Early recognition of regional cardiac ischemia using a 3-axis accelerometer sensor

Elle, Ole Jakob; Halvorsen, Steinar; Gulbrandsen, Martin Gunnar; Aurdal, Lars; Bakken, André; Samset, Eigil; Dugstad, Harald; Fosse, Erik

doi:10.1088/0967-3334/26/4/009

Cited by 39 publications

(24 citation statements)

References 10 publications

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“…The sensor replicated our previously reported results (Elle et al 2005) and gave additional support to the claim that accelerometer data can be used to detect regional cardiac ischemia. There was no biological response to the encapsulation and no damaging of the tissue caused by the shape of the sensor.…”

Section: Animal Experimentssupporting

confidence: 83%

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Assembly and packaging of a three-axis micro accelerometer used for detection of heart infarction

Imenes

Aasmundtveit

Husa

et al. 2007

Biomed Microdevices

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In coronary artery bypass grafting there is a risk of graft occlusion which may result in myocardial infarction. A three-axis acceleration sensor may give additional information about heart function during surgery and the first postoperative days. This paper describes the assembly and packaging of a three-axis micro acceleration sensor for use in clinical trials. The sensor was connected to a cable for power supply and signal output and moulded in silicone. Testing of the encapsulation showed leakage currents well below the 10 muA limit for direct cardiac applications. A hydrogen peroxide gas plasma method was used for sterilization. In animal experiments the sensor was sutured to the heart and no fatigue failures ensued due to the cycling strain forces from the heart. The sensor has been qualified for clinical trials.

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Section: Animal Experimentssupporting

confidence: 83%

“…In animal experiments we have previously demonstrated that a three-axis accelerometer can be used to detect regional cardiac ischemia (Elle et al 2005). This study used a prototype accelerometer.…”

Section: Introductionmentioning

confidence: 99%

Assembly and packaging of a three-axis micro accelerometer used for detection of heart infarction

Imenes

Aasmundtveit

Husa

et al. 2007

Biomed Microdevices

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“…In an occluded area, there is a noticeable change to stronger power of higher harmonics of the signal. Early recognition of regional cardiac ischemia is possible through analysis of the accelerometer signal real-time via the fast Fourier_ transform (39). Although the primary application of this device will be in adults vulnerable to cardiac ischemia, it could also have tremendous implications for monitoring of pediatric patients after heart surgery or cardiac transplantation.…”

Section: Piezoelectric Materialsmentioning

confidence: 99%

Smart Materials Applications for Pediatric Cardiovascular Devices

2008

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"Smart Materials" are materials that change their shape, color, or size in response to an externally applied stimulus. While smart materials have already made a tremendous impact on our lives through their applications in liquid crystal displays, headphones, fuel injection systems, flexible cell phone antennas, and many other commercial products, they also have the potential to help many pediatric patients. This review focuses on with the present and potential applications of shape memory alloys, piezoelectric materials, and the relatively newer class of materials called magnetostrictive and ferromagnetic shape memory alloys in the design of pediatric cardiovascular devices. (Pediatr Res 63: 552-558, 2008) "S mart Materials" are materials that change their shape, color, or size in response to an externally applied stimulus. Examples of "external stimuli" include changes in temperature, application of an electric or magnetic field, and changes in moisture or pH. Thus, whereas other materials play passive structural roles in devices, smart materials can actually be manipulated in situ.During the last few decades smart materials have had a tremendous impact on a variety of fields. For example, chromogenic materials are the basis of all liquid crystal displays and photochromes allow eyeglasses to change to sunglasses in the presence of sun light. The basis of lighter igniter switches, headphones, and recent fuel injection systems is piezoelectrics whereas the flexible cell phone antennas and eyeglasses are shape memory smart materials. Many more commercial applications for smart materials are already available and new ones are being studied by a wide range of organizations.This review focuses on with the potential applications of shape memory alloys, piezoelectric materials, and the relatively newer class of materials called magnetostrictive and ferromagnetic shape memory alloys (FSMA) in the design of pediatric cardiovascular devices. Whereas shape memory alloys like nitinol (a nickel-titanium alloy) change shape in response to a change in temperature, magnetostrictive or ferromagnetic materials change their shape in response to a magnetic field. NiMnGa (nickel-manganese-gallium) and Terfenol-D represent the best known examples of FSMA and magnetostrictive materials respectively. The more mature class of piezoelectric materials, e.g., BaTiO 3 and lead zirconate titanate (Pb(ZrTi)O 3 )-commonly called PZT, change shape with an electrical field; or, conversely, generate an electrical signal in response to a forced change in shape. All of these materials can be used as either an actuator or a sensor.Smart materials have begun to have a significant impact in the field of medicine. Although a number of applications already exist, it is only a matter of time before many more pediatric applications will emerge for these smart materials. SHAPE MEMORY ALLOYSNitinol introduction. NiTi or nitinol is a nickel-titanium shape memory alloy. Nitinol is a pneumonic for NickelTitanium, developed by the Naval Ordinance Labo...

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“…2 By measuring the cardiac motion using a miniaturized 3-axis accelerometer attached to the epicardial surface, previous studies have been able to distinguish between ischemic and normal conditions in pigs as well as humans. [3][4][5] Using an accelerometer to detect cardiac motion abnormalities might therefore prove beneficial when used in the intra-and post-operative phase.…”

Section: Introductionmentioning

confidence: 99%

Gravity Compensation Method for Combined Accelerometer and Gyro Sensors Used in Cardiac Motion Measurements

et al. 2017

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A miniaturized accelerometer fixed to the heart can be used for monitoring of cardiac function. However, an accelerometer cannot differentiate between acceleration caused by motion and acceleration due to gravity. The accuracy of motion measurements is therefore dependent on how well the gravity component can be estimated and filtered from the measured signal. In this study we propose a new method for estimating the gravity, based on strapdown inertial navigation, using a combined accelerometer and gyro. The gyro was used to estimate the orientation of the gravity field and thereby remove it. We compared this method with two previously proposed gravity filtering methods in three experimental models using: (1) in silico computer simulated heart motion; (2) robot mimicked heart motion; and (3) in vivo measured motion on the heart in an animal model. The new method correlated excellently with the reference (r > 0.93) and had a deviation from reference peak systolic displacement (6.3 ± 3.9 mm) below 0.2 ± 0.5 mm for the robot experiment model. The new method performed significantly better than the two previously proposed methods (p < 0.001). The results show that the proposed method using gyro can measure cardiac motion with high accuracy and performs better than existing methods for filtering the gravity component from the accelerometer signal.

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Early recognition of regional cardiac ischemia using a 3-axis accelerometer sensor

Cited by 39 publications

References 10 publications

Assembly and packaging of a three-axis micro accelerometer used for detection of heart infarction

Assembly and packaging of a three-axis micro accelerometer used for detection of heart infarction

Smart Materials Applications for Pediatric Cardiovascular Devices

Gravity Compensation Method for Combined Accelerometer and Gyro Sensors Used in Cardiac Motion Measurements

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