JP2012016377A - Medical device having function to determine contrast medium injection condition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical device for setting further appropriate conditions for injecting medicinal solution to heavyweight and lightweight patients.SOLUTION: The medical device performs the following processes to determine injection conditions of contrast medium: determining a standard body weight of a patient; calculating a basic circulating blood volume (BV) of the patient using the patient's actual body weight as a parameter; calculating an ideal circulating blood volume (BV') of the patient using the patient's standard body weight as a parameter; calculating a ratio of the basic circulating blood volume (BV) to the ideal circulating blood volume (BV'); multiplying the standard body weight by the ratio to calculate a contrast basic body weight (CBW); and determining the injection conditions of the contrast medium based on the contrast basic body weight (CBW).

Description

  The present invention relates to a medical device having a function of determining an injection condition of a contrast medium to be injected into a patient, and in particular, a medical device capable of setting a more appropriate chemical solution injection condition even for a high-weight or low-weight patient. About.

At present, CT (Computed Tomography) scanner, MRI (Magnetic Resonance Imaging) apparatus, PET (Positron) as medical diagnostic imaging equipment.
Emission Tomography) devices, angiographic devices, and the like are known. When using such an imaging apparatus, a patient may be injected with a contrast medium, physiological saline, or the like (hereinafter also simply referred to as “medical solution”). Various proposals have been made.

  Conventionally, in order to obtain a suitable contrast effect according to each patient, it is known to determine a chemical solution injection condition (a chemical solution injection amount, etc.) in consideration of the patient's weight, age, sex, and the like. For example, Patent Document 1 proposes that the liquid injection condition is determined based on the lean body weight rather than the patient's body weight itself. “Lean body weight” refers to the weight obtained by subtracting the fat mass from the body weight of the patient, and by setting this lean body weight as a parameter, it is possible to set more appropriate drug solution injection conditions for each patient. It becomes possible.

WO2008 / 081830

The method described in Patent Document 1 as described above is useful in that the injection conditions can be optimized, but in the case of a high-weight (obesity type) or low-weight (lean type) patient, the weight and the amount of contrast medium There is a tendency for the correlation to be worse. Therefore, it is desired to develop an apparatus that can set more appropriate conditions for such a patient.
This invention is made | formed in view of the said subject, The objective is to provide the medical device which can set more appropriate chemical | medical solution injection | pouring conditions also to a high weight or low weight patient.

1. In order to achieve the above object, the medical device of the present invention comprises:
A medical device having a function of determining a contrast medium injection condition according to a patient,
Processing to determine the standard weight of the patient;
Calculating the patient's basic circulating blood volume (BV) using the patient's actual weight as a parameter;
Calculating the patient's ideal circulating blood volume (BV ′) using the patient's standard weight as a parameter;
A process for calculating a ratio between the basic circulating blood volume (BV) and the ideal circulating blood volume (BV ′);
A process of multiplying the standard weight by the ratio to calculate a contrast reference weight (CBW);
A process for determining the injection condition of the contrast agent based on the contrast reference body weight (CBW);
Is configured to do.

  “Determining the injection condition of the contrast agent” may be one in which the amount of the contrast agent is determined, the injection rate of the contrast agent may be determined, or those Both may be determined.

  In the medical device of the present invention, the contrast reference body weight (CBW) is obtained instead of the actual body weight or lean body weight, and the amount of contrast medium (one example) is determined based on this. According to such a method, it is possible to set more appropriate conditions for a patient with high weight (obesity type) or low weight (skin type) as compared with a method based on a conventional lean body mass. It becomes possible.

The medical device of the present invention may be as follows.
2. The medical device according to 1 above, wherein in the process of calculating an ideal circulating blood volume (BV ′), the blood volume is calculated based on the following equation.

BV ′ = (height / a) ^p × (weight / b) ^q × cd (Formula 1)
here,
a, b, c, d are positive constants p, q are constants (0 <p <1, 0 <q <1)

3. The medical device according to 2 above, wherein two types of formulas for men and women are prepared as the formula 1.

  According to such a configuration, it is possible to set a more appropriate injection condition in consideration of gender.

4. In addition,
Calculating the bone weight of the patient;
Recalculating the contrast-based body weight (CBW ′) using the calculated bone weight as a parameter;
And
In the process of determining the injection condition of the contrast agent, calculation is performed based on the calculated contrast reference body weight (CBW ′).
4. The medical device according to any one of 1 to 3 above.

  According to such a configuration, more appropriate injection conditions are set in consideration of the bone weight of the patient.

5. (i) In the process of calculating the bone weight of the patient,
Calculate the value of m% of the standard body weight as bone weight (W),
(Ii) In the process of recalculating the contrast reference weight (CBW ′),
A value obtained by subtracting the bone weight (W) from the standard body weight is calculated as a bone removal weight body weight,
A value obtained by multiplying the deboning weight body weight by the ratio of BV / BV ′ is calculated as a corrected body weight,
A value obtained by adding the bone weight (W) to the corrected body weight is calculated as a contrast basic body weight (CBW ′) of the patient.
5. The medical device according to 4 above.

6. The medical device according to any one of 1 to 5 above, wherein in the process of determining a contrast agent injection condition, an amount of the contrast agent is determined.

  As described above, according to the present invention, it is possible to provide a medical device capable of setting more appropriate drug solution injection conditions for high-weight and low-weight patients.

It is a perspective view which shows the chemical injection device of one form of this invention. FIG. 2 is a perspective view of the injection head of FIG. 1. It is a block diagram which shows typically the circuit structure of the chemical injection device of FIG. It is a flowchart which shows an example of an injection condition setting procedure. It is a table | surface which shows an example of patient information. FIG. 4 is a body weight-contrast medium amount correlation diagram based on actual body weight and a body weight-contrast medium amount correlation diagram based on contrast reference body weight.

[First Embodiment]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 has an injection head 110 for injecting a contrast medium or the like to a subject, and a controller device 50 connected thereto. In the present embodiment, the controller device 50 corresponds to a “medical device” recited in the claims.

  Various types of injection heads 110 can be used. In this example, a two-cylinder head that can be mounted with a syringe filled with a contrast medium and a syringe filled with physiological saline. Is used. In this example, the injection head 110 is held on the top of a movable caster stand.

  FIG. 2 is a perspective view showing an example of an injection head. The injection head 110 has a casing 111 that is long in the front-rear direction. A plurality of buttons 116 for switching the operation of the injection head 110 are arranged on the upper surface of the casing 111. Syringe holders 114 and 114 that are recessed in a semi-cylindrical shape to which a syringe is attached are provided at a position closer to the front of the upper surface of the housing. The radius of curvature of the inner surface of the syringe holding part 114 is formed slightly larger than the outer diameter of the large syringe, whereby the syringe is stably held by the syringe holding part.

Note that the small-diameter syringe may be configured to be attached to the holding unit 114 via an adapter (not shown).
Moreover, the syringe itself is a conventionally well-known thing, and has the cylindrical cylinder member 211 and the piston member 212 inserted so that it could slide with respect to the cylinder member 211 so that it might illustrate. A circular flange portion 211 a is formed at the base end portion of the cylinder member 211. A circular flange portion 212 a is also formed at the base end portion of the piston member 212.

  The injection head 110 also includes a piston drive mechanism 120 that pushes the piston member 212 of the syringe into the cylinder member 211. The piston drive mechanism 120 is provided in two systems so that each syringe can be operated separately. The piston drive mechanism 120 moves back and forth in the front-rear direction by receiving a motor (not shown) built in the casing 111, a link mechanism (not shown) for transmitting the power, and a force from the link mechanism. It has a presser member 122 and the like. A pair of claws are provided on the left and right sides of the front end portion of the presser member 122, and the flange portion 212a of the piston member 212 is gripped by the pair of claws.

  In addition to the configuration in which the presser member 122 directly grips the piston member 212, the presser member 122 and the piston member 212 may be coupled via an intermediate member (adapter) (not shown).

  Moreover, although illustration is abbreviate | omitted, the injection | pouring head 110 may have an IC tag reader for reading the information of the IC tag attached to a part of syringe. The IC tag may store information related to the syringe (syringe identification data, cylinder member pressure resistance, cylinder member inner diameter, piston member stroke, and the like). In the case of the prefilled type, information (for example, product name, component information, viscosity, expiration date, etc.) of the chemical solution filled in the syringe may be stored.

FIG. 3 is a block diagram schematically showing a circuit configuration of the chemical liquid injector of FIG.
As shown in FIG. 3, the controller device 50 includes a display 51 for displaying predetermined information, a hand switch 57 for receiving input from an operator, an input unit 58 for inputting information from the outside, And a control unit 55 that performs the above arithmetic processing. The input unit 58 is connected to another medical system by wired connection or wireless connection, and desired information (for example, patient physical information) is input from the system. The display 51 may be a touch panel type, and the operator may be configured to manually input predetermined information via the touch panel.

  As shown in FIG. 3, the injection head 110 has two systems of piston drive mechanisms 120 and 120, and these piston drive mechanisms 120 and 120 operate in response to a command from the controller 55 of the controller device 50. Is configured to do. 3 corresponds to a button on the top surface of the injection head, and an operator inputs via the input unit 116.

The control unit 55 is configured to perform the following processing.
(1) Processing for receiving input of patient information:
“Patient information” is, for example, information such as the height, weight, and sex of the patient. Such information may be input by an operator via the display 51 (touch panel) of the controller device 50, or may be input by sending information from a medical system (not shown) to the input unit 58. It may be a thing.

(2) Processing to determine the standard weight of the patient:
The standard body weight [Kg] is an example and can be determined using a generally known BMI formula.

Standard weight = 22 x (height [cm] / 100) x (height [cm] / 100) ... (male)
Standard weight = 21 x (height [cm] / 100) x (height [cm] / 100) ... (female)
The standard weight is obtained by substituting the patient information (height) input in the process (1) above into these equations and calculating.
Note that the above male formula having a coefficient of “22” may be commonly used without distinguishing between male and female.

(3) Processing for calculating a patient's basic circulating blood volume (BV) using the patient's actual body weight as a parameter "Basic circulating blood volume (BV)" is the circulating blood obtained using the patient's actual body weight as a parameter. In this embodiment, the blood volume is determined using the following equation.
BV = (height / 2.54) ^0.725 × (actual weight / 0.4536) ^0.423
× 33.164-1229
…(male)
BV = (height / 2.54) ^0.725 × (actual weight / 0.4536) ^0.423
× 34.85-1954
…(Woman)

The basic circulatory blood volume (BV) is obtained by substituting the patient information (height and weight) input in the processing of (1) above into these equations and calculating.
Note that the patient's weight or the like may be a value input in advance in an electronic medical record (an example), or may be a measurement value obtained by measuring height and weight immediately before imaging.

(4) Processing for calculating the ideal circulating blood volume (BV ′) of the patient using the standard body weight as a parameter “Ideal circulating blood volume (BV ′)” is the circulating blood volume obtained using the standard body weight as a parameter. In the present embodiment, the blood volume determined using the following equation.
BV ′ = (height / 2.54) ^0.725 × (standard weight / 0.4536) ^0.423
× 33.164-1229
…(male)
BV ′ = (height / 2.54) ^0.725 × (standard weight / 0.4536) ^0.423
× 34.85-1954
…(Woman)

  According to this equation, the blood volume (BV) basically increases as the height increases or the weight increases. However, since the index relating to height (0.725) and the index relating to weight (0.423) are both smaller than 1, the rate of increase becomes more moderate as the weight increases (height). That is, according to this equation, the blood volume of a patient with high weight and height is not calculated excessively, and as a result, the amount of contrast medium calculated based on the blood volume is also an appropriate amount.

(5) Processing for calculating the ratio between the basic circulating blood volume (BV) and the ideal circulating blood volume (BV ′):
Blood volume ratio = basic circulating blood volume (BV) / ideal circulating blood volume (BV ')

(6) A process of calculating the contrast reference weight (CBW) by multiplying the standard weight by the ratio:
Contrast reference weight (CBW) = standard weight × blood volume ratio

(7) Processing for determining the contrast medium injection condition based on the contrast reference body weight (CBW) In this processing, the contrast reference body weight (CBW) obtained in the above process (6) is used instead of the actual weight of the patient. Based on this, the injection condition of the contrast agent is determined. As an example, the amount of contrast medium injected is determined. The determination of the amount of contrast medium may use a table prepared beforehand (a table representing the relationship between the body weight and the amount of contrast medium corresponding thereto), or the contrast reference body weight (CBW) is set in a predetermined formula. What is calculated | required by substituting and calculating may be used.

  Next, the usage method of the chemical injection device of the present embodiment configured as described above will be described with a specific example. Of course, the present invention is not limited to the following specific numerical values.

  FIG. 4 is a flowchart showing an example of an injection condition setting procedure in the chemical injection device of this embodiment. As shown in the figure, patient information is first input to the controller device (step S1). Hereinafter, patient information as shown in FIG. 5 will be described as an example. In this example, patient height = 166.7 cm, weight = 91.4 kg (high weight), and gender = male.

  Next, the standard weight is calculated (step S2). Using the male formula shown in (2) above, the standard weight of this patient is determined to be 61 kg.

  Next, a basic circulating blood volume (BV) is calculated (step S3). By substituting height and weight (166.7 cm, 91.4 kg) into the formula for men shown in (3) above, BV = 5268.9 ml is obtained.

  Next, the ideal circulating blood volume (BV ′) is calculated (step S4). By substituting height and standard weight (166.7 cm, 61 kg) into the formula for male shown in (4) above, BV ′ = 4247.3 ml can be obtained.

Next, the blood volume ratio is calculated (step S5). Using the equation shown in (5) above,
Blood volume ratio = BV / BV ′ = 5268.9 / 4247.3 = 1.405
Is required.

Next, the contrast reference body weight (CBW) is calculated (step S6). Using the male formula shown in (6) above,
Contrast reference weight (CBW) = standard weight × blood volume ratio = 61 × 1.2405≈76 kg
Is required.

  When the contrast reference body weight (CBW) of the patient is obtained in this manner, the amount of contrast medium is then determined based on the contrast reference body weight of 76 kg using a conventionally known algorithm or data table (step S7). The series of steps described above determines the amount of contrast agent to be injected into the patient.

In addition, other items (for example, injection speed and injection time) of the chemical solution injection conditions can be determined using a conventionally known algorithm.
The piston drive mechanism 120 (see FIGS. 1 and 3) is driven in accordance with the medical solution injection conditions (injection speed, injection time, and injection amount) set in this manner, and a contrast medium is injected into the patient under predetermined conditions.

As described above, in the configuration of the present embodiment, the contrast reference body weight (CBW) is obtained instead of the actual body weight or lean body weight of the patient, and the amount of the contrast medium is determined based on the body weight. According to such a configuration, it is possible to set a more appropriate amount for a patient with high body weight (obesity type) or low body weight (slim type) as compared with the conventional method using lean body mass. It becomes.
In addition, according to the method of the present embodiment, the above-mentioned contrast reference weight (CBW) can be obtained only from the three pieces of information of the patient's weight, height, and sex, and the body fat is measured using a body fat scale or the like. Is also unnecessary from the viewpoint of clinical use.

  The present invention is not limited to the above. For example, in order to obtain the standard weight, a calculation formula of a method other than the BMI method may be used. Similarly, for example, the following formula (i) or (ii) may be used as a calculation formula for determining the circulating blood volume (BV).

(I) Example of blood volume calculation Basal circulating blood volume (BV) = 0.168H ³ +0.050 W + 0.444 (male)
Basal circulating blood volume (BV) = 0.250H ³ + 0.063W−0.662 (female)
Where H is height [m], W is weight [Kg]
(Ii) Other calculation examples of blood volume Basal blood volume (BV) = (0.3669 × H ³ ) + (0.032219 × W) +0.6041 (male)
Basal circulating blood volume (BV) = (0.3561 × H ³ ) + (0.03308 × W) +0.1833 (female)
Where H is height [m], W is weight [Kg]

FIG. 6 shows a weight-contrast medium amount correlation diagram based on actual body weight (FIG. 6A) and a weight-contrast medium amount correlation diagram based on contrast reference body weight (FIG. 6B). Yes. The horizontal axis represents the patient's weight [Kg], and the vertical axis represents the CT value [HU].
As shown in this figure, according to the method (FIG. 6B) for determining the amount of contrast medium based on the contrast reference body weight (CBW) as in this embodiment, the conventional method (FIG. 6A). As a result, the amount of contrast medium for high-weight patients and low-weight patients became more appropriate, and as a result, variation in CT values was suppressed for high-weight patients and low-weight patients.

[Second Embodiment]
The chemical injection device of the present invention may be configured to further perform the following processing in addition to the above steps.

(8) Calculation of bone weight As an example, this process is performed after the above-described step (S6) for calculating the contrast reference body weight (CBW).

In detail,
Performing the step of calculating the value of m% of the standard body weight as the bone weight (W),
As a step for recalculating the contrast reference weight (CBW ′), the following is performed.
That is, calculating a value obtained by subtracting the bone weight (W) from the standard body weight as a deboning weight body weight;
Calculating a value obtained by multiplying the deboning weight body weight by the ratio of BV / BV ′ as a corrected body weight;
A value obtained by adding the bone weight (W) to the corrected body weight is calculated as a contrast basic body weight (CBW ′) of the patient.

Using a specific example,
Bone weight (W) = standard body weight (about 61 kg) × 20% = 12.2 [kg]
Is calculated.

Then
Deboning weight body weight = standard body weight (about 61 kg) −bone weight (12.2 kg) = 48.8 [Kg]
Is calculated.

Then
Corrected body weight = deboned weight body weight (48.8 kg) x BV / BV 'ratio (1.2405) = 60.5 [Kg]
Is calculated.

Then
Patient contrast basic body weight (CBW ′) = corrected body weight (60.5 Kg) + bone weight (12.2 Kg) = 72.7 [Kg]
Is calculated.

  Thereafter, using the calculated contrast basic body weight (CBW ′ = 72.7 [Kg]) of the patient, the injection amount of the contrast agent and the like are determined as in the above embodiment.

  According to such a method, in addition to the formula of the first embodiment, the contrast basic body weight (CBW ′) is calculated in consideration of the bone weight, and the contrast medium amount is determined based on the calculated contrast body weight. The amount of contrast medium injected into the patient can be set to a more appropriate amount.

  Although some embodiments of the present invention have been described above, the present invention is not limited to the above. The method for determining the injection amount as described above is applicable not only when determining the injection amount of not only the contrast agent but also the anticancer agent, for example.

1 Chemical Solution Injection Device 50 Controller Device 51 Display Unit (Display)
55 Control Unit 110 Injection Head 111 Housing 114 Syringe Holding Unit 120 Piston Drive Mechanism 211 Cylinder Member 212 Piston Member A Syringe

Claims (5)

A medical device having a function of determining a contrast medium injection condition according to a patient,
Processing to determine the standard weight of the patient;
Calculating the patient's basic circulating blood volume (BV) using the patient's actual weight as a parameter;
Calculating the patient's ideal circulating blood volume (BV ′) using the patient's standard weight as a parameter;
A process for calculating a ratio between the basic circulating blood volume (BV) and the ideal circulating blood volume (BV ′);
A process of multiplying the standard weight by the ratio to calculate a contrast reference weight (CBW);
A process for determining the injection condition of the contrast agent based on the contrast reference body weight (CBW);
Is configured to do the
A medical device having a function of determining a contrast medium injection condition. further,
Calculating the bone weight of the patient;
Recalculating the contrast-based body weight (CBW ′) using the calculated bone weight as a parameter;
And
In the processing for determining the injection condition of the contrast agent, calculation is performed based on the calculated contrast reference body weight (CBW ′).
The medical device according to claim 1. (I) in the process of calculating the bone weight of the patient,
Calculate the value of m% of the standard body weight as bone weight (W),
(Ii) In the process of recalculating the contrast reference weight (CBW ′),
A value obtained by subtracting the bone weight (W) from the standard body weight is calculated as a bone removal weight body weight,
A value obtained by multiplying the deboning weight body weight by the ratio of BV / BV ′ is calculated as a corrected body weight,
A value obtained by adding the bone weight (W) to the corrected body weight is calculated as a contrast basic body weight (CBW ′) of the patient.
The medical device according to claim 2.   The medical device according to any one of claims 1 to 3, wherein an amount of the contrast medium is determined in the process of determining a contrast medium injection condition. An injection head for injecting a contrast medium into the patient;
The medical device according to any one of claims 1 to 4,
With
A medical solution injection system, wherein the medical device has a function as a controller device that controls the operation of the injection head.

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