JPH021230A - Flow rate measuring catheter - Google Patents
Flow rate measuring catheterInfo
- Publication number
- JPH021230A JPH021230A JP63143364A JP14336488A JPH021230A JP H021230 A JPH021230 A JP H021230A JP 63143364 A JP63143364 A JP 63143364A JP 14336488 A JP14336488 A JP 14336488A JP H021230 A JPH021230 A JP H021230A
- Authority
- JP
- Japan
- Prior art keywords
- sensor
- catheter
- blood
- measuring
- main body
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000012530 fluid Substances 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims description 16
- 239000008280 blood Substances 0.000 abstract description 21
- 210000004369 blood Anatomy 0.000 abstract description 21
- 230000017531 blood circulation Effects 0.000 abstract description 16
- 238000005259 measurement Methods 0.000 abstract description 14
- 239000000463 material Substances 0.000 abstract description 11
- 239000011810 insulating material Substances 0.000 abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 239000000853 adhesive Substances 0.000 description 7
- 230000001070 adhesive effect Effects 0.000 description 7
- 230000000747 cardiac effect Effects 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 238000012546 transfer Methods 0.000 description 5
- 239000007788 liquid Substances 0.000 description 4
- 210000004204 blood vessel Anatomy 0.000 description 3
- 238000009529 body temperature measurement Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 238000012423 maintenance Methods 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 230000004043 responsiveness Effects 0.000 description 3
- 210000005245 right atrium Anatomy 0.000 description 3
- 210000000709 aorta Anatomy 0.000 description 2
- 238000009530 blood pressure measurement Methods 0.000 description 2
- 210000001124 body fluid Anatomy 0.000 description 2
- 239000010839 body fluid Substances 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 238000001802 infusion Methods 0.000 description 2
- 239000003978 infusion fluid Substances 0.000 description 2
- 229910010272 inorganic material Inorganic materials 0.000 description 2
- 239000011147 inorganic material Substances 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 210000001147 pulmonary artery Anatomy 0.000 description 2
- 210000005241 right ventricle Anatomy 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 230000036772 blood pressure Effects 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 210000005246 left atrium Anatomy 0.000 description 1
- 210000005240 left ventricle Anatomy 0.000 description 1
- 235000016709 nutrition Nutrition 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 210000003492 pulmonary vein Anatomy 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 230000001954 sterilising effect Effects 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 230000009469 supplementation Effects 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Landscapes
- Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
Abstract
Description
【発明の詳細な説明】
イ、産業上の利用分野
本発明は流量測定用カテーテル、特に熱希釈法に基づく
血流量測定用カテーテルに関するものである。DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a catheter for measuring flow rate, and particularly to a catheter for measuring blood flow rate based on a thermodilution method.
口、従来技術
従来、血液の流速を測定する方法としては、レーザード
プラー法、パルス変調ドプラー法、超音波ドプラー法、
ピトー管カテーテル法、ホットフィルム法等がある。ま
た、心拍出量(トータル流量)を原理的に測定できる方
法として、インピーダンス法、電磁流1計法、アドミタ
ンスプレスモグラフィー等がある。Conventional techniques Conventionally, methods for measuring blood flow velocity include laser Doppler method, pulse modulation Doppler method, ultrasound Doppler method,
There are pitot tube catheterization methods, hot film methods, etc. Further, as methods that can theoretically measure cardiac output (total flow rate), there are impedance method, electromagnetic flow one-meter method, admittance spresmography, and the like.
他方、血管径の変化や血管内の流速分布の影響を受けず
に血流量(特に心拍出量)を測定できる優れた方法とし
て、フィック(Fick)の法則を利用した熱希釈法や
色素希釈法が用いられている。On the other hand, thermodilution and dye dilution using Fick's law are excellent methods for measuring blood flow (particularly cardiac output) without being affected by changes in blood vessel diameter or intravascular flow velocity distribution. law is used.
これらの方法は、冷水塊による低温や色素による着色の
如き体外から注入された物理量が血液によって希釈され
る速度を測定し、この測定値から心拍出量を求めるもの
である。These methods measure the rate at which a physical quantity injected from outside the body, such as the low temperature caused by a cold water mass or the coloring caused by a dye, is diluted by blood, and the cardiac output is determined from this measured value.
熱希釈法によれば、第7図のように、大静脈1を通して
カテーテル2を心臓3の右心房4、更には右心室5を経
て肺動脈6にまで導き、右心房4内へ冷水7を注入し、
先端付近のセンサ(通常はサーミスタ)8によって血液
の温度変化を測定する。即ち、冷水7による低温状態か
ら血流により回復する様子をサーミスタ8により抵抗変
化として測定する。なお、図中の9は左心房、10は左
心室、11は肺静脈、12は大動脈である。カテ−チル
2は、第7図、第8図、第9図及び第10図に示すよう
に、その本体13には冷水注入用の側孔14をはじめ、
サーミスタ8、バルーン16、バルーン16への送気・
排気用の側孔31が夫々設けられ、かつこれらに対応し
て冷水供給用のルーメン(図示せず)、サーミスタ8の
配線34用のルーメン18、圧力測定用のルーメン19
、バルーン16への空気送り込み用のルーメン20、更
には上流側の血圧測定用の第2の圧力測定用のルーメン
(図示せず)が夫々形成されたものである。According to the thermodilution method, as shown in FIG. 7, a catheter 2 is guided through the vena cava 1 to the right atrium 4 of the heart 3, further through the right ventricle 5 to the pulmonary artery 6, and cold water 7 is injected into the right atrium 4. death,
A sensor (usually a thermistor) 8 near the tip measures blood temperature changes. That is, the recovery from the low temperature state caused by the cold water 7 due to the blood flow is measured by the thermistor 8 as a change in resistance. In the figure, 9 is the left atrium, 10 is the left ventricle, 11 is the pulmonary vein, and 12 is the aorta. As shown in FIGS. 7, 8, 9, and 10, the catheter 2 has a main body 13 including a side hole 14 for injecting cold water.
Thermistor 8, balloon 16, air supply to balloon 16
Side holes 31 for exhaust are provided, and correspondingly a lumen (not shown) for supplying cold water, a lumen 18 for wiring 34 of the thermistor 8, and a lumen 19 for pressure measurement.
, a lumen 20 for feeding air into the balloon 16, and a second pressure measurement lumen (not shown) for measuring blood pressure on the upstream side.
そして、第9図の如くにカテーテル2を挿入(通常は経
皮挿入)して血流に乗せるに際し、バルーン16を膨ら
ませて(第10図では一点鎖線のように)カテーテル2
を運ぶ。Then, as shown in FIG. 9, when inserting the catheter 2 (usually by percutaneous insertion) and placing it in the bloodstream, the balloon 16 is inflated (as shown by the dashed line in FIG. 10).
carry.
生体内に挿入されたカテーテル2に対し、名コネクタ3
3.35.36を介して夫々、血流量演算表示装置37
、バルーン拡張・収縮用のシリンジ41、輸液ボトル4
2(注射筒43及び除菌フィルタ44が付属)が接続さ
れている。血流量演算表示装置37には、血流量針47
や条件設定キー46等が設けられている。上記に使用す
る注入液7は所定温度に冷却されて注入されるが、その
種類として患者の体液維持に用いられる維持液、又は栄
養補給のための輸液を使用するのが望ましい。即ち、そ
うした維持液又は輸液を用いることにより、血流量の測
定と同時に維持液等の補給も行え、非常に効率的であり
、体液のバランスを失うことなしに熱希釈法の実施に必
要な注入液を供給できる。Connector 3 to catheter 2 inserted into the living body
3, 35, and 36 respectively, the blood flow rate calculation display device 37
, syringe 41 for balloon expansion/deflation, infusion bottle 4
2 (includes syringe barrel 43 and sterilization filter 44) is connected. The blood flow calculation display device 37 includes a blood flow needle 47.
, a condition setting key 46, etc. are provided. The injection liquid 7 used above is cooled to a predetermined temperature and then injected, and it is preferable to use a maintenance liquid used for maintaining body fluids of a patient or an infusion liquid for nutritional supplementation. In other words, by using such maintenance fluids or infusions, it is possible to replenish maintenance fluids, etc. at the same time as measuring blood flow, which is very efficient and allows for the injection necessary for thermodilution without losing the balance of body fluids. liquid can be supplied.
上記において、センサ8によって得られた血液の温度変
化を下記式(1)により心拍出量に換算する。In the above, the blood temperature change obtained by the sensor 8 is converted into cardiac output using the following equation (1).
〔但し、vb
i
b
i
b
b
i
心拍出量(血液流量)
注入された冷水の量(ml)
血液の冷水注入前の温度(°C)
注入された冷水の温度 (°C)
血液の比熱
血液の比重
注入水の比熱
Si:注入水の比重
L 二時間(秒)
ΔTb:血液の温度変化
この場合、血流量の測定において第9図に示すフローに
沿って信号が処理される。即ち、カテーテル2への注入
液の温度を測定する測温部21の測定値をA/D変換器
26へ入れてデジタル化すると共に、カテーテル2のサ
ーミスタ8で血液温度を電気抵抗変化として検出し、こ
れをブリッジ回路23で電流信号として取出して地中回
路24で増巾し、更に経時的なドリフトを補償する自動
ゼロ調整回路25を経て上記A/D変換器26へ入力さ
れる。そして、A/D変換器26の出力は中央演算ユニ
ッ) (CPU)45で処理され、血流量が表示装置3
7で表示され、更にはプリンタ27で記録される。[However, vb i b i b b i Cardiac output (blood flow rate) Amount of injected cold water (ml) Temperature of blood before cold water injection (°C) Temperature of injected cold water (°C) Blood Specific heat of blood Specific gravity of injected water Specific heat Si: Specific gravity of injected water L 2 hours (seconds) ΔTb: Temperature change of blood In this case, signals are processed according to the flow shown in FIG. 9 in measuring blood flow. That is, the measured value of the temperature measurement unit 21 that measures the temperature of the liquid injected into the catheter 2 is input to the A/D converter 26 and digitized, and the thermistor 8 of the catheter 2 detects the blood temperature as a change in electrical resistance. This signal is extracted as a current signal by a bridge circuit 23, amplified by an underground circuit 24, and further inputted to the A/D converter 26 through an automatic zero adjustment circuit 25 that compensates for drift over time. The output of the A/D converter 26 is processed by a central processing unit (CPU) 45, and the blood flow rate is displayed on the display 3.
7 and is further recorded by the printer 27.
ところで、上記のカテーテル2においては、測温部28
を構成するセンサ8が第9図、第10図に示すようにカ
テーテル本体13に直接接触した状態で接着剤29で固
定された構造になっているために、これらと外部を流れ
る血液との間の熱伝導(即ち、血液からセンサ8への伝
熱は、本体13及び接着剤29を介して伝導されること
)によってセンサ8による測温が行われることになる。By the way, in the above catheter 2, the temperature measuring section 28
As shown in FIGS. 9 and 10, the sensor 8 constituting the catheter body 13 is fixed with an adhesive 29 in direct contact with the catheter body 13, so that there is a gap between the sensor 8 and the blood flowing outside. Temperature measurement by the sensor 8 is performed by heat conduction (that is, heat is transferred from the blood to the sensor 8 via the main body 13 and the adhesive 29).
しかし、本体13及び接着剤を介しての伝熱では、伝熱
量の一部が本体13及び接着剤29を加温又は冷却する
のに使われてしまい、結果として伝熱速度が低下してし
まうので、サーミスタからなるセンサ8が所定の温度を
検知するまでに要する応答時間が長くなる。即ち、セン
サ8が応答し難い構造であるため、例えば第3図(B)
に示す如くに温度L1に達するまでの時間Tが1.0〜
2.0秒と長くなってしまう(ここで、最高温度t、I
を1.0としたとき、温度が0から(1−4−)に達す
る迄の時間をTとする)。However, in heat transfer via the main body 13 and the adhesive, a portion of the heat transfer amount is used to heat or cool the main body 13 and the adhesive 29, resulting in a reduction in the heat transfer rate. Therefore, the response time required until the sensor 8 consisting of a thermistor detects a predetermined temperature becomes longer. That is, since the sensor 8 has a structure that makes it difficult to respond, for example, as shown in FIG.
As shown in the figure, the time T required to reach the temperature L1 is 1.0~
It takes a long time of 2.0 seconds (here, the maximum temperature t, I
When 1.0, let T be the time it takes for the temperature to reach from 0 to (1-4-)).
従って、センサ8の応答性が悪いため、作動中の温度変
化は第4図(B)のように、真の血液温度に対しセンサ
8による温度出力(検出温度情報)は大きくずれてしま
い、毎拍動毎(60bρmならば1秒毎)に温度が変化
する血管内の温度測定は大きな誤差を含む結果しか得ら
れない。換言すれば、第4図(日)に示した温度出力を
積分し、上述のフィックの法則に基づいて血流量を算出
しても、これは真の血:4を量からかなり誤差の大きな
ものとなってしまう。この傾向は、特に心拍数が増える
に伴って著しくなる。Therefore, due to the poor responsiveness of the sensor 8, the temperature output (detected temperature information) by the sensor 8 deviates greatly from the true blood temperature, as shown in Figure 4 (B), and the temperature changes during operation. Measuring the temperature inside a blood vessel, where the temperature changes every beat (every second for 60 bρm), can only yield results that include large errors. In other words, even if we integrate the temperature output shown in Figure 4 (Sunday) and calculate the blood flow volume based on Fick's law mentioned above, this is true blood: 4. There is a considerable error from the amount. It becomes. This tendency becomes particularly noticeable as the heart rate increases.
ハ0発明の目的
本発明の目的は、測定誤差を大きく減らし、正確な測定
を可能にする流量測定用カテーテルを提供することにあ
る。OBJECTS OF THE INVENTION An object of the present invention is to provide a flow rate measuring catheter that greatly reduces measurement errors and enables accurate measurements.
二0発明の構成
即ち、本発明は、熱希釈法による流体の流量測定に用い
るカテーテルにおいて、前記流体の温度を測定するため
の測温部がカテーテル本体とは実質的に断熱された状態
で設けられていることを特徴とする流量測定用カテーテ
ルに係るものである。20 Structure of the Invention That is, the present invention provides a catheter used for measuring the flow rate of a fluid by a thermodilution method, in which a temperature measuring section for measuring the temperature of the fluid is provided in a state substantially insulated from the catheter body. The present invention relates to a flow rate measuring catheter characterized in that:
ホ、実施例 以下、本発明の詳細な説明する。E, Example The present invention will be explained in detail below.
第1図〜第2図は、本発明の第1の実施例による熱希釈
法に基づく血流量測定用カテーテル22を示すものであ
る。但し、第7図〜第10図で述べた部分と共通の部分
には共通符号を付し、その説明を省略することがある。1 and 2 show a blood flow measurement catheter 22 based on a thermodilution method according to a first embodiment of the present invention. However, parts common to those described in FIGS. 7 to 10 are given common reference numerals, and their explanations may be omitted.
このカテーテル22は、既述した従来のカテーテル2と
は根本的に異なり、特に血流量測定のためのセンサ(即
ち、サーミスタ)8をカテーテル本体13とは実質的に
断熱された状態で設けていることが特徴的である。This catheter 22 is fundamentally different from the conventional catheter 2 described above, in that a sensor (i.e., a thermistor) 8 for measuring blood flow is provided in a state substantially insulated from the catheter body 13. This is characteristic.
即ち、本体13の所定箇所にてその外周にリング状凹部
50を形成し、この凹部内に多孔質の断熱材51 (例
えば高分子材料、無機材料を用いた発泡体など)を充填
し、サーミスタからなるセンサ8を断熱材51に固定し
ている。サーミスタ8からは既述した測定回路系へ導か
れる配線34が延びている。なお、サーミスタ8は実線
のように血液側に露出していてもよいが、仮想線で示す
如くに非断熱性のカバー材53(例えばステンレス鋼板
など)をサーミスタの近傍に被着すると伝熱性を良好に
しながら周面を平坦化できる効果もある。That is, a ring-shaped recess 50 is formed on the outer periphery of the main body 13 at a predetermined location, and a porous heat insulating material 51 (for example, a foam made of a polymeric material or an inorganic material) is filled into the recess, and a thermistor is installed. A sensor 8 consisting of the following is fixed to a heat insulating material 51. A wiring 34 extending from the thermistor 8 leads to the measurement circuit system described above. The thermistor 8 may be exposed to the blood side as shown by the solid line, but if a non-insulating cover material 53 (for example, a stainless steel plate) is attached near the thermistor as shown by the imaginary line, the heat conductivity can be improved. It also has the effect of flattening the circumferential surface while keeping it in good condition.
上記のように、本実施例の構造によれば、センサ8(従
って血液の測温部28)は、断熱材51によってカテー
テル本体13とは実質的に断熱された状態で固定されて
いるため、測定時にセンサ8と血液との間の熱伝達はも
はやカテーテル本体13を介しては行われず、直接的に
血液との間で、又はカバー材53を介して行われること
になる(これは、血液による加熱、冷却のいずれの場合
にも行われる)。この結果、センサ8が血液の温度変化
に迅速に応答してその変化を検出できることになるから
、いわば測温時の熱的時定数が小さくなり、例えば第3
図(A)のように所定温度に達する迄の時間Tが0.2
〜1 、0secと著しく短くなる。これは、サーミス
タ単体の熱的時定数が0.05〜0.5sec位である
ことを考慮すれば、この時定数に近いか若しくは同じで
あることを意味し、測定の精度が向上する。As described above, according to the structure of this embodiment, the sensor 8 (therefore, the blood temperature measuring section 28) is fixed in a substantially insulated state from the catheter body 13 by the heat insulating material 51. During measurements, the heat transfer between the sensor 8 and the blood no longer takes place via the catheter body 13, but directly with the blood or via the covering material 53 (this (This is done for both heating and cooling). As a result, the sensor 8 can quickly respond to and detect changes in blood temperature, so that the thermal time constant during temperature measurement becomes smaller, for example,
As shown in Figure (A), the time T required to reach the predetermined temperature is 0.2
~1,0 sec, which is significantly shorter. Considering that the thermal time constant of a single thermistor is approximately 0.05 to 0.5 seconds, this means that the time constant is close to or equal to this time constant, and the measurement accuracy is improved.
即ち、センサ8の応答速度が早いために、第4図(A)
のように、その温度出力は真の血液温度にほぼ追随した
誤差の著しく少ないものとなる。That is, since the response speed of the sensor 8 is fast, as shown in FIG.
As such, the temperature output approximately tracks the true blood temperature with significantly less error.
これは特に、心拍数が増える場合に顕著となり、第5図
に示すように、従来例では心拍数に応じて測定誤差が大
となっているのに対し、本発明に基づくカテーテルの使
用によって測定誤差が小さくなる上に誤差の分布範囲も
小さくなることが分かった。This becomes especially noticeable when the heart rate increases, and as shown in Figure 5, while in the conventional case the measurement error increases depending on the heart rate, the measurement error using the catheter based on the present invention increases the measurement error. It was found that not only the error becomes smaller, but also the error distribution range becomes smaller.
なお、本実施例においては、上記した金属板53に対す
るセンサ8の固定域の接触面積も小さい(即ち、固定に
接着剤を用いてもその使用量が少ない)ために、接着剤
による測定への影響は全くない。In this example, since the contact area of the fixed area of the sensor 8 with the metal plate 53 described above is small (that is, even if adhesive is used for fixing, the amount of adhesive used is small), so it is difficult to measure using adhesive. There is no effect at all.
第6図は、本発明の他の実施例を示すものである。FIG. 6 shows another embodiment of the invention.
この例によれば、第1図の例とは異なり、断熱材51を
充填せずに同領域を空洞54(即ち、空気のみ)とし、
カバー材53の周辺だけでカテーテル本体13と接着し
ている。この例でも、やはり熱応答性が良くなり、測定
誤差が少なくなる上に、センサ8をカバー材53を介し
て取り付は可能であってその取り付けが容易である。According to this example, unlike the example shown in FIG.
Only the periphery of the cover material 53 is bonded to the catheter body 13. In this example as well, the thermal response is improved, measurement errors are reduced, and the sensor 8 can be attached via the cover material 53, making the attachment easy.
以上、本発明を例示したが、上述の例は本発明の技術的
思想に基づいて更に変形が可能である。Although the present invention has been illustrated above, the above-mentioned example can be further modified based on the technical idea of the present invention.
例えば、上述の測温部の構造は種々変更してよく、セン
サ8をカバー材53に設けた開口(図示せず)に嵌め込
み固定してよい。断熱材51や金属板53の設ける領域
は上述の例のようにセンサ8の存在領域及びこの近傍の
みならず、カテーテル本体の外周面の全周に設けてもよ
い。金属板53の取り付けは嵌め込みによってよいし、
接着によってもよい。For example, the structure of the temperature measuring section described above may be modified in various ways, and the sensor 8 may be fitted and fixed into an opening (not shown) provided in the cover material 53. The area where the heat insulating material 51 and the metal plate 53 are provided is not limited to the area where the sensor 8 exists and its vicinity as in the above example, but may be provided all around the outer peripheral surface of the catheter body. The metal plate 53 may be attached by fitting,
Adhesion may also be used.
金属板53自体は、センサ8の熱的応答性を助長するた
めに熱伝導率の良い材質であることが望ましく、ステン
レス鋼(例えばS U 3304.316.316L)
以外にも、金、銀、白金等が挙げられる。The metal plate 53 itself is preferably made of a material with good thermal conductivity in order to promote the thermal responsiveness of the sensor 8, and is preferably made of stainless steel (for example, S U 3304.316.316L).
Other examples include gold, silver, platinum, etc.
断熱材51として他に、高分子材料、無機材料の発泡体
が使用できる。また、センサ8もサーミスタ以外に熱電
対を使用することができる。上述の金属板53は場合に
よっては使用しなくてもよい。In addition to the heat insulating material 51, a foam made of a polymeric material or an inorganic material can be used. Further, the sensor 8 can also use a thermocouple instead of a thermistor. The metal plate 53 described above may not be used depending on the case.
また、カテーテルの各部分の種類、サイズ、構造、材質
等は種々変更できる。Further, the type, size, structure, material, etc. of each part of the catheter can be changed in various ways.
なお、本発明のカテーテルは、上述の如くに心臓に挿入
するだけでなく、他の部位にも適用可能である。Note that the catheter of the present invention is not only inserted into the heart as described above, but can also be applied to other sites.
へ1発明の作用効果
本発明は上述した如く、血液等の流体の測温部がカテー
テル本体とは実質的に断熱された状態で設けられている
ため、測定時に測温部と流体との間の熱伝導はもはやカ
テーテル本体を介しては行われず、効率的に流体との間
で行われることになる。この結果、流体の温度変化に迅
速に応答してその変化を検出できることになるから、誤
差を少なくして正確に流量を測定することができる。1. Effects of the Invention As described above, the temperature measuring part of the fluid such as blood is provided in a state that is substantially insulated from the catheter body, so that there is no temperature difference between the temperature measuring part and the fluid during measurement. Heat transfer will no longer take place through the catheter body, but will take place effectively with the fluid. As a result, it is possible to quickly respond to and detect changes in the temperature of the fluid, thereby reducing errors and accurately measuring the flow rate.
第1図〜第6図は本発明の実施例を示すものであって、
第1図はカテーテルの主要部の拡大断面図、第2図は第
1図の■−■線断面図、
第3図は熱的応答性を比較して示すグラフ、第4図は温
度出力を比較して示すグラフ、第5図は心拍数による測
定誤差を比較して示すグラフ、
第6図は他の例によるカテーテルの第1図と同様の断面
図
である。
第7図〜第10図は従来例を示すものであって、第7図
は血流量測定時のカテーテル挿入状態を示す概略断面図
、
第8図はカテーテルの概略正面図、
第9図は血管内でのカテーテルを回路系と共に示す第8
図のIX−IX線拡大断面図、第10図は第8図のX−
X線拡大断面図である。
なお、図面に示す符号において、
1・・・・・・・・・大動脈
2.22・・・・・・・・・カテーテル4・・・・・・
・・・右心房
5・・・・・・・・・右心室
6・・・・・・・・・肺動脈
7・・・・・・・・・注入液
8・・・・・・・・・センサ(サーミスタ)13・・・
・・・・・・カテーテル本体28・・・・・・・・・測
温部
34・・・・・・・・・配線
50・・・・・・・・・凹部
51・・・・・・・・・断熱材
53・・・・・・・・・カバー材
である。1 to 6 show embodiments of the present invention, in which FIG. 1 is an enlarged sectional view of the main part of the catheter, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. Figure 4 is a graph comparing thermal responsiveness, Figure 4 is a graph comparing temperature output, Figure 5 is a graph comparing measurement errors due to heart rate, and Figure 6 is based on another example. FIG. 2 is a cross-sectional view similar to FIG. 1 of the catheter. 7 to 10 show conventional examples, in which FIG. 7 is a schematic sectional view showing the state of catheter insertion during blood flow measurement, FIG. 8 is a schematic front view of the catheter, and FIG. 9 is a blood vessel. No. 8 showing the catheter with its circuitry within the
Figure 10 is an enlarged sectional view taken along the line IX-IX in Figure 8.
It is an X-ray enlarged sectional view. In addition, in the symbols shown in the drawings, 1...Aorta 2.22...Catheter 4...
・・・Right atrium 5・・・・・・Right ventricle 6・・・・・・Pulmonary artery 7・・・・・・Infusion fluid 8・・・・・・・・・Sensor (thermistor) 13...
... Catheter body 28 ... Temperature measuring part 34 ... Wiring 50 ... Recessed part 51 ... . . . Insulating material 53 . . . Covering material.
Claims (1)
において、前記流体の温度を測定するための測温部がカ
テーテル本体とは実質的に断熱された状態で設けられて
いることを特徴とする流量測定用カテーテル。1. A catheter used for measuring the flow rate of a fluid by a thermodilution method, characterized in that a temperature measuring section for measuring the temperature of the fluid is provided in a state substantially insulated from the catheter body. Measuring catheter.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63143364A JPH021230A (en) | 1988-06-10 | 1988-06-10 | Flow rate measuring catheter |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63143364A JPH021230A (en) | 1988-06-10 | 1988-06-10 | Flow rate measuring catheter |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH021230A true JPH021230A (en) | 1990-01-05 |
JPH0533623B2 JPH0533623B2 (en) | 1993-05-20 |
Family
ID=15337068
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP63143364A Granted JPH021230A (en) | 1988-06-10 | 1988-06-10 | Flow rate measuring catheter |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH021230A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09215666A (en) * | 1996-02-09 | 1997-08-19 | Terumo Corp | Sensor probe for measuring flow velocity |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3040506U (en) * | 1997-02-13 | 1997-08-26 | 英一 鈴木 | Conduit that makes it easy to pull in electric wires |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62207435A (en) * | 1986-03-07 | 1987-09-11 | テルモ株式会社 | Catheter for measuring cardiac output |
-
1988
- 1988-06-10 JP JP63143364A patent/JPH021230A/en active Granted
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62207435A (en) * | 1986-03-07 | 1987-09-11 | テルモ株式会社 | Catheter for measuring cardiac output |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09215666A (en) * | 1996-02-09 | 1997-08-19 | Terumo Corp | Sensor probe for measuring flow velocity |
Also Published As
Publication number | Publication date |
---|---|
JPH0533623B2 (en) | 1993-05-20 |
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