血管撮影装置からの x 線（閾値）に起因するペースメーカー...

－ 9－

秋葉・中村・中谷・吉川：血管撮影装置からの X 線（閾値）に起因するペースメーカー誤作動

X

3 DDD

2

2

, , ,

, alert period 1

0.41 0.57mGy/0.01sec X-ray

1

1958

“

”

implantable cardioverter-defibrillator : ICD

40

QOL

1

electromagnetic interference : EMI

2005

X CT

2,3

1125001 X CT

3)

1,4 10)

X ICD

2

X

1,4 10)

血管撮影装置からの X線（閾値）に起因するペースメーカー誤作動

（平成 21年 10月 8日　受付）

秋葉　憲彦 1)，　中村　修 2)，　中谷　儀一郎 2)，　吉川　宏起 3)

1) 国立病院機構　東京医療センター放射線科2) 日本医療科学大学 保健医療学部3) 駒澤大学 医療健康科学部

－ 10－

駒澤大学医療健康科学部紀要　第 7号（2010）

C-MOS

X 53

3

DAR-3000 ST.

JUDE. MEDECAL AFFIRMITY DR S/N 328983

S/N 423536, S/N 454458 3

source to surface distance: SSD

70cm

,

entrance surface dose: ESD

UNIDOS Type-App. Nr.10005-50268, TN 30001-2462

0.6cc Fig. 1

DDD , blanking period, noise

sampling period alert period

60ppm pacing Heart simulator

70ppm inhibition

.

event histogram heart rate

histogram, percent of total time

3

76kV, 250mA, 0.01sec,

7.5FPS/sec, 10sec , 130kV, 500mA

0.1s, 7.5FPS/sec, 5sec X

A-P P-A

(pacing )

inhibition

Fig. 1 Geometric Figure of ESD using Chamber.

Pacemaker

B e d

SSD

I . I

Phantom

X-ray tube

－ 11－

秋葉・中村・中谷・吉川：血管撮影装置からの X 線（閾値）に起因するペースメーカー誤作動

r

3.1

X

60sec

mA, kV

(mGy/60sec) ,

,

3.2 Sensitivity

A-P sensitivity

0.5 2.5mV

160 200 250 320 400 500mA

60 120kV 1kV

sensitivity

sensitivity

3.3

A-P 60 120kV

0.04sec 7.5 FPS 5sec

sensitivity SSD50cm

1 2

X 1

160 200 250 320 400

Measurement ResultsStandard Exposure 76kV, 250mA, 0.01sec, 7.5frame / sec,10 sec

Pacing A:A pacing, V:V pacing

1.0 Sec Inhibition P:P wave, R:R wave

1.0 Sec

Fig. 2 Mesurement Results of Standard Exposure 76 kV, 250 mA, 0.01 sec, 7.5 frame/sec, 10 sec

No influence is found during pacing time and inhibitory time on ICPs at the standard and maximum exposure conditions(anterior

posterior exposure direction). Left arrow indicates the starting time of X-ray exposure, and the right arrow indicates the ending time.

－ 12－

駒澤大学医療健康科学部紀要　第 7号（2010）

500mA 60kV 1kV

1

0.04 0.08 0.1sec

2 FPS

FPS 1 1FPS

1 /sec 7.5FPS 7.5 /sec X

FPS 1 3 5 7.5 FPS

FPS

4

Fig. 2 76kV, 250mA, 0.01sec,

7.5FPS/sec, 10sec

1.0sec X

X

A V

X

P

R PM

3

, A-P, P-A

, P-A

,

, ,

Fig. 3 130kV, 500mA 0.1s, 7.5FPS/sec,

5sec

X , V R ,

A-V P-V X

,

4.2 Sec

Measurement Results Maximum Exposure 120kV, 500mA, 0.1sec, 7.5frame / sec,5.0 sec

Pacing A:A pacing, V:V pacing, P:P wave, R:R wave

Fig. 3 Mesurement Results of Maximum Exposure at the Pacing Period 120 kV, 500 mA, 0.1 sec, 7.5 frame/sec, 5 sec

The figure shows the pacing map at the maximum exposure condition A P exposure direction . The marker shows that R takes

the place of V and P-V changes to A-V soon after. Over sensing of the ICP is started by receiving the noises other than its basic

event and the pacing function is interrupted. The interruption period continues for 4.2 seconds.

－ 13－

秋葉・中村・中谷・吉川：血管撮影装置からの X 線（閾値）に起因するペースメーカー誤作動

4.2 Sec

4.2sec 181.5mGy X

1)

2

Fig. 4 ,

X , R ,P-R A-V

,

5.2sec 182.4mGy

X 0.2sec

X 11

2

Measurement Results Maximum Exposure 120kV, 500mA, 0.1sec, 7.5frame / sec,5.0 sec

Pacing A:A pacing, V:V pacing, P:P wave, R:R wave 5.2Sec

Fig. Mesurement Results of Maximum Exposure at the Inhibitory Period 120 kV, 500 mA, 0.1

sec, 7.5 frame/sec, 5 sec

The marker shows that R to appear and then P-R changes to A-V at the maximum exposure condition A-P

exposure direction . The interruption time is 5.2 seconds. It is indicated that the pacing from atrium to ventricle

occurs in spite of inhibitory period.

Sensitivity

Fig.5 Exposure Conditions Introduced Over Sensing of ICPs with Different Sensitivities (kV mA

－ 14－

駒澤大学医療健康科学部紀要　第 7号（2010）

4.1

4

182.4mGy/5sec 60sec

kV mA

182.4mGy/60sec

.

4.2 Sensitivity

Fig. 5 sensitivity

Sensitivity 0.5, 1.0,

1.5,2.0 ,

Sensitivity2.5

sensitivity

sensitivity

sensitivity

Fig. 6 Exposure Conditions Introduced Over Sensing of ICPs(kV mA

Fig. 7 Threshold of X-ray Dose Rate Introduced Oversensing of ICPs mGy/0.01sec

－ 15－

秋葉・中村・中谷・吉川：血管撮影装置からの X 線（閾値）に起因するペースメーカー誤作動

5sec

5sec

3sec

5.2sec

1.0 Second

Fig. 8 Oversensing of ICPs at Different FPS frame per second

－ 16－

駒澤大学医療健康科学部紀要　第 7号（2010）

4.3

4.2

FPS

1

Fig. 6 0.04 0.08 0.1sec

500mA,58kV

400 A 64kV 320mA 67kV 250mA 74kV

200mA 80kV 160mA 86kV

kV

, Fig.

6 Fig. 7

mGy/0.01sec

80msec 250mA 80kV 0.41mGy/0.01sec

40msec 400mA,64kV

0.52mGy/0.01sec 0.11mGy/0.01sec

2 FPS

Fig. 8 FPS

FPS 1 3 5 7.5 FPS

FPS X , A-V

P-V X

FPS

11) 2

1FPS 0.96sec

blanking period , sampling period

0.125sec1) Fig. 8 alert period

FPS

Fig. 9 Exposure Conditions kV mA and Dose Rate mGy/0.01sec Introduced Oversensing of ICPs at

Different FPS.

－ 17－

秋葉・中村・中谷・吉川：血管撮影装置からの X 線（閾値）に起因するペースメーカー誤作動

Fig. 9 FPS

FPS

Fig

7

mGy/0.01sec 1FPS 0.57

0.69mGy/0.01sec 3FPS 0.46 0.57mGy/0.01sec

5FPS 0.46 0.56mGy/0.01sec 7.5FPS 0.43

0.52mGy/0.01sec 1FPS

5

IC C-Metal-Oxide-Semiconductor(

C-MOS C-MOS

X

X PN

PN

X

1,4 10)

CT 360

X

7)

X X

Fig. 4 5sec 5.2sec

X

0.04 0.08 0.1sec

Fig. 7 FPS 1 3 5

7.5 FPS

Fig. 9

FPS

X

FPS

60ppm

0.01sec 0.99sec

X

1FPS

0.57 0.69mGy/0.01sec FPS

msec 0.41

0.57mGy/0.01sec

1FPS FPS 3 5 7.5 FPS

X C-MOS

6

X

P-A

X

A-P X

3

11) 2

－ 18－

駒澤大学医療健康科学部紀要　第 7号（2010）

FPS

sec

1sec X

0.41 0.69mGy/0.01sec

X 1 alert period

1 60ppm 1sec

1sec

1,4 10

X kV mA

C-MOS 1

X

X

X 5sec 3

7.

1

2007 11-19

2

X CT 3

2005(http://www.medtronic.co.jp).

3 X CT

1125001

2005 11.25.

4

X

2008 64 3 335-341

5

X

2008 64 7 795-804

6

X 2008 64 7

805-813

7

15(1),32-35, (2007)

8 Blamires NG,Myatt J. X-ray effects on pacemaker type

circuits. Pacing Clin Electrophysiol 1982;5(2):151-155.

9 Yamaji S, Imai S, Saito F. Does high-power computed

tomography scanning equipment affect the operation of

pacemakers? Circ J 2006;70(2):190-197.

10 Lewis M. Radiation dose issues in multi-slice CT s

ccaning. Impact technology up dateno.3,2005.(http://www.i

mpactscan.org/).

11

(http://www.soumu.go.jp/s-news/2002/020702_3_1.html).

－ 19－

秋葉・中村・中谷・吉川：血管撮影装置からの X 線（閾値）に起因するペースメーカー誤作動

Malfunction of the implantable cardiac pacemakers influenced by X-ray irradiation of over the threshold from the angiography equipment

Norihiko Akiba* Osamu Nakamura** Giichiro Nakaya** Kohki Yoshikawa ***

* Department of Radiology , National Hospital Organization Tokyo Medical Center

** Faculty of Health Science , Nihon Institute of Medical Science

*** Graduate Division of Health Sciences , Komazawa University

Abstract

This study performed experimental studies of the X-ray influence on implantable cardiac pacemakers (ICPs) from the angiography

equipment. Three ICPSs pacing in DDD mode were used exerimentalily in the angiographic study. Those ICPs were irradiated under

two exposure levels; one was the standard dose and the other was the maximum dose of the angiography equipment. The results showed

that the influence of irradiation on the ICPs was that of level 2 as classified by a research report from the Ministry of Internal Affairs and

Communications only when the maximum dose level was irradiated. In the following study, the conditions inducing over sensing of

ICPs in the angiography equipment were searched. In this study the influences of ICPs by the tube voltage, tube current, exposure time,

exposure period of X-ray by the angiography equipment were evaluated. The results showed that the over sensing of the ICPs were

determined mainly by the tube voltage and tube current. Interruptions were happened by lower tube voltage at the higher tube current

exposure and by the higher tube voltage at the lower tube current exposure. In conclusions, over sensing of the ICPs could be caused

regardless exposure time and exposure period when the only one pulse of X-ray over the threshold of 0.41 0.57mGy /0.01sec was

exposed in the alert period between the pacing events or sensing events.

Keywords:

over sensing, pacemaker, irradiation dose, alert period, exposure time exposure period