Content uploaded by Masniah Masra
Author content
All content in this area was uploaded by Masniah Masra on Apr 01, 2016
Content may be subject to copyright.
Development of Portable Finger Clubbing Meter
S. M. W. Masra1, a *, K. L. Goh2,b , J. S. Henry3,c , M. S. Muhammad4,d,
R. D. Djojodibroto5,e and R. Sapawi6,f
1,2,3,4,6Department of Electrical and Electronic Engineering, Faculty of Engineering,
5Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak
(UNIMAS), 94300 Kota Samarahan, Sarawak, Malaysia
awmmasnia@feng.unimas.my, bgohkl91@gmail.com, cjoys.sheena@gmail.com,
dmsaufee@feng.unimas.my, eddrahardjo@fmhs.unimas.my, fsrohana@feng.unimas.my
Keywords: Finger clubbing, Digital clubbing, Hippocratic finger, Digital index, Finger clubbing
meter
Abstract. Finger clubbing, also known as drumstick finger, is the medical symptom that is indicated
by the development of the sponginess or swelling in the nail beds of nails and toes. The higher grade
of clubbing on the patients can be easily identified with the presence of drumstick finger. The
existing available measurement device to identify the early stage of clubbing required much time
which is impractical for a busy clinic practice. This paper explains the determination of the finger
clubbing by using the Digital Index (DI) measurement, which was deployed by implementing and
developing the Portable Finger Clubbing Meter hardware and the Microsoft Visual Basic (VB)
Graphical User Interface (GUI). Finger circumference values of nail-fold (NF) and distal
interphalangeal joint (DIP) of twenty participants were measured using the developed hardware.
Data analysis was then performed using the GUI for DI computation, and the presence of finger
clubbing could be determined.
Introduction
Finger clubbing is a phenomenon where an individual experiences deformity in the fingers, in
which the occurrence of focal and bulbous swelling of distal phalanges is accompanied by the
alteration in nail bed’s angle [1]. Finger clubbing causes the nail-fold angles, shape, depth, and
width of the terminal phalanges of the fingers to grow in an abnormal manner [2]. Finger clubbing
is frequently associated with hypertrophic osteoarthropathy (HOA), the generation of subperiosteal
new bone, which is the formation of bone beneath the periosteum [3]. Periosteum is the dense
fibrous membrane that covers the bones and it functions as an attachment for muscles and tendons.
Hippocrates is the first person who described the possible clinical sign of chronic diseases in 400BC
[3]. Nevertheless, the underlying pathophysiology and clinical significance of finger clubbing are
still subjected too much arguments and debates.
One of the possible cases that are closely related to finger clubbing includes pulmonary
tuberculosis [4]. Matsumura et al. had carried out a study on the relation between tuberculosis and
finger clubbing in 1966. They had discovered that for clubbed finger, the end of phalange is swollen
with respect to the middle or proximal phalange. Nevertheless, the most significant feature of
clubbed finger observed is the profile angle with projection of more than 160o and the abnormally
curve-shaped nails [4].
According to Goroll and Mulley, ‘megakaryocyte hypothesis’ states that the failure of
fragmentation of megakaryocytes, which are the gigantic-sized bone marrow cells, into the platelets
at the finger or toes blood vessel contributes to clubbing [3]. The disruption of normal pulmonary
circulation would result in the inability of megakaryocytes to be fragmented into platelets. The
megakaryocytes, which are of larger sizes than the platelets, lodge in the fingertip during the
pulmonary circulation [3]. Then, megakaryocytes are fragmented into the platelets, and the platelet-
derived growth factor released results in unusual growth and vascular permeability.
Applied Mechanics and Materials Submitted: 2015-08-08
ISSN: 1662-7482, Vol. 833, pp 190-195 Revised: 2015-09-11
doi:10.4028/www.scientific.net/AMM.833.190 Accepted: 2015-11-20
© 2016 Trans Tech Publications, Switzerland Online: 2016-04-01
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans
Tech Publications, www.ttp.net. (ID: 49.50.236.211-17/03/16,09:27:01)
Symptoms such as periosteal elevation, new bone formation, and endosteal resorption, which is the
disintegration and assimilation of the thin layer of cells that line at the medullary cavity of the bone
in metacarpals, metatarsals and the distal ends of long bones are present [3]. The fingers and toes
may develop into soft-tissue swelling at the distal ends, which could eventually lead to finger
clubbing.
Profile angle measurement, hyponychial angle measurement, phalangeal depth ratio evaluation,
and Schamroth test are known as the effective techniques in measuring and evaluating finger
clubbing [2]. Estimation of the phalangeal depth ratio, which is also known as the Digital Index (DI)
ratio, could be used to determine the finger clubbing condition [2]. This is achieved by measuring
the ratio of nail-fold (NF) circumferences to the distal interphalangeal joint (DIP) circumferences of
a finger. For normal fingers, the NF circumferences should be of smaller value than the DIP
circumferences. However, this condition is reversed in those clubbed fingers. This is due to the
accumulation of the connective tissue deposited on the finger tips, thus expanding the pulps at the
terminal phalanx.
DI inspection has been shown to be effective in determining the finger clubbing condition,
regardless of age, sex, and ethnicity [2]. Fig. 1 reviews the measurement positions of the NF and
DIP circumferences of a finger.
Fig. 1 NF and DIP circumferences of a clubbed finger [2]
The conventional techniques used in measuring finger circumferences for evaluating the DI data
such as using the manual Vernier caliper and strings measurement method, as well as the manual
computation of DI, are proven to be inefficient and time-consuming [5]. Djojodibroto et al. has
conducted the research on finger clubbing by using this conventional method in measuring 23 male
subjects and 21 female subjects. They obtained an average DI data of 8.86 ± 0.29 (Mean ± SD),
with a nominal range from 8.15 to 9.41 [5]. Nevertheless, the average time consumption in
obtaining the DI data for each subject was 35:97 minutes ± 9:16 minutes (Mean ± SD), which was
considered inefficient and time-consuming.
The development of the portable finger clubbing meter and computer-controlled data
manipulation GUI software would be much more beneficial in diagnosing the finger clubbing and
measuring the DI data of the patients. The scope of this paper focuses on the measurement of
fingers’ NF and DIP circumferences and evaluation of the DI, in order to help the clinician to
evaluate and determine the finger clubbing condition of the patients in a simpler and accurate
manner.
Hardware Development
The device developed for measuring NF and DIP circumferences of each finger is known as the
Finger Clubbing Meter. It consists of a PIC16F887 microcontroller, liquid crystal display (LCD),
analog infrared range-detection sensor SN-GP2Y0A21, reflective plate, slider, non-stretchable
string, and USB cable as illustrated in Fig. 2. The dimension of the device is 36 cm × 720 cm × 4
cm. The body of this device is made of transparent plastic known as acrylic perspex. The
microcontroller PIC16F887 module takes the analog readings from the sensor and converts them
into digital readings. Then, the microcontroller processes the arithmetic calculation required in order
Applied Mechanics and Materials Vol. 833 191
to change the digital readings into the finger circumference values that are shown at the LCD
module attached to it. Fig. 3 illustrates the typical finger NF or DIP circumference reading measured
by the sensor.
Fig. 2 Design of portable finger clubbing meter
Fig. 3 LCD displaying the NF and DIP circumferences reading
PIC16F887 microcontroller module is implemented with firmware that is compiled and
generated from the C programming hardware description language code. The C programming code
is written using Microchip MPLAB X IDE, and then compiled using the XC8 compiler which is
installed within Microchip MPLAB X IDE. PICkit 2 software is launched in order to import the
firmware for implementation into the microcontroller. The microcontroller is mounted on Cytron
SKC40 board and connected to the computer via UIC00B programmer. When the connection
between PICkit 2 software and UIC00B programmer is established, the firmware is ready to be
transmitted and implemented into the microcontroller.
The C programming main source code consists of a set of arithmetic instruction used to create
the digital value display at the LCD, which represents the actual value of the finger circumference
detected by the analog infrared range-detection sensor. The procedure of taking NF and DIP
measurements is illustrated in the flowchart of Fig. 4. Initially, the finger is inserted into a
measuring loop that fits around the NF. This loop is attached to a reflective plate that can be
tightened by adjusting the slider. The distance of the reflective plate from the sensor represents the
circumference of the NF. The LCD will display the measurement of the NF and the data is recorded.
The same process is repeated at the DIP to determine its circumference. The value of DI is the sum
of ratios of the circumference at NF and DIP of the 10 fingers.
192 Innovative Engineering and Technology
Fig. 4 Flowchart of measuring finger clubbing
Software Development
Finger Clubbing Digital Index (DI) Evaluation Software is developed for computation of DI,
saving of diagnosis data, and future monitoring of the past medical check-up particulars. Fig. 5
illustrates the main layout for inputting the finger’s circumference measurement and calculating the
finger clubbing index. Clinician is allowed to key in the subject’s particulars and create new data
entry for saving the DI data.
Twenty empty textboxes are prepared by the GUI program for inputting the NF circumferences
and DIP circumferences. The textboxes are mapped on the respective finger’s NF and DIP positions
of the picture shown in the GUI program for better illustration and matching on the measured
finger’s NF and DIP positions. “Compute DI” button allows clinician to perform DI value
computation while “Update Data” button enables clinician to save or update the DI value into the
database. The GUI program performed the calculation of the DI value using Eq. 1 [5], with respect
to the data of all ten fingers as tabulated in Table 1.
Fig. 5 GUI of Finger Clubbing Digital Index (DI) Evaluation Software
t
o
s
n
r
m
q
l
p
k
j
e
i
d
h
c
g
b
f
a+++++++++=DI (1)
Applied Mechanics and Materials Vol. 833 193
Table 1 Measurement of NF and DIP for all 10 fingers
Right hand
finger
NB Value
(mm)
DIP Value
(mm)
Left hand
finger
NB Value
(mm)
DIP Value
(mm)
1 a f 1 k p
2 b g 2 l q
3 c h 3 m r
4 d i 4 n s
5 e j 5 o t
Results, Analysis and Discussions
The finger clubbing DI data collected from 20 subjects are tabulated and analyzed in details. The
values of DI for 13 female subjects is 9.17 ± 0.11 (Mean ± SD) and 9.18 ± 0.07 (Mean ± SD) for 7
male subjects. Overall, the DI value for all 20 subjects is 9.17 ± 0.11 (Mean ± SD).
The efficiency of the developed portable finger clubbing meter is evaluated based on the time
consumption in measuring the finger circumferences and computing the DI. The average time
consumption of computing the DI and evaluating finger clubbing for each subject is about 6:36 ±
1:24 min (Mean ± SD). The time consumption data are tabulated in graphical form such as
histogram and frequency polygon for better illustration on the data distribution, as shown in Fig. 6
and 7.
Fig. 6 Histogram for time consumption versus number of subjects
Fig. 7 Frequency polygon and the approximated near-normal data distribution curve
194 Innovative Engineering and Technology
From Fig. 7, it could be deduced that the time consumption applied in evaluating each subject’s
DI value displays the nearly normal distribution graph that is positively skewed. This literally means
that the time consumption is usually shorter and in the range of about 300 s, or 5 minutes. The time
consumption of 6:36 ± 1:24 min (Mean ± SD) in this project using portable finger clubbing meter
and its software proves to be more efficient compared to the time consumption in measuring the DI
values using string and calipers by Djojodibroto et al. [5], which has taken about 35:97 ± 9:16
minutes.
Summary
Finger Clubbing Meter has been successfully developed for measuring finger circumferences at
NF and DIP in accurate digitalized form. The firmware has been successfully implemented into the
PIC16F887 microcontroller module for proper functioning of the device. Microsoft Visual Basic
GUI software is applied for developing software named Finger Clubbing Digital Index (DI)
Evaluation Software, which is capable for computing DI and identifying finger clubbing in shorter
period of time. The value of DI in this study is 9.17 ± 0.11 (Mean ± SD) for all 20 subjects with a
range of 9.07 to 9.27. The average time taken to measure both NF and DIP circumferences using
Finger Clubbing Meter, and to compute DI values using Finger Clubbing Digital Index (DI)
Evaluation Software is 6:36 ± 1:24 minutes (Mean ± SD) with a range of 4 minutes 31 s to 9
minutes 30 s. It is proven that the developed device and its software are able to achieve significant
time savings in comparison to the existing measurement device.
Acknowledgment
This research was supported by Osaka Gas Foundation in Cultural Exchange (OGFICE).
References
[1] S.M. Lynn and R. Kilbey, Expert Review: examination for Finger Clubbing, The Journal of
Clinical Examination, vol. 11, 2011, pp.13-21.
[2] A.M. Kathryn, R.E.F. Donald, Does This Patient Have Clubbing?, JAMA, vol. 286, no. 3
(2001) 341-347.
[3] A.H. Goroll and A. G. Mulley, Evaluation of Clubbing, in Primary Care Medicine: Office
Evaluation and Management of Adult Patient, Philadelphia, USA: Lippincott Willians & Wilkins,
2009, p. 370.
[4] M. Matsumura et al, Tuberculosis and Clubbed Finger (in Japan), Abstracts of Tuberculosis
Research, vol. 27/28, 1968, pp. 77-81.
[5] R.D. Djojodibroto et al, Finger Clubbing: Do We Require Digital Index Quantitator?, Med J
Malaysia, vol. 69, no. 2 (2014) 60-63.
Applied Mechanics and Materials Vol. 833 195