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Analog circuit for fetal heart rate (fhr) detection application

Analog circuit for fetal heart rate (fhr) detection application / Low Zhi Qian
Tesis ini merangkumi reka bentuk litar analog yang digunakan untuk pengesanan kadar jantung janin (FHR). Kadar jantung adalah ukuran bagi manusia untuk memeriksa status badan. Pemantauan kadar jantung memainkan peranan penting dalam mengawal kesihatan janin kerana penyakit berkaitan jantung adalah punca utama kematian di kalangan bayi. Dalam kajian ini, electret mikrofon digunakan untuk mengesan gelombang bunyi dari sekeliling dan ia kemudian diperkuatkan untuk meningkatkan amplitud isyarat yang lemah untuk proses penapisan yang seterusnya. Selepas itu, penapis laluan jalur akan melemah isyarat yang tidak berada dalam julat dari 20Hz ke 200Hz. Litar direka akan disimulasikan dengan menggunakan LTspice dan kemudian dipateri pada stripboard untuk analisis dengan menjalankan eksperimen. Litar yang direka dijangka memberikan gandaan sebanyak 1016.38 dan melemah isyarat di luar julat frekuensi 2.258Hz-2080.5Hz. Hasil simulasi memberi gandaan tertinggi 996.9 dan mempunyai ralat peratus daripada 1.92% sehingga 3.38% berbanding dengan hasil teori. Untuk penapisan frekuensi, hasil simulasi menyediakan lebar jalur sebanyak 1.988kHz sahaja. Hasil eksperimen memberikan nilai gandaan 1005 tetapi ralat peratusan juga lebih tinggi iaitu 4.07%. Frekuensi cutoff atas yang diperoleh daripada eksperimen adalah sangat lemah hanya dalam julat 1026.06Hz ke 1661.78Hz dalam prestasi dengan 48.38% ralat peratusan. Litar ini juga mampu mengesan denyutan jantung yang dalam julat 36.24mVp-p ke 59.76mVp-p. Secara keseluruhan, litar yang dilaksanakan adalah berjaya kerana ia dapat memberikan gandaan yang tinggi bagi julat frekuensi yang ditetapkan. _______________________________________________________________________________________________________ This work presents the design of the analog circuit that is used for fetal heart rate (FHR) detection application. Heart rate is a measure for a human to examine his current body status. Heart rate monitoring plays crucial role in regulating the health of foetus as heart-related disease is top cause of death among the babies. In this research, electret microphone is used to detect the sound wave from surrounding and it is then amplified to increase the amplitude of weak signal for further filtering process. Next, bandpass filter will attenuate the frequency that is not in the range from 20Hz to 200Hz. The designed circuit was simulated using LTspice and then soldered on stripboard for further analysis by conducting experiment. Circuit designed is expected to provide the gain of 1016.38 and attenuates the signal outside the frequency range of 2.258Hz to 2080.5Hz. The simulation result provided the highest gain of 996.90 and had percentage difference from theoretical gain from 1.92% until 3.38%. For the frequency response, simulated result only provided the bandwidth of 1.988kHz. The experimental result provide the higher gain of 1005 but also higher percentage difference from theoretical gain of 4.07%. The upper cut-off frequency obtained from experiment was very weak in performance which in the range from 1026.06Hz until 1661.78Hz with 48.38% percentage error w.r.t. simulated result. The circuit is also able to detect heartbeat in the range of 36.24mVp-p to 59.76mVp-p. Overall, the circuit implemented is successfully because it able to provide high gain in the specified range of frequency.
Contributor(s):
Low Zhi Qian - Author
Primary Item Type:
Final Year Project
Identifiers:
Accession Number : 875008595
Language:
English
Subject Keywords:
analog; circuit; (FHR)
First presented to the public:
6/1/2019
Original Publication Date:
3/3/2020
Previously Published By:
Universiti Sains Malaysia
Place Of Publication:
School of Electrical & Electronic Engineering
Citation:
Extents:
Lenght in Time - 74
License Grantor / Date Granted:
  / ( View License )
Date Deposited
2020-03-03 09:48:22.202
Date Last Updated
2020-11-26 12:28:19.427
Submitter:
Mohd Jasnizam Mohd Salleh

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