None listed
Conditions
Brief summary
Project Summary This is a pilot study of a new, non-invasive, cuffless blood pressure measuring device, worn on the chest. This is a world first for Monash University engineers. Blood pressure (BP) measurement is an essential vital sign, and provides a cornerstone for diagnostic and treatment decisions in healthcare. Existing technology requires either uncomfortable arm cuff inflation, or invasive catheters placed into patient’s arteries. Monash University engineers have developed a device consisting of sensing pads (4 ecg dots) and a radar to be placed on the patient’s chest. Initial lab testing suggests that the device functions well in fit young volunteers. Further testing is now required on volunteers with a range of resting blood pressures and body shapes to determine how the device performs on a broader section of the adult population. We are evaluating this device at Cabrini on a reasonably healthy adult volunteer population aged 18 years and over. Some of the subjects need to have uncomplicated hypertension. The study requires most participants (N=29) to attend for an hour, wear the new device on their chest, and a normal ‘gold-standard’ BP cuff on their arm. The volunteer will then go through a range of tasks whilst having their BP measured both ways. The tasks involve resting on a bed, sitting up, clenching their hands and riding an exercise bike for a few minutes. A smaller sub-group of the healthiest participants (N=16) would be required to take a small dose of glyceryl trinitrate (GTN) to lower their blood pressure by a small amount, whilst resting on a trolley in a treatment room in the Emergency Department at Cabrini. We aim to establish the precision of the device by correlating what the new device against an established ‘gold standard’ method of BP measurement measures (arm cuff). The dataset of BP readings from the chest device allows the engineers to apply mathematical algorithms to convert the data into accurate blood pressure readings. The aim of the research is to develop a method whereby BP can be measured accurately, continuously, and without patient awareness or discomfort, thus in the future eliminating the need for a sphygmomanometer or arterial line catheter for patients.
Interventions
The intervention is a device that utilises new technology to measure blood pressure non-invasively and cufflessly using a methodology called Pulse Transit Time (PTT). Simple electrodes and a radar device are placed on the skin between two points of an artery (in this case, the aorta in the chest). The blood pressure is deducted from the resultant delay of the electrical and mechanical impulse created by the blood moving along the artery between the two points.
The device consists of:
(i) El
The intervention is a device that utilises new technology to measure blood pressure non-invasively and cufflessly using a methodology called Pulse Transit Time (PTT). Simple electrodes and a radar device are placed on the skin between two points of an artery (in this case, the aorta in the chest). The blood pressure is deducted from the resultant delay of the electrical and mechanical impulse created by the blood moving along the artery between the two points. The device consists of: (i) Electrodes and leads: *An electrode placed on each shoulder (similar to currently used ECG dots) *A chest electrode (the radar) placed in the middle of the sternum *A lead connecting the electrodes to the central processing unit (ii) Central processing unit (CPU) *A box that generates the radar signal out to the chest electrodes and receives the signals from the shoulder electrodes (iii) Laptop computer *Used to input the patient’s demographic data, non invasive arm cuff BP readings, visualise data obtained from the CPU, and host the algorithms used to deduct BP To test this device, the following procedures will be followed: Healthy adult volunteers will be enrolled. A minimum of 29 participants will undergo static and blood pressure raising protocol. These participants will undertake the following: Steps and manoeuvres 1 Measure lying BP 2 Change to sitting measure sitting BP 3 Handgrip both arms till failure, measure handgrip BP 4 Change to standing position, measure standing BP 5 Move to bike, Cycle for 2 min at 10-22 km/h or light effort Measure BP after light exercise (brief rest following this whilst BPs are measured only) 6 Cycle for 2 min at 22-30 km/h or Medium effort Measure BP after medium exercise (brief rest following this whilst BPs are measured only) 7 Cycle for 2 min at 30-40 km/h or Maximal effort Measure BP after heavy exercise (rest following this, see below) 8 Rest at sitting position for 5 min Measure sitting BP after 5 minutes rest A minimum of 16 further participants will undergo a static and Blood Pressure lowering protocol: First they will be screened for medical contraindications and consented for the utilisation of glyceryl trinitrate (GTN) medication. If able to proceed, the protocol will be as follows: Participants rest supine for 10 minutes, then they would have 300 micrograms of GTN administered sublingually (under the tongue) and possibly another 300mcg 10 minutes later. BPs would be measured before and after the medication administration. The second dose will be given if the participant remains well and the BP has been lowered at first post GTN dose by less than 15mmHg. (minimum of 50% of BP lowering measurements have to be in the range of - 16 to - 30mmHg from baseline reading, the remaining lowered BP readings have to be between -15 to -1mmHg from baseline). BPs will be measured 3 minutely from the first dose of GTN onwards for 30 minutes total. For all measurements of blood pressure by the new device, there will be a simultaneous measurement of the blood pressure by the gold standard control device. Blood pressures will be measured by a researcher who has been trained to take Blood Pressures accurately. This may be a research assistant with a science background, an engineer or a medical practitioner (Emergency Physician). The approximate duration of each session for each participant in either group will be approximately an hour. Training for researchers in how to measure Blood Pressures will meet or exceed the standards described in the International engineering protocol.
Sponsors
Monash University
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Diagnosis
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Adult volunteers (age 18 and over)
Exclusion criteria
Exclusion from any participation Inability to undergo informed consent (e.g. speak or read English, reliably process information to make an informed decision) Inability to undertake mild to moderate aerobic exercise (ride an exercise bike for 5 minutes) Inability to undertake mild to moderate isotonic exercise (clenched hand grips) Allergy to medical grade skin adhesive tapes History of mastectomy with axillary node clearance, preventing the use of arm Blood Pressure measurement devices Exclusion from the glyceryl trinitrate arm of the study Unwillingness to divulge past medical history to a research medical practitioner Past medical history of ischaemic heart disease (heart attack) Past medical history of cerebrovascular disease (stroke) Hypersensitivity to glyceryl trinitrate Systolic blood pressure less than 100 mmHg Pulse rate <50 or >150 Phosphodiesterase type 5 inhibitor use (sildenafil, vardenafil) within the last 4 days Allergy to medical grade skin adhesive tapes History of mastectomy with axillary node clearance, preventing the use of arm Blood Pressure measurement devices
Outcome results
None listed