miniature magnetic sensor using a tiny cloud of atoms has successfully tracked a human heartbeat for the first time.

　　一種采用“微小原子云”技術(shù)的迷你磁場(chǎng)傳感器，第一次成功地跟蹤到了人類的心跳。

　　In a new study, researchers from the National Institute of Standards and Technology (NIST) and the German national metrology institute tried out the sensors – which until now have been operated mostly in physics laboratories – in a near-clinical setting.

　　來(lái)自美國(guó)國(guó)家標(biāo)準(zhǔn)與技術(shù)研究院(NIST)和德國(guó)國(guó)家計(jì)量研究所的研究人員，在一項(xiàng)新研究中試驗(yàn)了這種傳感器。盡管直到目前為止，大部分研究尚處于物理實(shí)驗(yàn)室階段，但研究人員一直將臨床應(yīng)用作為目標(biāo)。

　　The new experiments were carried out at the Physikalisch Technische Bundesanstalt (PTB) in Berlin, Germany, in a building described as having the world"s best magnetic shielding – necessary to block the Earth"s magnetic field and other external sources from interfering with the high-precision measurements.

　　這項(xiàng)新的實(shí)驗(yàn)是在位于德國(guó)柏林的聯(lián)邦物理技術(shù)研究院(PTB)的一座大樓里進(jìn)行的。報(bào)道稱，這座大樓具有全世界最好的磁屏蔽效果。這項(xiàng)實(shí)驗(yàn)要求隔離地磁和其它外部場(chǎng)源，因?yàn)樗鼈儠?huì)對(duì)高精度的測(cè)量產(chǎn)生干擾。

　　The NIST sensor – a tiny container of about 100 billion rubidium atoms in gas form, a low-power infrared laser, and optics – measured the heart"s magnetic signature in picoteslas (trillionths of a tesla). The tesla is the unit that defines magnetic field strength.

　　NIST的傳感器是一個(gè)裝有約1000億氣態(tài)銣原子的小型容器，其內(nèi)部還帶有一個(gè)低功率紅外激光器和光學(xué)器件，可測(cè)量低至皮特斯拉的心臟磁場(chǎng)信號(hào)。（即一萬(wàn)億分之一特斯拉，特斯拉是磁感應(yīng)強(qiáng)度的計(jì)量單位。）

　　For comparison, the Earth"s magnetic field is a million times stronger (measured in millionths of a tesla) than a heartbeat, and an MRI machine uses fields several million times stronger still (operating at several tesla).

　　相比心跳，地磁場(chǎng)要強(qiáng)一百萬(wàn)倍（在百萬(wàn)分之一特斯拉數(shù)量級(jí)），磁共振成像機(jī)在靜止時(shí)的磁場(chǎng)就要強(qiáng)幾百萬(wàn)倍（而在工作時(shí)，可以強(qiáng)到幾個(gè)特斯拉）。

　　In the experiments at PTB, the NIST sensor was placed 0.20 inches (five millimeters) above the left chest of a person lying face up on a bed. The sensor successfully detected the weak but regular magnetic pattern of the heartbeat.

　　在PTB進(jìn)行的實(shí)驗(yàn)中，受試者趴在床上，NIST傳感器置于左胸以上0.2英寸（5毫米）。傳感器成功探測(cè)到心跳所伴隨的微弱而規(guī)則的磁場(chǎng)變化。

　　The same signals were recorded using the "gold standard" for magnetic measurements, a SQUID (superconducting quantum interference device). A comparison of the signals confirmed that the NIST mini-sensor correctly measured the heartbeat and identified many typical signal features.

　　研究者同時(shí)利用磁場(chǎng)測(cè)量的“金標(biāo)準(zhǔn)”——超導(dǎo)量子干涉器件(SQUID)對(duì)心跳信號(hào)進(jìn)行了記錄。兩種傳感器記錄的比較，證實(shí)NIST的迷你傳感器確實(shí)探測(cè)到了心跳，并獲得了許多典型的信號(hào)特征。

　　The NIST mini-sensor generates more "noise" (interference) in the signal but has the advantage of operating at room temperature, whereas SQUIDs work best at –452 degrees Fahrenheit (-269 degrees Celsius) and require more complicated and expensive supporting apparatus.

　　NIST的迷你傳感器在信號(hào)中產(chǎn)生了較多的“噪聲”（干擾），但具有室溫工作的優(yōu)點(diǎn)。而SQUID要在攝氏-269底（華氏-452度）才能進(jìn)入最佳狀態(tài)，并且需要更加復(fù)雜和昂貴的支持裝置。

　　A spin-off of NIST"s miniature atomic clocks, NIST"s magnetic mini-sensors were first developed in 2004. Recently, they were packaged with fiber optics for detecting the light signals that register magnetic field strength.

　　作為NIST小型原子鐘的副產(chǎn)品，NIST的這種迷你傳感器最早研發(fā)于2004年。目前，它們被封裝進(jìn)檢測(cè)光信號(hào)的光學(xué)器件，以記錄磁場(chǎng)的強(qiáng)度。

　　In addition, the control system has been reduced in size, so the entire apparatus can be transported easily to other laboratories.

　　此外，控制系統(tǒng)的體積更小，這樣整個(gè)裝置到能方便地運(yùn)送到其它實(shí)驗(yàn)室。

　　The new results, described in the journal Applied Physics Letters, suggest that NIST mini-sensors could be used to make magnetocardiograms, a supplement or alternative to electrocardiograms.

　　應(yīng)用物理雜志的介紹的這一新結(jié)果，意味著NIST的迷你傳感器可以用來(lái)進(jìn)行磁場(chǎng)測(cè)量，這種測(cè)量可補(bǔ)充或替代心電圖。

　　Further tests of the NIST atom-based magnetic sensors at PTB are planned and could confirm the potential for more biomedical applications.

　　目前NIST正計(jì)劃繼續(xù)在PTB對(duì)這種原子磁場(chǎng)傳感器進(jìn)行進(jìn)一步測(cè)試，以確認(rèn)其在醫(yī)學(xué)領(lǐng)域的應(yīng)用潛力。

　　相關(guān)產(chǎn)品：CM-01

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