Indirect measurement of systolic blood pressure in the lower limb using a mercury in rubber strain gauge

Bell, Gillian I.; Nielsen, Poul Ebbe; Lassen, N. A.; Wolfson, Bernard

doi:10.1093/cvr/7.2.282

Cited by 22 publications

(11 citation statements)

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“…The key advantage of real-time strain sensing over competing imaging analysis techniques like MRI is in the intraprocedural mode of use, which enables physicians to track sudden shifts in local contractions as they occur. Technologies, ranging from metal wires to Si plates and mercury-in-rubber structures, have been used for monitoring strain in various parts of the body (46)(47)(48), but none offers the combination of characteristics needed for epicardial applications. Ultrathin Si NM (49) configured into piezoresistors as narrow strips in rosettes with longitudinal, diagonal, and transverse orientations provide a solution, incorporated into the web platform (Fig.…”

Section: Resultsmentioning

confidence: 99%

Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy

Kim

Ghaffari

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

215

167

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Curved surfaces, complex geometries, and time-dynamic deformations of the heart create challenges in establishing intimate, nonconstraining interfaces between cardiac structures and medical devices or surgical tools, particularly over large areas. We constructed large area designs for diagnostic and therapeutic stretchable sensor and actuator webs that conformally wrap the epicardium, establishing robust contact without sutures, mechanical fixtures, tapes, or surgical adhesives. These multifunctional web devices exploit open, mesh layouts and mount on thin, bio-resorbable sheets of silk to facilitate handling in a way that yields, after dissolution, exceptionally low mechanical moduli and thicknesses. In vivo studies in rabbit and pig animal models demonstrate the effectiveness of these device webs for measuring and spatially mapping temperature, electrophysiological signals, strain, and physical contact in sheet and balloon-based systems that also have the potential to deliver energy to perform localized tissue ablation.flexible electronics | semiconductor nanomaterials | stretchable electronics | implantable biomedical devices | cardiac electrophysiology C ardiac arrhythmias occur in all component structures and 3D regions of the heart, resulting in significant challenges in diagnosis and treatment of precise anatomic targets (1). Many common arrhythmias, including atrial fibrillation and ventricular tachycardia, originate in endocardial substrates and then propagate in the transverse direction to affect epicardial regions (1, 2). Characterizing arrhythmogenic activity at specific regions of the heart is thus critical for establishing the basis for definitive therapies such as cardiac ablation (3). Advanced tools that offer sufficient spatial resolution (<1 mm) and intimate mechanical coupling with myocardial tissue, but without undue constraints on natural motions, would therefore be of great clinical importance (4-6). To date, cardiac ablation procedures have largely relied on point ablation catheters deployed in the endocardial space (1, 5, 7-9). Although successful in the treatment of simple arrhythmias originating in and around the pulmonary veins, these devices are poorly suited for treating complex arrhythmias, such as persistent atrial fibrillation (10-13), that arise from various sites inside the left atrium. Other classes of devices have demonstrated the utility of spatiotemporal voltage mapping using various modes of operation, including noninvasive surface mapping designs (14, 15), epicardial voltage-mapping "socks" (16-20), and endocardial contact and noncontact catheters, with densities approaching 64 electrodes (21-31). These solutions all exploit arrays of passive metal wirebased electrodes integrated on wearable vests and socks (14-20) or catheter systems (21-26) for mapping of complex arrhythmias. Building such mesh structures requires manual assembly and is only possible because the individual wires are millimeter scale in diameter and thus sufficiently large to be threaded to form a mesh.Fo...

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Section: Resultsmentioning

confidence: 99%

Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy

Kim

Ghaffari

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

215

167

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“…The non-invasive criteria for haemodynamically significant stenoses were established by use of a combination of segmental BP measurements (Bell et al, 1973;Nielsen et ul., 1973) and evaluation of the pulses in the common femoral and politeal arteries with the Doppler shift technique (Yao, 1970) as follows.…”

Section: Non-invasive Examinai'ionmentioning

confidence: 99%

“…Several non-invasive methods are employed, such as oscillometry (Hillestad, 1962), plethysmography (Dahn, 1965;Sigaard-Andersen, 1965), isotope techniques (Hurlow et al, 1978), segmental blood pressure measurements (Bell et al, 1973, Nielsen et al, 1973, and evaluation of the velocity and direction of the blood flow with the Doppler ultrasound technique-either alone (Gosling et al, 1971;Jager et al, 1985) or in combination with segmental blood pressure measurements (Fronek el al., 1978).…”

Section: Introductionmentioning

confidence: 99%

Validation of a non‐invasive method for localization of atherosclerotic occlusive disease in the legs

Jonason

Bäckbro²,

Ringqvist

et al. 1986

Clinical Physiology

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Summary. The accuracy in determining the level of haemodynamically significant occlusive arterial disease (stenosis of ≥50%) in the leg by a combination of segmental blood pressure measurements and evaluation of pulses with the Doppler shift technique was assessed in 50 patients (100 legs), using angiography as the reference method. For aorto‐iliac disease the sensitivity was 72%, the specificity 97% and the diagnostic accuracy 87%. For femoro‐popliteal disease the corresponding figures were 87%, 78% and 85%, respectively. The accuracy of a positive diagnosis was 93% for both levels. Similar results were obtained for combined aorto‐iliac and femoro‐popliteal disease. The accuracy in detecting calf disease was poor.

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“…A BP gradient a20 mmHg between the thigh and the calf, with a loss of the diastolic Doppler shift component in the popliteal artery, was regarded as a sign of stenosis in the superficial femoral or popliteal artery. Criteria for stenoses in the calf were a normal Doppler shift signal in the popliteal artery and a BP gradient 220 mmHg between the thigh and the calf or between the calf and the ankle (7, 9). Multiple stenoses are defined as signs of stenoses at more than one level.…”

Section: Definitionsmentioning

confidence: 99%

Factors of Prognostic Importance for Subsequent Rest Pain in Patients with Intermittent Claudication

Jonason

Ringqvist

1985

Journal of Internal Medicine

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Jonason T, Ringqvist I. (Department of Clinical Physiology, Vasterls Central Hospital, Vasterls, Sweden.) Factors of prognostic importance for subsequent rest pain in patients with intermittent claudication. Acta Med Scand 1985; 218: 27-33.The risk of developing rest pain during a six-year period was studied in 224 non-diabetic patients with intermittent claudication. Both smoking and multiple arterial stenoses in the leg were significantly correlated with an increased risk of developing rest pain. In nonsmokers and in those who had stopped smoking within one year after the initial examination, the cumulative percentage of patients without rest pain after six years was 92, and in smokers and those who stopped smoking after more than one year it was 79 (p<0.03 after adjustment for differences in the presence of multiple stenoses). In patients with single stenosis the cumulative percentage of patients without rest pain was 86, and in those with multiple stenoses 70 (p<0.05 after adjustment for differences in smoking habits). The results emphasize how important it is that patients with intermittent claudication do not smoke. The increased risk of rest pain associated with the presence of multiple arterial stenoses in the leg should be considered when making decisions concerning vascular surgery.

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Indirect measurement of systolic blood pressure in the lower limb using a mercury in rubber strain gauge

Cited by 22 publications

References 0 publications

Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy

Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy

Validation of a non‐invasive method for localization of atherosclerotic occlusive disease in the legs

Factors of Prognostic Importance for Subsequent Rest Pain in Patients with Intermittent Claudication

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