An artificial nose may be able to detect Parkinson’s disease early

一種人工鼻子或許能一早嗅出帕金森病

The inspiration came from the strange case of a retired nurse

靈感來自一位退休護(hù)士的奇特本領(lǐng)【新知】

?PARKINSON’S DISEASE is a progressive neurological disorder caused by the deaths of neurons in parts of the brain called the substantia nigra. Symptoms include loss of motor control, mood disturbance, ruined sleep and altered sense of smell. It is incurable. Early medical intervention can, however, relieve these symptoms and prolong survival. That makes prompt diagnosis desirable.

帕金森病是一種因腦內(nèi)黑質(zhì)區(qū)域中神經(jīng)元的死亡引起的進(jìn)行性神經(jīng)失調(diào)。其癥狀包括運動控制喪失、情緒紊亂、睡眠障礙和嗅覺改變。它無法治愈。但是盡早施加醫(yī)療干預(yù)可以緩解癥狀，延長生存期。這就使得及早確診很有益處。

Unfortunately, the initial signs of Parkinson’s vary from person to person and there is no specific test at this early stage which can reliably distinguish it from other brain illnesses. It therefore often goes undetected until clear and characteristic manifestations, such as tremors and slowed body movement, appear. But that may soon change. A study published in ACS Omega, by Chen Xing and Liu Jun at Zhejiang University, in China, describes an invention which may be able to detect Parkinson’s before the onset of tremulousness. The device in question is an artificially intelligent electronic nose.

不幸的是，帕金森病的最初癥狀因人而異，在發(fā)病的早期階段，還沒有哪種專門檢測能可靠地將它和其他腦部疾病區(qū)分開來。因此它經(jīng)常要等到出現(xiàn)明顯且典型的臨床表現(xiàn)，如顫抖和身體動作遲緩，才會被確診。但這種情況可能很快就會改變了。浙江大學(xué)的陳星和劉軍發(fā)表在《ACS Omega》期刊上的研究介紹了一項發(fā)明，或許能在震顫的癥狀出現(xiàn)前就檢測出帕金森病。這款設(shè)備是一個人工智能電子鼻。

A whiff of trouble

一絲麻煩的氣息

The quest the two researchers embarked on to build this nose began in 2019. That was when they heard reports of Joy Milne, a retired nurse living in Scotland, who could detect people with Parkinson’s from a distinctive odour they emitted—distinctive to her, at least, though for reasons still obscure, undetectable by others.

兩位研究人員制造這個電子鼻的探索始于2019年。當(dāng)時他們聽到有報道稱，住在蘇格蘭的退休護(hù)士喬伊·米爾恩（Joy Milne）能聞到帕金森患者散發(fā)出的一種特殊氣味，從而發(fā)現(xiàn)患病者。這種氣味至少對她來說是特殊的，不過其他人無法察覺，原因不明。

Mrs Milne first noticed this odour when her husband developed the illness. She made the general connection later, when she smelled it at sufferers’ support groups attended by her spouse. Tests using clothes worn by patients confirmed her ability. She even noted one seemingly healthy individual as having the disease months before other symptoms developed.

米爾恩第一次注意到這種氣味是在她丈夫患病之后。后來，當(dāng)她在丈夫參加的患者支持小組里聞到這種氣味時，才意識到普遍的關(guān)聯(lián)。用病人穿過的衣服進(jìn)行的測試證實了她的能力。她甚至指出一個看似健康的人已經(jīng)得病了，而此人要在幾個月后才出現(xiàn)其他癥狀。

Carting Mrs Milne around the world to sniff patients who may have Parkinson’s is, however, not a practical option, so researchers working with her looked for the odour’s source, with a view to detecting it in some other way. They found it in sebum, an oily secretion produced by the skin. The sebum of those with Parkinson’s, they discovered, has unusually high concentrations of certain volatile organic compounds, including dodecane, acetone and ethyl acetate. When these are acted on by yeast cells which live naturally on the skin, the result is the mysterious odour.

不過，讓米爾恩滿世界去嗅出帕金森患者并不可行，所以研究人員和她一同尋找這種氣味的來源，以期之后用其他方法來探測到它。他們在皮膚產(chǎn)生的一種油性分泌物皮脂中發(fā)現(xiàn)了這種氣味。他們發(fā)現(xiàn)，帕金森病患者的皮脂中某些揮發(fā)性有機(jī)化合物的濃度異常地高，包括十二烷、丙酮和乙酸乙酯。當(dāng)皮膚上自然存在的酵母細(xì)胞對它們起作用時，就會產(chǎn)生這種神秘的氣味。

This Parkinson’s-specific list can be detected using a laboratory technique called gas chromatography-mass spectrometry (GCMS), which is promising—for GCMS machines are a bit more deployable than Mrs Milne is. Unfortunately, they are still too complex and expensive to be used routinely in clinics. However, Dr Chen and Dr Liu, who are both biomedical engineers, reckoned they could come up with a cheaper and more portable alternative.

這個帕金森病專有的物質(zhì)清單可以用一種叫做氣相色譜質(zhì)譜聯(lián)用（GCMS）的實驗室技術(shù)檢測出來，這就很有希望了，因為部署這種機(jī)器總比讓米爾恩到處跑容易一些。遺憾的是，它們?nèi)匀贿^于復(fù)雜和昂貴，不能用作診所的常規(guī)設(shè)備。不過，生物醫(yī)學(xué)工程師陳星和劉軍認(rèn)為他們可以構(gòu)造出更便宜也更便攜的替代儀器。

The upshot is a machine not much bigger than a toaster. It turns a sample of sebum into a vapour that is then probed with sound waves. Different molecular mixtures have different effects on the waves, and, with a bit of training, a computer loaded with an appropriate piece of artificial intelligence can learn to recognise the pattern associated with sebum from Parkinson’s patients.

他們的成果是一臺比烤面包機(jī)大不了多少的機(jī)器。它將一份皮脂樣本轉(zhuǎn)化為蒸汽，然后用聲波探測。不同的分子混合物對聲波有不同的影響，在稍加訓(xùn)練后，一臺配備有恰當(dāng)?shù)娜斯ぶ悄艿碾娔X就能學(xué)會識別與帕金森患者的皮脂相關(guān)聯(lián)的模式。

The researchers tested their system on samples from 43 people with Parkinson’s disease and 44 who were healthy. They found it could correctly identify a Parkinson’s patient as having the disease about 70% of the time and a healthy control as being clear of it about 80%. That is not yet as good as Mrs Milne’s nose, which has a history of correctly identifying the presence of Parkinson’s all the time. But it is a start. If its reliability can be improved, the compactness and potential cheapness of the system Dr Chen and Dr Liu have come up with may eventually prove a boon for the early diagnosis of the illness. ■

研究人員對43名帕金森患者和44名健康受試者的樣本進(jìn)行了測試。他們發(fā)現(xiàn)，在病患組，70%的情況下該系統(tǒng)可以正確識別出患者，而在健康對照組，80%的情況下它可以排除掉未患病的受試者。這比不上米爾恩的鼻子——米爾恩一直以來識別帕金森患者的正確率是百分之百。但這只是一個開始。如果能提升可信度，那么陳星和劉軍發(fā)明的這個小巧簡潔、可能還會很便宜的系統(tǒng)或許最終會成為帕金森病早期診斷的一大福音。