The Mechanics of Breast Pumping: Compression Stimuli Increased Milk Ejection

SmartLact8: A Bio-Inspired Robotic Breast Pump for Customized and Comfort Milk Expression

According to the 2018 National Immunization Survey conducted by the Center for Disease Control and Prevention (CDC), 83.9% of the breastfeeding mothers in the United States have used a breast pump at least once. However, the majority of existing products use a vacuum-only mechanism to extract milk. This causes common breast injuries such as nipple soreness, breast-tissue damage, and lactation complications after pumping. The objective of this work was to develop a bio-inspired breast pump prototype, named as SmartLac8, that can mimic infant suckling patterns. The input vacuum pressure pattern and compression forces are inspired from term infants' natural oral suckling dynamics captured in prior clinical experiments. Open-loop input-output data are used to perform system identification for two different pumping stages that facilitates controller design for closed-loop stability and control. A physical breast pump prototype with soft pneumatic actuators and custom piezoelectric sensors was successfully developed, calibrated, and tested in dry lab experiments. Compression and vacuum pressure dynamics were successfully coordinated to mimic the infant's feeding mechanism. Experimental data on sucking frequency and pressure on the breast phantom were consistent with clinical findings.

Evaluation of a new lactation device 'Lactamo' designed to apply massage, heat or cold, and compression to the breast

BACKGROUND

Common approaches to manage breastfeeding problems such as pain, blocked ducts, and milk production issues include breast compression, breast massage, application of warmth or cold, medications, and breastmilk expression. Several devices are available to apply heat or cold to the breast, however, none promote breast compression and/or massage simultaneously. A new device 'Lactamo' has been developed to address this.

METHODS

This study was a pre-market evaluation of the Lactamo device. The aims were to determine user safety, and satisfaction of Lactamo. The study was conducted in an Australian tertiary maternity hospital in 2019-2020. Women who were less than 3 months post-partum and were currently breastfeeding participated in the study. We conducted structured telephone surveys at 1 and 4 weeks post supply of Lactamo. Questions included demographic information, feedback on safety, usage, and perceived benefits of Lactamo.

RESULTS

The cohort (n = 30) consisted of equal number of primiparous and multiparous women, 50% were born in Australia and the remainder from 11 other countries. A total of 41 telephone surveys were conducted with 27 women. Of these, 26 (96%) had used Lactamo, and the one that did not, felt she did not have a lactation concern to warrant using it. All women indicated that the device was safe to use and had no concerns, apart from one woman who experienced itching because of the device but continued to use it over clothing as she found it beneficial. Most women used it at room temperature or warmed. The frequency of use varied from once per week (17%) to daily (33%), and use was often prompted by a lactation concern such as engorgement, pain, blocked ducts, and low supply.

CONCLUSION

Lactamo was found to be safe, and a valuable aid for breastfeeding women. More research is needed to understand the efficacy of the device in treating breastfeeding problems such as pain, blocked ducts, and milk production issues.

In Vitro Flow Visualization in a Lactating Human Breast Model

Human milk extraction from the breast is affected by the infant's oral activities. Natural suckling by the infant includes both intraoral vacuum and peripheral oral compression during breastfeeding. However, the contribution of each of these motions to milk extraction at the outlet and at the duct bifurcations is unclear. In this work, we investigated the flow field in a lactating breast model considering bifurcated milk ducts and multiphase breast-infant interactions. A bio-inspired breastfeeding simulator device was utilized to mimic an infant's oral feeding mechanism during breastfeeding and extract the human milk-mimicking Fluid from the transparent and elastic lactating breast phantom during experiments. Using a particle image velocimetry system, we found that the oscillatory flow under vacuum pressure provides a higher velocity field at the outlet compared to that when an infant applies both vacuum and oral compression pressures. Additionally, the intraoral vacuum coordinated with the oral peripheral compression causes stronger vorticities and secondary flows at the adjunction of the bifurcated ducts than the vacuum-only case. Vacuum-only extraction yields an increase in flow velocity at the outlet and could be one of the reasons for nipple pain, whereas infant's oral activities on the breast generated more vortices in the milk duct adjunctions and might cause milk duct clogs. This phenomenon is rationalized based on the validation of a previous in vivo clinical study of milk production compared between commercial pumps and infant suckling. The fact that milk consumption of vacuum-only extraction is less than that of vacuum plus oral compression further explains the effectiveness of applying a natural suckling pattern in human lactation.

Evidence-Based Updates on the First Week of Exclusive Breastfeeding Among Infants ≥35 Weeks

The nutritional and immunologic properties of human milk, along with clear evidence of dose-dependent optimal health outcomes for both mothers and infants, provide a compelling rationale to support exclusive breastfeeding. US women increasingly intend to breastfeed exclusively for 6 months. Because establishing lactation can be challenging, exclusivity is often compromised in hopes of preventing feeding-related neonatal complications, potentially affecting the continuation and duration of breastfeeding. Risk factors for impaired lactogenesis are identifiable and common. Clinicians must be able to recognize normative patterns of exclusive breastfeeding in the first week while proactively identifying potential challenges. In this review, we provide new evidence from the past 10 years on the following topics relevant to exclusive breastfeeding: milk production and transfer, neonatal weight and output assessment, management of glucose and bilirubin, immune development and the microbiome, supplementation, and health system factors. We focus on the early days of exclusive breastfeeding in healthy newborns ≥35 weeks' gestation managed in the routine postpartum unit. With this evidence-based clinical review, we provide detailed guidance in identifying medical indications for early supplementation and can inform best practices for both birthing facilities and providers.

Nipple Deformation and Peripheral Pressure on the Areola During Breastfeeding

Breastfeeding is a complex process where the infant utilizes two forms of pressure during suckling, vacuum and compression. Infant applied compression, or positive oral pressure, to the breast has not been previously studied in vivo. The goal of this study is to use a methodology to capture the positive oral pressure values exerted by infants' maxilla (upper jaw) and mandible (lower jaw) on the breast areola during breastfeeding. In this study, the positive and negative (vacuum) pressure values are obtained simultaneously on six lactating mothers. Parallel to the pressure data measurements, ultrasound images are captured and processed to reveal the nipple deformations and the displacements of infants' tongues and jaw movements during breastfeeding. Motivated by the significant differences in composition between the tissue of the breast and the nipple-areola complex, the strain ratio values of the lactating nipples are obtained using these deformation measurements along with pre- and postfeed three-dimensional (3D) scans of the breast. The findings show an oscillatory positive pressure profile on the breast under both maxilla and mandible, which differs from clinical indications that only the mandible of an infant moves during breastfeeding. The strain ratio varies between mothers, which indicates volume changes in the nipple during feeding and suggests that previous assumptions regarding strain ratio for nonlactating breasts will not accurately apply to breast tissue during lactation.

Comparative Assessment of Excretion of Milk from Two Breast Pumps with Different Vacuum Strength and Duration

BACKGROUND

Breastfeeding is the best source of food for the newborn. In a situation wherein it is not possible to breastfeed a baby, it may be necessary to express milk from the mother's breast using a breast pump. To achieve lactation success before a baby's suckling can ensure the effective extraction of milk, breast pumps must meet specific biomechanical requirements. However, the parameters of the vacuum stimuli by which milk is expressed remain nonoptimized.

SUBJECTS AND METHODS

Forty-nine lactating women of 21-30 years of age who volunteered to be included in this study were examined. Women had been lactating and breastfeeding normally for 6-7 days. A new method was developed to compare the amount of milk ejected by vacuum pulses of different amplitudes or duration.

RESULTS

It was found that for most nursing women, the vacuum stimuli with amplitude of about 190 mm Hg, duration of 0.7 second, and frequency of 1 impulse/s are optimal for removing milk from the breast of a woman.

CONCLUSIONS

Optimization of the amplitude and duration of the vacuum stimuli increased the efficacy of the breast pump.

Progesterone-Containing Gel Does Not Eliminate Postpartum Breast Engorgement?

BACKGROUND

Severe breast engorgement can cause substantial discomfort for mothers and interfere with an infant's ability to feed at the breast. The aim of the study was to clarify the possibility that the percutaneous progesterone-containing gel (Progestogel) can eliminate severe postpartum breast engorgement in lactating women.

SUBJECTS AND METHODS

Twenty three patients were examined. The Progestogel for transdermal therapy in an amount of 2.5-3 g was applied to the breast. Before application and 20 min after application the density of the mammary glands was measured by a tonometer.

RESULTS

According to our observations, within 20 min application of 2.5-3 g of the Progestogel on the breast skin does not result in reducing breast swelling, engorgement and tenderness.

CONCLUSIONS

After 20 minutes, transdermal application of Progestogel does not reduce the degree of engorgement of the mammary glands in the postpartum period.