Micro Medical Ltd introduces the MicroRMA (Respiratory Muscle Analyser), a patient friendly, handheld device enabling the quick and efficient examination of both the Endurance and Strength of the respiratory muscles;
The driving force behind the ability to breathe
The MicroRMA is simply connected to a PC or laptop, by USB, to provide healthcare professionals with an essential breakthrough in the fields of respiratory assessment and pulmonary rehabilitation, where the relationship between the patient and their ability to breath is of critical importance.
Endurance Testing
The MicroRMA controls the loading of a Constant Resistance (1), which is the most natural simulation of increased workload during normal tidal breathing. The cumulative energy expended against this load (pressure x flow x time) represents the endurance of the respiratory muscles. Only with the MicroRMA is the healthcare professional able to establish the endurance of the respiratory system in isolation:
A treadmill designed specifically for the lungs
The MicroRMA has the unique ability to isolate and quantify the endurance of the respiratory muscles, concentrating solely upon the patient's ability to breathe.
Advantages of MicroRMA
This sets the MicroRMA apart from current tests which indirectly estimate values for respiratory endurance, such as walking treadmills, cycle ergo-spirometry or the 6 minute walk. These tests are greatly influenced by factors outside the respiratory system, such as the patient's weight, general fitness, disability, experience of the test etc, and do not provide a direct, reliable measurement of the endurance of those crucial respiratory muscles.
The evolution of Constant Resistance, into an accessible, user friendly and portable form, also advances the field of respiratory muscle endurance measurements beyond the documented practice of Pressure Threshold Loading. The limitations inherent to Pressure Threshold Loading, such as the unnatural and irregular breathing style, make it unsuited for reproducible measurements of endurance, requiring intensive patient training and thus susceptible to the learning effect (2)
The unique mechanics of the MicroRMA counter these previous limitations by allowing the application of a Constant Resistance load to both the inspiratory and/or expiratory cycle, whilst the patient maintains their natural respiratory or breathing rate. This ensures the respiratory muscle endurance is measured at their daily levels and accurately reflects the ability of the patient to sustain breathing over a long period of time in their natural environment
Image Below: The Respiratory Rate graph for the maintenance of the patient's natural breathing pattern.
Image Below: The natural flow pattern maintained throughout the course of the respiratory endurance test using the MicroRMA.
This simple, user friendly measurement of the endurance of the respiratory muscles is thus able to provide reproducible results for long term trending and comparison.
Constant Resistance
Each patient has a natural level of resistance within the respiratory system which is being overcome on a daily breath by breath basis. The MicroRMA, meanwhile, is able to apply an additional Constant Resistance (Pressure/Flow) load at the mouth, encouraging the respiratory muscles to work harder to maintain natural breathing.
Image Below: Constant Resistance Graph
The level of Constant Resistance, and thus the work required of the respiratory muscles, is gradually increased based upon a preset patient protocol. This increasing workload can be applied to both the inspiratory and expiratory cycle, and the patient is required to overcome the increasing Constant Resistance whilst maintaining their natural respiratory rate.
Image Below: The simple up and down arrows enable protocol customisations. The level of Constant Resistance (KPa/l/s), the number of Breathing Cycles at each level and the Respiratory rate are fully configurable.
The PC software calculates the resultant cumulative Energy (Pressure x Flow x Time) as the patient responds to this increasing Constant Resistance by working the respiratory muscles harder.
Image Below: An example of the Total Energy graph expended against the increasing workload.
Respiratory Muscle Endurance
This final figure of total Energy (Joules or Calories) represents the truest picture of the endurance of the pulmonary muscles, in accordance with the clinical definition:
"Muscle endurance is the ability to sustain a specific muscular task over time"
ATS/ERS Joint Statement on Respiratory Muscle Testing
Am J Respir Crit Care Med Vol166 pp518-624, 2002
This new and previously inaccessible information can then be used in a number of important fields:
The MicroRMA, within a pulmonary rehabilitation programme, provides important independent information regarding the effectiveness and efficiency of the patients' progress. Whether the coordinated programme employs medication, Inspiratory Muscle Training (4), physiotherapy, exercise or a combination of these, the MicroRMA is able to provide objective baseline and post-therapy measurements of pulmonary endurance and aid general respiratory training.
COPD Disease Management
The MicroRMA is able to provide important information on the progression of the COPD disease state, emphasising muscle wastage and respiratory weakness, an essential factor in the patients' ability to breathe unaided
Exacerbations and Hospital Admission
The MicroRMA is able to aid the rapid clinical assessment of COPD exacerbations, in addition to providing the information required to assess patient readiness to make the transition back to the community.
Ventilator Weaning
The MicroRMA has the potential to quantify the level of respiratory endurance required for a patient to be successfully weaned from a ventilator.
Pre-Operative Screening and Therapy (5)
The MicroRMA has the potential to quantify the level of respiratory endurance required for a patient to survive the trauma of thoracic, abdominal and cardio surgery, and form the core constituent of a coordinated pre-operative therapy programme.
Mouth Pressures (Strength Testing)
The MicroRMA PC software is able to control pressures and flows at the mouth, and will perform advanced and informative Mouth Pressures at User Defined Volumes.
The measurement of Mouth Pressures at User Defined Volumes addresses issues regarding the performance of static pressure tests at RV and TLC, an unnatural state in the breathing cycle. As no patient breathes at RV (PImax) or TLC (PEmax) levels, this judgement of strength, whilst useful, does not provide a full picture of the patients' ability to generate respiratory pressures during normal daily tidal breathing activities.
The MicroRMA is able to overcome these important limitations and provide the fullest picture yet of the strength of the respiratory muscles, during the respiratory cycle, at the user defined volumes.
MicroRMA Research Options
The unique mechanics behind the MicroRMA provides unprecedented access to a whole new field of research into respiratory mechanics and performance. The patented rotary variable aperture, driven by a precision servo motor under the control of a microprocessor, can be programmed to perform any combination of pressure, flow, time,volume, power, resistance and energy calculations relating to respiratory dynamics.
Possible applications include:
- Sleep Apnoea Studies
- Ventilator Setting Investigations
- Maximum Power Tests
Micro Medical Ltd is able to customise software protocols around your research requirements, taking the hard work out of your study preparations. The Micro Medical Ltd Research and Development Department provide pharmaceutical and laboratory research solutions throughout the world and it is this knowledge, expertise and experience that can help you establish the protocol for your respiratory research project.
To discuss a quotation regarding your project requirements, and access expertise accumulated over 20 years of respiratory innovation, please do not hesitate to contact Micro Medical Ltd through the International Sales contact page.
Appendix
(1) The Constant Resistance generated by the patented variable aperture of the MicroRMA is NOT to be confused with Fixed Orifice Resistance or Pressure Threshold Loading
Constant Resistance (figure A), as opposed to fixed orifice, (where the resistance increases as the square of the flow, figure B), or pressure thresholds, (where the resistance jumps from infinite to zero as the pressure threshold is crossed, figure C), simulates the natural breathing pattern, essential for the practical assessment of the patient's respiratory endurance. In the same manner as an exercise treadmill imposes a naturally increasing workload during normal walking or running activities, the MicroRMA's use of Constant Resistance imposes a naturally increasing workload during normal tidal breathing activities.
(2) Pressure Threshold Learning Effect
".. the breathing pattern may change systematically over these early exposures to progressive threshold loading in a way that would lessen the work of breathing or the sensation of respiratory effort. then the improvement in performance (Pthmax) may represent the result of neuropsychological adaptation to the task rather than respiratory muscle conditioning."
The Effects of Learning on the Ventilatory Responses to Inspiratory Threshold Loading
Eastwood, Hillman, Morton, Finucane, Am J Resp Crit Care Med, vol 158, 4, 1190-96, October 1998.
Pulmonary rehabilitation is a coordinated patient therapy program that combines activities such as inspiratory muscle training, general exercise, physiotherapy, nutritional counselling, education and more. In the absence of Pulmonary Rehabilitation the COPD patient typically falls into a vicious cycle of physical, social and psychosocial decline, as shown below:
Pulmonary Rehabilitation, meanwhile, is designed to improve and optimise the patient's physical and social performance, thus improving autonomy. The MicroRMA is able to become a crucial part of this rehabilitation process, assessing the progress of the most important ingredient of the rehabilitation programme, the ability to breath.
"All COPD patients benefit from exercise training programs, improving with respect to both exercise tolerance and symptoms of dyspnoea and fatigue"
GOLD (Global Initiative for Chronic Obstructive Lung Disease) Guideline
"Pulmonary rehabilitation leads to statistically significant and clinically meaningful improvements in Health Related Quality of Life, Functional Exercise Capacity and Maximum Exercise Capacity. Pulmonary rehabilitation reduces dyspnoea... total number of hospitalisation days as well as total number of hospitalisations required for patient with COPD in the years following the completion of a comprehensive pulmonary rehabilitation programme.. fewer home visits"
NICE (National Institute of Clinical Excellence) COPD Guidelines
"Pulmonary rehabilitation is effective in all settings including hospital inpatient, hospital outpatient, the community, and possibly home"
BTS (British Thoracic Society) Standards of Care Subcommittee on Pulmonary Rehabilitation 2001. Thorax, vol.56, no. 11, pp. 827-834
(4) Inspiratory Muscle Trainers, such as the Respironics IMT available from Micro Medical Ltd, can be used alongside, and in conjunction with, the MicroRMA, to provide a coordinated pulmonary muscle rehabilitation training programme.
Maintenance of Inspiratory Muscle Training in COPD patients: one year follow-up
Weiner, Magadle, Beckerman, Weiner, Berar-Yanay.
ERJ 2004; 23:61-65
Targeted inspiratory muscle training improves respiratory muscle function and reduces dyspnoea in patients with chronic obstructive pulmonary disease.
Harver, Mahler, Daubenspeck.
Ann Intern Med 1989 Jul 15
Inspiratory Muscle Training combined with general exercise reconditioning in Patients with COPD
Weiner, Azgad, Ganaml.
Chest 1992;102:1351-1356
(5) Pre-Operative Screening and Therapy
"Preoperative IMT (Inspiratory Muscle Training) reduced the incidence of PPC’s (Post Operative Pulmonary Complications) and duration of post Operative hospitalization in patients at high risk of developing a pulmonary complication undergoing CABG (Coronary Artery Bypass Surgery) surgery. Pre-Operative Intensive Inspiratory Muscle Training to Prevent Post-Operative Pulmonary Complications in High-Risk Patients Undergoing CABG Surgery The Journal of the American Medical Association, 2006; 296: 1851-1857"
"The decrease in these parameters (inspiratory muscle function, pulmonary function tests and arterial blood gases) can be prevented by prophylactic inspiratory muscle training, which may also prevent post surgical pulmonary complications"
Prophylactic Inspiratory Muscle Training in Patients Undergoing Coronary Artery Bypass Graft.
World Journal of Surgery, vol.22, 5, May 1998, p427-431
Please note: This product is not yet approved for sale in the USA