic element (7) is not only a sensor for transmitting pressure data but also generating Energy and pressure are converted into electrical energy by the piezoelectric ceramic device (1) and output to the rectifier circuit (2). The rectifier circuit (2) adopts a diode bridge rectifier circuit, and the current generated by each piezoelectric ceramic element (7) passes through A diode bridge rectifier circuit performs bridge rectification. After rectification, it is sent to the energy storage circuit device (3); the energy storage circuit device (3) is a large-capacity electrolytic capacitor (9), and the electric current generated by the piezoelectric ceramic device (1) charges it, when the energy storage capacitor When the energy in (9) is sufficient for the load (10) to work, the energy storage capacitor (9) is discharged, that is, the energy storage capacitor (9) is in two processes of charging and discharging. When the energy storage capacitor (9) is equal to the equivalent capacitance (8) of the piezoelectric ceramic piezoelectric ceramic device (1), the energy storage capacitor (9) can store the maximum energy; the voltage regulator (4) is used to adjust The capacitor inputs the voltage and outputs a stable voltage for the load to work.

The present invention is a device that is implanted in a joint and uses the pressure generated when the joint moves to provide intermittent power supply through piezoelectric ceramic equipment. It uses the technology of converting the energy generated by piezoelectric ceramics under pressure into electrical energy. Electric ceramic device, full-wave bridge rectifier circuit, energy storage element capacitor and voltage regulation circuit. The current generated when the piezoelectric ceramic is under pressure is rectified by the full-wave bridge and stored in the energy storage capacitor. The energy storage capacitor provides voltage to the voltage regulation circuit, and the voltage regulation circuit outputs a stable voltage for subsequent circuit work. It provides an effective power supply method for realizing the two-way digital wireless pressure monitoring system for implanted joints in living organisms.

Claims (2)

1. interior piezoelectric ceramic intermittent electricity supply device of implantation joint is characterized in that, this electric supply installation comprises following four parts:

(1) piezoelectric ceramic device places in the implantation joint, comprises 3 piezo ceramic elements, and their under stress produce on the one hand electric current, and they are also as pressure transducer on the other hand, the transmission pressure data; Each piezo ceramic element has an outfan, and promptly three inputs of three of piezoelectric ceramic device outfans and following rectification circuit device link to each other;

(2) rectification circuit device, the electric current that is used for piezo ceramic element is under stress produced carries out rectification; Rectification circuit device comprises three diode bridge rectification circuits, and the every road electric current that is respectively input carries out rectification, and alternating current is converted to unidirectional current; The input of the output termination energy storage circuit device of rectification circuit device;

(3) the energy storage circuit device is used for storage of electrical energy, and charging process by the energy storage circuit device and discharge process are the subsequent conditioning circuit power supply; The outfan of energy storage circuit device links to each other with the input of voltage regulator;

(4) voltage regulator is used to regulate input voltage, the output burning voltage, and described voltage regulator outfan links to each other with load.

2. interior piezoelectric ceramic intermittent electricity supply device of implantation joint according to claim 1 is characterized in that, described energy storage circuit device is a jumbo electrochemical capacitor.

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