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”技術的迷你磁場傳感器，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.

　　來自美國國家標準與技術研究院(NIST)和德國國家計量研究所的研究人員，在一項新研究中試驗了這種傳感器。盡管直到目前為止，大部分研究尚處于物理實驗室階段，但研究人員一直將臨床應用作為目標。

　　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.

　　這項新的實驗是在位于德國柏林的聯(lián)邦物理技術研究院(PTB)的一座大樓里進行的。報道稱，這座大樓具有全世界最好的磁屏蔽效果。這項實驗要求隔離地磁和其它外部場源，因為它們會對高精度的測量產(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)部還帶有一個低功率紅外激光器和光學器件，可測量低至皮特斯拉的心臟磁場信號。（即一萬億分之一特斯拉，特斯拉是磁感應強度的計量單位。）

　　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，地磁場要強一百萬倍（在百萬分之一特斯拉數(shù)量級），磁共振成像機在靜止時的磁場就要強幾百萬倍（而在工作時，可以強到幾個特斯拉）。

　　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進行的實驗中，受試者趴在床上，NIST傳感器置于左胸以上0.2英寸（5毫米）。傳感器成功探測到心跳所伴隨的微弱而規(guī)則的磁場變化。

　　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.

　　研究者同時利用磁場測量的“金標準”——超導量子干涉器件(SQUID)對心跳信號進行了記錄。兩種傳感器記錄的比較，證實NIST的迷你傳感器確實探測到了心跳，并獲得了許多典型的信號特征。

　　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中產(chǎn)生了較多的“噪聲”（干擾），但具有室溫工作的優(yōu)點。而SQUID要在攝氏-269底（華氏-452度）才能進入最佳狀態(tài)，并且需要更加復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，它們被封裝進檢測光信號的光學器件，以記錄磁場的強度。

　　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，這樣整個裝置到能方便地運送到其它實驗室。

　　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.

　　應用物理雜志的介紹的這一新結果，意味著NIST的迷你傳感器可以用來進行磁場測量，這種測量可補充或替代心電圖。

　　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正計劃繼續(xù)在PTB對這種原子磁場傳感器進行進一步測試，以確認其在醫(yī)學領域的應用潛力。

　　相關產(chǎn)品：CM-01

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