TLT makes early research breakthrough in foetal heart monitoring
23 February 2012
Tarilian Laser Technologies, which has developed a unique optical sensor
platform for blood pressure measurement, has now made a further
innovation with the development of a ground-breaking early research
prototype for a foetal heart monitoring sensor.
The foetal heart rate (FHR) has been used as an indicator of foetal
well-being for over 160 years, becoming 'a routine part of clinical
practice' in obstetrics around the world. Currently there are two
principal methods of foetal heart monitoring: intermittent
auscultation and continuous monitoring.
This is a recommended method of measuring the foetal heartbeat if
it has been a “trouble free pregnancy” and would normally be taken
at 15-minute intervals during the early stage of pregnancy and every 5
minutes or once every contraction in the later stages. Intermittent
auscultation is carried out using either a Pinard stethoscope or a
hand held Doppler monitor. This equipment is also used in prenatal
care in outpatient clinics and the GP surgery.
For reasons relating to the health of the foetus, continuous
monitoring may be required using an electronic heart rate monitor.
Two types of monitors are commonly used:
- Cardiotocograph (CTG): this usually involves the use of an
ultrasound transducer to monitor the baby's heart rate and a
pressure transducer to monitor uterine contractions, both of which
are linked to a recording machine. This is usually undertaken
continuously in labour, although occasionally it is used
intermittently during labour.
A current problem with continuous
monitoring is the impractical size of the monitoring machines. In
most units, CTG requires the mother to wear a belt across her
abdomen while monitoring is being conducted, which restricts her
An alternative means of monitoring the baby's heart rate
with the CTG machine is to attach an electrode directly to the
baby's presenting part, usually its head. This form of continuous
monitoring is known as 'internal CTG' and requires a ruptured
amniotic sac (either spontaneously or artificially) and a scalp
electrode (clip) attached to the baby's head, also reducing the
Certain patterns of electronically monitored FHR recordings are
strongly associated with specific changes in foetal condition.
However, not infrequently, uncertainty exists in respect to
interpretation. Unnecessary operative interventions might be the
result of incorrect interpretation and overestimation of the
diagnostic potential of electronic FHR monitoring. Whereas certain
FHR patterns are sensitive indicators of foetal hypoxia, the
specificity is low.
It is rarely possible to quantitate hypoxia on the basis of FHR
records alone and information derived from FHR records only
represents one piece of information which always has to be
interpreted in the context of the clinical situation.
Tarilian Laser Technologies intends to target its sensor for both
intermittent auscultation and continuous monitoring markets.
company's proposed device has several unique selling points compared
to other devices currently available, either for intermittent
auscultation, or continuous monitoring, or both:
- Novel technique: the device would
distinguish itself from most other intermittent auscultation devices
in that it uses neither invasive Doppler ultrasound, nor is it a
simple sound wave amplifier. It utilises a unique optical technique
delivery a continuous beat to beat fetal heart rate measurement.
- Non-invasive foetal monitoring: the device would be the world's first passive truly non-invasive
foetal monitor. Doppler devices require the use of ultrasound,
whereas the optical-sensor-based device would not transmit any
energy at all into the maternal abdomen, the amniotic sack, the
foetus and placenta in any way. Currently, the effects of
"bombarding" a foetus with energetic ultrasound waves are not fully
known, and some clinicians and researchers have expressed concern
over the matter.
The TLT sensor also offers the following advantages:
- Increased mobility: the main problem with
current continuous monitoring devices is the reduced mobility
for the woman being monitored. The Tarilian sensor can be
miniaturized and will be a small “elastoplast”-type small sensor
that does not require the use of a belt or electrodes attached
to the mother/baby during labour.
- Increased sensitivity with foetal and maternal
monitoring: It is important to be able to distinguish
the fainter foetal heartbeat from the maternal heartbeat. This
requires high detection sensitivity and differentiating
software, which TLT has.
- Continuous beat-to-beat measurement: The
TLT sensor is non-invasive and be used continuously without
- Not position sensitive: Doppler devices
currently strive to obtain the widest beam profile possible in
order to increase the area in which you can place the monitor
and still detect the foetal signal. Hence they are effectively
position sensitive. The Tarilian device, however, very is small
and easily can detect a signal over a much larger range of
positions, easing use and minimising the chance of error.
- No gel required: disposable sensor — almost akin to a foetal
cardiovascular lab on a small elastoplast.
- Perfect technology for wireless connectivity.
According to Life Science Intelligence, globally, the 2008 market
for products used to monitor and treat neonatal and perinatal
patients was $1.2 billion and should grow to reach over $1.5 billion
by 2013. A recent Frost & Sullivan report reveals that the market is
growing in the EU due to a combination of higher awareness among
expectant mothers about the advantages of sophisticated monitoring,
as well as the non-invasiveness and greater safety offered by new
prenatal diagnostic techniques. The need for better accurate systems
has increased further as the progress in fertilisation technology
and trend towards pregnancies at later stages in life, has led to an
increased rate of multiple pregnancies and more chance of a mother
delivering prematurely. As the number of premature births rises, the
demand for neonatal monitoring devices has risen concomitantly.
In 2009, TLT won a significant grant from the East of England
Development Authority (EEDA) for its early research into this
application. Subsequent to the successful completion of this
proof-of-principle research, TLT is now committed to the forward
development of further prototypes and full clinical assessment.
Commenting on the success at TLT, Dr Sandeep Shah, CEO of TLT,
stated, "The key sets of historical innovations in obstetrics
occurred many many years ago with the giant figures of Joseph Lister
and Ignaz Semmelweis in the 1800s; through to the last century with
Ian Donald and Tom Brown and their discoveries around ultrasound.
"The TLT Team here are very excited about this ‘new century
development’ and the potential we have of further improving global
outcomes in pregnancy with our unique optical sensor that can be
simply applied by the mother and deliver very powerful data about
the baby to the midwife and doctor, including continuous
beat-to-beat foetal heart monitoring.
"The telemetric opportunities are also powerful and we have
opened discussions with a number of international companies to take
this forward, as we launch our latest new division of TLT Sapphire,
and a powerful new paradigm in foetal medicine.”