JP4584484B2 - Insulated power transmission connector and medical device having the power transmission connector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an implantable medical device and a power transmission connector that transmits power to a medical device used in the vicinity of a living body, and a medical device having the power transmission connector.
[0002]
[Prior art]
An artificial heart is an example of an implantable medical device and a medical device used in the vicinity of a living body. The artificial heart basically consists of a pump that replaces the heart and a controller that drives it, but at the present time, only the pump is implanted inside the body, and the controller is carried outside the body (used near the living body). Yes) the configuration is considered.
[0003]
In the future, the controller will also be implanted in the body, and it is thought that the necessary power will charge the battery implanted in the body by transcutaneous transmission and supply power, but this is a technical issue Still remains.
[0004]
In the above-described configuration in which the controller is carried outside the body, power is supplied to the controller by directly connecting the terminals connected to each other at the connector portion of the controller with a cable connected to an external power source. Therefore, complete airtightness is not maintained, and when the controller may get wet, such as during showers or rainy weather, a measure is taken such as covering.
[0005]
[Problems to be solved by the invention]
Considering the ease of use of the controller, it is desirable to increase the airtightness, particularly the level of waterproofing. However, this leads to an increase in the size of the connector and therefore an increase in the size of the controller, which is not preferable for improving the quality of life (QOL) of the user. Further, when a highly airtight connection terminal is used, the types of connectors are limited, and generally a seal utilizing the elasticity of plastic is used. This leads to an increase in the cost of the controller and a decrease in durability (for example, impact resistance), which is not preferable.
[0006]
In order to solve this problem, the present invention provides a non-contact power transmission, particularly an insulated AC power transmission connector for practical use even in the case of a high power load such as an artificial heart, and the power transmission connector. The medical device which has is provided.
[0007]
[Means for Solving the Problems]
In order to solve this problem, a medical device of the present invention is included in a receptor in which a plug including an I-shaped primary core can be inserted in an implantable medical device and a medical device used in the vicinity of a living body. When the plug is inserted into the receptor, the U-shaped secondary side core is generally arranged together with the I-shaped primary side core through the medical device frame formed of an insulator. A U-shaped secondary core that forms a high-permeability core that can be regarded as a closed circuit; and when the plug is inserted into the receptor, the I-shaped primary core and the U-shaped core Electric power is supplied to the medical device via electromagnetic induction type power transmission means including a secondary core .
[0008]
The power transmission connector of the present invention is a power transmission connector for an implantable medical device and a medical device used in the vicinity of a living body, and includes a plug including an I-shaped primary core, and a U-shaped plug. A receptor including a secondary core into which the plug can be inserted, and when the plug is inserted into the receptor, the I-shaped primary core and the U-shaped secondary core The receptor of the medical device, which forms a core with a high magnetic permeability that can be regarded as a closed circuit through a frame of the medical device formed of an insulating material, and from the plug to the receptor by application of AC power It is characterized by performing electromagnetic induction type power transmission. Here, and a fixing means for fixing the primary core of the shaped pre Symbol I in the secondary core and the predetermined positional relationship of the U-shaped.
[0009]
With the above structure, it becomes easy to increase the airtightness, in particular, the level of waterproofing by adopting an insulating type. It also leads to an increase in electrical safety.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
<Current power transmission system>
Most current artificial hearts use power of about 10 to 30 W. When trying to transmit such high power in a non-contact manner using the principle of electromagnetic induction, high efficiency is required. This is a different condition between contactless power transmission in a medical device and current general contactless power transmission.
[0012]
As an example of the current non-contact power transmission system, there is a system shown in FIG. 1, but in this case, the magnetic field lines are not confined in the core, so that high efficiency cannot be expected. Therefore, it can be used only when the current consumption on the secondary side is small.
[0013]
Therefore, in order to increase the efficiency of contactless power transmission using the principle of electromagnetic induction, a toroidal core having a closed core is generally used. However, it is disadvantageous in shape to apply it to a contactless power transmission connector for a medical device.
[0014]
<Power transmission connector of Embodiment 1>
In the first embodiment, as an example, a square core is used as shown in FIG. 2, and a transformer is connected by a connector plug (corresponding to core 1 in FIG. 2) and a receptor (corresponding to core 2 in FIG. 2). I made it up.
[0015]
In FIG. 2, reference numeral 10 denotes a case of a portable controller, which is formed of an insulator with a rectangular shape of, for example, 80 mm × 100 mm. A U-shaped secondary core 2 and a primary core 1 are disposed around the controller case 10 to form a transformer. Here, the core 1 around which the primary coil 11 is wound is inserted as a plug into a frame 30 made of an insulator, and a transformer is formed with the core 2 on the controller side around which the secondary coil 12 is wound. Non-contact power transmission by induction is performed. Therefore, if highly efficient contactless power transmission is possible with such a configuration, the portable controller circuit and the like are completely cut off from the outside by the insulator case 10 and the plug frame 30, so that the airtightness , So you don't have to worry about showers or rain.
[0016]
Whether or not the power transmission connector of this embodiment is practical is determined by how much the influence of the two gaps 21 and 22 caused by shutting off the core 1 and the core 2 is apparent from FIG. by. The gaps 21 and 22 have such a length that the coil 11 and the insulating frame 30 are separated from each other as shown in the AA ′ cross section of FIG.
[0017]
Hereinafter, the influence of the two gaps 21 and 22 will be described.
For example, N: number of turns per unit length of the coil L: average length of the entire length of the core J: current μ: magnetic permeability of the core μ _O : magnetic permeability in air (approximable by magnetic permeability in vacuum)
δ: Assuming the gap length, the magnetic flux density B created by the current circuit is
Outside the gap,
B = μNJ / L (1)
And in the gap,
B = (μNJ / L) / [1+ (μ / μ ₀ ) × (δ / L)] (2)
It is. Here, μ / μ ₀ can be regarded as the relative magnetic permeability, and the larger the value is, the closer the transformer coupling coefficient k becomes to 1, and the leakage inductance can be reduced. Since k is a parameter that determines the frequency characteristic and the minimum value of the insertion loss (see FIG. 5), it is recommended that the core design has a relative permeability of about 1000 and k = 0.999 in the transformer design. . As a material that is highly available and easy to process,
a) When silicon steel is used: about 500
b) When Ni—Zn ferrite is used: 10 to 1000
As an application of the present invention, 500 or more is sufficient, and here, as an example, μ / μ ₀ = 500 to 1000 (3)
And
[0018]
In addition, δ / L is determined by mechanical design, but the size of the controller carried outside the body is
100mmx80mmx30mm (D)
As an example here,
δ = 1mm, L = 360mm
And Therefore,
δ / L = 1/360 (4)
It is. therefore,
(Μ / μ ₀ ) × (δ / L) = 1.4 to 2.8 (5)
Therefore, the expression (2) is 0.42 to 0.26 times as large as the expression (1), which causes an error in the later-described design expressions (6) and (7). However, there is no practical problem in power transmission from the primary side to the secondary side.
[0019]
Next, the number of turns of the coil and the voltage / current on the primary side will be described from the relationship between input / output voltage and current.
[0020]
Assuming that the plug and the receptor are the primary side and the secondary side, respectively, and the number of turns, current, and voltage are N1, N2, J1, J2, V1, and V2, the following relationship is approximately established.
[0021]
V2 =-(N2 / N1) V1 (6)
N2 / J2 = -N1 / J1 (7)
Since the voltage V2 and the current J2 required for the secondary-side controller are known, the necessary power transmission can be performed by determining N1, N2, V1, and J1 according to the equations (6) and (7). . In addition, since the magnetic flux is confined in the core when the coil is evenly wound around each core, highly efficient power transmission becomes possible.
[0022]
<Example of portable controller according to Embodiment 1>
FIG. 4 is an external view of the portable controller according to the first embodiment.
[0023]
In FIG. 4, the portable controller is provided with a layer 41 for a power transmission connector, and the power transmission connector is mounted thereon. The power transmission connector layer 41 and the controller circuit layer 42 are also separated.
[0024]
For example, if the cross section of the core 1 of the power transmission connector is a square of 5 mm × 5 mm, the power transmission connector layer 41 may be about 1 cm thick. Since the core 1 into which the insulating frame 30 is inserted needs to be fixed with screws 13 or the like, a dimension that can be operated with a finger is determined.
[0025]
In order to reduce the thickness of the portable controller, an electromagnetic insulating frame is provided inside the core and a circuit is provided therein.
[0026]
<Power Transmission Connector of Embodiment 2>
In the second embodiment, as an example, a circular core is used as shown in FIGS. 6 and 7, and a connector plug (corresponding to a primary core in FIG. 6) and a receptor (corresponding to a secondary core in 62). The transformer was made up in.
[0027]
In FIG. 6, 64 is a case of a portable controller, and a U-shaped secondary core that is considerably smaller than the first embodiment and an I-shaped primary core are arranged in a part of the controller case 64. Form a transformer. Here, the primary core around which the primary coil 61 is wound is covered with an insulator 63 and inserted as a plug into a U-shaped receptor formed on a part of a controller case 64 made of an insulator. Thus, a transformer is formed by the secondary core on the controller side around which the secondary coil 62 is wound, and non-contact power transmission by electromagnetic induction is performed. The gap in the present embodiment is the sum of the thickness of the insulator 63 on the plug side and the thickness of the case 64.
[0028]
7 is a cross-sectional view taken along the lines BB ′ and CC ′ of FIG.
[0029]
Since highly efficient contactless power transmission is performed with such a configuration, the portable controller circuit and the like are completely cut off from the outside by the insulator case 64 and the plug insulator 63, so that airtightness is maintained. There is no need to worry about showers or rain. In addition, unlike the first embodiment, the core is made compact, so the connector is small, and it is only necessary to provide a simple structure (such as a claw) so that the plug does not come off from the receptor. The connector can be easily attached and detached.
[0030]
<Example of portable controller according to Embodiment 2>
FIG. 8 is an external view of a portable controller having the power transmission connector of the second embodiment. The portable controller 80 of the present example has an external shape of 80 mm long × 120 mm wide × 30 mm thick, and a connector portion 60 is provided at substantially the center of the horizontal frame. In addition, the installation position of a connector part is not limited to this example.
[0031]
9 is a cross-sectional view taken along the line DD ′ of FIG. As is apparent from FIG. 9, according to the second embodiment, the connector portion can be realized with the minimum necessary size depending on the size of the core corresponding to the transmission power and the number of turns of the coil. The connection can be made by a simple insertion operation into the receptor of the plug having the same feeling as that of the connection.
[0032]
<Example of artificial heart of this embodiment>
FIG. 10 is a diagram showing a configuration example of an artificial heart including a portable controller (Wearable Controller) equipped with the power transmission connector of the present embodiment.
[0033]
FIG. 10 shows an example of a left ventricular assist pump (Pump), in which the left ventricular assist pump in the body and the portable controller outside the body are connected by a percutaneous cable (Percutaneous Cable) to be controlled and monitored. . In FIG. 10, power transmission to a battery (Battery) of the portable controller is performed via the power transmission connector of the present embodiment at a hospital console having a monitor.
[0034]
Note that the present invention is not limited to power transmission in principle, and can be applied to information transmission because it can transmit an AC signal. For example, data from a portable controller in FIG. Can be sent to the hospital console or data can be sent to update the parameters of the portable controller.
[0035]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the insulated power transmission connector for alternating currents which can perform transmission of high electric power can be provided. Further, since the primary side and the secondary side can be insulated on the order of about 1 mm, airtightness (particularly waterproof) is high, and electrical safety can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of conventional electromagnetic induction type power transmission.
FIG. 2 is a diagram illustrating a configuration example of an electromagnetic induction power transmission connector according to the first embodiment.
FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG.
FIG. 4 is a diagram illustrating an appearance of a portable controller according to the first embodiment.
FIG. 5 is a diagram illustrating a relationship between a transformer coupling coefficient and frequency characteristics;
6 is a diagram illustrating a configuration example of an electromagnetic induction power transmission connector according to a second embodiment. FIG.
7 is a cross-sectional view taken along the lines BB ′ and CC ′ of FIG. 6;
FIG. 8 is a diagram illustrating an appearance of a portable controller according to the first embodiment.
9 is a cross-sectional view taken along the line DD ′ of FIG.
FIG. 10 is a diagram showing a configuration example of an artificial heart using the power transmission connector of the present embodiment.

Claims (3)

In an implantable medical device and a medical device used in the vicinity of a living body,
A U-shaped secondary core included in a receptor into which a plug including an I-shaped primary core can be inserted , wherein the plug is inserted into the receptor and formed of an insulator. A U-shaped secondary core that forms a high-permeability core that can be regarded as a closed circuit together with the I-shaped primary core through a medical device frame ;
When the plug is inserted into the receptor , power is supplied to the medical device via electromagnetic induction type power transmission means including the I-shaped primary core and the U-shaped secondary core. A medical device characterized by being supplied. A power transmission connector of an implantable medical device and a medical device used in the vicinity of a living body,
A plug including an I-shaped primary core;
A receptor including a U-shaped secondary core into which the plug can be inserted, and when the plug is inserted into the receptor, the I-shaped primary core and the U-shaped secondary core The receptor of the medical device that forms a high-permeability core that can be regarded as a closed circuit through a frame of the medical device formed of an insulator with a side core;
An electric power transmission connector for performing electromagnetic induction type electric power transmission from the plug to the receptor by application of alternating current power. 3. The power transmission connector according to claim 2, further comprising fixing means for fixing the I-shaped primary core to the U-shaped secondary core in a predetermined positional relationship.

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